Oral Surgery

Question 1

Incisal

Answer 1

Refers to the biting surface of an anterior tooth (incisor and canine)

Question 2

Occlusal

Answer 2

Refers to the biting surface of a posterior tooth (premolar and molar)

Question 3

Apical

Answer 3

toward the root tip

Question 4

Mesial

Answer 4

toward the midline

Question 5

Crown

Answer 5

portion of the tooth covered by enamel or visible within the oral cavity

Question 6

Root

Answer 6

portion of the tooth covered by cementum

Question 7

Pediatric dentition

Answer 7

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

Question 8

Adult dentition

Answer 8

• 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)

Question 9

Normal occlusion (class I)

Answer 9

Mesiobuccal cusp of maxillary first molar occludes with the buccal groove of the mandibular first molar

Question 10

Class II occlusion (overbite)

Answer 10

Meiobuccal cusp of maxillary first molar is mesial or anterior to the mesobuccal groove of the mandibular first molar

Question 11

Class III occlusion (underbite)

Answer 11

Meiobuccal cusp of maxillary first molar is distal or posterior to the mesobuccal groove of the mandibular first molar

Question 12

Surgical treatment for maxillary hypoplasia and maxillary excess

Answer 12

segmental le fort 1 osteotomies

Question 13

Surgical treatment for mandibular hypoplasia

Answer 13

bilateral sagittal split osteotomy

Question 14

Surgical treatment for mandibular hyperplasia

Answer 14

bilateral sagittal split osteotomy for mandibular setback or le fort 1 osteotomy for advancement of maxilla or combination of both

Question 15

Placement of nasopalatine block

Answer 15

local anesthetic deposited at the foramen (5-7mm posterior to maxillary dental midline)

Question 16

Placement of greater palatine block

Answer 16

Anesthetic deposited halfway between maxillary second molar and palatal midline

Question 17

Location of mental nerve foramen

Answer 17

Between the mandibular premolars

Question 18

Microbes that contribute to odontogenic infections

Answer 18

50% are mixed aerobic/anaerobic

Important pathogens: fusobacterium, prevotella, streptococcus

Question 19

Radicular (periapical) cyst

Answer 19

Round or oval lesion that arises from residual odontogenic epithelium and nonvital pulp. Tx with enucleation of cyst, endodontic treatment or tooth extraction

Question 20

Dentigerous cyst

Answer 20

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.

Question 21

Odontogenic keratocyst

Answer 21

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.

Question 22

Calcifying epithelial odontogenic tumor

Answer 22

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.

Question 23

Clear cell odontogenic carcinoma

Answer 23

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.

Question 24

Adenomatoid odontogenic tumor

Answer 24

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.

Question 25

Odontogenic myxoma

Answer 25

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.

Question 26

Calcifying odontogenic cyst

Answer 26

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

Question 27

Ameloblastoma

Answer 27

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.

Question 28

Odontoma

Answer 28

Appear on radiograph as either amorphous mixed density lesions or like balls of tiny teeth. Can be complex or compound. Treat with enucleation.

Question 29

Fibrous dysplasia

Answer 29

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.

Question 30

Ossifying fibroma

Answer 30

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.