Mandibular symphysis

In human anatomy, the facial skeleton of the skull the external surface of the mandible is marked in the median line by a faint ridge, indicating the mandibular symphysis (Latin: symphysis menti) or line of junction where the two lateral halves of the mandible typically fuse in the first year of life (6–9 months after birth).The lowest (most inferior) end of the mandibular symphysis — the point of the chin — is called the "menton".[4] When filter feeding, the baleen whales, of the suborder Mysticeti, can dynamically expand their oral cavity in order to accommodate enormous volumes of sea water.[5] Many primitive proboscideans belonging to the group Elephantiformes have a greatly elongated mandibular symphysis.[6] This article incorporates text in the public domain from page 172 of the 20th edition of Gray's Anatomy (1918)
Humpback skeleton showing the flexible "slingshot" symphysis present in baleen whales
Skull and jaws of the "tetralophodont gomphothere " Tetralophodon longirostris , a proboscidean demonstrating mandibular symphysis elongation
Anatomical terms of bonefacial skeletonmandiblesymphysismental protuberancemental tuberclegeniohyoidgenioglossusbaleen whalesgomphothereTetralophodon longirostrisproboscideanearly whalesproboscideansElephantiformeselephantspublic domainGray's AnatomyMaxillaAnteriorIncisive fossaCanine fossaInfraorbital foramenOrbital bonesAnterior nasal spineInfratemporalAlveolar canalsMaxillary tuberosityOrbitalInfraorbital grooveInfraorbital canalGreater palatine canalZygomatic processFrontal processAgger nasiAnterior lacrimal crestAlveolar processPalatine processIncisive foramenIncisive canalsForamina of ScarpaIncisive boneBody of maxillaMaxillary sinusZygomaticOrbital processZygomatico-orbitalTemporal processZygomaticotemporalLateral processZygomaticofacialPalatinePterygopalatine fossaPterygoid fossaHorizontal platePosterior nasal spinePerpendicular plateSphenopalatine foramenHard palatePyramidalSphenoidalMandibular prominenceLingual foramenMental foramenMandibular incisive canalMental spineMylohyoid lineSublingual foveaSubmandibular foveaAlveolar part Mylohyoid grooveMandibular canalLingulaMandibular foramenCoronoid processMandibular notchCondyloid processPterygoid foveaNasal boneInternasal sutureNasal foraminaInferior nasal conchaEthmoidal processMaxillary processLacrimalPosterior lacrimal crestLacrimal grooveLacrimal hamulusPrognathismRetromolar spacehuman musculoskeletal system