Topics

Topic

design image
Pterygomandibular raphe

The pterygomandibular raphe is a fibrous band of connective tissue that extends from the hamulus of the medial pterygoid plate to the posterior end of the mylohyoid line of the mandible. It serves as an important anatomical landmark in oral and maxillofacial surgery and is a key site for local anesthesia (inferior alveolar nerve block). Understanding its anatomy, function, and imaging appearance is essential for dentists, oral surgeons, and radiologists, particularly for surgical planning and evaluation of soft tissue pathology in the oropharyngeal region.

Synonyms

  • Buccopharyngeal raphe

  • Fibrous pterygo-mandibular band

  • Oral fascia raphe

  • Mylohyoid-pterygoid raphe

Function

  • Serves as an attachment site for the buccinator and superior pharyngeal constrictor muscles, forming part of the oropharyngeal wall.

  • Helps maintain tension between the buccal mucosa and pharyngeal wall.

  • Guides muscle contraction during swallowing and speech.

  • Serves as a landmark for inferior alveolar nerve block injections in dentistry.

MRI Appearance

T1-weighted images:

  • Appears as a thin, low-signal linear band of fibrous tissue extending from the medial pterygoid plate to the mandible.

  • Surrounded by high-signal fat in the buccal space, providing natural contrast.

  • Pathological processes (e.g., fibrous thickening, tumors) may appear slightly hyperintense or enhance after contrast.

T2-weighted images:

  • The raphe remains low signal relative to surrounding fat and soft tissues.

  • Edema or inflammation in adjacent muscles or soft tissue appears hyperintense, highlighting abnormal changes.

STIR (Short Tau Inversion Recovery):

  • Fat suppression improves visibility of pathology.

  • Normal raphe is low signal; inflamed or fibrotic changes appear hyperintense, making subtle abnormalities detectable.

CT Appearance

  • On non-contrast CT, the pterygomandibular raphe is soft tissue density, usually not directly visible unless thickened or involved in pathology.

  • Surrounded by air in the oral cavity and buccal space, which appears hypodense, providing natural contrast.

  • Bony landmarks (medial pterygoid plate and posterior mandible) are clearly visible.

MRI images

Pterygomandibular Raphe mri axial image -img-00000-00000