Trauma Flashcards

Question

Acute dacryocystitis following trauma is treated by all of the following except: A. warm compresses B. intubation of the canaliculi and injection of dye C. systemic or topical nasal decongestants D. incision and drainage

Answer 1

ANSWER: B RATIONALE: Dilation, intubation and dye injection are diagnostic, not therapeutic measures. Moreover, these maneuvers should not be attempted in the face of an acute dacryocystitis. Incision and drainage of the lacrimal sac, administration of medicaments (systemic or topical decongestants,) or palliative care(warm compresses) are acceptable treatment modalities.

Answer 2

ANSWER: D RATIONALE: Ectropion and entropion can affect the contact of the inferior lacrimal punctum with the tear fluid decreasing lacrimal fluid flow through the punctum and leadin to epiphora. Traumatic telecanthus can also lead to alterations in tear flow and drainage in the medial aspect of the inferior palpebral area and decrease lacrimal drainage through the inferior canilculus. The codnition affect lacrimal fluid drainage but not lacrimal fluid delivery to the palpebral fissure. Although a laceration through the laterial aspect of the upper eyelid can disrupt tear flow from the lacrimal gland, such a decrease in tear production would not lead to epiphora.

Answer 3

ANSWER: C RATIONALE: The incidence of nasolacrimal disruption is 0.2% following nasal fracture, 3-4% following midface fractures, 17-21 % following naso-ethmoidal fractures, almost non existent following zygomatic-maxillary fractures. The location of the zygoma is so far removed from the lacrimal apparatus so as to make it a concomitant injury.

Answer 4

ANSWER: A RATIONALE: Plane radiography is incapable of confirming a CSF leak. While magnetic resonance is helpful with soft tissues, without dye, this diagnostic aid is useless. A similar rationale exists for non- contrast CT. An intrathecal injection of dye, and confirmation of the dye at distant sites is diagnostic.

Answer 5

ANSWER: D RATIONALE: Movement of an alloplastic implant is generally asymptomatic. Injury to the infraorbital nerve produces anesthesia or paresthesia over it's cutaneous distribution (the lower eyelid area). Horner's syndrome, caused by a disruption in the sympathetic innervation to the upsilateral maxillofacial region, is characterized by: a constricted pupil (by unopposed parasympathetic constriction), ptosis (by loss of smpathetic inneration to Mueller's muscle), and anhidrosis (by interruption of sympathetic innervation to cutaneous sweat glands). The symptoms described are most consistent with retrobulbar hematoma, and require prompt diagnosis and intervention.

Answer 6

ANSWER: B RATIONALE: The recent development and improvements in miniaturized bone plate systems has greatly enhanced treatment of midface fractures and diminished but not obviated the need for wire suspension with direct wiring techniques. While wires may provide minor resistance to deformation in an anterior and posterior direction, they offer no resistance superiorly. The best answer is that the resist deformation in an inferior direction and thereby resist facial elongation.

Answer 7

ANSWER: C RATIONALE: Dilation may mask signs and symptoms of neurologic injury. Pupillary dilation does not aid in a visual acuity examination but is utilized to fully visualize the retina, vessels and the optic disc. Pre-existing visual acuity defecits (such as myopia and presbyopia) can mimic traumatic visual acuity loss; and therefore the use of prescription eyeglasses can facilitate the distinction of pretaumatic from traumatic visual defecits. Topical tetracaine is a local anesthetic and is of no value in the evaluation of visual acuity. If pretraumatic myopia is prsent, acuity evaluation while looking through a pinhole can substitute somewhat for corrective lenses if such lenses are not available.

Answer 8

ANSWER: A RATIONALE: Iridocyclitis is a traumatic anisocoria and many times points towards the injury. Fat herniation occurs with aging and of itself is not necessarily indicative of traumatic septum violation. Herniated fat without lid laceration is therefore of no consequence; however, fat herniation through a lid laceration indicates septum violation and mandates the need for careful evaluation for penetrating globe injury. Penetrating globe injury is diagnosed by visualization of the globe surface. The lid should be examined prior to the administration of local anesthesia because edema and local anesthesia may limit motility.

Answer 9

ANSWER: D RATIONALE: Cartilagenous lacerations should be approximated to reconstruct anatomy and prevent chronic chondritic inflammation. Interrupted sutures may promote cartilage margin overlap; the use of figure of eight sutures prevents overlap of lacerated cartilage margins. Cartilage has a limited vascurlar supply, originating from overlying soft tissue; therfore extensive debridement of overlying soft tissue should be discourage.

Answer 10

ANSWER: D RATIONALE: The purpose of the trans-canthal wire is to secure the canthal ligament and boney segment in the pretraumatic position. Pull of the soft tissues displaces the bone and canthal ligament in an anterior and inferior direction. Therefore a wire placed posterior and superior to the original insertion provides a vector whose resistance to displacement is most ideal and provides the best alignment.

Answer 11

ANSWER: D RATIONALE: This is a classic tension pneumothorax and treatment is a clinical diagnosis with immediate needle decompression of the second intercostal space, midclavicular line The time involved in waiting for a chest x-ray might prove lethal. Insertion of a chest tube in a controlled fashion to facillitate lung re-expansion normally follows needle deompression of the tension pneumothroax. Endotracheal intumbation with positive pressure ventilation often worsen a tension pneumothrorax, but may be indicated for other types of chest injuries.

Answer 12

ANSWER: A RATIONALE: These findings are consistent with a Class II hemorrhage, 750-1500ml, The vitals signs or such a blood loss are consistent with those in response A. Response D reflects the vital signs of a Type IV blood loss, Response C a Type III and Response B a Type I.

Answer 13

ANSWER: B RATIONALE: According to the Glascow Coma Scale, the patient can open his eyes in response to commands speech, (3 out of 4); localizes pain, (5 out of 5); yet produces inappropriate words, (3 out of 6); for a Glascow coma score of 11.

Answer 14

ANSWER: D RATIONALE: Fronto-orbital injuries are the most frequent in this age group. Because the antrum, sphenoid, ethmoid and frontal sinuses are not yet pneumatized in this age group, fronto-basilar (or roof) injuries most commonly occur. Wall or floor injuries occur in young children.

Answer 15

ANSWER: B RATIONALE: The septovomerine suture determines growth in this area. If this suture is involved in trauma growth consequences are a concern since neither of the other sutures, if involved, provides as deforming a growth consequence.

Answer 16

ANSWER: D RATIONALE: According to a recent cadaveric study involving specimens with intact soft tissue, the mean distance from the inferior orbital rims to the annulus of Zinn is 39.4 mm +/- 2/9 mm. Previously cited studies on dry skulls, using bony landmarks only with no soft tissue references at the orbital apex provide clinically less useful information.

Answer 17

ANSWER: B RATIONALE: With the advent of rigid internal fixation, contour deficits and irregularities are infrequent. Using modern aseptic protocols, osteomyelitis is very uncommon. While mucoceles do occur in rare instances when sinus membrane regenerates, pain remains the most frequent of chronic problems.

Answer 18

ANSWER: C RATIONALE: Mandibular injury is associated with c-spine injury, but mid- and upper are associated with death. Mid- and upper-facial third injuries initially act as shock absorbers until a particular magnitude of impact, after which they transmit force to the neurocranium. The more commonly results in fatality than does trauma to the lower 1/3 of the facial skeleton.

Answer 19

ANSWER: B RATIONALE: The inter-canthal distance in adult Caucasians is 33 + mm. This varies minimally with gender and race. The other answers are outside of this range.

Answer 20

ANSWER: B RATIONALE: The annulus of Zinn contains the ophthalmic artery and its branches. The oblique muscles originate outside of the annulus. The annulus is distant from the lacrimal bone, and does not contain the maxillary division of the trigeminal nerve.

Answer 21

ANSWER: B RATIONALE: Below are figures adapted from the original article on nasoethoidmal fractures published by Markowitz and Manson in 1991. Choice B is the correct answer. Choice A represents a Type I fracture. Choice C doesn't fit into any classification scheme since it doesn't address the region of the canthal ligaments. Choice D represents a Type III fracture. This figure depicts the nasoethmoidal region. The region shaded is the central fragment. The inset figure represents a Type I fracture, where the canthal ligament is attached to a large central fragment and there is no comminution of the fractured nasoethmoidal region. This figure represents a Type II fracture. There is some comminution of the nasoethmoidal region but the canthal ligament is attached to a substantial fragment of bone. This figure represents a Type III fracture. The canthal ligament is detached or there is severe comminution with the canthal ligament attached to a small fragment of bone.

Answer 22

ANSWER: C RATIONALE: The temporal branches lie immediately beneath the superficial layer of the temporal fascia, just above the superficial layer of the deep temoral (temporalis) fascial. Dissection below the superficial temporal fascia this layer may injure the nerve. Dissection beneath the superficial layer of the deep temporal fascia preserves the temporal facial nerve branches.

Answer 23

ANSWER: D RATIONALE: Several studies have shown that the subciliary approach has the highest rate of post operative scleral show. The scar contracture associated with the infraorbital approach does no affect the orbicularis to the same degree as for other incisions. The transconjunctival incision is associated with minimal scleral show. The design of the upper blepharoplasty incision is associated with the least percentage of this complication.

Answer 24

ANSWER: C RATIONALE: Beta 2 transferrin is found only in the brain and eyes. The patient's CSF may be contaminated with blood and therefore mimic serum. The dipstick test is colorimetric and if contaminated with red blood, may alter the results. Again, CSF may be contaminated with nasal secretions or blood and thus mimic those fluids rather than CSF.

Answer 25

ANSWER: C RATIONALE: Both homopolymer and copolymer products follow the same metabolic degradation pathway culminating in the citric acid cycle, ultimately ending with the production of carbon dioxide and water.

Answer 26

ANSWER: D RATIONALE: With a right subcondylar fracture, the action of the right lateral pterygoid muscle would be reduced and the patient would deviate to the right upon opening, and would experience diminished left lateral excursion. Lastly, decreased right ramus height would cause an occlusal prematurity on the right side.

Answer 27

ANSWER: B RATIONALE: Motor and sensory nerves are affected. Light stimulation in the left eye produces no consensual reflex in the right eye, since the oculomotor nerve carries parasympathetic branches that allow consensual pupillary constriction. The left eye consensual light reflex is preserved. Only abduction (via cranial nerve VI) and adduction (via cranial nerve IV) of the right globe are possible.

Answer 28

ANSWER: C RATIONALE: Low velocity wounds are characterized by a small and clean cut or ragged entrance wound but no exit wound. When hard tissue is struck fracture, comminution and displacement occurs, but external avulsion is rare. The soft tissue cavitation is minimal. Low velocity missiles travel at less than 2000 ft/sec.

Answer 29

ANSWER: C RATIONALE: Initial resuscitation for pediatric patients is done with crystalloid solution, and the volume administered is determined by body weight. Fluid resuscitation is not accomplished with set amounts of fluid., nor is colloid an appropriate medium for initial intravascular resuscitation.

Answer 30

ANSWER: D RATIONALE: The bone anatomy of the orbital walls has been well defined. Often forgotten in clinical practice, however is the elevation of the infero-medial orbital wall behind the equator of the globe. In addition, significant alteration of the bony anatomy along the medial wall is sometimes not appreciated because displacement can result in a straight medial wall that to the uninitiated appears normal.

Answer 31

ANSWER: D RATIONALE: Following blunt trauma visual recovery after decompression is not likely whenever there was immediate blindness, penetrating ocular injury, or failure to respond to the initiation of high-dose steroids.

Answer 32

ANSWER: B RATIONALE: Ectropion results from overzealous dissection, tissue injury or pexing of the periorbita. Thinning of the lip and inward rotation of the vermillion should only be a consideration if the periosteum was dissected from the anterior maxilla. Following coronal or hemicoronal flap elevation and exposure of the zygomatic bone and malar eminence, posterio-superior resuspension of the periosteum is indicated to prevent tissue sagging.

Answer 33

ANSWER: D RATIONALE: Isolated tooth avulsion is treated by splinting for seven tot en days with isolation from occlusal function and endodontic therapy on theeth with fully developed apices. In the case of a true alveolar fracture, three to four weeks, or twenty one to twenty eight days is an appropriate duration of arch bar fixation.

Answer 34

ANSWER: D RATIONALE: Immediate extraction does not give the tooth any chance for survival. If splinted in the intruded position, the tooth is condemned to a malposition. If splinted in the proper position, the expanded alveolus would not permit intimate root contact between the surrounding alveolus and periodontal ligament remnants on the root and therefore preclude survival. Observation for a year indicates that the tooth is ankylosed. Observation for 4-8 weeks and then extraction if no re-eruption is observed is the most appropriate answer.

Answer 35

ANSWER: D RATIONALE: Augmentin. This antibiotic is bacteriocidal for the range and spectrum of human and animal bite pathogens including Staphylococcus species and Pasteurella multocida

Answer 36

ANSWER: A RATIONALE: Nasolacrimal duct intubation may bypass a disrupted nasolacrimal apparatus and avoid the morbidity associated with a dacryocystorhinostomy. Dacryocystorhinostomy is reserved for a chronic condition. Cannulation should be instituted for both inferior and superior canaliculi.

Answer 37

ANSWER: D RATIONALE: This patient exhibits no symptoms of massive hemorrhage from the facial gunshot wounds, and is hemodynamically unstable with a penetrating abdominal injury. This is a clssic indication for an emergency celiotomy for intra-abdominal hemorrhage control. CT abdominal scans or diagnostic peritoneal lavage may be indicated in blunt tauma with evidence of intra- abdominal hemerrhage; but these procedures are time-consuming and are indicated if there is greater hemodynamic control. From the clinical presentation, although eventual head and neck angiography may be indicated, the more emergent problem is shock from abdominal blood loss and must be addressed first by cleotomy.

Answer 38

ANSWER: B RATIONALE: 'The concept of resting skin tension lines (RSTLs) was introduced by Borges and Alexander in 1962. They based their definition of these RSTLs on how a wound tends to behave following incision of the skin, i.e., whether the wound gapes widely or very little. It has been known for decades (Dupuytren, 1834, Langer 1861) that skin incisions placed right angles to skin tension lines produce widely gaping wound margins. If these lines are followed during the incisions or excision of scars and neoplasms generally a far better result will be achieved than if the incisions cross the tension lines. The course of the facial tension lines does not always coincide with normal wrinkle lines due to aging.' The answer is B. All of the other lacerations are at right angles to the RSTLs

Answer 39

ANSWER: C RATIONALE: Epidural hematoma, usually caused by a middle meningeal arterial bleed, occurs between the dura mater and the inner table of the calverium. The classic triad of trastentorial herniation includes decerebrate posturing (extension of the arm at the elbows with internal arm rotation), a fixed and dilated pupil on the side of the herniation, and coma. Decerebrate posturing indicates neurologic damage at or below the midbrain. Decorticate posturing indicates severe neurologic damage in the hemisphere above the midbrain; and is clinically typified by arm flexion and fist clenching.

Answer 40

ANSWER: D RATIONALE: All three of theses musculoskeletal injuries are typified by rhabdomyolysis and electrolyte disturbances including hyperkalemia and metabolic acidosis. Complications include renal failure from myoglobin precipitation in nephrons, metabolic derangements from acidosis, and hyperkalemia. Treatment includes minimization of myoglobin-induced renal impairment by fluid expansion and osmotic diuresis by mannitol to minimize myoglobin deposition, sodium bicarbonate to treat metabolic acidosis and to alkalinize the urine to promote myoglobin solubility/excretion. Cardiac sequelae of hyperkalemia may be emergently opposed by intravenous calcium administration. Spironolactone, a potassium-sparing diuretic, would not be included in such treatment, although a loop diuretic such as furosemide may be useful.

Answer 41

ANSWER: B RATIONALE: The best answer is to re-approximate landmarks by suturing the lid at the gray line. A lid may be repaired by a number of techniques, each of which has a specific time limitation, therefore 24 hours may vary. Aggressive debridement should be avoided. Split thickness skin grafts are not the most desirable modality as they may have texture and color differences.

Answer 42

ANSWER: C RATIONALE: Dysphagia, pain on swallowing, is not part of the classic triad described by the other answers: a palpable fracture, . hoarseness (if the vocal chords are compromised); and comprised breathing.

Answer 43

ANSWER: B RATIONALE: Disc displacement may occur from the injury or the treatment, but has not been shown to be significantly different for the two different types of treatment. Likewise, the incidence of ankylosis has not been shown to be statistically different with either treatment. Facial weakness via cranial nerve V damage is only possible in the setting of open reduction.

Answer 44

ANSWER: C RATIONALE: The need for absolute stability for these types of fractures negates wire or miniplate fixation. DCP causes interfragmentary compression with possible bone devitalization and necrosis. The reconstruction plate is specifically indicated in these instances.

Answer 45

Answer: C Rationale: The phrenic nerve innervates the diaphragm and arises from cervical segments 3, 4, and 5. Therefore, a cervical spine injury at this level would likely cause severe ventilatory dysfunction, affecting tidal volume, vital capacity, or FEV1. A is incorrect, since parasympathetic innervation to the heart arises from Cranial Nerve X and the sympathetic innervation arises from the cervical sympathetic trunk, and both join to form the cardiac plexus. B is incorrect, since the injury only involves C4-5 (and not C3); the phrenic nerve would probably still be somewhat functional, and some ventilation would be expected. D is incorrect. This is a completely random answer, not necessarily related to this injury. Reference: Hollingshead's Manual of Practical Anatomy

Answer 46

``` Answer: C Rationale: Intubated patients receive a 'T' since they are unable to verbally respond Best Eye Response. (4) No eye opening. Eye opening to pain. Eye opening to verbal command. Eyes open spontaneously. Best Verbal Response. (5) 1. No verbal response 2. Incomprehensible sounds. 3. Inappropriate words. 4. Confused 5. Orientated Best Motor Response. (6) 1. No motor response. 2. Extension to pain. 3. Flexion to pain. 4. Withdrawal from pain. 5. Localising pain. 6. Obeys Commands. Reference: ATLS Manual, 1997 ```

Answer 47

Answer: D Rationale: The principle of the Champy technique is for fixation in the zone of tension with natural functional forces aiding in the approximation of the fracture in the area of compression. Reference: Champy M, Lodde JP, Scmitt R, et al.

Answer 48

Answer: A Rationale: Dissections posterior to the parotid and through the parotid have been described. Classically the dissection carried between the cervicofacial trunk and the temporofacial trunk of the facial nerve. The dissection may be on either side of the marginal mandibular branch. This approach is best for lower subcondylar fractures and more limited for higher fractures. The incision begins approximately 0.5 cm below the earlobe. Reference: Hinds EC: Correction of prognathism by subcondylar osteotomy. J Oral Maxillofac Surg 16:209, 1958 Ellis E III, Zide MF: Surgical Approaches to the Facial Skeleton. Baltimore. Lippincott Williams & Wilkins. 1995

Answer 49

Answer: C Rationale: The two classic articles on this subject quote incidences of 0% and 6% frequency of the marginal mandibular branch of the facial nerve being found below the inferior border of the mandible anterior to the facial artery. Posterior to the facial artery, 19% of the time the marginal mandibular branch of the facial nerve may be located below the inferior border of the mandible up to 1 (or1.2) cm. Anterior to the facial artery the marginal mandibular branch of the facial nerve has one branch only 21% of the time. Reference: Ziarah HA. Atkinson ME. The surgical anatomy of the mandibular distribution of the facial nerve. [Journal Article] British Journal of Oral Surgery. 19(3):159-70, 1981 Sep Dingman R, Grabb W: Surgical anatomy of the mandibular ramus of the facial nerve based on the dissection of 100 facial halves. Plast Reconstr Surg 29:266-272, 196

Answer 50

Answer: B Rationale: Compound or open mandible fractures have been shown to have reduced infection rates when perioperative antibiotics have been used. The use of postoperative courses of antibiotics has not been shown to affect the rate of infection. Reference: Zallen RD, Curry JT:A study of antibiotic usage in compound mandibular fractures. J Oral Surg; 33:431, 1975. Abubaker AO, Rollert MK:Postoperative antibiotic prophylaxis in mandibular fractures:A preliminary randomized double-blinded and placebo controlled clinical study. J Oral Maxillofac Surg; 59:1415, 2001.

Answer 51

Answer: C Rationale: Extended exposure of the facial skeleton is indicated for management of many complex facial fractures. Re-suspension of the soft tissue is important to establish proper facial form. Midface exposure via vestibular incision avoids key suspensory areas, thus simple closure is usually indicated. Symphysis exposure via a submental incision leaves the origin of the mentalis muscle attached to the surround soft tissue and/or bone. Re-suspension via this approach is not indicated. With exposure of the orbital floor via a transconjunctival incision simple closure is all that is indicated. When the zygomatic process is exposed via a coronal approach the superficial layer of the temporalis fascia is incised and periosteum overlying the arch is detached. This can result in ptosis of the suborbicularis oculi fat pad. This fat pad must be re-suspended to the lateral orbit. Reference: Manson PN, Clark N, Roberston B, et al Subunet Principles in Midface Fractures:The Importance of Sagittal Buttresses, Soft Tissue Reductions and Sequencing Treatment of Segmental Fractures. Plast Reconstr Surg 103:1287-1306, 1999.

Answer 52

Answer: D Rationale: In order to allow healing of a fracture of the atrophic mandible, the fixation technique must neutralize the tension forces on the mandible. The only fixation technique that satisfies these criteria is the use of a reconstruction plate. Reference: Sikes JW, Smith BR, Mukherjee DP. An In-Vitro Study of the Effect of Bony Buttressing on Fixation Strength of a Fractured Atrophic Edentulous Mandible Model J Oral Maxillofacial Surgery 58:56-61, 2000.

Answer 53

Answer: C Rationale: Fracture of the inner and outer table of the frontal sinus with communition and CSF leak represent the most complex of frontal sinus injuries. The dual tears associated with the frontal sinus leak must be repaired and they are usually approached via a coronal incision with the removal of a portion of the frontal bone. With communition of the posterior table ORIF of these fractures would be difficult. Because of the rapid growth of respiratory mucosa any and all remnants of epithelium within the sinus must be removed and the bony walls curetted to remove any epithelium remnants. Obliteration of the sinus is indicated when there is an intact posterior sinus wall. This allows for maintenance of the material used for obliteration to remain within the sinus cavity. In all cases of obliteration of the frontal sinus, obliteration of the nasofrontal ducts is also indicated to prevent respiratory microflora from entering into this cavity or entering into the sinus, thus preventing infection. In this case, due to the fracture of the inner and outer table of the frontal sinus with associated CSF leak, all of the posterior table should be removed to allow for expansion of the frontal lobes into the residual cavity. The outer table is reconstructed in this procedure. In all cases of cranialization of the frontal sinus, the nasofrontal drainage system is obliterated. Reference: Rohrich RJ, Hollier LH. Management of Frontal Sinus Fractures; Changing Concepts. Clinics in Plastic Surgery 19:219-232:1

Answer 54

Answer: A Rationale: The zones of the neck were originally described by Dr. Monson in 1969. Zone 1 is defined as the area from the clavicles to the cricoid cartilage. The risk of injury to the great vessels is common in this area. Zone 2 represents the area from the cricoid cartilage to the angle of the mandible. It is the largest area of the neck and thus is most likely to be injured with penetrating neck trauma. Zone 3 represents the region from the angle of the mandible to the base of the skull. The area presents the most difficult area for surgical access. Reference: Reference:Monson DO, Saletta JD, Freeark RJ. Carotid Vertebral Trauma. J Trauma 9:987- 99, 1969.

Answer 55

Answer: C Rationale: The anterior and posterior ethmoidal arteries will require identification when performing medial orbital wall or roof dissections. The vessels may also be identified for ligation in order to control nasal bleeding. The anterior ethmoidal foramen transmits the anterior ethmoidal artery and anterior ethmoidal branches from the nasociliary nerve. The posterior ethmoidal foramen transmits the posterior ethmoidal artery and the spheno-ethmoidal nerve from the nasociliary nerve. These foramina can be located posterior to the junction of the medial orbital wall and orbital roof. The anterior ethmoidal foramen is located twenty to twenty-five millimeters behind the medial orbital rim and the posterior ethmoidal foramen is located twelve millimeters posterior to this point or approximately thirty-two to thirty-seven millimeters. Reference: Ochs MW. Orbital and Ocular Trauma. Miloro M (Ed):Peterson's Principals of Oral and Maxillofacial Surgery, Second Edition. BC Decker, Inc. Hamilton, Ontario 2004. p. 465

Answer 56

Answer: B & C Rationale: The child is too young for cricothyroidotomy and percutaneous tracheostomy is not indicated for emergency airway. Cricothyroidotomy is not recommended in children less than 12 years of age, since the cricoid cartilage is the only circumferential support to the upper trachea. ATLS teaches that a child may be temporarily oxygenated with needle jet insufflation, but this technique does not provide ventilation and is not a definitive airway. Although surgical tracheostomy is unappealing in this age category, it is the procedure of last resort in this scenario. Reference: Advanced Trauma Life Support for Doctors Course Student Manual, 7th Ed., First Impression Press, 2004, page 48,49,250

Answer 57

Answer: C Rationale: Class III hemorrhagic shock is characterized by tachycardia, tachypnea, mental status changes and measurable fall in systolic blood pressure, but without the significant narrowing of pulse pressure seen in Class IV shock. Also the tachycardia and tachypnea are worse in Class IV shock. Lactated Ringers or 0.9% normal saline is the fluid of choice for initial resuscitation. Given excessive hemorrhage, >20%, red blood cells should be replaced to maintain oxygen carrying capacity. Cross-matched is the ideal choice, but time constraints (30 min) may require Type-specific blood (5-15 min) to be used. Reference: Advanced Trauma Life Support for Doctors Course Student Manual, 7th Ed., First Impression Press, 2004, page 75 Miloro M, et al. Peterson's Principles of Oral and Maxillofacial Surgery, 2nd Edition. Pg 343. BC Decker Inc, 204.

Answer 58

Answer: C Rationale: Salivary-cutaneous fistulae are potential sequelae to the retromandibular approach. To help avoid this complication it is recommended that a “water tight” closure be performed. Reference: Ellis E. Zide M. Surgical Approaches to the Facial Skeleton Williams and Wilkins, Media, PA, 1995

Answer 59

Answer: C Rationale: Intravenous fluids administered to acutely brain-injured patients should normotonic in order to maintain normovolemia. Hypovolemia and hypervolemia is harmful to these patients. Hyperglycemia from use of glucose-containing fluids is harmful to the injured brain. Normal saline or Ringer's lactate is recommended for resuscitation. Serum sodium levels need to be monitored to prevent hyponatremia which can lead to brain edema. Reference: Advanced Trauma Life Support for Doctors. Student Course Manual, 7th Edition, p.165. American College of Surgeons 2004.

Answer 60

Answer: C Rationale: There are three vertical buttresses of the midface:zygomatico-maxillary, pterygo-maxillary, and naso-maxillary. These structures consist of thicker supporting regions of bone that transmit and/or resist forces to the base of the skull. The horizontal buttresses of the midface are the (1) pyriform aperture, (2) maxillary alveolus and palate, (3) orbital rims and (4) base of the skull. Reference: Fonseca, RJ, Oral and Maxillofacial Trauma Vol 1, Advances in Maxillofacial Trauma Surgery, Elsevier 2005. Manson P, et al. Plastic and Reconstructive Surgery. Structural Pillars of the Facial Skeleton:An Approach to the Management of Le Fort Fractures. July 1980, 66(1) pg. 57.

Answer 61

Answer: C Rationale: Repair of detached medial canthal tendons during a severe naso-orbital ethmoidal fracture repair involves reattachment of one or both tendons to the posterior lacrimal crest in a slightly posterior and superior direction to overcome the forces of migration, relapse, and telecanthus. Reference: Fonseca, RJ, Oral and Maxillofacial Trauma Vol 2, Diagnosis and Treatment of Midface Fractures, Elsevier 2005

Answer 62

Answer: B Rationale: Integrity of the temporo-facial trunk of the facial nerve can be assessed by performing a corneal reflex (tearing to touching the ipsilateral cornea.) The afferent and efferent limbs of the reflex involve the first division of the trigeminal nerve and facial nerve respectively. Strabismus is associated with defects in cranial nerves III, IV, and VI. Reference: Bates, B, A Guide to Physical Examination and History Taking, The Nervous System, JB Lippincott 2002

Answer 63

Answer: C Rationale: Displaced anterior table fractures should be opened with careful inspection of the sinus mucosa. A non-displaced posterior table fracture without CSF leak can be managed without obliteration of the frontal sinus. Occlusion of the nasofrontal ducts requires removal of all sinus mucosa from the frontal sinus, inversion of the mucosa into the ducts, and elimination of dead space. This eliminates the possibility of developing a hematoma or seroma. Fat has been historically used with most success; no filler, hydroxyapatite, glass wool, bone, cartilage, muscle, absorbable gelatin sponge and fabric, acrylic have also been used. Reference: Miloro M, et al. Peterson's Principles of Oral and Maxillofacial Surgery, 2nd Edition. Pg 496-501. BC Decker Inc, 204.

Answer 64

Answer: C Rationale: Infraorbital or rim incision results in the worst esthetics and offers no advantages. The subciliary incision has an ectropion rate of approximately 6 %, whereas the transconjunctival incision has an ectropion/entropion rate of approximately 1.2 %. Thus, the transconjunctival incision as the approach of choice to avoid ectropion. Reference: Miloro M, et al. Peterson's Principles of Oral and Maxillofacial Surgery, 2nd Edition. BC Decker Inc, 2004.

Answer 65

Answer: D Rationale: All of the above cited answers are potential complications to frontal sinus fractures. Meningitis is the most common EARLY complication. The remainders of the answers are delayed or late potential complications. Frontal sinus complications can occur many years after injury (often greater than 20 years after injury). The most serious complications: can include displacement of the frontal bone in the brain and floor of frontal sinus into the orbit. Infectious complications, such as meningitis or intracranial abscess occur via bacterial spread through posterior table fractures or the diploe veins of Behçet; or by osteomyelitis, or mucocoele formation. Mucoceles are the most common chronic complication with diagnosis made via CT scanning. Periodic review by CT should be done every 1, 2 and 5 years following surgery. Symptoms include headache and can include loss of smell (anosmia.). Reference: Fonseca, RJ, Oral and Maxillofacial Trauma, Third Edition, 2005, Vol 2, pp 731-32. Miloro M, et al. Peterson's Principles of Oral and Maxillofacial Surgery, 2nd Edition. Pg 503. BC Decker Inc, 204.

Answer 66

Answer: A Rationale: The reconstruction plate is designed to bear the entire load of the mandibular movement across the fracture site. The remaining methods mentioned do not adequately stabilize the fracture segments and increase the possibilities for non-union and infection. Reference: Miloro, M. et al, Peterson's Principles of Oral and Maxillofacial Surgery, 2nd Edition, page 375, BC Decker INC, 2004

Answer 67

Answer: D Rationale: Full thickness skin graft from the opposite upper lid is preferred due to similar skin thickness, color, texture and availability with minimal donor site morbidity. This avoids scar and ectropion. Reference: Sandler NA, Evaluation and management of traumatic eyelid injury, OMS Knowledge Update vol 3, AAOMS, 2001

Answer 68

Answer: D Rationale: Exposed cartilage will not accept a skin graft. Composite free auricular grafts and microvascular reanastomosis have poor success rates due to poor venous drainage. The bipedicled flap nicely and predictably reconstructs the posterior helical defect. If the avulsed segment is 1 cm or less it can be reattached and allowed to revascularize. Larger avulsive injuries, the “pocket principle” can be used where the detached ear is dermabraded and reattached to the stump and then buried under a skin flap in the posterior auricular region to provide vascular supply. 2-3 weeks later the revascularize ear is uncovered and allowed to reepithelialize. Reference: Dierks EJ, Deeb GR, Evaluation and management of ear injuries, OMS Knowledge Update vol 3, AAOMS, 2001

Answer 69

Answer: A & B Rationale: Sialoceoles that repeatedly reform, even after aspiration, and pressure dressings, and antisialogogues may indicate a parotid capsular or Stensen's duct injury that requires early reexploration and repair. Sialocoele formation within 48 hours can indicate an injury to the salivary ductal system and exploration of the injury is needed. The patient also needs to have antibiotic coverage with penicillin or a cephalosporin. Reference: Fonseca RJ and Walker RV, “Management of soft tissue injuries”, Oral and Maxillofacial Trauma, vol 1, pg. 642. WB Saunders, 1991

Answer 70

Answer: D Rationale: Exposed cortical cranial bone will not accept skin grafts. Rotational-advancement flaps with multiple galeal releasing incisions parallel to the long axis of the flap will provide adequate coverage in most instances. Reference: Fonseca RJ and Walker RV, Management of soft tissue injuries, Oral and Maxillofacial Trauma, vol 1, WB Saunders, 2001

Answer 71

Answer: D Rationale: The retina is an extension of the brain, and will have similar reaction in the presence of ischemia. Signs and symptoms of visual impairment, severe ocular pain should be evaluated for retrobulbar hematoma. Computed tomography evaluation can demonstrate signs of retrobulbar hematoma formation, but immediate treatment with a lateral canthotomy based on clinical symptoms and signs should be completed prior to a lengthy CT scan. Other signs of optic nerve compromise include (1) afferent papillary defect (2) visual field loss and (3) color vision defects. Reference: Girotto JA, Gamble WB, Robertson B, et al, Blindness After Reduction of Facial Fractures, Plast Reconstr Surg 102:1821, 1998. Miloro M, et al. Peterson's Principles of Oral and Maxillofacial Surgery, 2nd Edition. Pg 472. BC Decker Inc, 204.

Answer 72

Answer: C RATIONALE: The emergency procedure of choice for acute visual acuity loss associated with acute orbital compartment syndrome is dissection of the lateral canthus and disinsertion of at least the inferior crus of the lateral canthal tendon, which allows complete mobility of the lower lid. Visual loss without clear signs consistent with increased IOP is not an indication for this procedure. Other primary indications for lateral canthotomy and cantholysis include an IOP greater than 40 mm Hg and proptosis, which may be used as a criterion for unconscious patients whose visual acuity cannot be determined. Secondary criteria include afferent pupillary defect, ophthalmoplegia, cherry-red macula, optic nerve head pallor, and severe pain, but these are all considered less sensitive or very late signs. Contraindication for this procedure would be a suspected ruptured globe. REFERENCE: Fonseca, RJ, Walker, R, Oral and Maxillofacial Trauma Volume 1, WB Saunders, 1991

Answer 73

Answer: C Rationale: A grossly comminuted zygomatic complex fracture will not be stable with a closed technique. Comminuted segments of the infraorbital rim are a poor guide to placement of the zygoma. The zygomatic-frontal suture is a poor reference for placement of the zygoma. In high energy grossly comminute fractures, the sphenozygomatic suture with its broad contact can aid in the anatomic reduction of the fracture. Reference: Baley JS, Goldwasser MS, Management of Zygomatic complex fractures. In: Miloro M ed, Peterson's Principles of Oral and Maxillofacial Surgery Second edition BC Deker, London 2004 Chapter 23.2 pp 452

Answer 74

Answer: A Rationale: The optic nerve and retinal tissue, unlike skeletal muscle, have been shown to be extremely sensitive to pressure and hypoxia. Irreversible ischemic damage often occurs within 60 minutes and certainly within 2 hours. Megadose steroids have been recommended during the first 8 hours following injury. The outcome in patients with traumatic optic neuropathy with no light perception on presentation is a poor prognostic factor. Likewise patient presenting with traumatic optic neuropathy after penetrating trauma have a worse prognosis than those with blunt facial trauma. Reference: Wang BH, Robertson BC, Girotto JA, Liem A, Miller NR, Iliff N, Manson P, Traumatic optic neuropathy: A review of 61 patients. Plastic Reconstructive Surg 2001; 107:1653-1664

Answer 75

Answer: C Rationale: The management of a patient with a traumatic hyphema is to use topical cycloplegics and carbonic anhydrase inhibitors to decrease intraocular pressure. Rebleeding can occur in 5- 30% of the patients with hyphema. Reference: Baley JS, Goldwasser MS, Management of Zygomatic complex fractures. In:Miloro M ed, Peterson's Principles of Oral and Maxillofacial Surgery Second edition BC Deker, London 2004 Chapter 23.2 pp 459

Answer 76

Answer: B Rationale: A CT scan of an orbit that has a trapdoor appearance with clinical and radiographic evidence of inferior rectus muscle incarceration is more like to occur in children than in adults and it warrants early intervention to prevent ischemic necrosis to the rectus muscle. Steroids are may be used in cases where there is no evidence of muscle entrapment and mild restricted motility. By its nature, a trapdoor defect seldom requires an implant to bridge a defect. Reference: Ochs MW, Orbital and ocular trauma. In: Miloro M ed, Peterson's Principles of Oral and Maxillofacial Surgery Second edition BC Deker, London 2004 Chapter 24 pp 479

Answer 77

Answer: B Rationale: While calcium phosphate bone cement is a near ideal alloplast in that it has unlimited availability, is biocompatible, has high mechanical strength, has a low risk for infection, is radiopaque and is incorporated into the bone, it does have drawbacks. It is expensive, and when placed directly over dura or sinus membranes, it breaks up and a chronic foreign body reaction ensues. This is particularly true for the pediatric population. Reference: D'Addario M, Haug RH, Talwar R: Biomaterials for Use in Frontal Sinus Obliteration. Journal of Long-Term Effects of Medical Implants. 14: 455-465, 2004.

Answer 78

Answer: A Rationale: β2 transferrin is one of two major variants of iron binding transferrin glycoproteins forum in several forms of various body fluids. β2 transferrin lacks a carbohydrate side chain which increases its positive charge, permitting isolation during electrophoresis. β2 transferrin is only found in cerebrospinal fluid, aqueous humor and perilymph. Thus, with the exception of contamination by a ruptured globe, it is an ideal substance to distinguish between cerebrospinal fluid, nasal secretions and serum. Reference: Brandt MT, Jenkins WS, Fattahi TT, Haug RH:Cerebrospinal Fluid:Implications in Oral and Maxillofacial Surgery. J Oral Maxillofac Surg. 60:1049-1056, 2002.

Answer 79

Answer: B Rationale: In the recumbent position, intracranial pressure, and thus cerebral spinal fluid pressure, is about 8 to 12 mm Hg or 110 to 150 mm H2O. Autoregulation maintains this pressure. Reference: Brandt MT, Jenkins WS, Fattahi TT, Haug RH:Cerebrospinal Fluid:Implications in Oral and Maxillofacial Surgery. J Oral Maxillofac Surg. 60:1049-1056, 2002.

Answer 80

Answer: D Rationale: While concomitant injury has been associated with hyphema and permanent visual loss, it is not the primary cause in traumatic hyphema. Retinal artery spasm is not associated with hyphema. Both increased intraocular pressure and traumatic mydriasis are concomitant problems. Corneal staining from myoglobin is the primary cause of permanent loss of vision. Reference: Brandt MT, Haug RH:Traumatic Hyphema: A Comprehensive Review. J Oral Maxillofac Surg. 59:1462-1470, 2001.

Answer 81

Answer: B Rationale: Children possess a higher cardiac output than adults. Under the physiologic stress of trauma, the child's stroke volume cannot increase, so that under stress proportionate increases in stroke volume cannot occur and increases in cardiac output are rate determined. Bradycardia could result in hypoxia and hypercapnia, and is ominous. The child's proportional blood volume is greater than an adult. However, the absolute blood volume and therefore tolerable absolute blood loss is less, so that minor injuries may result in blood loss which is physiologically significant. The child's blood pressure is maintained through physiologic compensation (vasoconstriction, tachycardia, myocardial contractility). This compensation may be misleading by masking volume reduction. The healthy child has an increased total systemic physiologic reserve, thus with trauma, symptoms of hypoxemia or hypovolemia may not occur until a potentially catastrophic hypovolemia has occurred. Reference: American College of Surgeons Committee on Trauma:ATLS Advanced Trauma Life Support Program for Doctors. 7th Edition, American College of Surgeons, Chicago, IL, 2004, pgs 243-262.

Answer 82

Answer: D Rationale: When considering maxillofacial injury and cervical spine injury, a cause and effect relationship exists between the mandible and cervical spine. There is also a relationship between neurocranial injury and mid- and upper-facial third facial injuries. Approximately one out of every fifty patients with a mandibular fracture will suffer a cervical spine fracture. The vast majority of these are subluxation injuries. When the mandible sustains a force applied to it, the reaction of the body is to move away from the force. This “twisting of the neck, when accentuated, results in a subluxation injury of the cervical spine. Reference: Haug RH, Wible RT, Likavec MJ, et al:Cervical spine fractures and maxillofacial trauma. J Oral Maxillofac Surg 49:725-729, 1991.

Answer 83

Answer: A Rationale: The human and animal population is very similar in their oral flora. Each has a predomination of Streptococcus species and numerous gram negative anaerobic organisms. Each has numerous species of viruses and some mycobacteria have been reported. It is however, Pasteurella multocida that is only found in the non-human population Reference: Haug RH, Assael L, “Infections in the Maxillofacial Trauma Patient”, Chapter 17 in Topazian RG, Goldberg MH, Hupp J (Eds.). Oral and Maxillofacial Infections. Philadelphia PA, W B Saunders, 2002, pp 359-380.

Answer 84

Rationale: Condyle fractures have been reported to occur most commonly in pediatric patients (15- 60%). With increasing age, the angle is involved more commonly. Anatomic Distribution of Mandibular Injury in Pediatric Patient Condyle 15-60% Alveolus 8-50.6% Body 6-44% Symphysis 2-40% ParaSymph 23-33% Angle 3-27% Ramus 1-10% Coronoid 0-19% Reference: Kaban LB, et. al. Pediatric Oral and Maxillofacial Surgery. Ch. 25 Facial Trauma II: Dentoalveolar Injuries and Mandibular Fractures, Baumann A, et. al. p.446. Haug R, Foss J. Maxillofacial injuries in the pediatric patient. Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology & Endodontics, 90:2, 2000, p.131.

Answer 85

Answer: D Rationale: The low incidence of midfacial fractures in children can be explained by the elasticity of the child’s facial bones, the retrusive position of the maxilla, nose and infraorbital rims and the anatomic protection afforded by the cranium. Reference: Kaban LB, et. al. Pediatric Oral and Maxillofacial Surgery. Ch. 24 Facial Trauma I: Midfacial Fractures, Baumann A, et. al. p.425. Posnick JC. Craniofacial and Maxillofacial Surgery in Children and Young Adults. Ch 30 Primary Craniomaxillofacial Fracture Management, Posnick JC. p.704, 716.

Answer 86

Answer: C Rationale: Open reduction internal fixation (ORIF) is rarely indicated in the pediatric population. Most condylar fractures can be treated with a combination of intermaxillary fixation or analgesics and soft diet. Minor occlusal discrepancies will equilibrate with continued growth and dental eruption. Children in the permanent dentition who have persistent malocclusion at the time of initial treatment or after a period of intermaxillary fixation should be considered for ORIF to restore ramal height and occlusal function.

Answer 87

Answer: C Rationale: Management of the pediatric trauma patient differs from that of the adult. Lack of compensatory reserves in the pediatric patients can lead to a sudden cardiovascular collapse. This occurs rather quickly since tachycardia, vasoconstriction and increased myocardial contractility will initially mask the presenting signs and symptoms. Body surface ratio does not affect shock response, but does affect both heat and insensible fluid loss in the pediatric patient. Reference: Haug R, Foss J. Maxillofacial injuries in the pediatric patient. Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology & Endodontics, 90:2, 2000, p.128. Miloro M, et. al. Peterson’s Principles of Oral and Maxillofacial Surgery. Ch 27 Pediatric Craniomaxillofacial Fracture Management, Posnick JC, et. al. p.528.

Answer 88

Answer: A Rationale: In a "clean" (minimally or noncontaminated) would in a previously immunized patient who has not received a booster in the past 10 years, a booster dose of 0.5 ml of toxoid booster is recommended. This timeline decreases to 5 years for a "dirty" or contaminated wound. If there is no history of immunization or an unknown history, the tetanus immunization series is begun; with the addition of tetanus immune globulin (TIG) for dirty wounds.

Answer 89

Answer: B Rationale: Relative indications for removal of teeth in the line of mandibular fractures include: Presence of obvious pathology (caries, periodontal disease) Gross mobility of involved teeth Teeth that prevent adequate reduction of fracture Teeth with fractured roots Teeth with exposed apices Reference: Peterson 2nd edition, Principles of management of mandibular fractures. P 401-434, Fonseca, Oral and Maxillofacial Trauma, Mandibular fractures, P 479-522, 2005,

Answer 90

Answer: A Rationale: Poorly controlled seizure disorders, mental retardation, and psychiatric disorders are relative contraindication for closed reduction of mandible fractures in which maxillomandibular fixation would be poorly tolerated. \. If possible, an attempt should be made to perform an open reduction with rigid fixation for these patients. Reference: Peterson 2nd edition, Principles of management of mandibular fractures. P 401-434, 2004 Fonseca, Oral and Maxillofacial Trauma, Mandibular fractures, P 479-522, 2005

Answer 91

Answer: A Rationale: Intracapsular condylar head fractures with a normal occlusion should be observed. These patients do not need intermaxillary fixation since there is no change in occlusion. The management also includes soft dies, pain control and range of motion exercise to regain normal interincisal opening after the initial healing period. Reference: Peterson 2nd edition, Principles of management of mandibular fractures. P 401-434, 2004 Fonseca, Oral and Maxillofacial Trauma, Mandibular fractures, P 479-522, 2005

Answer 92

Answer: B Rationale: Hyphema is a contraindication to orbital exploration due to the possibility of re-bleeding into the anterior chamber, which can lead to corneal staining and glaucoma. Reference: Peterson 2nd edition, Principles of Oral & Maxillofacial Surgery, Orbital and ocular trauma, P 463-490, 2004 Brandt MT, Haug RH. Traumatic hyphema: a comprehensive review. J Oral Maxillofac Surg, 59, 1462, 2001.

Answer 93

Answer: A Rationale: Chemosis is edema of palpebral and bulbar conjuctiva. This does not lead to diplopia. Other conditions including hematoma, muscle entrapment and a nerve injury will cause double vision. Reference: Peterson 2nd edition, Principles of Oral and Maxillofacial Surgery, Orbital and ocular trauma, P 463-490, 2004 Fonseca, Oral and Maxillofacial Trauma, ophthalmic consequences of maxillofacial trauma, p 693-720, 2005

Answer 94

Answer: B Rationale: Zide’s criteria for open reduction of condyle fractures includes the following relative and absolute indications: Reference: Zide MF. Open reduction of mandibular condyle fractures. Indications and technique. Clin Plast Surg. 1989 Jan; 16(1):69-76. Peterson 2nd edition, , Principles of management of mandibular fractures. P 401-434, 2004 Fonseca, Oral and Maxillofacial Trauma, Mandibular fractures, P 479-522, 2005

Answer 95

Answer: B Rationale: Facial nerve injuries medial to a vertical line from the lateral canthus do not need to be explored because there is increased terminal facial nerve branch arborization and therefore multiple small branches exist. Exploration of such small branches is not practical. This wound should be managed as any other facial laceration. Reference: Peterson 2nd edition, Principles of Oral & Maxillofacial Surgery, Soft tissue injuires, P 357-370, 2004 Fonseca, Oral and Maxillofacial Trauma, Applied surgical anatomy of the head and neck, p 281-328, 2005,

Answer 96

Answer: C Rationale: Carotid-cavernous fistulae (CCF) are potential complications of craniofacial trauma. Signs and symptoms are related to the abnormal flow of blood (shunting) between a high flow (internal carotid) to a low flow system (cavernous sinus). Patients often complain of a swollen red eye, orbital pain, loud buzzing sound and swishing sound, proptosis and visual changes. Although cavernous sinus thrombosis, orbital apex syndrome and temporal arteritis may have visual disturbances, none will display an unusual buzzing sound. CCF can occur within days to weeks following trauma. Reference: Origitano TC, Al-Meffy O. Aneurysms of the cavernous sinus: treatment options and consideration. In: Youmans RJ. Neurological Surgery. Philadelphia: WB Saunders, 1995, 1320-1335. Fattahi T, Brandt MT, Jenkins WS, et al. Traumatic carotid-cavernous fistula: pathophysiology and treatment. J Craniofacial Surg, 14:1, 2003.

Answer 97

Answer: B Rationale: Penetrating neck injuries can have significant morbidity and mortality. Zone 1 extends from the clavicle to the cricoid. Zone 2 is from the cricoid to the inferior border of the mandible. Zone 3 is from the mandibular angle to the skull base. Physical examination of zone 2 is most easily accomplished due to its location and ease of access. While studies in addition to physical exam may be indicated in Zone 2 penetrating injuries, Zones 1 and 3 more often require further diagnostic tools such as an arteriogram or esophagoscopy. Reference: Advanced Trauma Life Support Student Manual. Initial assessment and management, P 21-46, American College of Surgeons. Sixth Edition. 1997. Miloro, M. et al, Peterson’s Principles of Oral and Maxillofacial Surgery, Second Edition, Initial management of the trauma patient, p 327-356, BC Decker 2004, chapter 18

Answer 98

Answer: C Rationale: Condylar displacement usually occurs in an anterior and medial direction secondary to the lateral ptyergoid muscle pull. The patient will have a premature bite on the ipsilateral side and upon opening will deviate to the ipsilateral side as well. 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

Answer 99

Answer: C Rationale: Bone healing has been divided into 2 categories: primary and secondary. Primary bone healing is characterized by less than 1 mm gap between bone edges, no bony mobility and no callus formation. This type of healing occurs following placement of load-bearing plates. Secondary bone healing occurs with formation of a hematoma, fibroblast infiltration, cartilaginous and bony callus formation, and then remodeling. This type of healing occurs following closed reduction of fractures. 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 Abubaker OA. Oral and Maxillofacial Surgery Secrets. Maxillofacial trauma, 197-206 2001

Answer 100

Answer: D Rationale: The medial pole of the TMJ condyle by position does not function as a primary determinant of mandibular vertical height. As such, open or closed surgical approaches for such a fracture are unwarranted; and the injury is managed with soft diet and range of motion exercises. Reference: Sicher, H; and DuBrul, EL: Temporomandibular articulation. In, Oral Anatomy (6th Ed.) CV Mosby Co. St. Louis. pp. 160 - 191, 1975. Quinn, PD: Color Atlas of Temporomandibular Joint Surgery. CV Mosby, St. Louis, 1998. Assael, LA: Hard Tissue Trauma. In, Temporomandibular Joint Disorders - Diagnosis and Treatment. Kaplan, AS and Assael, LA (Eds) WB Saunders, Philadelphia, 1992. pp.224-237. Mercuri, LG: Temporomandibular Joint Disorders. In: Kwon, PH; and Laskin, DM (eds) Clinician' Manual of Oral and Maxillofacial Surgery 3rd ed. 2001 Quintessence. Chicago. Kobinson DA, Hohn FI: Traumatic injuries. In, Laskin DM, Greene CS, Hylander WL (eds): Temporomandibular Disorders: An Evidence-Based Approach to Diagnosis and Treatment. 2006 Quintessence. Chicago.