Dentoalveolar Flashcards
What is the classification system of third molars?
Pell and Gregory:
A-C (relation to second molar), 1-3 (relation to ascending ramus)
A: Third molar occlusal plan in line with 2nd molar
B: Third molar between occlusal plane and cervical junction
C: Below Cervical jntion
1: MD diameter anterior to ramus
2: Half lf crown covered by ramus
3: Tooth completely in ramus
Winter’s:
Based on angle between occlusal plane and longintudinal axis of third molar
Inverted: <0, very rare
Horizontal: 0-30 (10%)
Mesioangular: 31-60 (most common 45%)
Vertical: 61-90 (40%)
Distoangular: >90 (5%)
What are the indications of third molar removal?
Pericoronitis (most common reason)
Ortho, pericoronal pathology, caries, fracture, unexplained pain (5% removal helps), overlying prosthesis, periodontal disease
What is the anatomy of the IAN in relation to 3rd molar removal and the incidence of injury?
-1% injury incidence
-Generally nerve located buccal and apical
What is the anatomy of the lingual nerve in relation to 3rd molar removal and incidence of injury?
-0.6-2% incidence
-Average 2.8mm below crest and 2.5mm medial to lingual cortex
-4.6-21% of lingual nerves at or above crest of bone
-22% reported at lingual plate of bone
-Turns towards tongue at region of first/second molars
At what age does the risk of complications increase in 3rd molar removal?
25
What radiographic signs describe intamacy of IAN with roots of 3rd molar? (Rood’s Criteria)
-Darkening of root
-Deflection of root
-Narrowing of root
-Bifid root apex
-Diversion of canal
-Narrowing of canal
Interruption in white line of canal
What is alveolar osteitis?
-Incidence between 1-30% (subjective criteria)
-Seen at POD 3-7
-Theory: Fibrinolytic activity leads to break down of clot
-Risk factors: Tobacco smoke, increased age, pericoronitis, birth control, female gender, inexperienced surgeon, inadequate irrigation, increased medical co-morbidities
When can a root tip be left in place?
-Non-infected
-Small (<2mm)
-Risk of surgery outweighs benefit
What is the incidence of bleeding with 3rd molar surgery?
.2-5.8%
-Must rule out coagulopathies
How does gelfoam work?
-Absorbable gelatin spone
-Matrix for blood clot formation
-Gelatin made from purified porcine skin
-May cause excessive granuloma or fibrosis
How does Avitene work?
-Microfibrillar collagen
-Mechanically broken down bovine collagen
-Aggregates platelets onto fibrils and acts as a matrix for blood clot formation
How does HemCon/Chitoflex work?
-Chitosan dressing
-Polysaccharide from shellfish
-Positively charged to attract erythrocytes
-Acts as a scaffold for clotting
-Dissolves in 48h
How does thrombin work?
-Promotes clot formation through activated bovine prothrombin
-Activates factors IIA
-Acts as a serine protease converting fibrinogen to fibin
How does surgicel work?
-Oxidized regenerated methylcellulose
-Binds platelets
-Negative pH is bacteriostatic and precipitates fibrin
-More effective than gelatin sponge
-Aids in pressure hemostasis
-Causes prolonged healing,
-Can be neurotoxic (acidic environment)
How does a collaplug work?
-Cross-linked collagen
-Promotes platelet aggregation
How does a teabag help with hemostasis?
-Tanin serves as a vasoconstrictor
How does Amicar work (aminocaproic acid)?
-Stabilizes clot by inhibiting plasmin
How does TXA work (5% tranexamic acid)?
-Antifibrinolytic, inhibits conversion of plasminogen into plasmin
What is the management for displacement of a root into the sinus?
-Most commonly palatal root of maxillary 1st molar
-Take PA to verify position
-Attempt to suctioning into sinus to remove
-Pack sinus with xeroform gauze and pull out in one stroke
-Preform antral lavage
-Have patient block opposite nostril and blow nose
-Enlarge opening and explore
-fragments 3 mm or less that are not infected can be left in place (inform patient)
-Removal with Caldwell-Luc approach
How are OACs managed?
-3-6 mm: Place gel foam and close with figure-eight suture
->6mm: May require tension free primary closure, exicision of fistulous tract and inversion into the sinus. Consider buccal fat pad closure, buccal finger flap or tongue flap
-Sinus precautions 2 weeks, decongestants, antibiotics that cover sinus flora, no blowing nose
What is the management of displacing a root into the submandibular/sublingual space?
-Lingual cortex thins out in more posterior region
-Displacement often inferior to mylohyoid muscle
-First attempt to milk root back through cortical hole via manipulation
-Attempt at a lingual flap extended anterior to premolar with an incision to detach mylohyoid muscle
-Allow 6 weeks for fibrosis
-Get a CT scan to localize root
-May require transcutaneous approach via submandibular incision
What is the management for displacement of a root into the infratemporal space?
-Likely due to lack of retractor protection with excessive force/poor visualization
-Most likely lateral and inferior to pterygoid plate
-May attempt to manipulate tooth back manually
-Extend incision and retrieve with hemostat
-Allow 4-6 weeks to allow for fibrosis, obtain CT scan and use a spinal needle to identify, diessect along needle length
-Reported to preform a hemicoronal incision
-If no functional deficit and asymptomatic, may leave in place
What is the management for displacement of a root into the IAN canal?
-Retrieval attempts may lead to nerve damage
-Single attempt with suction should be attempted
-If root is not infected and no neurologic abnormality, consider leavign in place
-If sensory complication, must retrieve
-CT scan should be taken to ensure location
-Can approach by unroofing extraction site, lateral window intraoral or submandibular incision
What is the management for aspiration of a foreign object during dentoalveolar procedure?
-Heimlich maneuver may be attempted
-If under GA, deepen level of sedation and attempt visualization and removal with Magills
-If no respiratory distress, likely ingested
-Obtain abdominal and CXR to rule out
-Assume aspiration, place on right side and in trendelenburg, watch for signs of hypoxia and respiratory distress. ER for removal
