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