ORAL SURGERY Oral and maxillofacial Surgery Flashcards
what are the two requirements for adequate visualization?
assistance and access
when is a dental extraction indicated with pulpal necrosis and irreversible pulpitis?
when endodontics is not an option
what are common teeth extracted for orthodontics?
maxillary and mandibular first premolars and third molars
when are malposed teeth indicated for extraction?
- teeth that cause mucosal trauma and cannot be repositioned with orthodontics
- teeth in hyperocclusion that are unopposed and interfering with other restorative care
describe when extractions are indicated for patients in need of radiation therapy
- patients needing radiation therapy for head and neck cancer should be evaluated for the health of the dentition
- questionable teeth should be extracted before radiation therapy
elective dentoalveolar surgery in extremely ill patients should be carefully considered by the practitioner. what are examples of cases where the patients health may be so compromised that they cannot withstand a surgical procedure?
- severe uncontrolled metabolic diseases (brittle diabetes)
- end stage renal disease
- advanced cardiac conditions (unstable angina)
- leukemia and lymphoma
- hemophilia or platelet disorders
- head and neck radiation
- intravenous bisphosphonate treatment
- pericoronitis
- acute infectious stomatitis and malignant disease
extractions in patients with a history of heck and neck radiation can lead to ___. these patients are commonly treated with ___ therapy before dentoalveolar surgery
- osteoradionecrosis
- hyperbaric oxygen
patients treated with intravenous bisphosphonates are at increased risk of ___
osteonecrosis of the jaw
describe the treatment of pericoronitis
- an infection of the soft tissues (cellulitis) around a partially erupted mandibular third molar
- the infection should be cleared before extracting the involved tooth
- antibiotics, irrigation, and removal of the maxillary 3rd molar should be considered as part of the treatment of pericoronitis
what is the purpose of radiographic examination prior to extractions?
- relationship of associated vital structures
- configuration of roots
- condition of surrounding bone
- mechanical principles involved in tooth extraction
what are some examples of indications for surgical extractions?
- after initial attempts at forceps extraction have failed
- when the patient has especially dense bone
- in older patients, owing to less elastic bone
- short clinical crowns with severe attrition (bruxism)
- hypercementosis or widely divergent roots
- extensive decay or crown loss
the term ___ includes both impacted teeth and teeth that are in the process of erupting. the term ___ is occasionally used interchangeably with the term impacted.
- unerupted
- embedded
what is the primary reason teeth fail to erupt?
inadequate arch length
what are reasons all impacted teeth should be considered for removal at the time of diagnosis?
- prevention of periodontal disease in teeth adjacent to impacted teeth
- prevention of dental caries, pericoronitis, root resorption of adjacent teeth, odontogenic cysts and tumors, and jaw fractures
- treatment of pain of unexplained origin
- facilitation of orthodontic treatment
what are the contraindications to extraction of impacted teeth?
- extremes of age (preteen or asymptomatic full bony impaction in patients >35)
- compromised medical status
- likely damage to adjacent structures
what are the angulation classifications of impacted teeth?
mesioangular (least difficult), horizontal, vertical, and distoangular (most difficult)
the ___ classification of impacted teeth refers to the relationship of the tooth to the anterior border of the ramus, and the relationship to the occlusal plane
pell and gregory
what is a class 1 pell and gregory impaction?
normal position anterior to the ramus
what is a class 2 pell and gregory impaction?
one half of the crown is within the ramus
what is a class 3 pell and gregory impaction?
entire crown is embedded within the ramus
what is a class A pell and gregory impaction?
tooth at the same plane as other molars
what is a class B pell and gregory impaction?
occlusal plane of third molar is between the occlusal plane and the cervical line of the second molar
what is a class C pell and gregory impaction?
third molar is below the cervical line of the second molar
what are factors that make impaction surgery less difficult?
mesioangular position, pell and gregory class 1 ramus and class A depth, roots 1/3 to 2/3 formed, fused conical roots, wide PDL, large follicle, elastic bone, separated from second molar, separated from IAN, soft tissue impaction
what are factors that make impaction surgery more difficult?
distoangular, pell and gregory class 2 or 3 ramus and class B or C depth, long thin roots, divergent curved roots, narrow PDL, thin follicle, dense inelastic bone, contact with second molar, close to IAN, complete bony impaction
what is the most common flap design for tooth extraction?
envelop flap is the most common, but releasing incisions are often used
when releasing incisions are made, the base (vestibular) portion of the flap should always be ___ than the apex (crestal). why?
- wider
- to maintain adequate blood supply to released soft tissues
describe possible involvement of the lingual nerve in creating a flap for mandibular third molars
- the mandible posterior to the third molar thins and diverges laterally
- an incision made too far medially can damage the lingual nerve causing numbness on that half of the tongue
when removing bone, care should be taken not to injury the ___ cortex of the mandible
lingual
why is copious irrigation of the wound important in extractions?
to avoid the presence of fractured tooth or bone spicules below the soft tissue flap, which may lead to subperiosteal abscess
what are the 3 concepts of prevention of soft tissue injuries during extractions?
- pay strict attention to the soft tissues to prevent injuries
- develop adequate sized flaps
- use minimal force for retraction of soft tissue
what typically causes puncture wounds in the palate, tongue, or other soft tissue areas during extractions?
- excessive and uncontrolled force to the instruments
- wounds are treated with pressure to stop any bleeding and are left open to heal by secondary intent
- antibiotics may be needed, depending on the injury
how should oral-antral communications be managed?
- figure eight suture over the socket
- sinus precautions
- antibiotics
- nasal spray to prevent infection and keep the ostium open
what are the four most common tooth displacement locations?
- maxillary molar root into maxillary sinus
- maxillary third molars into infratemporal fossa
- mandibular molar roots forced into the submandibular space through the buccal cortical bone
- tooth lost into the oropharynx
what is the concern if a tooth is lost into the oropharynx?
- may result in airway obstruction
- pt should be transported to an emergency department for chest and abdominal radiographs
what are the most common injuries to adjacent teeth during extractions?
- fracture of teeth or restorations
- luxation of adjacent teeth
what can happen if cortical fracture occurs during mandibular third molar extraction?
damage to the lingual nerve, causing loss of sensation and taste on that side of the tongue
after mandibular third molar extractions, patients with numbness lasting more than ___ weeks should be referred for microneurosurgical evaluation
4
bleeding is an uncommon complication of dental extractions. what are some causes of excessive bleeding?
- injury to inferior alveolar artery
- muscular arteriolar bleed from elevation of a mucoperiosteal flap
- bleeding related to the patients hemostasis
what are examples of patients with altered hemostasis?
- pt’s who are taking warfarin or drugs for platelet inhibition
- pt’s with hemophilia or von willebrand’s disease
- pt’s with chronic liver insufficiency
what is the treatment for a subperiosteal abscess?
drainage of the abscess and antibiotic treatment
a dry socket is also called ___. what percent of mandibular third molar extractions result in a dry socket?
- localized osteitis
- 3%
how are dry sockets treated?
- does not require antibiotics
- heals with irrigation of the socket and local treatment for pain control
when is tori removal indicated?
they are considered a variation of normal and only need to be removed when there is a need for denture or partial denture construction, or because of repeated trauma to the area
when is soft tissue surgery indicated for denture or partial denture construction?
if they limit the ability to achieve appropriate thickness of denture material or interfere with appropriate fit of the prosthesis
what are areas for soft tissue surgery in preparation for denture or partial denture construction?
- mandibular retromolar pad
- maxillary tuberosity
- excessive alveolar ridge tissue
- inflammatory fibrous hyperplasia
- labial and lingual frenum
what are the principles that are important for the success of dental implants?
- primary stability
- quantity and quality of bone
- anatomic structures
what area are implants typically more successful and why?
anterior mandible because of the denser cortical bone, compared to the loose cancellous bone and thin cortical bone present in the posterior maxilla
what are the four types of bone quality?
- type I-IV
- type I has the thinnest marrow and thickest cortical bone
- type IV is mostly marrow with thin cortical bone
which bone quality types are associated with higher implant success rates?
types I-III, regardless of implant height
which anatomic structures do we consider when determining success of an implant?
- sinus
- adjacent teeth
- inferior alveolar nerve and mental nerve
what is the minimum required distance between an implant and each of the following structures:
buccal plate, lingual plate, maxillary sinus, nasal cavity, and incisive canal?
- buccal plate - 1mm
- lingual plate - 1mm
- maxillary sinus - 1mm
- nasal cavity - 1mm
- incisive canal - avoid midline maxilla
what is the minimum required distance between an implant and each of the following structures: interimplant distance inferior alveolar canal mental nerve inferior border adjacent natural tooth
- interimplant distance - 3mm between outer edge of implants
- inferior alveolar canal - 2mm from superior aspect of bony canal
- mental nerve - 5mm from anterior or bony foramen
- inferior border - 1mm
- adjacent natural tooth - 1.5mm
what are the ways alveolar ridges can be augmented for prosthesis retention?
- grafting of the alveolus
- distraction osteogenesis (DO)
what are the types of grafts?
autogenous, allograft, xenograft, and bone morphogenic protein (BMP)
what are the most common graft sites for autogenous bone?
- anterior cortex of the symphysis (when volume of bone needed is smaller)
- lateral cortex of the ramus and external oblique ridge
- iliac crest
- rib
what is the advantage and disadvantage of autografts?
- biocompatability is the greatest advantage
- disadvantage is the requirement of a second surgical site
allograft material is obtained from ___
cadaver bone that is processed to ensure sterility and to decrease substances in the bone that can trigger host immune response
what are the advantages and disadvantages of allografts?
- advantage is that it avoids the need for a second surgical site
- disadvantages are the processing of the allograft destroys the osteoinductive capability of the bone while the osteoconductive property remains, and a greater amount of the grafted material is resorbed compared with autorafts
where is xenograft material obtained from?
a genetically different species than the recipient (ex. bovine)
what are the advantages and disadvantages of xenografts?
- similar to allografts
- no second surgical site
- significant resorption after grafting
describe using bone morphogenetic protein (BMP) as a grafting material
- induces bone formation and enhances graft healing
- recombinant human BMP (rhBMP-2) has been used in maxillofacial skeleton reconstruction
- to reconstruct a larger bony defect, BMP can be combined with allograft, using osteoinductive and osteoconductive properties from both graft materials
___ is a biologic process of new bone deposition and formation between osteotomized bone surfaces that are separated by gradual traction
distraction osteogenesis (DO)
does distraction osteogenesis require grafting materials?
no, because it uses the body’s innate ability to generate new bone
what is distraction osteogenesis useful for?
useful in providing height or length to bone, but is less useful in providing width of bone
___ maintains height and width of the alveolar ridge after teeth removal
alveolar ridge preservation (socket preservation)
what does the success of alveolar ridge preservation depend on?
atraumatic extraction without compromising buccal and lingual bone
what are the steps of alveolar ridge preservation?
- extraction site is thoroughly cleaned to remove debris and granulation tissues
- grafting materials such as allograft or xenograft are placed in the socket and covered by resorbable collagen membrane
- resorbable sutures are used to secure grafting material and membrane, and primary closure at the surgical site is usually unnecessary
what are signs of a facial bone fracture?
pain, contour deformity, ecchymosis, laceration, abnormal mobility of the bone, numbness, crepitation, and hematoma
mandible fractures can almost always be identified on a ___
panoramic radiograph
suspected mandible fractures should always be visualized in at least two radiographs, including ___
panoramic view, Towne’s view, posterior-anterior skull view, or lateral oblique view
what are the most common sites for the mandible to fracture?
condyle, the angle, and the symphysis
what are the classifications of mandible fractures?
greenstick, simple, comminuted, or compound
___ is a fracture of the bone in which one side of the bone is broken and the other only bent
greenstick fracture
___ is a fracture of the bone only, without damage to the surrounding tissues or breaking of the skin
simple fracture
___ is a break or splinter of the bone into more than two fragments
comminuted fracture
___ is an injury in which a broken bone pierces the skin, causing a risk of infection (bone would be exposed through mucosa)
compound fracture
what is the contemporary treatment for mandible fractures that are displaced and mobile?
- open reduction and internal fixation using titanium bone plates and screws
- if the patient has teeth, the occlusion is used to guide the surgeon during the repair of the fracture
- other methods include lingual splinting (pediatric patients) and intermaxillary fixation (wiring the jaws closed)
midface fractures are best evaluated with ___
- computed tomography (CT) scans of the face
- two orientations (axial and coronal) are needed for full evaluation of fractures of the midface, which can involve the maxilla, zygoma, nose, and orbits
how are maxillary fractures classified?
- le fort levels I-III
- simple (closed), compound (open), and comminuted
which le fort level is a fracture that separates the inferior portion of the maxilla in a horizontal fashion, extending from the piriform aperture of the nose to the pterygoid maxillary suture area?
le fort I
which le fort level is a fracture involving separation of the maxilla and nasal complex from the cranial base, zygomatic orbital rim area, and pterygoid maxillary suture area?
le fort II
which le fort level is a fracture which is complete separation of the midface at the level of the naso-ortibal-ethmoid complex and zygomaticofrontal suture area, that also extends through the orbits bilaterally?
le fort III (cranofacial separation)
how are maxillary le fort fractures, orbital fractures, and zygomatic fractures usually managed?
- internal rigid fixation
- isolated zygomatic arch fractures can often be reduced with a minor surgical procedure and without the use of bone plates and screws
how are simple nasal fractures repaired?
with internal and external splints
evaluation of a patient with a dentofacial deformity is guided by the principle of ___ and ___
balance and symmetry
orthognathic surgery is performed to correct severe skeletal discrepancies that prevent appropriate ___ and most often is done in conjunction with ___
- dental occlusion
- orthodontics
in facial symmetry evaluations, patients are evaluated according to normal facial proportions. vertically, the face is divided into relatively equal ___. horizontally, the face is divided into relatively equal ___. patients can be described as having ___ or ___ profiles.
- thirds
- fifths
- concave or convex
which angles classification is normal dental occlusion with a straight profile?
class I (orthognathic)
which angles classification describes the mandibular first molars and canines in a posterior position relative to the maxillary counterparts, and the face appears posteriorly convergent?
class II (retrognathic)
which angles classification describes the mandibular first molars and canines in an anterior position relative to the maxillary counterparts, and the face appears to be anteriorly convergent?
class III (prognathic)
what are the main images used in treatment planning for orthognathic surgery?
- lateral cephalograms
- however, panoramic radiographs, anterior-posterior cephalograms, and periapical radiographs are taken as needed
when treatment planning for orthognathic surgery, what does cephalometric analysis combined with facial evaluation help determine?
- the jaw primarily involved in the deformity
- direction of growth of the jaws
- most ideal procedure for the patient’s diagnosis
what are the primary diagnoses in patients with dentofacial deformity?
maxillary hyper- or hypoplasia, and mandibular hyper- or hypoplasia
what is apertognathic?
anterior open bite
___ is the term used to describe a maxilla that is too long and the patient has an excessively gummy smile
vertical maxillary excess
what is horizontal transverse discrepancy?
the patient is in posterior crossbite
what is macro- or microgenia?
when the chin is too big or too small
describe maxillary surgery
- referred to as le fort I osteotomies
- maxilla can be moved forward and down more easily than it can be moved up or back
- it can also be segmented into two or three pieces to position the occlusion better
describe mandibular surgery
- most often done using one of two osteotomies (bilateral sagittal split osteotomy or vertical ramus osteotomy)
- mandible can be moved anteriorly to correct retrognathia, or posteriorly to correct prognathism
- in addition, the chin can be moved using a genial osteotomy (genioplasty) to correct macrogenia or microgenia
how is distraction osteogenesis useful in treating deformities of the facial skeleton?
- with DO, oral and maxillofacial surgeons have much greater flexibility in treating difficult deformities
- pts with deformities such as cleft lip and palate and hemifacial microsomia previously required difficult surgeries
- DO involves cutting an osteotomy to separate segments of bone and the application of an applicance that facilitates the gradual and incremental separation of bone segments
what is the differential of facial pain?
pathology of dental structures, muscles, joints, blood vessels, salivary glands, sinuses, eyes, ears, and central and peripheral nervous systems
for pain to be experienced from a physiologic perspective, what 3 things must occur?
- transduction (activation of A delta and C fibers to the spinal cord or brainstem)
- transmission (pain information in the central nervous system sent to the thalamus and cortical centers for processing of sensory and emotional aspects)
- modulation (limitation of rostral flow of pain information from the spinal cord and trigeminal nucleus to higher cortical centers)
when pain lasts longer than ___ months, it is defined as chronic, and the ___ aspects are especially important in patient treatment and management
4-6 months, psychological
what is trigeminal neuralgia?
- prototypic neuropathic facial pain (tic douloureux)
- trigger point pain that manifests as electrical, sharp, shooting, and episodic, followed by refractory periods
- most commonly seen in patients >50
how is trigeminal neuralgia treated?
- medically treated with anticonvulsant drugs (carbamazepine, oxcarbazepine, gabapentin)
- surgically treated with microvascular decompression (Janetta procedure), stereotactic radiosurgery, percutaneous needle rhizotomy, or entry zone balloon root compression
what is odontalgia secondary to deafferentation (atypical odontalgia)?
- occurs as a result of trauma or surgery (endodontic therapy or extraction)
- these procedures result in damage to the afferent pain transmission system
- proposed mechanisms include peripheral hyperactivity at the surgical site and CNS hyperactivity secondary to changes int eh second order nerve in the trigeminal nucleus
postherpetic neuralgia is a potential sequela of ___
herpes zoster infection
describe postherpetic neuralgia
- pain is classically described as burning, aching, or electric shock-like
- treated medically with anticonvulsants, antidepressants, or sympathetic blocks
what is ramsay hunt syndrome?
herpes zoster infection of the sensory and motor branches of cranial nerves VII and VIII resulting in facial paralysis, vertigo, deafness, and cutaneous eruption of the external auditory canal
describe how neuromas may occur after nerve injury
- proximal section of the transected nerve forms sprouts filled with schwann’s cells and other neural elements
- this area (neuroma) can become very sensitive to stimuli and can cause chronic neuropathic pain
burning mouth syndrome is most commonly seen in ___
pregnant women
what do patients with burning mouth syndrome complain of?
- pain, dryness, and burning of the mouth and tongue
- may also complain of altered taste sensation
burning mouth syndrome is believed to be secondary to ___
a defect in pain modulation
what is the treatment for burning mouth syndrome?
- 50% of patients have symptoms that resolve without treatment over a 2 year period
- hormonal therapy has not been proven to be efficacious, and anticonvulsants and antidepressants have not yielded consistent results
chronic headache is categorized as being ___, ___, or ___
migraine, tension type, or cluster
the presenting symptoms of temporal arteritis (giant cell arteritis) are often difficult to differentiate from other causes of jaw and head pain, and a delay in diagnosis often leads to ___
blindness in the affected side
what is the source of somatic pain?
- musculoskeletal (TMJ, periodontal, muscles)
- visceral (salivary gland, dental pulp)
- increased stimulus yields increase in pain
what is the source of neuropathic pain?
- damage to pain pathways (TN, trauma, stroke)
- pain independent of stimulus intensity
what is the source of psychogenic pain?
-intrapsychic disturbance (conversion reaction, psychotic delusion, malingering)
what is the source of atypical pain?
facial pain of unknown cause/diagnosis pending
what are the classifications of temporomandibular disorders?
myofascial pain, disc displacement disorders, degenerative joint disease, systemic arthritic conditions, chronic recurrent dislocation, ankylosis, neoplasia, and infections
what is the most common cause of masticatory pain and compromised function?
myofascial pain disorder
___ is characterized by diffuse, poorly localized pain in the preauricular region, often involving other muscles of mastication
myofascial pain disorder
in myofascial pain disorder, pain and tenderness develop as a result of ___
- abnormal muscle function and hyperactivity
- a parafunctional activity may be etiologically related to this clinical entity (wear facets may be seen)
- it can also be the result of disc displacement disorders and degenerative arthritis
patients with myofascial pain disorder who have nocturnal parafunctional habits have symptoms that are worse in the ___
morning
disc displacement disorders are seen with and without reduction. what does reduction mean?
the return of the normal disc to condyle relationship
in disc displacement with reduction, normal ___ without ___ can be seen despite joint and muscle tenderness
normal interincisal opening without deviation
what do the clicks correspond to in disc displacement disorders with reduction?
- opening click corresponds to the condyle moving over the posterior area of the anteriorly displaced disc, resulting in reduction
- the reciprocal click (closing) occurs when the jaw is closed and disc fails to maintain its normal reduced relationship to the condyle
nonreduction disc displacement disorders result in limited ___ and resultant ___ on opening
limited range of motion and resultant ipsilateral deviation on opening
what are examples of systemic arthritic conditions?
- rheumatoid arthritis, systemic lupus erythematous, crystalline arthropathies including calcium pyrophosphate dyhydrate deposition (pseudogout)
- there are usually other clinical systemic signs and symptoms with these conditions
___ occurs when the mandibular condyle translates anterior to the articular eminence and requires mechanical manipulation to achieve reduction
chronic recurrent dislocation
chronic recurrent dislocation is associated with ___ and ___
pain and muscle spasm
in chronic recurrent dislocation, when the problem becomes chronic (multiple recurrences), what are the interventions?
botulinum toxin A (botox) injection of lateral pterygoids or surgery
TMJ ankylosis can occur intracapsularly or extracapsularly and can be ___ or ___
fibrous or bony
which type of TMJ ankylosis results in more limitation of motion?
bony ankylosis
what is the most common cause of TMJ ankylosis?
- trauma
- however, surgery radiation therapy, and infection can also result in TMJ ankylosis
how does a patient with TMJ ankylosis present?
- severely restricted range of motion that may be accompanied by pain
- patients are often able to demonstrate limited translation on the affected side but nonetheless have severe limitation on interincisal opening
what does nonsurgical therapy for TMJ dysfunction include?
patient education, physical therapy, pharmacotherapy, and occlusal considerations
what are the nonsurgical treatment objectives for TMJ dysfunction?
decrease pain symptoms and improve function
which types of TMJ dysfunction involves surgery as the preferred initial treatment of choice?
ankylosis and severe symptomatic degenerative joint disease
what are medications used for treatment of TMJ disorders?
nonsteroidal antiinflammatory drugs, steroids, narcotic and nonnarcotic analgesics, antidepressants, and muscle relaxants
what are the physical therapy options for management of TMJ disorders?
- biofeedback, ultrasound, transcutaneous electrical nerve stimulation (TENS), massage, thermal treatment, exercise, and iontophoresis
- may of these modalities result in increased circulation to the affected region, facilitating the removal of painful metabolic by products and delivering therapeutic medications
what is believed to be the method by which transcutaneous electrical nerve stimulation (TENS) relieves TMJ disorder pain?
may override pain input or results in the release of endogenous endorphins
what are the two occlusal splint classifications?
autorepositioning or anterior repositioning
when are autorepositioning occlusal splints indicated in TMJ disorders? how does it work?
- used for muscle and joint pain when no specific anatomically based pathologic entity can be identified
- it is designed to have no working or balancing interferences with full arch contact
- it reduces intraarticular pressure
how does the anterior respositioning occlusal splint work to reduce TMJ disorder pain?
protrudes the mandible into a forward position, hypothetically recapturing the normal disc to condyle relationship
T or F:
the role of occlusion in TMJ disorders is unclear
true
how can occlusal modification be achieved in the management of TMJ disorders?
equilibration, prosthetic restoration, orthodontics, or orthognathic surgery
arthrocentesis has been shown to be beneficial in patients with ___
internal derangement
describe arthrocentesis as a management option for TMJ disorder
- 1-2 needles are placed into the superior joint space
- a few milliliters of saline or lactated Ringer’s solution is injected
- lavage
what is the efficacy of arthrocentesis based on?
distention of the joint capsule, release of adhesions, and potential for removal of chemical mediators associated with joint pathology
what are the surgical treatment options for TMJ disorders?
arthrocentesis, arthroscopy, disc repositioning, disc repair or removal, condylotomy, and total joint replacement
what is arthroscopy?
surgical treatment for TMJ disorder that involves the placement of two cannulas to allow access for intracapsular instrumentation of the superior joint space
what patients is disc repositioning surgery (open arthroplasty) useful for?
patients with painful, persistent clicking-popping and closed lock
describe the disc repositioning surgery (open arthroplasty) procedure
- disc is mobilized and a posterior wedge may be removed
- suturing is used to reposition the disc into a more anatomically desirable position
does disc repositioning surgery (open arthroplasty) provide good results?
good results initially, but 10-15% of patients report no benefit or worsening of symptoms postoperatively
when is disc repair or removal (discectomy) indicated?
when the disc is severely damaged
what are the reported results of disc repair or removal (discectomy)?
wide variation in reported results, ranging from excellent resolution to severe degeneration and associated pain and dysfunction
when the disc is removed (discectomy), recommendations for replacement have been made. what are some options?
- some prosthetic materials have been proven to be problematic, so there is a tendency to favor autogenous materials
- preferred tissues include temporalis muscle and fascia, fat, and auricular cartilage
what TMJ disorders indicate a condylotomy procedure?
treatment of internal derangement with and without reduction, degenerative joint disease, and chronic dislocation
how is a condylotomy accomplished?
- perform an intraoral vertical ramus osteotomy
- proximal segment is not fixated, which theoretically allows the soft tissues to reposition the condyle and disc passively into a more functionally neutral position
what TMJ disorders is total joint replacement indicated for?
severely pathologic joints, as seen in rheumatoid arthritis, severe degenerative joint disease, ankylosis, neoplasia, and posttraumatic destruction
what is the most common autogenous grafting material used in total joint replacement? what is the disadvantage of this material?
- costochondral bone graft
- this material does not address fossa pathology, which may be significant and must be addressed in pathologic joints associated with the use of some prosthetic materials
total prosthetic TMJ reconstructions usually involve a prosthetic ___ and ___. what are the results of this technique?
- condyle and fossa
- results have been variable and may reflect the complexity and diversity of the cases studied
odontogenic infections are polymicrobial. what are the most common organisms?
aerobic gram positive cocci, anaerobic gram positive cocci, and anaerobic gram negative rods
what percent do the following bacteria contribute to odontogenic infections?
anaerobic only, aerobic only, and mixed anaerobic and aerobic
- anaerobic only 50%
- mixed 44%
- aerobic only 6%
in the development of odontogenic infections, the highly virulent ___ species initiate the infectious process after inoculation into deep tissues. ___ occurs, followed by proliferation of ___.
- aerobic streptococcus
- cellulitis
- anaerobic organisms
- the aerobic organisms consume oxygen, making the microenvironment favorable for the anaerobes
in odontogenic infections, once the infection is into deep tissues, it follows the path of ___
least resistance
when an odontogenic infection has entered deep tissues, it may travel through the ___ space or perforate through a thin area of ___ and directly enter an anatomic space. the most common space involved is the ___.
- intramedullary space
- bone cortex
- vestibular space
odontogenic infections that have entered deep tissues often drain spontaneously and result in ___
an asymptomatic, chronic draining fistula
what are the common fascial spaces involved in odontogenic infections?
vestibular, buccal, canine, sublingual, submandibular, submental, masticator (pterygomandibular, masseteric, superficial temporal, and deep temporal), and lateral pharyngeal spaces
fascial spaces are referred to as potential spaces because ___
- under healthy conditions, there is no space
- abscess formation causes cavities along these anatomic planes
as an abscess in a fascial space matures and spreads, more of these spaces become involved, resulting in ___
increased pain, trismus, dysphagia, and dysphonia
in odontogenic infections that have spread to fascial spaces, canine space infections and deep temporal space infections can result in ___
cavernous sinus thrombosis via the opthalmic veins
in odontogenic infections that have spread to fascial spaces, lateral pharyngeal infections can traverse the ___ and ___ spaces and spread to the mediastinum
retropharyngeal and prevertebral spaces
are infections of the fascial spaces considered life threatening medical emergencies?
yes
treatment of odontogenic infections requires adherence to what 6 principles?
- determine the severity of the infection through history and physical examination
- evaluate state of patients host defence mechanisms
- determine whether the patient should be treated by a general dentist or specialist
- treating the infection surgically
- support patient medically
- choose and prescribe appropriate antibiotics
what are the criteria for referral to OMFS in odontogenic infection cases?
difficulty swallowing, difficulty breathing, dehydration, moderate to severe trismus (interincisal opening <20mm), swelling extending beyond the alveolar process, elevated temp (>101F), severe malaise and toxic appearance, compromised host defenses, need for general anesthesia, or failed prior treatment
treating odontogenic infections surgically is fundamental in the management of odontogenic infections. what are the goals of surgery?
removal of the source of infection and decompression and drainage of purulence
what should be done before incision and drainage in the management of odontogenic infections?
- collect a specimen for culture and sensitivity (ideally before initiation of antibiotics)
- usually at least 2mL of purulent aspirate is adequate
- use 5-10mL syringe and 18-gauge needle
- gram stains should also be obtained to guide antibiotic management
describe the use of antibiotics in the treatment of odontogenic infections. what are the risks and benefits?
- the determination that there is a need must first be established
- if there is evidence of bacterial invasion into underlying tissues that is greater than hose defenses can resist, antibiotics should be used
what are the indications for antibiotic use in odontogenic infections?
infection spreading beyond the alveolar process, rapidly progressive infection, previous therapy with multiple antibiotics, nonresponsive infection (>48 hours), recurrent infection, and compromised host defenses
is routine empiric therapy acceptable in the treatment of odontogenic infections? why or why not?
- yes, because the causative bacteria seen in odontogenic infections are highly predictable
- the choice should be effective against streptococci and oral anaerobes
what are the typical empiric antibiotics used in the management of odontogenic infections?
- penicillin V
- if pt is allergic to penicillin, clindamycin and clarithromycin are good choices
- low toxicity and side effects
- bactericidal preferred over bacteriostatic (especially in immunocompromised hosts)
- use narrow spectrum over broad spectrum
___ is inflammation of the medullary portion of bone
osteomyelitis
what are the 3 mechanisms by which osteomyelitis spreads? what are the most common initiating causes?
- infection, inflammation, and ischemia (usually begins in the medullary space involving the cancellous bone. cortical bone, periosteum, and soft adjacent tissues eventually become involved)
- most common initiating causes are odontogenic infections and trauma
osteomyelitis is relatively rare. where is it more commonly seen?
- mandible more than maxilla due to difference in blood supply
- hematobenous spread of infection to bone cause cause osteomyelitis, but this mechanism is rarely seen in the jaw
- patients with host defense suppression are more likely to get osteomyelitis
describe the microbiology of osteomyelitis
- similar to odontogenic infections
- streptococci, anaerobic cocci, and gram negative rods
how is osteomyelitis treated?
- medically and surgically
- adequate debridement, use of appropriate antibiotics, and medical assessment to rule out and treat any host factors that may predispose the patient to developing osteomyelitis
describe how bisphosphonate medications can cause osteonecrosis of the jaw
- they inhibit osteoclast activity, resulting in decreased bone resorption
- affect osteoblast activity, which indirectly influences osteoclasts
- can cause chronic bony exposure that does not heal and spontaneous exposure of alveolar bones (BRONJ)
how is BRONJ diagnosed?
nonhealing bony exposure in jaws for at least 8 weeks and current or previous bisphosphonate use without history of radiation therapy to jaws
T or F:
BRONJ has a greater association with oral bisphosphonate use than with intravenous bisphosphonate use
false, greater with IV
before initiating bisphosphonate therapy, patients should have a thorough dental exam and should be treated occordingly. when possible, bisphosphonate therapy should be delayed to allow adequate healing time after oral surgery. how long should the delay be?
2-3 weeks
the risk of BRONJ is increased as duration of bisphosphonate therapy exceeds ___ years
3
what are the treatment adjustments that should be made for patients receiving bisphosphonate therapy?
- no adjustments if therapy is less than 3 years and who have no comorbid risk factors
- otherwise, 3-month drug holiday is recommended
what is the treatment for a patient with stage 1 BRONJ?
- antibacterial mouth rinse
- clinical follow up on a quarterly basis
- patient education and review of indications for continued bisphosphonate therapy
what is the treatment for a patient with stage 2 BRONJ?
- oral antibacterial mouth rinse
- symptomatic treatment with oral antibiotics and pain medication
- only superficial debridements to relieve soft tissue irritation
what is the treatment for a patient with stage 3 BRONJ?
- antibacterial mouth rinse
- antibiotic therapy and pain control
- surgical debridement or resection for longer term palliation of infection and pain
what are the 4 types of biopsies?
cytology, aspiration, incisional, and excisional
what are the suction considerations when performing biopsies?
use low volume suction with a gauze-wrapped suction tip to avoid aspirating the specimen
what are the indications for using a laser when performing biopsies?
- indicated when concerns for hemostasis are significant
- fine peripheral zone of necrosis occurs on the specimen
- sharp scalpels should be used if possible
in biopsy specimen management, proper specimen care requires that the tissue be placed in ___ in a volume ___x that of the specimen
10% formalin in a volume 20x that of the specimen
describe wound management in biopsy cases
either a primary closure (if possible) or placement of periodontal dressings in cases of gingival or palatal biopsies in which secondary healing would be necessary
what is oral brush cytology useful for?
- detecting cancerous and precancerous lesions
- monitoring or screenings lesions in an adjunctive role to observation
what is the oral brush cytology method?
- cytology brush is placed over suspicious lesion and rotated 5-10 times to obtain cells from all three epithelial layers
- collected cells are transferred to a glass slide where a fixative is placed
what are the categories assigned to oral brush cytology specimens?
negative, positive (definitive evidence of cellular atypia or carcinoma), or atypical (abnormal epithelium)
-all positive and atypical findings should undergo definitive scalpel biopsy
what is the method for aspiration biopsy (fine needle aspiration)?
special syringe and needle are used to collect cells from a clinically or radiographically identified mass
what are the uses for aspiration biopsies?
- relatively low morbidity and high diagnostic accuracy for most lesions
- simple aspiration of a hard or soft tissue lesion to determine if the lesion is solid, cystic, or vascular
- indicated in any intraosseous lesion before surgical exploration
when is the incisional biopsy technique used?
when a lesion is large (>1cm), polymorphic, suspicious for malignancy, or in an anatomic area with high morbidity
when is the excisional biopsy technique used?
smaller lesions (<1cm) that appear benign and on small vascular and pigmented lesions
what is the difference between incisional and excisional biopsies?
excisional biopsy is the removal of the entire lesion and a perimeter of surrounding uninvolved tissue (margin)
most intraosseous lesions are of ___ origin, usually ___.
- odontogenic
- inflammatory
- when this is not the case, biopsy is usually indicated unless the history suggests otherwise
all radiolucent lesions that require biopsy should be ___ first
- aspirated
- this provides the dentist with information regarding the nature of the lesion (solid, cystic, fluid filled, air filled, vascular) or whether surgery should proceed (for fluid filled cyst)
___ flaps are always used for intraosseous lesions and should be ___, over sound bone allowing ___mm margins, and avoid major neurovascular structures
- mucoperiosteal
- full thickness
- 4-5mm
when are osseous windows necessary in intraosseous biopsies?
- central lesions of the jaw
- determined by size of the lesion, cortical perforations, and proximity to teeth and neurovascular structures
in intraosseous biopsies, if an osseious window is necessary, should you include the bony structure in your submission to the pathologist?
yes
in cases of intraosseous biopsies when osseous windows are cut, after the lesion is removed, ___mm of adjacent osseous tissue should be removed by curettage in all directions
1mm
goals of surgical management of cysts and tumors are ___ and ___
eradication of the pathologic entity and esthetic functional rehabilitation
cysts and cyst-like lesions can be classified as ___ or ___
fissural or odontogenic
how are cysts of the jaw treated?
enucleation, marsupialization, a staged combination of the two , or enucleation and curettage
what are the categories of resection for tumors or the jaws?
marginal, partial thickness, total, and composite
what are the most common malignant tumors of the jaws?
epidermoid carcinomas (squamous cell)
which tissues, other than bone, can give rise to primarily malignancies of the head and neck?
salivary glands, blood vessels, lymphatics, muscle, bone, and other connective tissue
which cancers can metastasize to the head and neck region?
cancer of the breast, prostate, lung, kidney, thyroid, hematopoietic system, and colon
when a primary cancer of the head and neck is diagnosed, clinical staging should be performed before definitive treatment. what might staging include?
- thorough history and physical examination
- CT scans
- positron emission tomography scans
- chest radiographs
- panendoscopies
what are the basic treatments for malignant tumors of the jaws?
combinations of surgery, radiation therapy, and chemotherapy
decisions for treatment of head and neck malignancies are driven by ___
- histologic type, stage, location, and whether it is a primary or metastatic lesion
- in addition, before any definitive treatment, the patient’s wishes and medical comorbidities must be taken into consideration
what are treatment options for reconstruction after removal of jaw tumors?
ranges from no reconstruction with wound management and secondary healing (possible removable prosthetic use) to complex microvascular osteocutaneous reconstruction with placement of endosseous implants
