Peter from Anatomy Zone introduces the mandible, highlighting it as the lower jawbone and noting that it is both the largest and strongest bone in the face.
The term 'mandible' originates from Latin, meaning to chew. It connects with the skull at the temporomandibular joint and consists of a central body and two rami that meet at an angle. The anterior protuberance forms the chin, marked by a ridge called mandibular symphysis where bone parts unite early in life. This area encloses mental tubercles on either side.
Internal Surface of the Mandible The internal surface superiorly from the mandibular body houses teeth within a specialized fibrous joint known as a gomphosis, formed between tooth roots and sockets in the mandible or maxilla. The mental spines on either side of the symphysis provide attachment for muscles: superior mental spines for genioglossus muscle and inferior mental spines for geniohyoid muscle. A ridge called mylohyoid line extends posterosuperiorly from midline symphysis, giving origin to mylohyoid muscle.
External Surface Features of Ramus The ramus is identified as a large flat lateral aspect of the mandible's external surface which provides an origin point for powerful masseter muscles.
The mandibular ramus features two bony processes: the coronoid process and the condyloid process. The coronoid process, a thin flat eminence arising anteriorly, serves as an attachment for the temporalis muscle. In contrast, the thicker condyloid process consists of both the mandibular condyle and neck; it is crucial for articulation.
The condyloid processes of the mandible articulate with the temporal bone at the temporomandibular joint, separated by a concave mandibular notch traversed by masseteric vessels and nerve. The lateral pterygoid muscle attaches to this process's neck. Two major foramina in the mandible are reviewed: mandibular foramen (housing inferior alveolar nerve and artery) and mental foramen (where these structures exit as mental nerve). This provides sensory innervation to lower lip and chin.