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)