A 38-year-old male with a periapical radiograph showing the mandibular premolar region. What bony structure would be at risk during periosteal elevation for a procedure to extract tooth #17 on the lingual side? (Refer to lingual nerve diagram)

Correct answer: B. Lingual nerve

• A. INCORRECT. The lingual cortical plate is a bony structure that is reflected during the surgical flap. While it can be inadvertently damaged, the soft tissue structure (nerve) at risk during elevation is the lingual nerve.
• B. CORRECT. The lingual nerve lies in immediate proximity to the lingual aspect of the mandible in the third molar region. As shown in the anatomical diagram, the lingual nerve runs superficially along the lingual side of the mandibular alveolar process and can be easily damaged during periosteal elevator placement on the lingual cortex during third molar surgery.
• C. INCORRECT. The mylohyoid muscle attaches to the mylohyoid ridge (internal oblique ridge) and forms the floor of the mouth. While care must be taken with this muscle, the nerve at risk during periosteal elevation is specifically the lingual nerve.
• D. INCORRECT. The submandibular gland duct (Wharton's duct) opens at the sublingual caruncle anteriorly. It is not the primary structure at risk during lingual periosteal elevation for third molar surgery.