Oral Surgery Flashcards
Incisal
Refers to the biting surface of an anterior tooth (incisor and canine)
Occlusal
Refers to the biting surface of a posterior tooth (premolar and molar)
Apical
toward the root tip
Mesial
toward the midline
Crown
portion of the tooth covered by enamel or visible within the oral cavity
Root
portion of the tooth covered by cementum
Pediatric dentition
Primary dentition or baby teeth
- 2 incisors, 1 canine, 2 molars in each quadrant for 20 teeth total
- no premolars
- Teeth are referenced by the letters A-T
- Primary teeth begin to erupt around 8 months of age with completion of primary eruption by 24 months of age
Adult dentition
- 2 incisors, 1 canine, 2 premolars, 3 molars each quadrant for 32 teeth total
- Referenced by numbers 1-32
- General ages for eruption: incisors (6-9 years), canines (9-11 years), premolars (10-12 years), molars (6-7 1st molar, 11-13, 2nd molar, 17-20 3rd molar)
Normal occlusion (class I)
Mesiobuccal cusp of maxillary first molar occludes with the buccal groove of the mandibular first molar
Class II occlusion (overbite)
Meiobuccal cusp of maxillary first molar is mesial or anterior to the mesobuccal groove of the mandibular first molar
Class III occlusion (underbite)
Meiobuccal cusp of maxillary first molar is distal or posterior to the mesobuccal groove of the mandibular first molar
Surgical treatment for maxillary hypoplasia and maxillary excess
segmental le fort 1 osteotomies
Surgical treatment for mandibular hypoplasia
bilateral sagittal split osteotomy
Surgical treatment for mandibular hyperplasia
bilateral sagittal split osteotomy for mandibular setback or le fort 1 osteotomy for advancement of maxilla or combination of both
Placement of nasopalatine block
local anesthetic deposited at the foramen (5-7mm posterior to maxillary dental midline)
Placement of greater palatine block
Anesthetic deposited halfway between maxillary second molar and palatal midline
Location of mental nerve foramen
Between the mandibular premolars
Microbes that contribute to odontogenic infections
50% are mixed aerobic/anaerobic
Important pathogens: fusobacterium, prevotella, streptococcus
Radicular (periapical) cyst
Round or oval lesion that arises from residual odontogenic epithelium and nonvital pulp. Tx with enucleation of cyst, endodontic treatment or tooth extraction
Dentigerous cyst
Develops in relationship to crown of erupting tooth. most common in the third molar and maxillary canine region. Tx with removal of impacted tooth and enucleation or decompression of cyst.
Odontogenic keratocyst
Has an orthokeratinized lining. More common in mandible. Up to 40% recurrence rate with simple enucleation. Multiple OKCs seen in basal cell carcinoma syndrome. Tx with enucleation and curettage for small cysts, large inaccessible cysts decompress and enucleate if then amenable. Recurrent cysts require en bloc or segmental resection.
Calcifying epithelial odontogenic tumor
Aka pindborg tumor. Peak incidence is in the 5th decade. More common in molar area of mandible. Can be radiolucent; cortical expansion with soap bubble appearance. It is an unencapsulated tumor. Tx by resection with 1cm margins. Histology shows liesegang rings (concentric calcified ring) and amyloid like protein.
Clear cell odontogenic carcinoma
Rare tumor more common in older women in their 50s. 3:1 female to male predilection. Low grade malignancy from odontogenic epithelium. Mandible most commony effected. Large cells with clear cytoplasm histologically similar to renal cell carcinoma. Treat with wide local excision with 1cm margins.
Adenomatoid odontogenic tumor
2/3 occur in young females, 2/3 are seen in anterior maxilla (canine region), 2/3 are associated with unerupted tooth. Can form sclerotic border on radiography. Histologically encapsulated with gland like rosettes (small duct like structures). Tx by enucleation.
Odontogenic myxoma
More common in the mandible. Predilection for children and young adults. Trabecular patter on radiography. Histologically hypocellular tumor that overproduces glocosaminoglycan ground substance (myxoid substance) and can look like normal dental papilla or follicle. Unencapsulated. Tx with 1cm margin resection.
Calcifying odontogenic cyst
Aka Gorlin cyst. More common in mandible. Only odontogenic cyst that produces opacifications on radiographs. Histologically similar to ameloblastomas with peripheral palisading nucelli with reverse polarity. Contain ghost cells (eosinophilic, glassy cells with no nucleus). Treat with enucleation
Ameloblastoma
Most common in patients ages 30-50. Typically asymptomatic but can become large and disfiguring. Can be unicystic or multicystic. Histology shows peripheral columnar cells with reverse polarization.
Ameloblastic carcinoma is very rare. Early metastasis to lung and brain.
Odontoma
Appear on radiograph as either amorphous mixed density lesions or like balls of tiny teeth. Can be complex or compound. Treat with enucleation.
Fibrous dysplasia
Due to mutation in GNAS-1 gene. Histology shows woven bone without osteoblastic rimming, bone trabeculae are not connected. More common in the maxilla. Cranial neuropathies associated with foraminal narrowing. Painless swelling occurring during 1st 2 decades of life. Pain may occur during periods of growth or hormonal changes. Disease usually stable after age 25. Imaging may show multilocular radiolucency with cortical thinning or a mixed ground glass appearance. Markers for metabolic bone disease (calcium phosphate, alk phos, calcitonin, PTH) are usually normal. Evaluate for skin changes and endocrine workup. Biopsy needed for diagnosis.
Ossifying fibroma
A variant of fibrous dysplasia. Appears as a localized painless swelling. Mandible more commonly affected. Occurs in 3rd-4th decade. Histologically similar to dibrous dysplasia but have more distinct borders. Treat with enucleation because lesions are well encapsulated.
