Mylohyoid boutonniere
Mylohyoid boutonniere is a normal focal discontinuity in the mylohyoid muscle, which may permit the sublingual salivary gland, fat or vessels - or a combination thereof - to protrude out from the sublingual space into the submandibular space.
Epidemiology
The finding has been observed in up to 77% of normal individuals undergoing head and neck cross-sectional imaging studies, of whom it is seen bilaterally in 67% .
Gross anatomy
The mylohyoid muscle is a sling-like structure that forms the floor of the oral cavity. This muscle divides the sublingual space from the submandibular space; however, communication between the two spaces posterior to the mylohyoid muscle is maintained.
The mylohyoid muscle consists of two halves, both of which have a broad origin from the mylohyoid line along the inner mandible and the body of the hyoid bone. The two halves insert centrally at the fibrous median raphe to form a sling. Traditionally, the mylohyoid muscle is depicted as a continuous muscle sling; however, recent cross sectional imaging (CT and MRI) studies have demonstrated discontinuity in the mylohyoid muscle, allowing normal structures of the sublingual space to protrude through the defect .
History and etymology
Boutonnière is French for buttonhole, a befitting term as the morphology resembles a buttonhole.
Related pathology
Rarely, pathologic entities (e.g. ranula) can also extend through the boutonniere defect.
Siehe auch:
Assoziationen und Differentialdiagnosen zu Mylohyoid boutonniere: