Anatomy Flashcards
What are the 4 muscles of mastication?
Masseter
Temporalis
Medial pyterygoid
Lateral pyterygoid
What is the function of the masseter?
Elevate mandible, closes jaw
Where do the masseter muscles lie?
Zygomatic arch to ramus and angle of mandible
Function of the temporalis?
Elevates mandible and retracts jaw
Where do the temporalis muscles lie?
Temporal bone to coronoid process and ramus
Function of lateral pyterygoid
Open jaw, mandible forwards and downwards
Where do lateral pyterygoid run
Small head -sphenoid bone to disc of TMJ
Large head- lateral pyterygoid plate - pyterygoid fovea
Function of medial pyterygoid
Closes jaw - elevates mandible pulls it forward
Name 3 facial muscles
Buccinator - cheek
Oris- Mouth
Frontalis- forehead
What are the functions of the tongue
Speech, taste,mastication and swallowing
What are the tongue intrinsic muscles
Inside, bundles, alter the shape
what are the tongue extrinsic muscles
Outside, move tongue around alter position
5 Effects of tongue on developing dentition
Tongue pressure can result in lisp AOB pro clination of upper incisors Fwd tongue posture can obstruct eruption Large tongue ( macroglossia) can delay eruption
What is the basal bone in the maxilla
Stable, defines skeletal pattern
What is alveolar bone
Dependent on existing teeth and is remodelled as teeth move.
Extracting teeth causes loss of alveolar bone
How does maxilla grow
Foetus ossification of bone
Filling in of sutures
Drift
Periosteal remodelling
What age does maxilla growth stop for girls and boys
Girls 15 Boys 17
How does mandible grow
Foetus 6 weeks mandible ossifies Age 2, two halves fuse Body length increases, apposition,deposition Vertical growth Periosteal activity
What age does mandibular bone growth stop in girls and boys
Girls 17
Boys 19
Where and when do growth rotations occur
mandible, puberty
What is a forward growth rotation
Favorable
Increased posterior FH > anterior FH
Well balanced face proportions
Increased overbite
What is a backward growth rotation
Unfavorable
Decreased posterior FH < anterior FH
Reduced overbite
AOB
Last teeth to erupt in maxillary arch other than 2 an 3rd molars
Upper 3 an Upper 5
Last teeth to erupt in mandibular arch other than 2 an 3rd molars
Lower 5s
What age is a maxillary canine favorably palapable
9-10 its visible age 11
