ABOMS Oral & Maxillofacial Surgery Exam Questions 2026–2027 | Correct Answers & Detailed Rationales | OMS Board Certification PDF

ABOMS Oral & Maxillofacial Surgery
Exam Questions 2026–2027 | Correct
Answers & Detailed Rationales | OMS
Board Certification PDF
ABOMS ORAL & MAXILLOFACIAL SURGERY EXAM QUESTIONS 2026–2027



DOCUMENT OVERVIEW

• comprehensive board-style questions with detailed rationales covering all core
OMS competencies—designed for self-assessment and knowledge reinforcement
during exam preparation.

• Study strategically by working through topics systematically, timing yourself
on question sets, reviewing rationales for both correct and incorrect options to
identify knowledge gaps and reinforce clinical decision-making.




QUESTION 1

What is the primary blood supply to the mandible?

A) Maxillary artery only

B) Anterior superior alveolar artery and branches

C) Inferior alveolar artery and its branches

D) Buccal and lingual arteries

E) External carotid artery and superficial temporal artery

✓ CORRECT ANSWER: C) Inferior alveolar artery and its branches

RATIONALE: The inferior alveolar artery, a terminal branch of the maxillary artery,
enters the mandibular foramen and travels within the mandibular canal, providing
the primary blood supply to the body of the mandible, teeth, and alveolar process.
The mental artery branches off to supply the anterior teeth and chin, while the
incisive artery continues posteriorly. Understanding this vascular anatomy is critical

,for surgical planning, preventing hemorrhagic complications, and managing inferior
alveolar nerve blocks. The other options describe vascular supplies to other
maxillofacial structures but not the primary blood supply to the mandible.




QUESTION 2

Which nerve is most commonly injured during sagittal split ramus osteotomy
(SSRO)?

A) Lingual nerve

B) Inferior alveolar nerve

C) Buccal nerve

D) Mental nerve

E) Mylohyoid nerve

✓ CORRECT ANSWER: B) Inferior alveolar nerve

RATIONALE: The inferior alveolar nerve travels within the mandibular canal,
making it vulnerable to injury during sagittal split ramus osteotomy, particularly
during splitting of the buccal and lingual cortices and removal of the wedge.
Temporary paresthesia occurs in up to 30% of SSRO cases, while permanent
sensory deficit is reported in 0.5–3% of cases. The nerve's anatomy within the canal,
the extent of the split, and the surgeon's technique all influence injury risk. While
lingual nerve injury can occur (0.2–3.6%), it is less common than IAN injury. Proper
technique, careful soft tissue retraction, and anatomical understanding minimize
iatrogenic nerve damage.




QUESTION 3

A 35-year-old presents with severe facial trauma. CT imaging shows a Le Fort
II fracture. What structures are primarily involved?

,A) Bilateral maxillary tuberosities and palate

B) Nasal bones, maxilla, and orbital floors bilaterally

C) Anterior maxilla, pyriform aperture, medial orbital walls, and infraorbital rims

D) Bilateral maxillae, pterygoid plates, and anterior cranial base

E) Unilateral maxilla, zygomatic arch, and temporal bone

✓ CORRECT ANSWER: C) Anterior maxilla, pyriform aperture, medial orbital
walls, and infraorbital rims

RATIONALE: A Le Fort II fracture (pyramid fracture) is characterized by bilateral
fracture lines through the pyriform aperture, medial orbital walls, infraorbital rims,
and anterolateral maxilla. The fracture extends posteriorly through the lateral walls
of the maxillary sinuses and often the pterygoid plates. This mid-facial fracture is
more severe than Le Fort I but less extensive than Le Fort III. The nasal bones are
involved, and the fracture results in separation of the nose, medial orbits, and
anterior maxilla from the facial skeleton. Early recognition and appropriate fixation
prevent long-term complications including malocclusion, enophthalmos, and
cosmetic deformity.




QUESTION 4

In the context of oral and maxillofacial pathology, which benign tumor is
most likely to undergo malignant transformation?

A) Pleomorphic adenoma

B) Ameloblastoma

C) Odontogenic keratocyst

D) Unerupted tooth

E) Dentigerous cyst

✓ CORRECT ANSWER: B) Ameloblastoma

, RATIONALE: Ameloblastoma is an odontogenic tumor derived from ameloblastic
epithelium with a reported malignant transformation rate of 3–5%, making it the
benign odontogenic tumor with highest transformation potential. Risk factors
include recurrent/multilocular lesions, long disease duration, and surgical
manipulation. While odontogenic keratocysts have high recurrence rates (up to
62%), malignant transformation is rare (<1%). Pleomorphic adenomas of salivary
glands have malignant potential (2–10%), but ameloblastoma's epithelial origin and
aggressive biological behavior place it at higher risk. Comprehensive surgical
treatment with adequate margins and long-term surveillance are essential for
management.




QUESTION 5

A 28-year-old undergoes extraction of an impacted mandibular third molar.
Postoperatively, the patient reports "cotton mouth" sensation in the anterior
two-thirds of the tongue. This is most consistent with injury to which nerve?

A) Glossopharyngeal nerve

B) Lingual nerve

C) Hypoglossal nerve

D) Chorda tympani

E) Vagus nerve

✓ CORRECT ANSWER: B) Lingual nerve

RATIONALE: The lingual nerve provides sensation to the anterior two-thirds of the
tongue and is a branch of the trigeminal nerve (CN V3). Its anatomical proximity to
the third molar region (particularly the lingual alveolar crest and distolingual aspect
of the extraction socket) makes it vulnerable to operative trauma, including
stretching, crushing, and cutting. Lingual nerve injury occurs in 0.4–22% of third
molar extractions, resulting in ipsilateral paresthesia or dysesthesia of the anterior
two-thirds of the tongue, floor of mouth, and lingual gingiva. Most injuries resolve