A patient habitually places smokeless tobacco in the anterior mandibular labial vestibule. If an abscess were to develop from this habit, to which fascial space is the infection MOST likely to spread?

Correct answer: A. Submandibular space

• A. CORRECT. The anterior mandibular labial vestibule is bordered inferiorly by the mentalis and platysma muscles. Infection/abscess forming in this region spreads inferiorly and medially into the submandibular space. The lymphatic drainage of the anterior mandibular mucosa is primarily to the submandibular and submental lymph nodes, confirming the anatomical relationship.
• B. The buccal space is bounded by the buccinator muscle medially and skin laterally — typically affected by posterior maxillary or mandibular infections, not anterior vestibular disease.
• C. The sublingual space lies between the oral mucosa of the floor of the mouth and the mylohyoid muscle — infections from mandibular premolars and first molars with apices above the mylohyoid may spread here.
• D. The pterygomandibular space is deep to the ramus between the medial pterygoid and mandible — infected from mandibular third molars or IANB injections, not anterior vestibular pathology.