Floor of Mouth Anatomy — MFDS Part 1 MCQ

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EasyAnatomy (Head & Neck)Floor of Mouth AnatomyMFDS Part 1

Which paired muscle forms the muscular diaphragm that constitutes the main floor of the mouth?

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Correct answer: A — Mylohyoid

The correct answer is A, mylohyoid. The right and left mylohyoid muscles meet at the median raphe to form a broad muscular sheet, commonly termed the oral diaphragm. This constitutes the principal muscular floor of the mouth and separates the sublingual space above from the submandibular space below, although anatomical gaps may occur. Geniohyoid lies superior to the mylohyoid and reinforces only the anterior midline region rather than forming the main diaphragm. Genioglossus and hyoglossus are extrinsic muscles of the tongue. The anterior belly of digastric lies inferior to the mylohyoid in the submental region and therefore does not form the oral floor.

Reference: Noguchi T, et al. Structural analysis of the mylohyoid muscle as a septum dividing the floor of the oral cavity for the purposes of dental implant surgery. International Journal of Implant Dentistry. 2023;9:49. https://pubmed.ncbi.nlm.nih.gov/38066306/