Mandible
The mandible (from Latin mandibula, "jawbone") or inferior maxillary bone forms the lower jaw and holds the lower teeth in place.
Components
The mandible consists of:
- a curved, horizontal portion, the body. (See body of mandible).
- two perpendicular portions, the rami, which unite with the ends of the body nearly at right angles. (See ramus mandibulae)
- Alveolar process, the tooth bearing area of the mandible (upper part of the body of the mandible)
- Condyle, superior (upper) and posterior projection from the ramus, which makes the temporomandibular joint with the temporal bone
- Coronoid process, superior and anterior projection from the ramus. This provides attachment to the temporalis muscle
Foramens
- Mandibular foramen, paired, in the inner (medial) aspect of the mandible, superior to the mandibular angle in the middle of the ramus.
- Mental foramen, paired, lateral to the mental protuberance on the body of mandible.
Nerves
Inferior alveolar nerve, branch of the mandibular division of Trigeminal (V) nerve, enters the mandibular foramen and runs forward in the mandibular canal, supplying sensation to the teeth. At the mental foramen the nerve divides into two terminal branches: incisive and mental nerves. The incisive nerve runs forward in the mandible and supplies the anterior teeth. The mental nerve exits the mental foramen and supplies sensation to the lower lip.
Articulations
The mandible articulates with the two temporal bones at the temporomandibular joints
Pathologies
One fifth of facial injuries involveves mandibular fracture.[2] Mandibular fractures are often accompanied by a 'twin fracture' on the contralateral (opposite) side.
The mandible may be dislocated anteriorly (to the front) and inferiorly (downwards) but very rarely posteriorly (backwards).
See also
Additional images
References
- ↑ hednk-023 — Embryology at UNC
- ↑ Levin L, Zadik Y, Peleg K, Bigman G, Givon A, Lin S (August 2008). "Incidence and severity of maxillofacial injuries during the Second Lebanon War among Israeli soldiers and civilians". J Oral Maxillofac Surg 66 (8): 1630-3. PMID 18634951. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WKF-4T0F864-K&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_version=1&_urlVersion=0&_userid=10&md5=e05fa24fcd1ba3f710eea659d919b6eb. Retrieved on 2008-07-16.
External links
This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant.
Bones of head and neck: the facial bones of the skull |
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Maxilla |
Surfaces
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Anterior: fossae (Incisive fossa, Canine fossa) - Infraorbital foramen - Anterior nasal spine
Infratemporal: Alveolar canals - Maxillary tuberosity
Orbital: Infraorbital groove - Infraorbital canal
Nasal: Pterygopalatine canal
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Processes
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Zygomatic process
Frontal process (Agger nasi, Anterior lacrimal crest)
Alveolar process
Palatine process (Incisive foramen, Incisive canals, Foramina of Scarpa, Incisive bone, Anterior nasal spine)
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Other
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Body of maxilla - Maxillary sinus
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Zygomatic |
Orbital process (Zygomatico-orbital) - Temporal process (Zygomaticotemporal) - Lateral process (Zygomaticofacial)
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Palatine |
Fossae
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Pterygopalatine fossa - Pterygoid fossa
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Plates
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Horizontal plate (Posterior nasal spine) - Perpendicular plate (Pterygopalatine canal, Sphenopalatine foramen, Pyramidal process)
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Processes
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Orbital - Sphenoidal
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Mandible |
Body
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external surface (Symphysis menti, Mental protuberance, Mental foramen) - internal surface (Mental spine, Mylohyoid line, Sublingual fovea, Submandibular fovea) - Alveolar part of mandible
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Ramus
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Mylohyoid groove (Mandibular canal, Lingula) - Mandibular foramen - Angle
Coronoid process - Mandibular notch - Condyloid process - Pterygoid fovea
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Minor/
nose |
Nasal bone: Internasal suture - Nasal foramina
Inferior nasal concha: Ethmoidal process - Maxillary process
Vomer: Wing
Lacrimal: Posterior lacrimal crest - Lacrimal groove - Lacrimal hamulus
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