lecture 16

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Supralaryngeal Anatomy
1
Supportive Framework
• Facial Skeleton
• Mandible
• Cervical Vertebrae
2
Skull
• Composed of 22 irregular or flattened bones
• Joined together with sutures (immovable, fibrous)
• Principal sutures:
–
–
–
–
Sagittal
Coronal
Lambdoidal
Occipitomastoid
• 2 Main parts of skull:
– Cranium (braincase)
– Facial skeleton (forms framework for organs of
mastication)
3
Bones of the Face
•
•
•
•
•
•
•
•
Mandible (1)
Maxillae (1)
Nasal Bones (2)
Palatine Bones (2) & Nasal Conchae (2)
Zygomatic Bones (2)
Lacrimal Bones (2)
Hyoid Bone (1)
Total= 14
Vomer (1)
4
Bones of Cranial Skeleton
• Ethmoid Bone (1)
• Frontal Bone (1)
• Parietal Bones (2)
• Occipital Bone (1)
• Temporal Bones (2)
• Sphenoid Bone (1)
Total= 8
5
Skull
Frontal Bone
Ethmoid
Perpendicular
Process
Maxilla
Nasal Bone
Zygomatic
Bone
Vomer
Mandible
6
Lateral Skull
Parietal
Bone
Coronal
Suture
Frontal
Bone
Nasal
Bone
Maxilla
Lambdoidal
Suture
Zygomatic
Arch
Mandible
7
Bones of The Facial Skeleton:
Mandible
• Single Bone; U-Shaped
• Upper surface of a tooth bearing mandible is the
alveolar arch
– Dental alveolus (tooth socket)
• Angle of mandible approximates a right angle (90
degrees)
• Function for Speech: Houses the lower teeth and
forms points of attachment for the tongue & other
muscles
8
Maxillae
• Maxillae are second largest bones in the face
• Paired bone, forms entire upper jaw &
contributes to the formation of the roof of the
mouth
• Articulates with 9 bones:
– Frontal, Ethmoid, Nasal Lacrimal, Zygomatic,
Palatine, Vomer, inferior nasal concha
9
Nasal Bones
• Two small oblong plates of bones, forms
bridge of nose
• Situated medially to the frontal process
of the maxillae
• Articulate with frontal bone above &
perpendicular plate of ethmoid
• Articulate with septal cartilage too
10
Palatine Bones
• Located at the back of the nasal cavity
• Form the 3 cavities:
– The floor and lateral walls of the nasal cavity
– The roof of the mouth
– The floor of the orbital cavity
• Articulates with 6 bones: Palatine from
opposite side, Sphenoid, Ethmoid, Maxilla,
Inferior nasal choncha & Vomer
11
Lacrimal Bones
• Smallest of facial bones
• Forms part of the medial walls of the
orbital cavity
• Each has an orbital and nasal surface
• Articulates with 4 bones: Frontal,
Ethmoid, Maxilla & Inferior Nasal
Choncha
12
Zygomatic Bones
• Articulates with the frontal, sphenoid,
maxillary and temporal bones
• Contributes to the lateral wall and floor
of the orbital cavity
• Important muscles of articulation and
mastication attach to the zygomatic bone
13
Vomer
• Inferior half of bony septum
• Unpaired, thin quadrilateral plate
• Articulates with maxillae & palatine
bones inferiorly
• Perpendicular plate of ethmoid &
rostrum superiorly
14
Bones of Cranium
• Ethmoid: Unpaired, contributes to facial skeleton,
articulates with 15 bones
• Frontal: Unpaired, forms anterior part of braincase,
articulates with 12 bones
• Parietal: forms most of rounded roof of cranium,
articulates with 5 bones
• Occipital: Unpaired, forms lower & back portions
of cranium
• Temporal: Paired, forms lateral base & sides of
braincase
15
Bones of Cranium: Sphenoid
• The bone in the base of the skull forming the
roof of the pharyngeal & nasal cavities
• Resembles a bat in flight
– Greater & lesser wings
• Medial & lateral pterygoid plates
– Hammulus of pterygoid
• Attaches jaw bone through pterygomandibular raphe
• Serves as pulley for the tendon that stretches the soft
palate taught
16
Sphenoid Bone
Lesser Wing of
Sphenoid
Greater Wing of
Sphenoid
Pterygomandibular
Ligament
Hammulus of the
Pterygoid
17
Dentition
• Housed within the alveoli of the maxilla &
mandible
• Provide mechanism for mastication & articulatory
surfaces for many speech sounds
• Upper & lower dental arches contain same number
of teeth
• Four types of teeth:
–
–
–
–
incisors
cuspids
bicuspids
molars
18
Dentition
• Teeth larger in upper arch
• Upper arch overlaps lower arch (normally)
• Five surfaces:
– Medial- movement along arch to midline
– Lateral-movement along arch away from midpoint
– Mesial surface- surface “looking” along the arch
toward the midpoint between central incisors
– Distal surface- Surface of any tooth that is farthest
from the midline point
– Buccal surface- contact with cheek
– Lingual surface- facing the tongue
19
Mandibular Dental Arch
3rd Molar
Palatine
Bone
1st Molar
2nd Bicuspid
1st Bicuspid
Cuspid
Lateral Incisor
Central Incisor
2nd Molar
20
Dental Occlusion
• Process of brining the upper & lower
teeth into contact
• Proper occlusion essential for successful
mastication
• Bite down lightly and leave molars
occluded, sets orientation of arch &
occlusion
21
Malocclusions
• Class I: First molar of the mandibular arch is onehalf tooth advanced of the maxillary molar, upper
incisors project beyond lower (overjet), Upper
incisors naturally hide lower incisors (overbite)
• Class II: First mandibular molar are retracted at
least one tooth from the maxillary molars
(mandible retracted)
• Class III: First mandibular molar is advanced
farther than one tooth beyond the first maxillary
molar (mandible protruded)
22
Malocclusions
Class I
Malocclusion
Class II
Malocclusion
Class III
Malocclusion
23
Reading/Assignments
• Seikel: Pgs. 261-299
• Dickson: Pgs. 179-194
24
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