<prompt> Trismus is due to spasm of which of the following muscle FMGE Dec 2018BuccinatorLateral pterygoidMedial pterygoidMentalis  <response>: M - Medial pterygoid - inseed to ramus of mandible from inner side T - Temporalis - inseed into coronoid process of mandible M -Masseter-- inseed to ramus of mandible from outside Lateral pterygoid - depressor of mandible - pull mandible antero-inferiorly and open the mouth Antagonize MTM muscles Tetanus neonatorum - spasm of masseter Trismus - spasm of muscles of mastication especially medial pterygoid muscle. Mentalis: Deepest muscle of lower group arising from mandible just inferior to incisor teeth, with fibers passing downward medially to inse into skin of chin. It raises protrudes lower lip as it wrinkles skin of chin Help position lip when drinking from cup when pouting Buccinator: Compresses cheek against teeth is used in acts like blowing 