Pterygomandibular raphe
Muscles of the pharynx and cheek. (Pterygo-Mandibular ligament labeled at center, vertically.)
Details
Part ofBuccopharyngeal fascia
OriginPterygoid hamulus of the medial pterygoid plate
InsertionMylohyoid line of the mandible
Identifiers
Latinraphe pterygomandibularis
TA98A05.3.01.102
TA22178
FMA55618
Anatomical terminology

The pterygomandibular raphe (pterygomandibular fold[1] or pterygomandibular ligament) is a thin[2] tendinous band of buccopharyngeal fascia. It is attached superiorly to the pterygoid hamulus of the medial pterygoid plate, and inferiorly to the posterior end of the mylohyoid line of the mandible. It gives attachment to the buccinator muscle (in front), and the superior pharyngeal constrictor muscle (behind).

Structure

Open mouth, view from front. The pterygomandibular ligaments are marked with arrows. Note that in this mouth the lower wisdom teeth have been removed, slightly changing the shape of the pterygomandibular ligaments that usually curve and attach to the mandible around them.

The pterygomandibular raphe is a tendinous band[2][3] formed by the buccopharyngeal fascia. It is a paired structure, with one on each side of the mouth.[3] Superiorly, it is attached to the pterygoid hamulus of the medial pterygoid plate of the sphenoid bone; inferiorly, it is attached to the posterior end of the mylohyoid line of the mandible.[2][3]

Relations

The pterygomandibular raphe is the common meeting point of the superior pharyngeal constrictor muscle and the buccinator muscle. This common attachment makes the raphe a junction of the oral cavity, oropharynx, and nasopharynx.[3]

The inferior alveolar nerve passes lateral to the raphe; the raphe is therefore a landmark for a nerve block of this nerve.[2]

The general location of the raphe is indicated by the pterygomandibular fold.[3]

Attachments

The pterygomandibular raphe gives attachment to the central portion of the buccinator muscle anteriorly, and to the superior pharyngeal constrictor muscle posteriorly.[2]

Variation

In foetuses, the pterygomandibular raphe is always very prominent. However, in adults, it may become less distinctive. It is very large and distinctive, in around 36% adults. It is fairly small, and only an upper triangular portion visible, in around 36% of adults. It is not visible in around 28%, making the superior pharyngeal constrictor muscle and the buccinator muscle continuous. This may vary by ethnic group.[4]

Clinical significance

When the mandible is splinted for gradual realignment (such as to treat sleep apnea), the pterygomandibular ligament slightly resists the realignment.[5]

The raphe is a landmark for administration of inferior alveolar nerve blocks.[2][3][1]

History

The pterygomandibular ligament was first noted in 1784.[3]

See also

References

  1. ^ a b Fehrenbach, Margaret J.; Herring, Susan W. (2017). Illustrated Anatomy of the Head and Neck (5th ed.). St. Louis: Elsevier. p. 267. ISBN 978-0-323-39634-9.
  2. ^ a b c d e f g h Standring, Susan (2020). Gray's Anatomy: The Anatomical Basis of Clinical Practice (42th ed.). New York. p. 625. ISBN 978-0-7020-7707-4. OCLC 1201341621.((cite book)): CS1 maint: location missing publisher (link)
  3. ^ a b c d e f g h i j Rao, D.; Sandhu, S.J.S.; Ormsby, C.; Natter, P.; Haymes, D.; Cohen, I.; Jenson, M. (2017-04-01). "Review of the Pterygomandibular Raphe". Neurographics. 7 (2): 121–125. doi:10.3174/ng.2170196.
  4. ^ Shimada, Kazuyuki; Gasser, Raymond F. (1989). "Morphology of the pterygomandibular raphe in human fetuses and adults". The Anatomical Record. 224 (1): 117–122. doi:10.1002/ar.1092240115. ISSN 1097-0185. PMID 2729614. S2CID 36677456.
  5. ^ Brown, Elizabeth C; Jugé, Lauriane; Knapman, Fiona L; Burke, Peter G R; Ngiam, Joachim; Sutherland, Kate; Butler, Jane E; Eckert, Danny J; Cistulli, Peter A; Bilston, Lynne E (2021-04-01). "Mandibular advancement splint response is associated with the pterygomandibular raphe". Sleep. 44 (4). doi:10.1093/sleep/zsaa222. ISSN 0161-8105. PMID 33146716.