Download lecture 16

Supralaryngeal Anatomy
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Supportive Framework
• Facial Skeleton
• Mandible
• Cervical Vertebrae
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Skull
• Composed of 22 irregular or flattened bones
• Joined together with sutures (immovable, fibrous)
• Principal sutures:
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–
–
–
Sagittal
Coronal
Lambdoidal
Occipitomastoid
• 2 Main parts of skull:
– Cranium (braincase)
– Facial skeleton (forms framework for organs of
mastication)
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Bones of the Face
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•
•
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•
•
•
•
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)
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Bones of Cranial Skeleton
• Ethmoid Bone (1)
• Frontal Bone (1)
• Parietal Bones (2)
• Occipital Bone (1)
• Temporal Bones (2)
• Sphenoid Bone (1)
Total= 8
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Skull
Frontal Bone
Ethmoid
Perpendicular
Process
Maxilla
Nasal Bone
Zygomatic
Bone
Vomer
Mandible
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Lateral Skull
Parietal
Bone
Coronal
Suture
Frontal
Bone
Nasal
Bone
Maxilla
Lambdoidal
Suture
Zygomatic
Arch
Mandible
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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
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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
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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
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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
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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
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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
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Vomer
• Inferior half of bony septum
• Unpaired, thin quadrilateral plate
• Articulates with maxillae & palatine
bones inferiorly
• Perpendicular plate of ethmoid &
rostrum superiorly
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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
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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
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Sphenoid Bone
Lesser Wing of
Sphenoid
Greater Wing of
Sphenoid
Pterygomandibular
Ligament
Hammulus of the
Pterygoid
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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
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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
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Mandibular Dental Arch
3rd Molar
Palatine
Bone
1st Molar
2nd Bicuspid
1st Bicuspid
Cuspid
Lateral Incisor
Central Incisor
2nd Molar
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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
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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)
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Malocclusions
Class I
Malocclusion
Class II
Malocclusion
Class III
Malocclusion
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Reading/Assignments
• Seikel: Pgs. 261-299
• Dickson: Pgs. 179-194
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