part 2 Flashcards
What functions does the medial pterygoid have?
- works synergistically with the masseter and temporalis to suspend and elevate the mandible
- protrusion of the mandible with teeth slightly apart is it most active state
- unilateral action creates lateral devation and works synergistically with the ipsalateral lateral pterygoid
- inhibited with active mandibular depression
What are the attachments of the medial pterygoid?
- lateral pterygoid plate of the sphenoid, pyramidal process of palatine bone, tuberosity of the maxilla
- inserts inferior and posterior part of medial ramus and angle of the mandible
What are the attachments of the lateral pterygoid?
Two heads
- upper- infratemporal crest and the interior lateral surface of the greater wing of the sphenoid TO the disc
- lower- lateral pterygoid plate of the sphenoid TO condylar neck and ramus of the mandible
What is the function of the lateral pterygoid?
- laterally deviation the mandible to the contralateral side
- eccentrically control position of the disc with mandibular elevation
How does shortening of the lateral pterygoid effect occlusion pattern?
- Premature contact anterior opposite
2. premature contract posterior same side
What muscle was once thought to be part of the temporalis muscle?
shenomandibularis
What are the attachments and innervation of the sphenomandibularis muscle?
- greater wing of the sphenoid
- temporal crest of the mandible
- branches of the buccal nerve off the mandibular nerve off of CN V
What TMJ muscle is theorized to contribute to cluster headaches and why?
- sphenomandibularis
2. it is thought spasm will compress the maxillary nerve against the posterior maxillary wall
What are the attachments of the masseter?
- Deep- posterior 1/3 of the inferior border of zygomatic bone and from the entire zygomatic arch TO superior half of the mandibular ramus and lateral surface of the coronoid process
- Superficial- lower surface of the zygomatic arch TO the mandibular angel and lower part of the ramus
What innervates the masseter?
Masseteric nerve from the anterior branch of the mandibular branch of CN V
What are the attachments of the digastric muscle?
ORIGIN- Two bellies
1.posterior- mastoid notch of the temporal bone and sometimes the styloid process of the of the sphenoid bone
2.anterior- digastric fossa of the lower border of the mandible close to the symphasis
INSERTs- the two bellies joint together passing through a tendonis loop that that perforates the stylohyoid muscle at the hyoid bone
What is the innervation of the styloid muscle?
- anterior belly- mylohoid branch of inferior alveolar of CNV
- posterior belly- facial nerve (CN VII)
What is the function of the digastric muscle?
- raises the hyoid bone
2. open the jaw when the hyoid is stabilized from below
What are the attachments of the stylohyoid muscle?
styloid process TO hyoid bone posterior superior
What innervates the stylohyoid?
CN VII facial nerve
What are the attachments of the omohyoid?
- upper margin of the scapular near suprascapular ligament (sometimes on the ligament) TO the hyoid bone
- TWO bellies meet at a central tendon held down by the SCM
What is the innervation of the omohyoid?
ansa cervicalis C1-3
What function does the omohyoid serve?
the omohyoid assists in swallowing, vomiting, respiration, and some scapulo-clavicular actions
What impact does thumb sucking having on the hyoid muscles and what other pathology causes similar changes?
- it elevates the hyoid so that the suprahyoids shorten and the infrahyoids lengthen
- forward head position has a similar impact
What are the attachments of the styologlossus muscle?
anteriorlateral surface of styloid process of the temporal bone and styolmandibular ligament TO tongue and hypoglossus muscle