Page 129 - Edited - Webster HEAD AND NECK - part 1

OTHER ACCESSORY LIGAMENTS OF THE TEMPOROMANDIBULAR JOINT

HN107

SPINE OF
SPHENOID

CUT EDGE OF LATERAL
PTERYGOID PLATE -
LOWER PART REMOVED
SML

HAMULUS OF MEDIAL
PTERYGOID PLATE
PTERYGOMANDIBULA
R RAPHE STYLOMANDIBULAR
3rd MOLAR TOOTH LIGAMENT (SHEETS)
SML = SPHENOMANDIBULAR
LIGAMENT

LINGULA

These collagenous bands contribute little to
the stability of the joint. HOWEVER, they
distort the mandible’s movements so that THE
MANDIBLE DOES NOT SWING AROUND
ITS CONDYLES AS A SIMPLE HINGE.
Instead, the axis of rotation shifts as the NOTION
mandible moves. A fixed notional axis of AL AXIS
rotation passes transversely through both OF
lingulae. THE CONDYLES THEREFORE ROTATION:
TRAVEL BACKWARDS & FORWARDS, TIP OF
WITHIN THE PROFILE OF THE LINGULA
MANDIBULAR FOSSA, AS THE MOUTH
OPENS & CLOSES. K.E.W.

OPEN/CLOSE
MOVEMENTS IF
JOINT WERE A
SIMPLE HINGE:
IMAGINE
MANDIBLE
SUSPENDED BY A
STIFF WIRE
THROUGH THE
CONDYLES.

A BETTER APPROXIMATION: MANDIBLE SUSPENDED ON A STIFF
WIRE (AXIS OF ROTATION) THROUGH LINGULA OF EACH RAMUS
K.E.W.