Buccinator muscle Buccinator muscle The buccinator ( ) is a thin quadrilateral muscle occupying the interval between the maxilla and the mandible at the side of the face. It forms the anterior part of the cheek or the lateral wall of the oral cavity. It arises from the outer surfaces of the alveolar processes of the maxilla and mandible, corresponding to the three pairs of molar teeth; and behind, from the anterior border of the pterygomandibular raphé which separates it from the constrictor pharyngis superior. It is attached upon the buccinator crest as far forward as the first molar tooth. The fibers
Orbicularis oris muscle of muscular fibers surrounding the orifice of the mouth, but having different direction. It consists partly of fibers derived from the other facial muscles which are inserted into the lips, and partly of fibers proper to the lips. Of the former, a considerable number are derived from the buccinator and form the deeper stratum of the orbicularis. Some of the buccinator fibers—namely, those near the middle of the muscle—decussate at the angle of the mouth, those arising from the maxilla passing to the lower lip, and those from the mandible to the upper lip. The uppermost and lowermost fibers of