Lecture 5: Osteology and the Muscles of Mastication Flashcards
What is a foreman?
Openings into the bone through which nerves and blood vessels pass
What is the mandibular foreman?
The large opening in the mandible through which the lower jaw nerve passes
What is the lingula?
A small bone projection just in front of the mandibular foreman (used as a reference when delivering anesthetic
Where is the mental foreman?
Located between the lower bicuspids on the outside of the mandible (on either side)
Where is the coronoid process?
It is part of the mandible, and is the front-protruding portion where muscles attach
Where is the head of the mandible?
The portion of the mandible that forms the jaw joint
What are the three main bones that provide anchors for moving the mandible?
- -Temporal bone
- -Zygomatic bone (cheek bone)
- -Sphenoid bone (towards the front-center of the skull, just in front of temporal bone. Butterfly shaped)
What three muscles attach to the three anchor bones for the mandible?
Temporalis muscle->temporal bone
Masseter muscle -> zygomatic bone
Lateral Pterygoid muscle ->sphenoid bone
What is the greater palatine foreman? What is another name for it?
- -The furthest back point at which nerves enter the hard palate
- -Anterior palatine foreman
What is the incisive foreman? What is another name for it?
- -The point where the nerve connected to the anterior palate back to the cuspids passes through
- -Nasal Palatine Foreman
What is the muscle side that moves during contraction called?
Insertion
What are the four main muscles involved in moving the mandible?
Masseter
Temporalis
Medial pterygoid
Lateral pterygoid
What are some common symptoms of TMJ disorder?
o Headaches, jaw pain, grinding or clenching of teeth
o Worn out teeth
o Jaw doesn’t open evenly
o Muscle around TM is sensitive
What does it mean to palpate?
To squeeze or touch
What is unique about the lateral pterygoid?
The only muscle of the four that is responsible for opening your jaw
What is TMJ disorder?
When the muscle between the skull and the mandible slips, and bone rubs against bone
How can TMJ Disorder/TMD be treated?
Remedies range from an NTI appliance to surgery
What is a leaf cage?
Plastic strips used to equilibrate a patients jaw (so dentist knows which teeth are hitting first, and if then need adjusting)
How do NTI appliances work?
- -Only about 20% of the force of your jaw is allowed by the body when the front teeth are in contact
- -The NTI appliance focuses force on a small area of the anterior mandibular teeth. When the brain senses that the force has reach 20%, the mandibular controlling muscles will stop contracting
What three points are used when equilibrating the jaw?
- -Left head of mandible
- -Right head of mandible
- -Leaf Cage (plastic strips)
When a muscle contracts there is usually a side of the muscle that moves a bone and another side that stays stationary. What is the stationary side called?
The origin
What is it called when muscles contract?
The action
What is the moving bone (attached to a contracting muscle) called?
The insertion
What is the OIA (Origin, Insertion, and Action) of the Masseter muscle?
O-zygomatic arch
I-external surface of mandible
A-elevate the mandible
–Muscle you can feel by your cheek bone when you clench your jaw
