osteology of mandible Flashcards
parts of manbible
body and a pair of rami
how many surface and borders of body
outer and inner surface
upper and lower border
features of outer surface
- symphysis menti
the line at which two halves meet and is marked by a faint ridge - mental protuberance
triangular projecting ridge on the lower median part. the inferolateral angles of protuberance forms the mental tubercles - mental foramen- lies below the interval between premolar teeth
- oblique line is the cont of shrp anterior border of ramus and runs downwards and forwards towards mental tubercle
- incisive fossa- depression below incisors
features of inner surface
- mylohyoid line - prominent ridge that runs obliquely downwards and forwards the third molar tooth to the median area below genial tubercles
- submandibular fossa is below the mylohyoid line, which has the gland
- sublingual fossa above the mylohyoid line and has its gland
- superior and inferior tubercles found on the posterior surface of the symphysis menti and these are 4 small elevations
- mylohyoid groove present on ramus extends to the body below the posterior end of mylohyoid line.
what does the upper border and lower border have
sockets for teeth-upper
lower border(base) has midline depression called digastric fossa
how is the anatomy of the ramus
Ramus is quadrilateral in shape
1> two surfaces lateral and medial
2> four borders upper lower anter postr
3>two processes coronoid and condyloid
describe the two surfaces of ramus
lateral surface is flat +has oblique ridges
medial surface has
1. mandibular foramen- lies above centre iof ramus at the level of occlusal surface of teeth. leads to the mand canal whcih descends in body opens as mental foramen.
- lingula- at ant margin of mand for. sharp tongue shaped projection and directed towards condyloid process
- mylohyoid groove - below mand for and ends in the sumandibular fossa
borders of ramus
- upper- thin + curved down forming a mandibular notch
- lower- backward cont of base if mandible it ends by becoming continius with posterior border at angle of mandible.
- ant border- thin
- post is thick
the two processes of ramus
- coronoid is flat triangular projection from anterosuperior part of ramus its ant border is cont with ant border of ramus and its post border bounds the mandibular notch
2.condyloid - strong upward proj from posterosuperior part of ramus. upper end is expanded to form the head
head is covered by fibrocartilageand articulates with the temporal bone to form TMJ
construction below head is neck
anterior surf has depression called pterygoid fovea
oblique line and its attachment
- buccinator - on lat side of body
- depressor labii inferioris and dep anguli oris - below mental foramen
incisive fossa
mentalis and mental slips of orbicularis oris
inner and outer surface
are covd by muc memb of mouth
mylohyoid line
mylohyoid muscle
posterior end of mylohyoid line
sup constrictor
pterygo mandibular raphe is attached behind third molar
upper genial tubercle
genioglossus
lower genial tubercle
geniohyoid
digastric fossa
ant belly of dg
lower border of ramus
deep cervical fascia and platysma
lat surf of ramus (ex PS part)
masseter
posterosuperior part of lat surf of ramus
parotid gland
lingula
sphenomandibular ligament
medial surf of ramus behind mylohyid groove
medial pterygoid
apex and medial surf of coronoid process extending to ant border of ramus
temporalis
pterygoid fovea
lat pterygoid
