Jaw

It is a unique bone that contains the lower dental arch. It consists of a horizontal portion, the body, and two perpendicular portions, the branches, which join the body at an almost right angle.

Body

Outer Face

  • Mentonian protuberance – triangular eminence
  • Mentonian Symphysis (Anthropometric Point) – smooth crest on midline
  • Mental foramen – depression on either side of the symphysis. Passage of vessels and mental nerve
  • External Oblique Line

Inner face

  • Mentonian Spine – pair of spines near the symphysis
  • Digastric fossa – just below the mental spines
  • Sublingual fossa – above the mylohyoid line
  • Submandibular fossa – below the mylohyoid line
  • Mylohyoid Line (Internal Oblique) – beside the symphysis and running backwards

edges

  • Superior or Alveolar – receives the sixteen teeth of the lower dental arch
  • Bottom

branches

They have two faces, four edges and two processes:

  • Lateral surface – presents oblique ridges for insertion of the masseter muscle
  • Medial Face – has the following structures:
  • Mandibular foramen - passage of inferior alveolar vessels and nerve
  • Mylohyoid sulcus
  • Mandibular lingula – prominent ridge above the mylohyoid groove


Lower Edge – meets the angle of the mandible

Posterior Border – is covered by the parotid gland

Anterior Edge – continues with the oblique line

Superior Border – has two very important processes: Coronoid Process and Condylar Process (articulates with the articular disc of the temporomandibular joint – TMJ). Between these two processes we find the mandibular notch.


The Mandible articulates with two bones: Temporal (2).

JAW - BACK VIEW
 Osso Mandíbula - Vista Anterior
Source: NETTER, Frank H.. Atlas of Human Anatomy. 2nd edition Porto Alegre: Artmed, 2000.
JAW - SIDE VIEW
 Osso Mandíbula - Vista Lateral
Source: NETTER, Frank H.. Atlas of Human Anatomy. 2nd edition Porto Alegre: Artmed, 2000.
JAW - MEDIAL VIEW
 Osso Mandíbula - Vista Medial
Source: NETTER, Frank H.. Atlas of Human Anatomy. 2nd edition Porto Alegre: Artmed, 2000.
JAW - ANTEROMEDIAL VIEW
 Osso Mandíbula - Vista ântero-medial
Source: NETTER, Frank H.. Atlas of Human Anatomy. 2nd edition Porto Alegre: Artmed, 2000.
JAW - BACK VIEW
 Osso Mandíbula - Vista Posterior
Source: NETTER, Frank H.. Atlas of Human Anatomy. 2nd edition Porto Alegre: Artmed, 2000.

Are you ready to test your knowledge? Then click below to take the quiz on the subject.

Continue your studies on related systems