Mandible
Definition
[edit]The mandible is the horseshoe-shaped bone that forms the lower jaw and holds the lower teeth. It consists of a horizontal portion, the body, and two vertical portions, the rami (singular: ramus), which articulate with the temporal bone to form the temporomandibular joint (TMJ).
Unlike the maxilla, which is fused to the skull, the mandible is a movable structure essential for mastication, speech, and facial expression.
Anatomical Features
[edit]1. The Body of the Mandible
[edit]The horizontal part of the bone that supports the lower dentition.
- Alveolar process: The superior margin containing the sockets for the mandibular teeth.
- Mental Foramen: An opening typically located below the second premolar that transmits the mental nerve and vessels.
- Mental Protuberance: The bony prominence forming the chin.
- Mylohyoid Line: A ridge on the internal surface where the mylohyoid muscle attaches, forming the floor of the mouth.
2. The Ramus
[edit]The vertical part of the mandible that extends upward.
- Condylar process: The posterior projection that articulates with the glenoid fossa of the temporal bone.
- Coronoid process: The anterior projection that serves as the attachment point for the temporalis muscle.
- Mandibular Notch: The depression between the condylar and coronoid processes.
- Mandibular Foramen: Located on the internal (medial) surface of the ramus; it is the entry point for the inferior alveolar nerve.
3. The Angle of the Mandible
[edit]The junction where the inferior border of the body meets the posterior border of the ramus. It is a major attachment site for the masseter muscle and medial pterygoid muscle.
Clinical Significance
[edit]Local Anesthesia
[edit]The Inferior Alveolar Nerve Block (IANB) is the most common anesthetic