TMD/ Facial Pain

Question 1

When assessing the efficacy of myofascial trigger points injections what substance should be used as a control?
A. Xylocaine
B. Sterile water
C. Dry needling of the trigger point
D. Normal saline

Answer 1

Answer: D
Rationale:
Normal saline is used as the control in studies of efficacy of trigger point injection solutions.
Reference:
Byrn C, Olsson J, Falkheden L, Lindh M, Hosterey U, Fogelberg MN, Linder LE, Bundertorp O. Subcutaneous sterile water injections for chronic neck and shoulder pain following whiplash injuries. Lancet, 1993;341:449-52.

Question 2

Which of the following classes of drugs may provide benefits of both analgesia and reduction of bruxism in the myofascial pain patient?
A. Monoamine oxidase inhibitors
B. Tricyclic antidepressants
C. Nonsteroidal anti-inflammatory medications D. Selective serotonin reuptake inhibitors

Answer 2

Answer: B
Rationale:
Tricyclic antidepressants, including specifically amitriptyline, have been suggested to be effective in alleviating pain in chronic pain syndromes and in reducing bruxism by an unknown mechanism. None of the distractors have been shown to decrease bruxism. SSRI’s may increase bruxism.
Reference:
Karlis, V and Glickman, R. Nonsurgical management of temporomandibular disorders. In Miloro, M (ed). Peterson’s Principles of Oral and Maxillofacial Surgery, 2nd ed. 2004 Hamilton: BC Decker p. 953.

Question 3

Comparison of outcomes one year after arthroscopy, discectomy, modified condylotomy, and disc repositioning surgery for TMJ internal derangement is most correctly summarized by which of the following statements?
A. Superior pain relief and diet improvement after arthroscopy
B. Statisticallyindistinguishablepainreliefanddietimprovement
C. Superior pain relief and improved diet after disc repositioning surgery D. Statisticallyindistinguishablerangeofmotion

Answer 3

Answer: B
Rationale:
A prospective investigation comparing outcomes one year after arthroscopy, discectomy, condylotomy, and disc repositioning for internal derangement showed no statistically significant differences in pain reduction or diet improvement. Greater improvement in contralateral range of motion occurred with condylotomy and arthroscopy, presumably due to intracapsular scarring following discectomy and disc repositioning.
Reference:
Hall HD, Indresano TA, Kirk WS, et al. Prospective multicenter comparison of 4 temporomandibular joint operations. J Oral Maxillofac Surg 2005;63:1174-1179

Question 4

Which statement most accurately describes the TMJ disc?
A. Convex superior surface, concave inferior surface
B. Composed primarily of Type-2 collagen
C. Biconcave cross-sectional morphology
D. Composed of hyaline cartilage

Answer 4

Answer: C
Rationale:
In cross section the disc has a biconcave shape. This shape enhances load distribution between the surfaces of the condyle and temporal bone. The disc is composed of fibrous connective tissue. The disc has little or no innervation.
Reference:
Mohamed,S:Developmental and Clinical Anatomy and Physiology of the Temporomandibular Joint. In Fonseca RJ, Bays RA, Quinn PD (eds):Oral and Maxillofacial Surgery Vol 4. 2000, WB Saunders, Philadelphia, p 8.

Question 5

Which of the following best describes the correct sequence of structures encountered superior to the zygomatic arch with a preauricular approach to the temporomandibular superior joint space?
A. Skin, superficial deep temporal fascia, temporoparietal fascia, subgaleal fascia, capsule
B. Skin, subgaleal fascia, temporoparietal fascia, temporalis fascia, capsule
C. Skin, temporoparietal fascia, superficial deep temporalis fascia, subgaleal fascia, capsule
D. Skin, temporoparietal fascia, subgaleal fascia, temporalis fascia, capsule

Answer 5

Answer: D
Rationale:
Temporoparietal fascia is continuous superiorly with galea. Subgaleal fascia is a discrete fascial layer deep to temporoparietal fascia. The layer immediately deep to subgaleal fascia is temporalis fascia. Temporalis fascia is immediately superficial to joint capsule.
Reference:
Politi M, Toro C, Cian R, Costa, F, et al. The deep subfascial approach to the temporomandibular joint. J oral Maxillofac Surg 2003;62:1097-1102.
Ellis EE, Fide MF. Surgical Approaches to the facial skeleton. Williams and Wilkins, Baltimore, 1995 p.167-911.

Question 6

The auriculotemporal nerve:
A. originates from 2 roots surrounding the anterior deep temporal artery.
B. innervates the stapedius muscle.
C. innervates the lateral pterygoid muscle.
D. has communications with the otic ganglion.

Answer 6

Answer: D
Rationale:
The auriculotemporal nerve is one of several nerves provides sensation to the TMJ and a portion of the ear. Its origin is by two roots that surround the middle meningeal artery. The stapedius muscle is innervated by the facial nerve. The lateral pterygoid is innervated by pterygoid branches form the 3rd division of the trigeminal nerve. Auriculotemporal contributions to the otic ganglion supply afferent innervation to the parotid gland.
Reference:
Mohamed,S: Developmental and Clinical Anatomy and Physiology of the Temporomandibular Joint. In Fonseca RJ, Bays RA, Quinn PD (eds): Oral and Maxillofacial Surgery Vol 4, 2000, WB Saunders, Philadelphia, p. 14.

Question 7

What statement is true about internal derangement of the TMJ?
A. Disc morphology is more important than disc position.
B. Disc mobility is more important than disc position.
C. Disc position is more important than disc mobility.
D. Disc morphology is more important than disc mobility.

Answer 7

Answer: B
Rationale:
Disc displacement may follow or precede alteration in the surface characteristics of the joint, although contemporary literature has discounted the importance of both disc displacement and the value of surgical disc repositioning. Impaired disc mobility is more closely related to alterations in the internal milieu of the joint and altered joint mechanics than is disc position. Disc displacement, though a marker of internal derangement, is probably not as important as altered disc mobility
Reference:
Dolwick, MF: Temporomandibular Joint Disc Displacement: A Clinical Perspective. In, Sessle, BJ; Bryant, PS; Dionne, RA (Eds): Temporomandibular Disorders and Related Pain Conditions. Progress in Pain Research and Management. Vol 4 1995 IASP Press. Seattle. pp.79 – 87.
Mercuri, LG and Laskin, DM: Indications for Surgical Treatment of Internal Derangements of the TMJ. Oral Maxillofac Surg Clin N Am 1994;6:223.

Question 8

The temporal branch of the seventh cranial nerve is located in which soft tissue plane when approaching the TMJ via a preauricular approach?
A. Within the superficial temporal fat pad
B. Within the subcutaneous fat
C. Deep surface of the temporalis fascia
D. Deep surface of the temporoparietal fascia

Answer 8

Answer: D
Rationale:
The temporal branch of the facial nerve is most commonly found on the deep surface of the temporoparietal fascia and superficial to the temporalis fascia.
Reference:
Ellis, E, Zide, M: Surgical Approaches to the Facial Skeleton, Baltimore, 1995, Williams and Wilkins, pp. 167-168

Question 9

In the preauricular approach to the TM joint what best describes the location of temporal branch of the facial nerve?
A. Deep to temporalis fascia, 8-35 mm anterior to the external auditory canal
B. Deep to temporoparietal fascia, 8-35 mm anterior to the external auditory canal
C. Deep to temporoparietal fascia, mean 3.5 cm anterior to the external auditory canal
D. Deep to temporalis fascia, mean 3.5 cm anterior to the external auditory canal

Answer 9

Answer: B
Rationale:
The main trunk of facial nerve exits from the skull at the stylomastoid foramen and subsequently enters the parotid gland. The temporal branch of the facial nerve emerges from the parotid gland and crosses the zygoma deep to or within the temporoparietal fascia to innervate the frontalis muscle in the forehead. The temporal branch crosses the zygomatic arch 8-35 mm (mean 2.0cm) anterior to the most anterior portion of the external auditory canal.
Reference:
Quinn P: Color atlas of temporomandibular joint surgery. 1988 Mosby St. Louis pps. 30- 31.
Ellis E, Zide: Surgical approach to the facial skeleton. 1995 Lippincott Williams & Wilkins, Baltimore pps. 163-185.
Al-Kayat A, Bramley P: Modified pre-auricular approach to the temporomandibular joint and malar arch. Br J Oral Surg 1980;17:91.

Question 10

MR image generation is a function of which mechanism?
A. Detection of tissue positron emission
B. Detection of tissue features as a radiofrequency signal
C. Detection of tissue gamma irradiation
D. Detection of ionizing radiation which has traversed the tissue

Answer 10

Answer: B
Rationale:
Choice A describes Positron emission tomography (PET). It is a nuclear medicine imaging technique which produces a three dimensional image or map of functional processes in the body. PET is a valuable technique for some diseases and disorders, because it is possible to target the radio-chemicals used for particular bodily functions. Choice C Describes Bone Scan. A bone scan is a nuclear medicine study to detect bone abnormalities. The patient is injected with a small amount of radioactive material and then scanned with a Gamma camera, a device sensitive to the radiation emitted by the injected material. Several gamma-emitting radioisotopes are used, one of which is technetium-99m. When administered to a patient, a gamma camera can be used to form an image of the radioisotope’s distribution by detecting the gamma radiation emitted. Such a technique can be employed to diagnose a wide range of conditions (e.g. spread of cancer to the bones).
Choice D Describes X-ray. X-rays are primarily used for diagnostic medical imaging and crystallography. X-rays are a form of ionizing radiation and as such can be dangerous. Ionizing radiation is a type of particle radiation in which an individual particle (for example, a photon, electron, or helium nucleus) carries enough energy to ionize an atom or molecule (that is, to completely remove an electron from its orbit). If the individual particles do not carry this amount of energy, it is essentially impossible for even a large flood of particles to cause ionization. These ionizations, if enough occur, can be very destructive to living tissue. By far, the most significant source of man-made radiation exposure to the general public is from medical procedures, such as diagnostic X-rays, nuclear medicine, and radiation therapy. Some of the major radionuclides used are I-131, Tc-99, Co-60, Ir-192, Cs-137. These are rarely released into the environment.
The American Board of Oral and Maxillofacial Surgery 102
2007 Oral and Maxillofacial Surgery Self Assessment Tool (OMSSAT)
Reference:
Grainger & Allison’s Diagnostic Radiology: A Textbook of Medical Imaging, 4th ed., Copyright © 2001 Churchill Livingstone, Inc.

Question 11

Low signal intensity on a T-1 weighted TMJ MRI is characteristic of which substance? A. Joint effusion
B. Marrow
C. Cortical bone D. Fat

Answer 11

Answer: C
Rationale:
Magnetic resonance imaging (MRI) is a noninvasive method of mapping the internal structure of the body which completely avoids the use of ionizing radiation and appears to be without hazard. It employs radiofrequency (rf) radiation in the presence of carefully controlled magnetic fields in order to produce high quality cross-sectional images of the body in any plane. It portrays the distribution of hydrogen nuclei and parameters relating to their motion in water and lipids.
The exposure of the tissue to a Radiofrequency (RF) radiation causes the nuclei in the lower energy state to jump to the higher energy state. MR Imaging is based on the observation of the relaxation that takes place after the RF pulse has stopped and subsequent return of the excited nuclei from the high energy to the low. In pure water, the T2 and T1 times are approximately identical. For biological material, the T2 time is considerably shorter than the T1 time. By varying imaging it is possible to weight the signal to produce T1-, T2- or PD-weighted (proton density) images. From a medical perspective, it means that MR Imaging can provide multiple channels to observe the same anatomy. For instance in a brain image, white matter appears in a light grey in T1 and a dark grey in T2. Grey matter appears grey in both images. The Cerebro-Spinal Fluid (CSF) appears black in T1 and white in T2. The background of the image (air) appears black in both images. Fluid matters such as edema and water appear white (or whiter) on the T-2 image compared to T-1, while bone will appear darker.
Reference:
Grainger & Allison’s Diagnostic Radiology: A Textbook of Medical Imaging, 4th ed., Copyright © 2001 Churchill Livingstone, Inc. .

Question 12

Which of the following structures lies in closest proximity to the medial aspect of the TMJ?
A. Carotid artery
B. Middle meningeal artery
C. Internal jugular vein
D. 3rd division of Trigeminal nerve

Answer 12

Answer: B
Rationale:
The mean distance from the outer aspect of the zygomatic arch to the middle meningeal artery has been reported as 31 mm (range: 21-43 mm). This vessel is located slightly forward of the center (i.e., depth) of the glenoid fossa (mean: 2.4 mm). The mean distances from the outer aspect of the zygomatic arch to the carotid artery (37.5 mm; range: 29-48 mm), internal jugular vein (38.3 mm; range, 31-49 mm), and the third division of the trigeminal nerve (35 mm; 24-46 mm) were greater than that of the middle meningeal artery, but are nevertheless at risk for injury during TMJ surgery.
Reference:
Talebzadeh, N. Rosenstein, TP. Pogrel, MA. Anatomy of the structures medial to the temporomandibular joint. Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 1999; 88): 674-78.

Question 13

Patients who undergo unilateral segmental mandibular resection with preservation of a short condylar segment can be expected to have what findings prior to delayed mandibular reconstruction:
A. painful disc displacement with the condyle out of the fossa.
B. painless normal disc relationship with the condyle in the fossa.
C. painless disc displacement with the condyle out of the fossa.
D. painless normal disc relationship with the condyle out of the fossa.

Answer 13

Answer: D
Rationale:
Unilateral segmental mandibular resection does not affect the relationship between the disc and the condyle. Most condyles with a short condyle-ramus remnant will displace out of the fossa while retaining a normal relationship to the disc. Clinical symptoms of TMJ pain, TMJ noise, or muscular pain are not associated with partial mandibulectomy defects.
Reference:
Yoshiki H, Toshirou K, Kazutoshi N, Kanichi S: Magnetic resonance imaging findings and clinical symptoms in the temporomandibular joint in patients with mandibular continuity defects. J Oral and Maxillofac Surg 2000;50: 487-493.

Question 14

A TMJ MRI has been obtained on a symptomatic 19-year-old. Which clinical scenario is most compatible with this imaging study? (MRI shows unilateral disk displacement without reduction)
A. Bilateral clicking
B. Recent cessation of clicking with deviation on opening C. Unilateral reciprocal clicking
D. Bilateral crepitace

Answer 14

Answer: B
Rationale:
This MRI demonstrates unilateral disc displacement without reduction. Preservation of near normal disc morphology is consistent with recent progression to disc displacement without reduction. The contralateral joint disc position is normal. No clicking would be expected and, in fact, this patient stopped clicking and experienced a closed lock with deviation to the locked side 3 weeks prior to the MRI. The MRI demonstrates normal condylar morphology without evidence of arthrosis.
Reference:
Katzberg RW, et al. Magnetic resonance imaging of the temporomandibular joint meniscus. Ora Surg Oral Med Oral Pathol 1985;59:332.
Anderson QN. Temporomandibular joint imaging: treatment planning. In: Fonseca RJ, Bays RA, Quinn PD (eds):Oral and Maxillofacial Surgery Vol 4. 2000, WB Saunders, Philadelphia, pp129-142.

Question 15

A 12 year-old male is noted to have his mandibular dental and symphysis midlines 3 mm to the right of his facial midline. Centric occlusion position approximates centric relation position. These findings are most consistent with:
A. myofascial pain dysfunction.
B. internal derangement of the right TMJ.
C. left lateral pterygoid spasm.
D. internal derangement of the left TMJ.

Answer 15

Answer: B
Rationale:
Mandibular asymmetry in a growing child is often associated with an internal derangement on the short side. This association is associated with a small or deformed condyle and decreased vertical ramus height on the affected side.
Reference:
Schellhas KP, Pollei SR, Wilkes CH: Pediatric Internal Derangements of the Temporomandibular Joint: Effect on facial development. Am J Orthodont Dentofac Orthoped, 1993;104:51-59

Question 16

What is the most common configuration of TMJ disc displacement? 
A. Medial
B. Anteromedial 
C. Anterior
D. Anterolateral

Answer 16

Answer: C
Rationale:
Of 58 consecutive TMJ patients imaged by 3-DIMENSIONal MRI 44/116 (38%) had anterior displacement of the TMJ disk. 23/116 (20%) had anterolateral displacement, 10/116 (9%) had medial displacement, and 10/116 (9%) had anteromedial displacement.
Reference:
Simmons HC, Gibbs SJ: Initial TMJ disk recapture with anterior repositioning appliances and relation to dental history. J Craniomandib Prac 1997;15:281-295.

Question 17

Which of the following skeletal jaw deformities is most likely associated with long- standing bilateral TMJ disc displacement without reduction?
A. High mandibular plane angle Class II malocclusion
B. Asymmetric Class II malocclusion
C. Low mandibular plane angle Class II malocclusion D. Class III malocclusion

Answer 17

Answer: A
Rationale:
TMJ internal derangement should be suspected in patients with mandibular deficiency, symmetrical and asymmetric Class II malocclusion, and vertical ramus deficiency with anterior open bite. Of the skeletal deformity options, high mandibular plane angle Class II patient is most likely to be associated with bilateral non-reducing disc displacements. Nickerson and Link reported that 11/11 open bite patients and 29/33 Class II patients had bilateral internal derangements.
Reference:
Link JL, Nickerson JW. Temporomandibular joint internal derangements in an orthognathic surgery population. Int J Adult Orthod Orthognath Surg 1992;7:161-9 Gidarakou IK, Tallents RH, Kyrkanides S, et al. Comparison of skeletal and dental morphology in asymptomatic volunteers and symptomatic patients with bilateral disc displacement with reduction. Angle Orthod 2002;72:541-46.

Question 18

Which of the following is the most common complaint in TMD patients? A. Pain with opening
B. Open lock C. Headache D. Tinnitus

Answer 18

Answer: C
Rationale:
Forty-eight consecutive TMD patients were asked 86 different symptoms on initial diagnostic visit. The occurrence of the symptoms was: Cephalalgia 94%, Painful to chew food 94%, Pain upon opening or closing mouth 90%, Open lock 13%.
Reference:
Simmons HC, Gibbs SJ: Anterior Repositioning Appliance Therapy for TMJ Disorders: Specific symptoms relieved and relationship to disk status on MRI. J Craniomandib Prac 2005;23:89-99

Question 19

Which of the following devices is an absolute contraindication to performing an MRI of the temporomandibular joint?
A. Cardiac pacemaker
B. Titanium dental implants C. 
Orthodontic appliances 
D. Prosthetic knee joint

Answer 19

Answer: A
Rationale:
A cardiac pacemaker can malfunction when subjected to a strong magnetic field. The other choices are typically not affected by the magnetic field.
Reference:
Quinn, P: Color Atlas of Temporomandibular Joint Surgery, St. Louis, 1998, Mosby, p. 23.

Question 20

What tissue type demonstrates a bright signal on T1-weighted MR images? 
A. Fat
B. Muscle 
C. Bone
D. Cartilage

Answer 20

Answer: A
Rationale:
Fat appears as a bright (white) signal on conventional T1 weighted MRI.
Reference:
Cunningham, L et al. Magnetic resonance imaging of the head and neck. Atlas of the Oral and Maxillofacial Surgery Clinics of North America 2003;11:87-88.

Question 21

A 21 year-old patient with a two week history of painful limited opening (20 mm interincisal) presents with the following MRI images. What is the most likely diagnosis?
A. Acute TM joint effusion
B. Disc displacement without reduction 
C. Disc displacement with reduction
D. Lateral pterygoid fibrosis

Answer 21

Rationale:
C. The question presents a patient with acute onset of hypomobility. T1 weighted MRI images in closed and open mouth views are presented. The disc is displaced in the closed mouth view, and does not reduce in the open mouth image. Muscle fibrosis would not occur acutely. Joint effusion is best imaged with a T2 weighted MRI.
Reference:
Katzberg, RW. Temporomandibular joint imaging. Radiology 1989;170:297-307 Manzione, JV, Katzberg, RW, Tallents, RH. Magnetic resonance imaging of the temporomandibular joint. J Am Dent Assoc 1986;113:398-402.

Question 22

Which statement is true regarding TMJ magnetic resonance imaging technique?
A. Sagittal images should be parallel to the long axis of the condyle
B. Coronal images should be perpendicular to the long axis of the condyle
C. Image should be acquired with surface coils
D. Open mouth images should be acquired at an opening that does not produce an opening click

Answer 22

Answer: C
Rationale:
MRI of the TMJ image slice thickness should never be more than 3 mm. Sagittal images should be perpendicular and coronal images parallel to the condylar long axis. Open mouth images should be acquired at an opening that produces an opening click as this click may represent a reducing disc.
Reference:
Gibbs SJ, Simmons HC: A protocol for magnetic resonance imaging of the temporomandibular joint. J Craniomandib Prac 1998 16:236-241.

Question 23

A T2 weighted image of the temporomandibular joint best demonstrates which of the following joint abnormalities?

A. Superior joint space adhesions
B. Perforation of the Temporomandibular Disc
C. Arthrosis of the bony condyle
D. Joint effusion

Answer 23

Answer: D
Rationale:
T2 weighted images best demonstrate structures with high water content. Joint effusion is best demonstrated by this modality.
Reference:
Quinn, P: Color Atlas of Temporomandibular Joint Surgery, St. Louis, 1998, Mosby, p. 22.

Question 24

What statement best describes a Wilkes Stage III TMJ internal derangement?
A. Non-reducing disk displacement-chronic
B. Non-reducing disk displacement-subacute/acute
C. Reducing disk displacement-chronic
D. Reducing disk displacement-subacute/acute

Answer 24

Answer: B
Rationale:
In the Wilkes Classification of internal derangement stage III represents a non-reducing disk displacement that is acute or subacute. Early stage III internal derangements may be reducible with mandibular manipulation. Late stage III internal derangements represent permanent disc displacement.
Reference:
Bays, R: Surgery for Internal Derangement. In Fonseca, R (ed): Oral and Maxillofacial Surgery, Vol. 4. Philadelphia, WB Saunders, 2000, p 276.

Question 25

Which of the following is consistent with Wilkes Stage III internal derangement? A. Painless reducing disc B. Painless nonreducing perforated disc C. Painful reducing disc D. Acute or subacute painful nonreducing disc

Answer 25

Answer: D Rationale: Stage III refers to disc displacement without reduction often associated with pain but prior to any hard tissue changes. A. Describes Stage I B. Describes Stage V C. Describes Stage II Reference: Bays RA :Surgery for Internal Derangement. In Fonseca RJ, Bays RA, Quinn PD (eds):Oral and Maxillofacial Surgery Vol 4. 2000, WB Saunders, Philadelphia ,p. 276.

Question 26

What results are expected 6 months after TMJ arthrocentesis for pain and limitation of motion from osteoarthritis? A. Increased range of motion and decreased pain B. Unchanged range of motion and decreased pain C. Increased range of motion and unchanged pain D. Decreased range of motion and decreased pain

Answer 26

Answer: A Rationale: Arthrocentesis is a safe procedure that in many instances results in the osteoarthritic TMJs returning to a healthy functional state. Failure of arthrocentesis suggests that the painful limitation is most probably caused by changes such as fibrous adhesions or osteophytes that require surgical intervention for their removal. Of 38 TMJs treated with arthrocentesis, 26 joints responded favorably; pain and dysfunction scores were reduced from 9.86 ± 0.73 to 3.39 ± 0.76 and from 11.34 ± 0.66 to 3.4 ± 0.69, respectively (P

Question 27

Regarding TMJ discectomy and dermal graft placement, which of the following is most correct? A. With joint function, dermis assumes a biconcave shape. B. Dermis grafting prevents condylar erosion after discectomy. C. Dermis grafting has not been demonstrated superior to discectomy alone. D. Dermis grafting limits intraarticular adhesion formation.

Answer 27

Answer: C Rationale: There is little evidence that dermal graft placement produces results superior to discectomy, alone. Dermis does not assume a biconcave shape and does not prevent condylar erosion after discectomy. Dermal grafting does no prevent intraarticular adhesion formation. Reference: Bays RA :Surgery for Internal Derangement. In Fonseca RJ, Bays RA, Quinn PD (eds):Oral and Maxillofacial Surgery Temporomandibular Disorders. Philadelphia, WB Saunders, 2000 , Volume 4, p 292.

Question 28

``` The expected outcome after unilateral temporomandibular joint discectomy without disc replacement is: A. open bite. B. loss of range of motion. C. subcondylar cyst formation. D. formation of a pseudo-disc. ```

Answer 28

Answer: D Rationale: MR imaging after discectomy without disc replacement has demonstrated formation of new tissue between the condyle and fossa. This tissue has been referred to as pseudo- disc because of its location. Loss of mandibular height, open bite, crepitation, loss of range of motion, though described in isolated cases, are not the usual outcome of discectomy. Accelerated condylar arthrosis has also been observed but with avoidance of early joint loading is not expected. Subcondylar cyst formation is a manifestation of osteoarthritis and not associated with discectomy. Reference: Susumu T, Tsuguo S, Masashi Y: Long-term magnetic resonance imaging after temporomandibular joint discectomy without replacement. J Oral Maxillofac Surg 2000;58:739-745.

Question 29

To protect the facial nerve in the pre auricular approach to the temporomandibular joint, the incision through the fascia and periosteum in the area of the zygomatic arch should not be more than ________ cm from the anterior border of the external auditory canal. A. .8 cm B. .5cm C. 1.5cm D. 2.2cm

Answer 29

Answer: A Rationale: The facial nerve crosses the zygomatic arch .8cm to 3.5cm anterior to the anterior border of the external auditory canal. Therefore, the incision through temporoparietal fascia and periosteum should not be more than be .8cm anterior to the anterior border of the external auditory canal. Reference: Ellis, E, Zide, M: Surgical Approaches to the Facial Skeleton, Baltimore, 1995, Williams and Wilkins, p. 165.

Question 30

Condylotomy for symptomatic internal derangement has the greatest positive clinical effect with regard to improvement in: A. pre-existing malocclusion. B. position of a non-reducing disc. C. symptoms associated with Wilkes stage II and III internal derangement. D. symptoms associated with Wilkes stage IV and V internal derangement.

Answer 30

Answer: C Rationale: Pain and diet are significantly improved 3 years after modified condylotomy for internal derangement. Disc position is improved at least 70% of the time with disc displacement with reduction. Non-reducing disc displacement is unaffected by condylotomy. Late stage internal derangement joints with degenerative joint disease (Wilkes Stage IV, V) have less satisfactory pain relief after modified condylotomy. Although modified condylotomy can be applied simultaneously to the patient with Class III malocclusion and symptomatic internal derangement this is not well documented and a represents a more novel application of condylotomy. Reference: Hall HD, Navarro ZE, Gibbs SJ: Prospective study of modified condylotomy for treatment of nonreducing disc displacement. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2000;89:147-158. Hall HD, Navarro ZE, Gibbs SJ: One- and three-year prospective outcome study of modified condylotomy for treatment of reducing disc displacement. J Oral Maxillofac Surg 2000;58:7-17.

Question 31

Compared to no disc replacement, the main advantage of placing a dermis graft in conjunction with TMJ discectomy is: A. enhanced pain relief. B. improved range of motion. C. decreased joint noise. D. decreased regressive condylar remodeling.

Answer 31

Answer: C Rationale: Interpositional dermis can decrease joint noise after discectomy. No clinical evidence of joint sounds such as crepitus was found in 33 of 35 operated joints evaluated an average of 2 years after discectomy with placement of a dermis interpositional graft. Dermis grafting has no effect on pain response, range of motion or the incidence of regressive condylar remodeling following discectomy. Reference: Dimitrioulis G: The use of dermis grafts after discectomy for internal derangement of the temporomandibular joint JOMS. J. Oral Maxillofac Surg 2005;63:75

Question 32

``` Which branch of cranial nerve VII is at greatest risk with the pre-auricular approach to the temporomandibular joint? A. Buccal B. Zygomatic C. Cervical D. Temporal ```

Answer 32

Answer: D Rationale: The most commonly injured branch of the facial nerve is the temporal branch with preauricular approach to the TMJ. Less commonly, the zygomatic branch may be injured. Reference: Vallerand WP, Dolwick MF. Complication of temporomandibular joint surgery. Oral Maxillofac Clin North Am 1990;2:481-8.

Question 33

``` What statement describes a functional deficit associated with injury to the frontal branch of the facial nerve? A. Lagophthalmos B. Exposure keratitis C. Brow ptosis D. Hypertropia ```

Answer 33

Answer: C Rationale: Injury to the frontal branch of the facial nerve causes frontalis weakness and brow ptosis. Lagophthalmos and exposure keratitis are associated with injury to the zygomatic branch of the facial nerve. Hypertropia refers to globe elevation from impaired globe depressor function, as may be seen in injury to the inferior division of the oculomotor nerve. Reference: Quinn P: Color atlas of temporomandibular joint surgery; 1998 Mosby St. Louis p.31

Question 34

``` During intra-articular TMJ surgery, preservation of the medial capsule, may avoid damage to which vascular structure? A. The internal maxillary artery B. The masseteric artery C. The deep temporal artery D. The middle meningeal artery ```

Answer 34

Answer: D Rationale: The middle meningeal artery is immediately medial to the temporomandibular joint. Preservation of the medial joint capsule will minimize injury to this vascular structure. Options a,b,c, are incorrect because none of these vessels course immediately adjacent to the medial portion of the TMJ. Reference: Mohamed,S:Developmental and Clinical Anatomy and Physiology of the Temporomandibular Joint. In Fonseca RJ, Bays RA, Quinn PD (eds):Oral and Maxillofacial Surgery Vol 4, 2000 WB Saunders, Philadelphia, p 4.

Question 35

``` Compared to discectomy, a more common complication of modified mandibular condylotomy is? A. Change in occlusion B. Post operative joint noise C. Intraarticular adhesions D. Condylar arthrosis ```

Answer 35

Answer: A Rationale: Condylar “sag” and loss of ramus height can lead to a posterior occlusal prematurity on the side of a modified condylotomy. Occlusion changes following discectomy, if any, are mild and transient. Joint noise is more common after discectomy because of intraarticular scarring/adhesions. Reference: Bays RA :Surgery for Internal Derangement. In Fonseca RJ, Bays RA, Quinn PD (eds): Oral and Maxillofacial Surgery Vol 4, 2000, WB Saunders, Philadelphia, p. 297.

Question 36

During TMJ arthrotomy, what structure is most likely to be the source of bleeding during entry into the superior joint space? A. Superior head of the lateral pterygoid muscle B. Inferior head of the lateral pterygoid muscle C. Retrodiscal tissue D. Posterior temporalis muscle

Answer 36

Answer: C Rationale: The retrodiscal tissue has a robust blood supply and can be encountered as the lateral capsule is incised and the joint space entered. a. and b. are incorrect because they are encountered at the very anterior and medial region of the joint. d. is incorrect because it is usually encountered before the joint capsule has been opened. Reference: Mohamed,S:Developmental and Clinical Anatomy and Physiology of the Temporomandibular Joint. In Fonseca RJ, Bays RA, Quinn PD (eds):Oral and Maxillofacial Surgery Vol 4 2000 WB Saunders, Philadelphia, p 6.

Question 37

``` During modified mandibular condylotomy surgery what is the maximum distance that the oscillating blade must extend medially beyond ramus at the level of the midsigmoid notch to place the internal maxillary artery at least risk of injury? A. 20 mm B. 15 mm C. 10 mm D. 5 ```

Answer 37

Answer: D Rationale: The mean distance from the internal maxillary artery to the midsigmoid ramus is only 3.3 mm. In addition to the risk of injury to the internal maxillary artery, a branch of the internal maxillary artery, the masseteric artery, passes through the sigmoid notch to supply the masseter muscle. Both arteries are at risk during modified condylotomy. Reference: Fujimura K, Segami N, Kobayashi S. Anatomical study of the complications of intraoral vertico-sagittal ramus osteotomy. J Oral Maxillofac Surg 64:384-389, 2006

Question 38

``` The surface of the mandibular condyle is covered with what material? A. Hyaline cartilage B. Synovium C. Fibrous connective tissue D. Fibrocartilage ```

Answer 38

Answer: D Rationale: The TMJ articular surface of the condyle covered with fibrocartilage. best suited to loading of the articular surface, while also allowing remodeling. A, B, and C do not form the covering of the condyle. Reference: Mohamed, S: Developmental and Clinical Anatomy and Physiology of the Temporomandibular Joint. In Fonseca RJ, Bays RA, Quinn PD (eds): Oral and Maxillofacial Surgery. Vol 4, 2000, WB Saunders, Philadelphia, p 8.

Question 39

``` Marked degenerative TMJ disease has been associated with which condition? A. Multiple sclerosis B. Hemophilia C. Cystic fibrosis D. Grave’s disease ```

Answer 39

Answer: B Rationale: Hemarthrosis is a common consequence of moderate to severe coagulopathies. Recurrent bleeding into the temporomandibular joint may occur in afflicted individuals resulting in marked degradation of articular surfaces of the mandibular condyle and temporal bone, and fibrosis. The mechanism responsible for these degenerative changes involves the generation of free radicals from Fe++ released from degraded hemoglobin. Some patients with multiple sclerosis may complain of radiating, electric shock-like pain limited to trigeminal dermatomes. Though the clinical presentation is characteristic of trigeminal neuralgia, it is conceivable that this pain could be mistaken as TMJ arthralgia, particularly if the pain was felt in the dermatome of CN V3. However, multiple sclerosis is not associated with an increased incidence of degenerative TMJ disease. Likewise, there is no evidence that the prevalence of degenerative TMJ disease is higher in patients with either Grave's disease or cystic fibrosis. Reference: Kaneda T. Nagayama M. Ohmori M. Minato F. Nakajima J. Shikimori M. Hemarthrosis of the temporomandibular joint in a patient with hemophilia B: report of case. J Oral Surg 1979;37:513-4. Nishioka GJ. Van Sickels JE. Tilson HB. Hemophilic arthropathy of the temporomandibular joint: review of the literature, a case report, and discussion. Oral Surg, Oral Med, Oral Pathol 1988; 65:145-50.

Question 40

``` Which of the following molecules has been implicated in the pathogenesis of degenerative TMJ diseases and can be inhibited by tetracyclines? A. Tumor necrosis factor alpha (TNF) B. Interleukin 1 beta (IL-1) C. Matrix metalloproteinase 1 (MMP1) D. Cathepsin D ```

Answer 40

Answer: C Rationale: Matrix metalloproteinases (MMPs) are enzymes which degrade molecules in the extracellular matrices (e.g., collagens, proteoglycans) of articular tissues of the TMJ. To date, four MMPs have been isolated from diseased human TMJs (MMP1, MMP2, MMP3, MMP9). These matrix degrading enzymes require zinc as a co-factor for activity. Tetracyclines inhibit these enzymes by chelation of zinc. Recent animal studies and limited clinical trials indicate that tetracyclines may limit progression of some degenerative TMJ diseases by inhibition of these matrix degrading enzymes. TNF and IL-1 are potent cytokines that have also been isolated from symptomatic human TMJs. These signaling molecules are believed to induce the synthesis of MMPs and other molecules that are involved in tissue degradation and inflammation. However, the activities of TNF and IL-1are not affected by tetracyclines. Cathepsin D is an intracellular endopeptidase that is involved in the intracellular degradation of molecules. Cathepsin D has been identified in synoviocytes of the TMJ. The activity of this enzyme is not affected by tetracyclines. Reference: Milam SB. Pathogenesis of degenerative temporomandibular joint arthritides. Odontology 2005;93):7-15. Zardeneta G. Milam SB. Lee T. Schmitz JP. Detection and preliminary characterization of matrix metalloproteinase activity in temporomandibular joint lavage fluid. International Journal of Oral & Maxillofacial Surgery. 1998;27:397-403. Haskin CL. Milam SB. Cameron IL. Pathogenesis of degenerative joint disease in the human temporomandibular joint. Critical Reviews in Oral Biology & Medicine. 1995;6:248-77. Kiyoshima T. Tsukuba T. Kido MA. Tashiro H. Yamamoto K. Tanaka T. Immunohistochemical localization of cathepsins B and D in the synovial lining cells of the normal rat temporomandibular joint. Archives of Oral Biology. 1993;38:357-9.

Question 41

``` A 46 year-old female presents with bilateral preauricular pain, restricted jaw movement and slight apertognathia. CT and MR images reveal marked erosions of the articular surfaces of both TMJs with mild joint effusions. Distal interphalangeal joint swelling and pitting fingernails (i.e., nail dystrophy) are observed on general examination. The patient has a negative rheumatoid factor, but is HLA-Bw38 and HLA-DR4 positive, anemic, and has a mildly elevated erythrocyte sedimentation rate. What is most likely diagnosis is? A. Psoriatic arthritis B. Gout C. Anklyosing spondylitis D. Reiter syndrome ```

Answer 41

Answer: A Rationale: Psoriatic arthritis is an erosive polyarthritic disease occurring in patients with psoriasis (psoriatic skin lesions). Psoriasis is a genetically determined disease, and HLA-Bw38, HLA-DR4, and HLA-DR7 are genetic markers for psoriatic arthritis. The disease is slightly more prevalent in women. Several forms of the arthropathy appear to exist. Clinical findings suggestive of psoriatic arthritis include skin lesions, distal interphalangeal joint swelling, and pitting fingernails (i.e., nail dystrophy). This condition often results in an elevated ESR and anemia. Crystal deposition diseases are believed to be genetic or acquired metabolic disorders that result in the formation of crystals derived from uric acid (gout) or calcium pyrophosphate dihydrate (pseudogout) in tissues of affected joints. Gout is typically a slowly progressive monoarthritide (in initial phases) with restricted mandibular range of motion. Gout predominantly affects older men (peak incidence in 5th decade of life). Focal crystal deposits, termed tophi, are classically found in the helix or antihelix of the ear in chronic cases. These deposits normally appear as small papular masses that rarely ulcerate or become infected. Leukocytosis, elevated ESR, and elevated uric acid are commonly observed on serology. Apertognathia is also rare. CBC, ESR, uric acid and anti-nuclear antibody studies are typically within normal limits. Reiter syndrome is an asymmetrical inflammatory oligoarthritic condition consisting of painless mucocutaneous lesions, conjunctivitis, urethritis, and arthritis affecting predominantly young men (9:1-99:1 male to female ratio) who have recently experienced an infection (Chlamydia, Campylobactor, Shigella, Salmonella, HIV). Onset is typically 1-4 weeks after infection. Reference: The American Board of Oral and Maxillofacial Surgery 137 2007 Oral and Maxillofacial Surgery Self Assessment Tool (OMSSAT) Espinoza LR. Cuellar ML. Silveira LH. Psoriatic arthritis. Current Opinion in Rheumatology.1992;4:470-8. Kononen M. Wolf J. Kilpinen E. Melartin E. Radiographic signs in the temporomandibular and hand joints in patients with psoriatic arthritis. Acta Odontologica Scandinavica. 1991;49):191-6. Barthelemy I. Karanas Y. Sannajust JP. Emering C. Mondie JM. Gout of the temporomandibular joint: pitfalls in diagnosis. Journal of Cranio-Maxillo-Facial Surgery. 2001;2):307-10. Bomalaski JS. Jimenez SA. Erosive arthritis of the temporomandibular joint in Reiter's syndrome. Journal of Rheumatology. 1984;11:400-2.

Question 42

``` This 29 year-old male presented with slowly progressing malocclusion and chin deviation. What is the most likely diagnosis based on CT images? (Imaging shows large, well-cirumscribed, proliferative, nodular lesion on the condylar head, not affecting the cortical border of the condyle.) A. Osteochondroma B. Giant cell lesion C. Osteosarcoma D. Condylar hyperplasia ```

Answer 42

Answer: A Rationale: This represents a slow growing well-circumscribed benign lesion. Osteosarcoma would be poorly circumscribed and the margins of the native condyle would be indistinct. Giant cell lesions typically would present as a destructive radiolucency rather than a proliferative, radiopaque process. In condylar hyperplasia the native condyle is usually dramatically enlarged in all dimensions. Reference: Stanton, D Stewart, J: Tumors of the Temporomandibular Joint. In Fonseca, R (ed): Oral and Maxillofacial Surgery, Vol. 4. Philadelphia, WB Saunders, 2000, pp 369-373. Waldron, C: Bone Pathology. In Neville, C (ed): Oral and Maxillofacial Pathology. Philadelphia, WB Saunders, 1995, p 472. 

Question 43

Select from the list the appropriate laboratory evaluations for a 12 year old girl with 8 weeks of intermittent daily fever, macular rash and swelling/pain involving the wrists, knees, ankles and TM joints: ANA (antinuclear antibodies) CRP (C-Reactive protein) CBC (complete blood count) C-ANCA(cytoplasmic antineutrophil cytoplasmic antibody) RF(rheumatoid factor) ESR(erythrocyte sedimentation rate) LFTs(liver function tests) A. CBC, LFTs, CRP, ANA, RF, ESR B. LFTs, CRP, ANA, RF, ESR C. C-ANCA, CRP, ANA, RF, ESR D. C-ANCA, LFTs, CRP, ANA, RF, ESR

Answer 43

Answer: A Rationale: The clinical scenario suggests systemic juvenile rheumatoid arthritis (Still's disease). Systemic JRA is marked by fever, rash, hepato-splenomegally, anemia, leukocytosis, and any number of joints may be affected, including the TMJ. Laboratory studies should include complete blood count, liver function tests (e.g AST, ALT), erythrocyte sedimentation rate and CRP. Minor AST and ALT enzyme elevations are often present. The ESR is typically elevated in children with systemic onset JRA and may exceed 100 mm/hr; normal sedimentation rates are rare when the disease is active. The level of C-reactive protein, another acute phase reactant, is usually elevated as well. Screening for rheumatic diseases should include rheumatoid factor and antinuclear antibodies. Antinuclear antibodies and RF are rarely seen in systemic onset JRA. Their presence suggests alternative diagnoses. RF, for example, may be associated with Sjögren's syndrome or the early onset of adult type RA in teenagers. Both RF and ANA may be present in children with mixed connective tissue disease. However, these conditions rarely mimic systemic onset JRA. Anti-neutrophil cytoplasmic antibodies with a cytoplasmic staining pattern (c-ANCA) have been found to have a high degree of sensitivity and specificity for Wegener's granulomatosis and is not an appropriate test to order in this child. The American Board of Oral and Maxillofacial Surgery 140 2007 Oral and Maxillofacial Surgery Self Assessment Tool (OMSSAT) Reference: Rimon A, Zeharia A, Mimouni M, Mukamel M: Temporomandibular joint pain in pediatrics: the clinical approach and differential diagnosis; Pediatric Rheumatology Online, Volume 3, Number 3 2005. (http://www.pedrheumonlinejournal.org/may-june05/TMJ-Pain.htm) Cassidy, JT, Petty, RE. Juvenile rheumatoid arthritis. In: Cassidy, JT, Petty, RE (Eds) Textbook of Pediatric Rheumatology, 4th ed, 2001 W.B. Saunders Company, Philadelphia, p. 218.

Question 44

``` A 20 year-old female presented with a previous history of TMJ clicking, isolated left TM joint pain, and limited opening. Physical examination now reveals left pre-auricular tenderness and crepitus. You obtain the following radiograph. The most likely diagnosis is: (Imaging is a terrible pan that is non-diagnostic) A. psoriatic arthritis. B. avascular necrosis. C. osteoarthrosis. D. rheumatoid arthritis. ```

Answer 44

Answer: C Rationale: The history of past TMJ clicking suggests a long-standing internal derangement. The radiographic changes are that of arthrosis, consistent with a previously clicking joint. Psoriatic and rheumatoid arthritis are both systemic arthropathies that involve multiple joints. Avascular necrosis may possibly be diagnosed my MR imaging but has no characteristic panoramic radiographic appearance. Reference: Silverstein K. Arthritis of the temporomandibular joint. In Fonseca, R (ed): Oral and Maxillofacial Surgery Vol. 4. Philadelphia, WB Saunders, 2000 p. 73-92.

Question 45

A healthy 65 year-old male presents with a chief complaint of generalized intermittent headache of 40 years duration. Over the past year his left TMJ is making a grinding noise when he eats. He denies any TMJ pain or locking. What is your clinical diagnosis from this patient’s history and image? (Pan shows changes in the shape of the left condyle to become pointy and spear-like) A. Avascular necrosis of the mandibular condyle B. Degenerative joint disease C. Synovial chondromatosis D. Rheumatoid arthritis

Answer 45

Answer: B Rationale: a. The concept of “avascular necrosis” of the TMJ condyle is unproven. b. This is a case of a patient with long standing “headache” unrelated to TMJ since he has no TMJ pain or dysfunction. He does however exhibit primary, age related DJD of the TMJ which if misdiagnosed can lead to unnecessary surgical intervention. c. The patient has no TMJ pain and dysfunction which would be hallmarks of chondromatosis along with joint noise. d. The patient has no history of systemic arthritis, TMJ pain or dysfunction. Involvement of the TMJ as the initial joint in systemic rheumatoid arthritis is rare. Unilateral TMJ rheumatoid is also rare. The American Board of Oral and Maxillofacial Surgery 143 2007 Oral and Maxillofacial Surgery Self Assessment Tool (OMSSAT) Reference: Dolwick, MF: Temporomandibular Joint Disc Displacement: A Clinical Perspective. In, Sessle, BJ; Bryant, PS; Dionne, RA (Eds): Temporomandibular Disorders and Related Pain Conditions. Progress in Pain Research and Management. Vol 4 1995,IASP Press. Seattle. pp.79 – 87. Milam, SB: Articular Disc Displacements and Degenerative Temporomandibular Joint Disease. In: Sessle, BJ; Bryant, PS; Dionne, RA (Eds): Temporomandibular Disorders and Related Pain Conditions. Progress in Pain Research and Management. Vol 4 1995 IASP Press. Seattle. Vol 4 pp.89 – 112.

Question 46

Which of the following is a prominent feature of type I condylar hyperplasia? A. Ankylosis B. Deviation of chin to contralateral side C. open bite on ipsilateral side D. bilateral crossbite

Answer 46

Answer: B Rationale: Ankylosis and crossbite are not usually features of type I condylar hyperplasia. Open bite is a prominent feature of type II condylar hyperplasia. Deviation of the chin is a common feature of type I but not type II condylar hyperplasia. Reference: Stanton D, Stewart, J: Tumors of the Temporomandibular Joint. In Fonseca, R (ed): Oral and Maxillofacial Surgery Vol. 4. Philadelphia, WB Saunders, 2000, p 365.

Question 47

``` Which of the following ligaments restricts posterior movements of the mandibular condyle? A. Stylomandibular ligament B. Sphenomandibular ligament C. Capsular ligament D. Lateral ligament ```

Answer 47

Answer: D Rationale: The lateral ligament, also known as the temporomandibular ligament, is a fan-shaped structure that runs obliquely in a posterior and caudal direction from the lateral aspect of the articular eminence to the posterior aspect of the mandibular condyle and lateral margin of the articular disk. The lateral ligament is composed of two elements: an outer oblique portion and an inner horizontal portion. The lateral ligament limits inferior and posterior displacement of the mandibular condyle, and to a limited extent the posterior displacement of the articular disk. The capsular ligament is a relatively thin structure originating from the rim of the glenoid fossa. This structure extends inferiorly to join the periosteum of the condylar process below the condylar head. The capsular ligament encloses the joint cavity, which is divided into a superior joint space and an inferior joint space by the articular disk. The stylomandibular ligament extends from the styloid process to the angle of the mandible. The sphenomandibular ligament, a remnant of the perichondrium of Meckel's cartilage, runs from the spine of the sphenoid bone to the mandibular lingula. The stylomandibular and sphenomandibular ligaments provide resistance to extreme anterior, lateral, and caudal displacements of the mandible, offering indirect support of the TMJ. Reference: Ten Cate, AR, Gross and micro anatomy. In: Zarb, GA, et al (eds) Temporomandibular Joint and Masticatory Muscle Disorders. 1994 Mosby, Munksgaard, p. 58.

Question 48

A 32 year-old patient presents with a history of increasing frequency of open lock. He now requires treatment in the local emergency room to be able to close his mouth. What intervention is most likely to provide long-term relief of his condition? A. Injection of the lateral pterygoid muscle with botulinum toxin B. Eminectomy C. Intra-articular injection of a sclerosing agent D. Temporalis muscle scarification

Answer 48

Answer: B Rationale: Comprehensive literature review reveals that the of the interventions listed, only eminectomy is likely to provide long-term control of recurrent dislocation. Distractors: Botulinum toxin may be of benefit, but the literature is scanty and the effect temporary. Sclerosing agents have a disproportionately low success rate. Temporalis scarification does not have reported long-term follow-up. Reference: Shorey, CW and Campbell, JH. Temporomandibular joint dislocation. Oral Surg, Oral Med Oral Pathol Oral Diag Endod 2000;89:662-8

Question 49

Agenesis of the mandibular condyle can be the result of which of the following? A. Malformation of the third branchial arch B. Damage to the stapedial artery during development in utero C. Folic acid deficiency D. Niacin deficiency

Answer 49

Answer: B Rationale: A. Agenesis of the mandibular condyle is also called “First Arch Syndrome” since the first, not the third, branchial arch is involved. B. This is the suspected etiology of hemifacial microsomia and related disorders, based on the work of Poswillo. C. and D. Vitamin deficiencies have nothing to do with this entity. Reference: Mercuri, LG: Temporomandibular Joint Disorders. In: Kwon, PH; and Laskin, DM (Eds): Clinician Manual of Oral and Maxillofacial Surgery 3rd ed. 2001 Quintessence Publishing Co. Chicago. Poswillo, D: The pathogenesis of Treacher-Collins Syndrome (mandibular-facial dysostosis). Br J Oral Surg 13:1, 1975. Troulis MJ, Kaban LB: Congenital and developmental anomalies. In, Laskin DM, Greene CS, Hylander WL (eds): Temporomandibular Disorders: An Evidence-Based Approach to Diagnosis and Treatment. 2006 Quintessence. Chicago.

Question 50

A 45 year-old male presents with recurrent left TMJ ankylosis and maximum interincisal opening of 10mm. 5 years ago he underwent closed reduction of a mandibular condyle fracture. One year after the closed reduction he underwent autogenous costochondral reconstruction for TM joint ankylosis. Subsequently he underwent repeat costochondral reconstruction for recurrent ankylosis. In this situation, which treatment demonstrates the lowest rate of recurrent ankylosis? A. Gap arthroplasty with the insertion of a permanent silicone rubber block B. Gap arthroplasty with the insertion of a temporalis muscle rotation flap and autogenous costochondral graft C. Gap arthroplasty with the insertion of autogenous fat graft D. Gap arthroplasty with the insertion of an alloplastic TMJ prosthesis

Answer 50

Answer: D Rationale: A. Silicone rubber implants are not a satisfactory material for use as a permanent interpositional implant in the TMJ. Silicone rubber has poor wear properties in load- bearing joints. B. Autogenous bone grafting for re-ankylosis of the TMJ has poor outcome. C. Autogenous fat grafting has been used successfully to prevent re-ankylosis of the TMJ, but not as a sole entity. D. Re-ankylosis of the TMJ is best managed by total TMJ alloplastic reconstruction and autogenous fat grafting to minimize heterotopic bone formation around the prosthesis.  Reference: Mercuri, LG: Temporomandibular Joint Disorders. In: Kwon, PH; and Laskin, DM (eds). Clinician Manual of Oral and Maxillofacial Surgery 3rd ed. 2001 Quintessence Publishing Co. Chicago. Anonymous.Recommendations for Management of Patients With Temporomandibular joint Implants. J Oral Maxillofac Surg 1993; 51:1164-72. Mercuri LG, Wolford LM, Sanders B, et al: Long-term follow-up of the CAD/CAM patient fitted total temporomandibular joint reconstruction system. J Oral Maxillofac Surg 2002;60:1440. Mercuri LG: TMJ Concepts Patient Fitted Total TMJ Reconstruction Prostheses. Oral Maxillofacial Surg Clinics North Am 2000;12:73.

Question 51

A 7 year-old child with a history of facial trauma at age 5 presents with oral opening limited to 4 mm and left-sided mandibular deviation. The surgical intervention most likely to provide functional and esthetic rehabilitation into adulthood is: A. alloplastic total joint reconstruction. B. alloplastic condylar replacement. C. gap arthroplasty with auricular cartilage graft. D. autogenous costochondral graft.

Answer 51

Answer: D Rationale: The history and image indicate bony ankylosis of the temporomandibular joint in a growing child. When reconstructing the temporomandibular joint in children, the surgeon must provide both functional anatomy and an environment in which growth may occur. Donor sites with growth potential are preferred. Alloplastic total or partial joint reconstruction or gap arthroplasty will not support growth. Reference: American Association of Oral and Maxillofacial Surgeons. Parameters and Pathways: Clinical Practice Guidelines for Oral and Maxillofacial Surgery. J Oral Maxillofac Surg, Version 3.0, TMJ-6, 2001

Question 52

``` During surgical removal of an ankylosed condyle brisk arterial bleeding is encountered and localized to the region medial to the lateral pterygoid muscle. Which terminal branch of the carotid artery is the most likely source of the bleeding? A. Internal maxillary artery B. Anterior deep temporal artery C. Masseteric artery D. Middle meningeal artery ```

Answer 52

Answer: D Rationale: The middle meningeal artery is a branch of the internal maxillary artery, coursing medially from the internal maxillary artery ascending between the sphenomandibular ligament and the lateral pterygoid muscle, passing through the foramen spinosum. The average distance from the glenoid fossa to the middle meningeal artery is 2.4 mm. The close proximity of the middle meningeal artery to the TMJ places it at risk during complex procedures that require dissection medical to the mandibular condyle. Reference: Cillo JE, Sinn D, Truelson JM. Management of middle meningeal and superficial temporoal artery hemorrhage from total temporomandibular joint replacement surgery with a gelatin-based hemostatic agent. J Craniofac Surg 2005;16:309-12

Question 53

``` TMJ Disc position is unchanged in what percentage of cases two years following arthrotomy for disc repositioning? A. 15% B. 25% C. 55 D. 85% ```

Answer 53

Answer: D Rationale: The concept of arthrotomy for disc repair was championed by McCarty and Farrar with their 1979 report of 327 disc repairs. In spite of reports describing successful outcomes, few reports have evaluated disc position following “repair.” Montgomery, et al imaged 35 joints an average of 2 years after disc repair and noted that disc position was unchanged in 86% of joints, worse in 6%, and improved in 8%. Assuming that these discs were repositioned at the time of surgery, these data suggest that disc position is prone to relapse at some point after disc repair. A smaller series of 23 joints showed persistent disc displacement in 48% of joints after disc repair.

Question 54

``` A variety of neurotransmitters play a role in the generation of orofacial pain. The primary neurotransmitter for pain is: A. Substance-P B. Serotonin C. Glutamate D. Prostaglandin I2 ```

Answer 54

Answer: C Rationale: Glutamate is the primary neurotransmitter for pain. It is the first agent released following trauma. Substance-P plays a major role in pain however it requires higher intensity stimulation for release compared to glutamate. Inflammatory messengers such as PGI2 and serotonin act through the activation of adenylate cyclase sensitive nocioceptive terminals.

Question 55

Modified condylotomy is principally indicated for which of the following conditions? A. Anterior disc displacement without reduction and associated degenerative joint disease B. Anterior disc displacement with reduction C. Central disc perforation with osteoarthrosis D. Superior joint space adhesions and chronic limited opening

Answer 55

Answer: B Rationale: Condylotomy has been shown to work most favorably in cases of anterior disc displacement, especially in the setting of disc displacement with reduction. Modified condylotomy can effect disc reduction and alter favorably the natural course of internal derangement in reducing disc displacement.

Question 56

In performing TMJ arthrocentesis, the initial point of entry into the superior joint space is: A. 10 mm anterior to the tragus, and 5mm inferior to the tragocanthal line. B. 10mm anterior to the tragus, and 2mm inferior to the tragocanthal line. C. 15mm anterior to the tragus, and 2mm inferior to the tragocanthal line. D. 15mm anterior to the tragus, and 5mm inferior to the tragocanthal line.

Answer 56

Answer: B Rationale: Puncture landmarks for arthrocentesis are established with reference to a line connecting the tragus and lateral canthus. The initial puncture should be 10 mm anterior to the tragus and 2 mm below the canthal- tragal line.

Question 57

What subnucleus of the trigeminal brainstem nucleus complex is primarily involved in the receiving and processing of facial pain? A. Subnucleus interpolaris of cranial nerve V. B. Subnucleus caudalis of cranial nerve IX. C. Subnucleus caudalis of cranial nerve V. D. Subnucleus oralis of cranial nerve V.

Answer 57

Answer: C Rationale: Trigeminal sensory nerves relay mechanical, thermal, chemical, and proprioceptive information from craniofacial regions. The trigeminal spinal nucleus is divided into oralis, interpolaris, and caudalis subdivisions. The subnucleus caudalis is the largest subdivision and is primarily responsible for facial pain.

Question 58

Muscle contraction type headache will most commonly result in which symptom? A. Unilateral pulsating head pain B. Prostration and nausea C. Scotoma and/or photophobia D. Sensation of a constricting band about the head

Answer 58

Answer: D Rationale: In contrast to vascular headache, muscle contraction type headache is usually not associated with visual symptoms, prostration and nausea. Muscle contraction headache can be acute or chronic and is associated with sustained contraction of skeletal muscles. The temporalis muscle is often involved in muscle contraction headache. Symptoms are usually generalized with the sensation of a “constricting band” about the head. The pain of muscle contraction headache is described as dull and throbbing in nature. Unilateral, pulsating headache associated with prostration/nausea, and visual symptoms are features of migraine headache.

Question 59

The use of contralateral coronoidectomy/coronoidotomy during the surgical management of bony TM joint ankylosis is most appropriately established by: A. Pre-operative CT imaging B. Examination under anesthesia with pharmacologic muscle relaxation C. Examination immediately after arthrotomy/excision of ankylosis D. Pre-operative MR imaging

Answer 59

Answer: C Rationale: Contralateral coronoidectomy/coronoidotomy may be necessary due to temporalis shortening/fibrosis. The requirement for contralateral coronoidectomy/coronoidotomy is established through examination of mandibular mobility after arthrotomy/excision of ankylosis.

Question 60

A key technical element in the performance of modified condylotomy that differs from vertical ramus osteotomy for mandibular setback is: A. Short vertical osteotomy directed from the sigmoid notch posteriorly through the posterior border of the ramus. B. Deliberate anterior re-positioning of the proximal segment. C. Long vertical osteotomy directed from sigmoid notch to the gonial angle. D. Deliberate partial detachment of the medial pterygoid muscle from the inferior aspect of the proximal segment.

Answer 60

Answer: D Rationale: A posteriorly directed osteotomy is more likely to be associated with excessive condylar sag, if not condylar displacement by unopposed lateral pterygoid activity. Medial pterygoid muscle is deliberately stripped from the inferior aspect of the proximal segment to produce condylar sag with modified condylotomy. To minimize or prevent condylar sag, lateral pterygoid stripping is minimized in vertical ramus osteotomy for mandibular setback.

Question 61

``` Which of the following findings may help differentiate TMJ osteoarthritis from rheumatoid arthritis? A. Prolonged morning stiffness B. Joint space narrowing C. Crepitant joint sounds D. Preauricular tenderness ```

Answer 61

Answer: A Rationale: Morning stiffness is typically found with rheumatoid arthritis but not osteoarthritis. Joint space narrowing, crepitant joint noise and preauricular pain may be seen in both conditions.

Question 62

``` What percentage of adults have an asymptomatic TM joint internal derangement? A. 0% B. 15% C. 30% D. 45% ```

Answer 62

Answer: C Rationale: Katzberg, et al discovered that 25/76 (33%) asymptomatic volunteers (no joint noise, locking, or pain or tenderness) had an internal derangement in one or both joints. 79/102 (79%) symptomatic patients had an internal derangement in one or both joints. The symptomatic participants were more likely to have disc displacement without reduction. Similar data is presented by Kircos, et al.

Question 63

``` What percent of infants and children under 5 years of age have been found to have a displaced TM joint disc? A. 0% B. 15% C. 30% D. 45% ```

Answer 63

Answer: A Rationale: In both adult and pediatric patients TMJ pain is associated with disc displacement in 77-94% of subjects. The incidence of painful disc displacement peaks during puberty. The prevalence of asymptomatic disc displacement is 6% in a population with a median age of 11 years (Hans, et al) and 34% in a population with a median age of 16-19 years (Ribeiro, et al). The high prevalence of disc displacement in asymptomatic joints suggests that internal derangement may be congenital. However, the finding by Paesani, et al of normal disc position in 60 joint imaged in children aged 2-5 years supports an acquired etiology for internal derangement.

Question 64

``` Patients with TM joint pain most likely to seek initial help at what ages? A. 0-20 years B. 20-40 years C. 40-60 years D. 60-80 years ```

Answer 64

Answer: B Rationale: Patients in the 20-40 year age range are most likely age group to seek treatment for internal derangement.

Question 65

Which of the following factors predispose to post-modified condylotomy malocclusion? A. Pre-operative class I occlusion B. Bilateral surgery C. Ligation of anterior teeth to arch bar D. Absent molar occlusion on the side opposite the condylotomy

Answer 65

Answer: B Rationale: Bite disturbance is minimized with a brief (1 week –unilateral, 2-3 weeks-bilateral) period of maxillomandibular fixation followed by a period (3-4 weeks-bilateral, 5 weeks-unlateral) of training elastic use. Bite disturbance is more common in the setting of bilateral condylotomy, pre-existing malocclusion, and missing molars on the operated side. Ligation of anterior teeth can allow for dental compensation and minimize open bite malocclusion especially after bilateral condylotomy.

Question 66

Which of the following complications associated with TM joint arthroscopy may be accounted for by the foramen of Huschke and Huguire’s canal? A. External auditory canal edema B. Intracranial extravasation of joint irrigant C. Perforation of the tympanic membrane D. Injury to the temporal branch of the facial nerve

Answer 66

Answer: A Rationale: External auditory canal edema and possibly tympanic membrane edema may be explained by extravasation joint irrigant through the foramen of Huschke, a residual defect in the tympanic plate. Another potential explanation for this complication is extravasation of fluid along the ligaments within Huguire's canal within petrotympanic fissure.

Question 67

Trigeminal neuralgia is characterized by: A. proxysmal unilateral pain in the distribution of one or more divisions of the 5th cranial nerve. B. predilection for males in the 4th decade of life. C. chronic, continuous, unilateral pain in the distribution of one or more divisions of the 5th cranial nerve. D. predilection for females in the 3rd decade of life.

Answer 67

Answer: A Rationale: Trigeminal neuralgia is characterized by paroxysmal, lacinating pain in the distribution of one or more of the divisions of the 5th nerve in a woman in the 6th or 7th decade of life. Pain of trigeminal neuralgia is usually provoked by trivial stimulation of the involved dermatome. Traumatic trigeminal neuralgia occurs in a younger population and is associated with tissue or nerve injury. Traumatic trigeminal neuralgia is characterized by continuous burning pain.

Question 68

The mechanism of action of the sumatriptan (Imitrex) in the management of migraine headache is: A. inhibition of pre-synaptic serotonin receptors. B. inhibition of cerebral vessel and dural pain fibers. C. down regulation of pain fibers by inhibition of Substance-P re-uptake. D. inhibition of the vasoconstrictor phase of migraine headache.

Answer 68

Answer: B Rationale: The mechanism of action of the sumatriptan and other “triptans” is by inhibition of cerebral vessel and dural pain fibers. Additionally, the “triptans” are serotonin agonists are directly bind 5-HT pre-synaptic receptors causing vasoconstriction. Thus, “triptans” modulate vascular headache pain by direct inhibition of dural/cerebral vascular pain fibers and by antagonism of cerebral vasodilation.

Question 69

Findings consistent with Wilkes stage IV TMJ internal derangement include: A. recent progression to disc displacement without reduction. B. maximum interincisal oral opening less than 25mm. C. altered mandibular condyle morphology. D. low condyle signal intensity on MR T2 images.

Answer 69

Answer: C Rationale: Wilkes stage IV (intermediate late stage) internal derangement is defined as complete disc displacement with hard-tissue degenerative remodeling changes and clinical chronicity. Interincisal opening is usually greater than 30mm in late-stage disease. Option A describes early Wilkes stage III (intermediate stage) internal derangement. Option B suggests a component of muscle guarding/splinting that does not define a particular Wilkes stage. Maximum opening usually exceeds 25 mm in stage IV internal derangement as a result of progressive disc deformity. Option D describes the controversial concept of avascular necrosis and is not associated with a particular Wilkes stage.

Question 70

Wilkes stage III (intermediate stage) internal derangement is best described by which of the following statements? A. Chronic location of disc and condyle anterior to the articular eminence. B. Major mechanical and inflammatory symptoms, moderate to marked disc deformity, partial or complete forward disc displacement C. Painless, early reciprocal clicking, no inflammatory symptoms, slight anterior disc displacement D. Clinical chronicity, complete forward disc displacement, hard and soft tissue degenerative remodeling

Answer 70

Answer: B Rationale: Option A describes chronic TMJ dislocation. Option C describes Wilkes stage I (early stage) internal derangement. Option D describes Wilkes stage IV (intermediate late stage) internal derangement.

Question 71

``` When applied to Wilkes stage II and early stage III anterior disc displacement modified condylotomy has been shown to effect MRI disc reduction in what percentage of joints? A. 10% B. 20% C. 50% D. 80% ```

Answer 71

Answer: D Rationale: Modified condylotomy is capable of effecting disc reduction in 80% of joints with anterior disc displacement with reduction (Wilkes stage II) or with discs that have recently progressed to non-reducing disc status (Wilkes early stage III).

Question 72

``` Sleep bruxism is associated with which of the following features? A. Periodic limb movement disorder B. Cessation of caffeine consumption C. Anxiety disorders D. Nasal CPAP use ```

Answer 72

Answer: C Rationale: Sleep bruxism shares many features with untreated obstructive sleep apnea. In an evaluation of over 13,000 subjects sleep bruxism was associated with anxiety disorders, caffeine consumption but is was not associated with periodic limb movement or nasal CPAP use.

Question 73

What statement best describes TMJ involvement in rheumatoid arthritis? A. TM joint involvement is present in greater than 80% with rheumatoid arthritis. B. There is poor correlation between TMJ radiographic changes and the severity of rheumatoid disease. C. Progression of TM joint bone loss is associated with elevated plasma levels of C-reactive protein. D. The most common CT radiographic finding is condylar osteophyte formation.

Answer 73

Answer: C Rationale: Elevated plasma C-reactive protein is associated with progression of TM joint bone loss. The next most common laboratory evaluation for RA is rheumatoid factor (RF) which is positive in 70-80% of patients. RF titers greater than 1:1280 are associated with severe and progressive disease. A positive anti-nuclear antibody (ANA) titer will be detected in 15-20% with rheumatoid arthritis. Radiographic TM joint involvement is seen in approximately 40% with rheumatoid arthritis. TM joint symptoms occur in approximately 30% with rheumatoid arthritis. The most common CT radiographic finding is decreased joint space.

Question 74

The concept of minimizing stress on the TM joint following mandibular ramus osteotomies to correct a Class II skeletal malocclusion is described by which statement? A. Avoidance of mandibular counterclockwise rotation and ramus lengthening with mandibular advancement B. Application of rigid fixation and early mandibular mobilization C. Simultaneous intracapsular TM joint surgery and ramus osteotomies for mandibular advancement D. Application of semi-rigid fixation

Answer 74

Answer: A Rationale: The concept of minimizing TM joint stress refers to measures to avoid counterclockwise mandibular rotation and ramus lengthening at the time of mandibular advancement. The type of fixation (rigid vs. semi-rigid vs. non-rigid) has no proven impact on joint problems after orthognathic surgery. Simultaneous arthrotomy and ramus osteotomies have not been demonstrated to control TM joint stress after orthognathic surgery.

Question 75

``` The roof of the glenoid fossa is formed primarily by the: A. petrous part of temporal bone. B. squamous part of temporal bone. C. temporal part of zygomatic bone. D. tympanic part of the temporal bone. ```

Answer 75

Answer: B Rationale: The roof of the fossa is formed primarily by the squamous portion of the temporal bone. It is separated from the tympanic plate by the squamotympanic fissure. The medial 2/3rds the roof of the fossa is inferior to the middle cranial fossa. The petrous portion of the temporal bone is pyramidal, wedged in at the base of the skull between the sphenoid and occipital bones and does not form part of the fossa.

Question 76

During surgical dissection of the TMJ the most posterior element of the temporal branch of the facial nerve transverses the zygomatic arch how many cm anterior to the most anterior concavity of the external auditory canal? A. Range of 1.5-3.0 cm with a mean of 1.5 cm B. Range of 1.5-3.0 cm with a mean of 2.0 cm C. Range of 0.8-3.5 cm with a mean of 2.0 cm D. Range of 0.8-3.5 cm with a mean of 1.5 cm

Answer 76

Answer: C Rationale: l-Kayat and Bramley performed 56 cadaveric dissections and measured the distance from the anterior concavity of the external auditory canal to the point where the temporal branch of the facial nerve crosses the zygomatic arch. The range was found to 0.8-3-5cm with a mean distance of 20 mm.

Question 77

What is characteristic of the presentation of psoriatic arthritis involving the TMJ? A. Polyarthritis in a man B. Affects 50% of patients with cutaneous psoriasis C. Serology positive for rheumatoid factor (RF) and antinuclear antibody (ANA) D. Bilateral TMJ arthritis with restricted opening

Answer 77

Answer: A Rationale: Psoriatic arthritis affects men more that women. It often presents as a rheumatoid-like, erosive polyarthritis affecting approximately 6% of the patients with psoriasis. Laboratory studies are usually negative for RF and ANA, and there are no rheumatoid nodules. TMJ involvement is characterized by episodic unilateral arthritis with restricted opening. Timing of exacerbation of TMJ and skin symptoms is often coincident.

Question 78

Which of the following modalities have a clinical application in the prevention of heterotopic bone formation after surgical treatment of bony ankylosis of the TM joint? A. Systemic corticosteroids B. Short-term bisphosphonate administration C. External beam irradiation D. Aggressive passive range of motion exercises

Answer 78

Answer: C Rationale: Various modalities have been employed to decrease heterotopic bone formation after surgical treatment of TM joint ankylosis. Bisphosphonates must be taken over a prolonged period of time to limit heterotopic bone formation. Low dose radiation therapy administered in the first few days following arthrotomy can also limit heterotopic bone deposition. Systemic corticosteroids have no role in limiting heterotopic ossification. Aggressive, passive range of motion exercises may actually stimulate heterotopic bone formation from muscle trauma.

Question 79

What statement most closely describes the Christiansen total TM joint prosthesis? A. System depends on CAD-CAM technology for fabrication of the condylar element. B. Fossa element is composed of pre-cured polymethylmethacrylate. C. Fossa element is composed of cobalt-chromium alloy. D. Fossa and universal condylar element are composed of cobalt-chromium alloy.

Answer 79

Answer: D Rationale: The Christiansen total TM joint prothesis fossa element is composed of cobalt-chromium alloy. Both pre- cured polymethylmethacrylate and cobalt-chromium condylar elements have been used with this system however the “universal” condylar prosthesis is composed of a polymethylmethacrylate head and cobalt- chromium ramus element. Though a patient-specific prosthesis can be fabricated using CAD-CAM technology, stock elements are available.

Question 80

``` Which facial feature is characteristic of skeletal deformity associated with advanced juvenile rheumatoid arthritis of the temporomandibular joint? A. Macrognathia and class I skeletal deformity B. Macrognathia and class II skeletal deformity C. Micrognathia and class I skeletal deformity D. Micrognathia and class II skeletal deformity ```

Answer 80

Answer: D Rationale: The TM joint is most often involved in the polyarticular subtype of juvenile rheumatoid arthritis (JRA). The clinical features of JRA of the TM joint include pain, joint tenderness, crepitant sounds, stiffness/decreased range of motion. Radiographic changes consist of condylar erosion, ramus shortening and an accentuated antegonial notch. The mandible appears micrognathic with clockwise rotation and the development of a Class II open bite malocclusion.

Question 81

Botulinum toxin type-A, when used in the treatment of chronic facial pain of muscular origin produces its effects by: A. spastic paralysis of the muscle. B. attenuation of muscle contraction through inhibition of acetylcholine release. C. increased inhibitory neuron Substance P production. D. acetylcholine re-uptake inhibition.

Answer 81

Answer: B Rationale: Botulinum toxins are a group of eight toxins elaborated by Clostridium botulinum, a gram positive anaerobic organism. The primary effect of botulinum toxin is receptor-mediated endocytosis of the toxin in the area of neuromuscular synapse with selective proteolysis of the vesicular protein SNAP (synaptonal associated protein). This event prevents the release of acetylcholine into the neuromuscular junction.

Question 82

A patient undergoes left temporomandibular joint reconstruction via a preauricular approach. One week later, he still is unable to raise his eyebrow or close his eye on the operated side. The most appropriate next step at this time is: D. observation for 3 weeks then perform EMG. E. surgical exploration of the wound. F. electromyography study. D. electroneurography study.

Answer 82

Answer: D Rationale: Electrophysiologic testing (EPT) is the most reliable prognostic tool for the assessment of post-traumatic nerve recovery. The utility of EPT is in its ability to differentiate injuries that will recover from injuries possibly requiring surgical intervention. EPT has limited applicability in the first three days post-injury because Wallerian degeneration is incomplete and false positive results are common. Proper timing of EPT should also take into account the 2-3 weeks necessary for denervational muscle changes following nerve injury. Electroneurography and electromyography are the two EPT modalities used to study facial nerve function. Electroneurography is the most accurate method of predicting of nerve recovery. When the response to electroneurography is less than 10% of the normal side a poor outcome is expected. Conversely, if the response to electroneurography remains greater than 10% of the response on the unaffected side up to three weeks post-injury the prognosis for spontaneous recovery is favorable. Electroneurography should first be performed after Wallerian degeneration is complete, approximately three days post-injury. Electromyography estimates the extent of muscle denervation and the timing and completion of functional recovery. Therefore electromyography is delayed for 2-3 weeks until denervation changes occur. Electromyography is most useful in the period 2-3 weeks post-injury to 15 weeks post-injury. Early EPT is widely recommended to assess the magnitude of nerve injury and determine the role for early nerve repair.

Question 83

What statement most closely describes the Lorenz total temporomandibular joint prosthesis? A. Cobalt-chromium ramus component with HA coating to enhance stability. B. Titanium ramus component with plasm sprayed coating to enhance stability. C. Ultra high molecular weight fossa component stabilized with screws. D. Polymethylmethacrylate fossa stabilized with screw fixation and polymethylmethacrylate bone cement.

Answer 83

Answer: C Rationale: The Lorenz total TM joint prosthesis is composed of cobalt-chromium ramus component. The host-bone surface of the ramus component is roughened with a titanium plasma coating. The fossa element is made of ultra-high molecular weight polyethylene that is stabilized with screws. Polymethylmethacrylate bone cement may also be used to fill voids but the cement is not designed as a load bearing medium.

Question 84

In the preauricular approach to the temporomandibular joint, the temporal branch of the facial nerve is located: A. superficial to the SMAS layer. B. deep to temporalis fascia. C. on the deep surface of the temporoparietal fascia. D. at least 3 cm anterior to the tragus.

Answer 84

Answer: C Rationale: The temporal branch of the facial nerve is situated between the temporoparietal fascia and the temporalis fascia on the deep surface of the temporoparietal fascia.

Question 85

``` After TMJ arthrotomy utilizing a preauricular approach, a patient reports sensory alteration of the preauricular skin. Damage to what nerve is responsible for this finding? A. Great auricular B. Auriculotemporal C. Chorda tympani D. Zygomaticotemporal ```

Answer 85

Answer: B Rationale: The auriculotemporal branch of the 3rd division of the 5th cranial nerve provides sensation to the preauricular skin.

Question 86

``` Examination of a 61 year old woman with a one year history of intermittent right TMJ pain reveals tenderness of the right mandibular condyle, crepitant joint sounds, and mandibular opening limited to 29mm. Both hands have firm, painless enlargements of the distal interphalangeal joints. A panoramic radiograph reveals cortical disruption of the right condyle. The erythrocyte sedimentation rate is 12mm/hour, latex fixation and antinuclear antibody (ANA) serology are negative. The most likely diagnosis is: A. rheumatoid arthritis. B. gouty arthritis. C. osteoarthritis. D. giant cell arteritis. ```

Answer 86

Answer: C Rationale: Osteoarthritis (OA) is a chronic non-inflammatory condition that effects the articular cartilage of synovial joints. Unlike rheumatoid arthritis the synovium is only involve secondarily. Osteoarthritis is the most common disease affecting the TM joint. In contrast to rheumatoid arthritis, when osteoarthritis involves the hands the DIP joint is most often involved. Unlike rheumatoid arthritis (RA), morning stiffness is not characteristic of OA but when present generally lasts less than 30 minutes. Radiographic changes in OA consist of subchondral sclerosis, condylar flattening, lipping and erosion. Laboratory findings in OA are unremarkable where as in RA the erythrocyte sedimentation rate is usually significantly elevated and the latex agglutination test is positive. Gouty arthritis of the TMJ is more likely to be seen in late stage disease. The initial joint most frequently affected in gout is the MTP of the great toe. Giant call arteritis does not affect the TM joint and is associated with an elevated sedimentation rate.

Question 87

``` A TMJ arthrotomy has been performed. The patient returns post-operatively with the complaint of flushing, warmth and perspiration in the temporal region on the operated side when eating. She is suffering from: A. hyperhydrosis syndrome. B. Frey’s syndrome. C. Froin’s Syndrome. D. Meniere’s syndrome. ```

Answer 87

Answer: B Rationale: Frey syndrome, or “gustatory sweating” is a relatively common complication of parotidectomy but uncommon following TM joint arthrotomy. It is believed to be caused by aberrant regeneration of post- ganglionic parasympathetic parotid secretomotor fibers with severed post-ganglionic sympathetic fibers innervating facial sweat glands.

Question 88

A patient with a history of diurnal bruxism presents with bilateral TMJ pain and muscle tenderness refractory to non-steroidal antiinflammatory medication. She has limited opening with absence of clicking, crepitus and deviation. A recent TMJ MRI is negative for internal derangement. Reasonable treatment at this point should include: A. occlusal equilibration. B. diagnostic arthroscopy for lysis and lavage. C. splint therapy. D. arthrocentesis with local anesthetic and intraarticular steroids.

Answer 88

Answer C Rationale: In the setting of normal TM joints, bruxism and muscular pain the most appropriate treatment should be initially directed towards the control of bruxism. Of the options listed, only splint therapy has a potentially beneficial role in the management of bruxism. In this clinical scenario there is no indication for initia irreversible treatments such as occlusal equilibration, arthroscopy, etc.

Question 89

Frey’s syndrome after TMJ reconstruction results from: A. transection of the auriculotemporal nerve. B. aberrant regeneration of sympathetic and parasympathetic fibers. C. damage to otic ganglion preganglionic parasympathetic fibers. D. aberrant regeneration of postganglionic adrenergic fibers.

Answer 89

Answer: B Rationale: Sympathetic innervation controls sweating and vascular smooth muscle tone. Postganglionic parasympathetic fibers from the otic ganglion are severed in this condition. Misdirected regeneration of parasympathetic fibers to sweat gland sympathetic fibers and receptors accounts for this condition.

Question 90

What statement is true regarding the action of the superior head of the lateral pterygoid muscle? A. Superior head is the principle cause of anterior disc displacement. B. Has the same origin as the inferior head of the lateral pterygoid muscle. C. Heterogeneous muscle with increased activity in closing, opening, protrusion, and contralateral jaw movement. D. Increased activity in closing, opening, retrusion and ipsilateral movements.

Answer 90

Answer: C Rationale: The action of the superior head of the lateral pterygoid muscle (SHLP) is controversial. However, sophisticated analysis of motor unit activity has demonstrated muscle unit heterogeneity in the SHLP. Therefore depending on the medial-lateral location of muscle units increased SHLP may occur with closing, opening, protrusion, and contralateral jaw movements.

Question 91

``` What is the least common variety of MRI diagnosed disc displacement in symptomatic TM joints? A. Medial B. Lateral C. Anterior D. Anterolateral ```

Answer 91

Answer: B Rationale: As many as seven types of disc displacement have been described in MR imaging of symptomatic TM joints. Werther, et al demonstrated that 74% of disc displacements fall into the two most common groups, anterior (45%) and medial rotary ((29%). Of the options listed lateral disc displacement is the least common, occurring in 2.5% of symptomatic joints. Similarly, Simmons found no case of lateral disc displacement in 58 symptomatic joints imaged with MRI.

Question 92

The arthrokinetic reflex is an orthopedic principle which describes: A. muscle spasms causing arthritides. B. muscles causing referred pain to an adjacent joint. C. internal derangement of joints causing spasms in adjacent muscles. D. internal derangements are secondary to muscle spasm.

Answer 92

Answer C Rationale: The arthrokinetic reflex is an orthopedic concept that states that internal derangement can cause muscle spasm in the muscles supporting that joint and that when the internal derangement is resolved the muscles cease to spasm. For example, in the setting of disc displacement with reduction, increased EMG activity of the temporalis and masseter muscles occurs when the condyle slides over the posterior band of the disc during closure. Muscle activity decreases when the disc position is normalized with mouth opening.

Question 93

What is most diagnostic to verify a temporomandibular joint source of facial pain? A. Magnetic resonance imaging B. Doppler auscultation of TMJ C. Detailed patient history D. Auriculotemporal nerve anesthetic block

Answer 93

Answer: D Rationale: Though MR imaging and doppler may depict an internal derangement and suggest a source for pain, internal derangement may occur coincidentally in the setting of complex facial pain not originating in the TM joint. Although a detailed history can often suggest the source of pain, diagnostic nerve blocks can be used to systematically localize a source of pain. Diagnostic anesthetic block of the auriculotemporal nerve largely eliminates the temporomandibular joint from a complex facial pain presentation and can facilitate localization of a pain source.

Question 94

Non-arthroscopic lysis and lavage of the temporomandibular joint is an effective adjunct in the management of: A. myofascial pain dysfunction. B. recent onset disc displacement without reduction. C. synovitis. D. temporal tendonitis.

Answer 94

Answer: B Rationale: Temporomandibular joint arthrocentesis includes lavage of the upper joint space, hydraulic distension, manipulation, and instillation of a corticosteroid. Arthrocentesis is indicated for acute or chronic limitation of motion due to anterior disc displacement without reduction and hypomobility due to restriction of condylar translation in the superior joint space.

Question 95

``` During surgery for bony ankylosis of the TM joint brisk skull base bleeding medial and anterior to the glenoid fossa is most likely from what vascular structure? A. Internal jugular vein B. Middle meningeal artery C. Internal carotid artery D. Ascending pharyngeal artery ```

Answer 95

Answer: B Rationale: The important vascular structure medial and anterior to the glenoid fossa is the middle meningeal artery (MMA). The mean anterior-posterior distance of the MMA from a line tangent to the maximum height of the glenoid fossa is 2.4mm. The distance of the internal carotid artery and internal jugular vein from the same landmark is 6.5 and 8.7mm respectively. Though injury to the MMA is uncommon, catastrophic bleeding may occur if this structure is violated during surgery medial to the TM joint.

Question 96

``` Maximum interincisal opening of 5 mm immediately following 3 weeks of maxillo-mandibular fixation is best explained by? A. Bony ankylosis B. Fibrous ankylosis C. Muscle splinting D. Hypertrophy of muscles of mastication ```

Answer 96

Answer: C Rationale: In the mandible, 3 weeks of IMF for an adult condyle fracture is just slightly longer than usual. However, it is not long enough to cause a fibrous or bony ankylosis. Hypomoblity following closed reduction is due to muscle splinting and guarding. This responds very well to physiotherapy. Ankylosis is a major complication of prolonged IMF, especially in children. Reference: Peterson 2nd edition, Principles of Oral and Maxillofacial Surgery, Principles of management of mandibular fracture, p 401-434, 2004 Fonseca, Oral and Maxillofacial Trauma, Mandibular fractures, p 479-522, 2005