TMJ & Muscles
of Mastication
+
Mandibular
Nerve
Dr Maan Al-Abbasi
PhD (UK)
MSc
MBChB
Infratemporal Fossa Contents
• Parotid gland (glenoid process)
• Maxillary artery
• Pterygoid venous plexus
• Otic PS ganglion
• Muscles of mastication
• Mandibular nerve
• Sphenomandibular ligament
Mandibular nerve
Mandibular
nerve
Lingual Nerve
• sensory to the:
1. anterior two thirds of
the tongue,
2. the floor of the
mouth, and
3. the lingual gingivae.
Mandibular Nerve V3
Otic parasympathetic ganglion
Otic parasympathetic ganglion
Muscles of
Mastication
• All supplied by Mandibular division
of Trigeminal (V3)
• All derived from pharyngeal arch
Temporalis
Opening - Depression
Opening - Depression
Opening - Depression
Closing - Elevation
Closing - Elevation
Functions of muscles of mastication
Lateral Pterygoids
• Upper head - involved mainly with chewing, and functions to anteriorly rotate the
disc on the condyle during the closing movement
• Lower head - exerts an anterior, lateral, and inferior pull on the mandible, thereby
opening the jaw, protruding the mandible, and deviating the mandible to the
opposite side
Medial Pterygoids
• Working bilaterally - assists in mouth closing.
• Working unilaterally – deviation of the mandible toward the opposite side
Functions of muscles of mastication
Masseter
• Elevate the mandible, thereby occluding the teeth during mastication.
Temporalis
• Assists with mouth closing/side-to-side grinding of the teeth.
• Also provides a good deal of stability to the joint
Temporomandibular Joint
• The articular surfaces of the TMJ are
lined by fibrous tissue (i.e. develops
in membrane)
Condylar joint
Hinge joint
Temporomandibular Joint
Temporomandibular Joint
Medial View
TMJ
Fossa
Disc
TMJ
TMJ
Biting
Biting
Pain
