Topics

Topic

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Angle of mandible

The angle of the mandible is the posteroinferior corner of the mandible formed by the junction of the body and the ramus. It is a prominent surface landmark of the lower face and an important site for muscular attachments, trauma, and radiologic assessment.

The mandibular angle varies in shape and prominence with age, sex, dentition, and muscle bulk, and it is frequently evaluated in maxillofacial imaging and surgery.

Synonyms

  • Gonial angle

  • Mandibular angle

Location

  • Situated at the junction of the body and ramus of the mandible

  • Located posteroinferiorly on each side of the mandible

  • Inferior to the mandibular foramen

  • Anterior to the mastoid region

  • Superficial to the submandibular region of the neck

Anatomical components

  • Body of mandible (horizontal component)

  • Ramus of mandible (vertical component)

  • Gonial angle:

    • The measurable angle formed between body and ramus

  • Cortical bone:

    • Thick outer cortex providing strength

  • Cancellous bone:

    • Internal trabecular structure

Relations

Laterally:

  • Skin and subcutaneous tissues

  • Platysma muscle

  • Masseter muscle (insertion)

Medially:

  • Medial pterygoid muscle (insertion)

  • Parapharyngeal space (superomedial)

Superiorly:

  • Ramus of mandible

  • Mandibular foramen (more superior and medial)

Inferiorly:

  • Submandibular gland region

  • Submandibular fascia

Posteriorly:

  • Parotid gland (superolateral proximity)

Muscle attachments

  • Masseter muscle: Inserts on the lateral surface of the angle

  • Medial pterygoid muscle: Inserts on the medial surface of the angle

  • Pterygomasseteric sling:

    • Combined muscular and fascial support around the angle

X-ray appearance

Mandible radiographs / panoramic (OPG):

  • Angle contour: Sharp or rounded depending on individual anatomy

  • Cortical margins: Smooth and continuous

  • Gonial angle: Clearly appreciable on lateral and panoramic views

  • Dental status influence: Tooth loss may alter angle configuration

CT appearance

Non-contrast CT:

  • Cortex: Hyperdense, sharply defined cortical bone

  • Trabecular bone: Intermediate density internally

  • Symmetry: Bilateral comparison readily assessed

  • Adjacent soft tissues: Clearly delineated

Post-contrast CT:

  • Bone: No enhancement

  • Adjacent muscles and glands: Expected soft-tissue enhancement

3D CT VRT appearance

Volume-rendered technique (VRT):

  • Angle morphology: Clearly visualized junction of body and ramus

  • Gonial angle: Easily measured and compared bilaterally

  • Surface integrity: Smooth outer contour without defects

  • Clinical utility: Excellent for trauma assessment and surgical planning

MRI appearance

T1-weighted images:

  • Cortical bone: Low signal intensity

  • Marrow within mandible: Intermediate to high signal (fatty marrow)

  • Adjacent muscles: Intermediate signal

T2-weighted images:

  • Bone cortex: Low signal

  • Marrow: Intermediate signal

  • Muscles: Intermediate signal with clear delineation

CT VRT 3D image

Angle of mandible 3D

CT image

Angle of mandible X RAY anatomy image -img-00000-00000