MANDIBLE- PARTS, ATTACHMENTS AND RELATIONS

Mental foramen	Present below the interval between the premolar teeth.
Mylohyoid ridge/line (Present on outer surface of body)	Extends obliquely from below the third molar to median area below the genial tubercles
Mylohyoid groove (Present on ramus)	Extends on to the body below the posterior end of mylohyoid line

Note:

The submandibular fossa is present below the mylohyoid line or ridge and it lodges submandibular gland.
The lingual fossa is present above the mylohyoid ridge and it lodges sublingual gland.
Infection from mandibular 2nd and 3rd molars spread to submandibular space as their root apices lie below the mylohyoid line.
Infection from mandibular premolars and 1st molar involve the lingual space as their root apices lie above the mylohyoid line.
The mandibular torus is commonly present above the mylohyoid line.
The inferior alveolar nerve is closely related to posterior end of mylohyoid ridge while the lingual nerve is closely related to mylohyoid groove.

Genial tubercles	four small elevations near symphysis menti. The upper genial tubercles give origin to genioglossus and the lower tubercle to the geniohyoid
Digastric fossa	The anterior belly of digastric arises from digastric fossa Note: The posterior belly of digastric arises from mastoid notch.
Mandibular or sigmoid notch	Masseteric nerve and vessels pass through mandibular the notch
Lingula	Tongue shaped projection near anterior margin of mandibular foramen. Gives attachment to sphenomandibular ligament
Incisive fossa	Gives origin to mentalis
Mental foramen	Mental foramen transmits the mental nerve and vessels
Mandibular foramen	Inferior alveolar nerve and vessels enters the mandibular canal through the mandibular foramen
Pterygoid fovea	A depression in the anterior surface of neck of condylar process. It gives attachment to a lateral pterygoid muscle.