Lecture 4 - Skull (Facial Bones) - University of Sydney PDF

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COMMONWEALTH OF AUSTRALIA Copyright Regulation WARNING This material has been reproduced and communicated to you by or on behalf of the University of Sydney in accordance with section 113P of the Copyright Act 1968 (Act). The material in this communication may be subject to copyright under the Act. Any further reproduction or communication of this material by you may be the subject of copyright protection under the Act. Do not remove this notice The University of Sydney Page 1 Lecture 4 Skull (Facial Bones) Dr Filip Vujovic DDS,PhD Slides: Dr Jonathan D. Hakim School of Medical Sciences The University of Sydney Lithograph from Joseph Maclise’s “The circulatory system” The University of Sydney (1844) Page 2  Lecture Outline – Overview of facial skeleton – Orbit (Zygomer, Maxillary & Lacrimal bones) – Nasal Cavity (Nasal, Vomer and Concha) – Paranasal Sinuses – Oral Cavity (Maxilla, Mandible & Palatine bone) – Hyoid bone The University of Sydney Page 3  Learning Objectives – Identify the facial bones of the skull – Identify the facial bones that make up the orbit, nasal cavity and oral cavity – Identify the paranasal sinuses – Describe the boney articulations of the facial bones – Identify and describe the bony landmarks of the facial bones The University of Sydney Page 4  Skull - Anterior & Lateral View Bones – Frontal bone – Nasal bone – Maxilla – Mandible – Zygomatic bone – Sphenoid bone – Temporal bone – Parietal bone – Lacrimal bone – Inferior Nasal Concha – Ethmoid The University of Sydney Page 5  Skull – Anterior View Frontal Bone 8. Nasal bone 16. Zygomatic Bone 22. Piriform Aperture (anterior nasal aperture) 19. Zygomatic Process of 20. Maxilla the Maxilla 24. Inferior Nasal Concha The superior and middle nasal concha are part of the ethmoid bone, whereas inferior nasal concha is a The University of Sydney separate bone. Mandible Page 6 Orbit The University of Sydney Page 7  Orbit - Bones Seven bones form the orbit: – Frontal bone – Ethmoid bone – Sphenoid bone – Zygomatic bone – Lacrimal bone – Maxilla – Palatine bone The University of Sydney Page 8  Zygomatic bones (Cheek bone) – Paired – Forms infraorbital margin – Articulates with maxilla, frontal bone, temporal & sphenoid bones – Contributes to formation of zygomatic arch The University of Sydney Page 9  Lacrimal bones – Paired – Contributes to medial wall of orbit – Nasolacrimal duct (tear duct) The University of Sydney Page 10  Maxilla – Paired – Contributes to orbit, nasal cavity & oral cavity – Articulates with nasal, lacrimal, zygomatic, ethmoid, vomer and palatine bones The University of Sydney Page 11 Maxilla - Lateral view 13. Frontal process 15. Infraorbital groove Floor of orbit 25. Maxillary tuberosity 22. Anterior Nasal Spine 17. Infra-orbital foramen 18. Zygomatic process 21. Alveolar process with teeth The University of Sydney Page 12 Nose & Nasal Cavity The University of Sydney Page 13  Nose – External Structure The root of the nose is formed by three bones: – Nasal bone – Frontal process of maxilla – Nasal process of frontal bone Three main cartilages form the dorsum & apex of the nose: Fibrofatty tissue – Lateral nasal cartilage (upper nasal) – Major alar cartilage (lower nasal) – Septal cartilage The University of Sydney Page 14  Nasal bones – Paired – Thin – Roof of nasal cavity The University of Sydney Page 15  Nose - Bones There are 8 bones that form the floor, roof, lateral wall: – Nasal – Frontal – Ethmoid – Sphenoid – Maxilla – Lacrimal – Inferior Nasal Concha – Palatine Right nasal cavity The University of Sydney Page 16  Nasal Septum Nasal septum has cartilaginous part anteriorly formed by septal cartilage, and bony part posteriorly. Bony nasal septum formed by: – Perpendicular plate of ethmoid bone anterosuperiorly – Vomer posteroinferiorly Vomer & medial pterygoid plates form the choanae (posterior nasal aperture) The University of Sydney Page 17  Anterior & Posterior Nasal Apertures Maxilla & nasal bones form the Vomer, palatine & sphenoid piriform aperture (anterior nasal (medial pterygoid plates) form the aperture) choanae (posterior nasal aperture) The University of Sydney Page 18 Regions of the Nasal Cavity Sphenoethmoidal recess Superior nasal concha & meatus Olfactory Middle nasal concha & meatus Respiratory Inferior nasal concha & meatus Respiratory Atrium Non-keratinized stratified squamous epithelium. In front of the conchae Nasopharynx Vestibule Respiratory epithelium Hairy skin Nostril (nares) The University of Sydney Page 19 Paranasal Sinuses Frontal Ethmoid Sphenoid Maxillary – All paired – Contained within respective bone – Lined with respiratory mucosa – Highly variable in shape, size and development – Function: Lighten the weight of the head, support immune defense of nasal cavity, humidify and warm inspired air, increase resonance of the voice, produce mucus that keeps your nose moist – Develop from & drain into nasal cavity The University of Sydney Page 20 Regions of Drainage Sphenoid Sinus Drains into sphenoethmoidal recess (superior & posterior to superior nasal concha) via its ostium (opening) Posterior Ethmoid Air Cells Drains into superior meatus Middle & Anterior Ethmoid Air Cells Drains into middle meatus Maxillary Sinus Drains into middle meatus. Partially via semilunar hiatus, but also via its own ostium Frontal Sinus Drains into middle meatus The University of Sydney Page 21 Regions of Drainage Nasolacrimal duct (lacrimal gland) Drains into inferior meatus The University of Sydney Page 22 Oral Cavity The University of Sydney Page 23  Oral Cavity – Maxilla – Mandible – Palatine bone The University of Sydney Page 24  (lateral wall of nasal cavity) (orbit) Palatine bones (hard palate) – Paired L-shaped bone – Join where their horizontal plates meet – Contribute to orbit, nasal cavity, hard palate The University of Sydney Page 25  Hard Palate Incisive foramen (opens from incisive canal) Palatine process of Maxilla Horizontal plate of Intermaxillary suture palatine bone Palatomaxillary suture Greater palatine foramen Lesser palatine foramen (part of pyramidal process of palatine bone) The University of Sydney Page 26  Mandible – Singular bone – Head (condyle) articulates with temporal bone at temporomandibular joint (TMJ) – Muscles of mastication attach to mandible to facilitate its actions The University of Sydney Page 27 Mandible (Lateral view) 19. Coronoid process 13. Condyle (Head) 14. Mandibular notch 15. Ramus (vertical) 21. External Oblique line (ridge) 16. Angle of mandible 20. Alveolar processes & teeth 18. Body of mandible (horizontal) Body consists of sockets (alveolae) and alveolar processes carrying teeth 22. Mental foramen 23. Mental protuberance The University of Sydney Page 28 Mandible – Medial View 27. Lingula 26. Mandibular foramen Opening for inferior alveolar nerve - leads to mandibular canal 31. Sublingual fossa 28. Mylohyoid groove (sulcus) Impression made by mylohyoid nerve Mylohyoid line Runs obliquely across body for attachment of mylohyoid muscle (floor of mouth) Digastric fossa 30. Submandibular fossa The University of Sydney Page 29 Mandible – Superior View 25. Mental spine(s) Also known as genial tubercle – for attachment of muscles The University of Sydney Page 30 Mandible – Posterior View The University of Sydney Page 31 Hyoid Bone – Small U-shaped solitary bone – Does not articulate with other bones – Superior to thyroid cartilage (larynx) – Important for muscle attachments of tongue, pharynx & neck Body - unpaired Greater Horn – paired, larger Lesser Horn – paired, smaller The University of Sydney Page 32 hyoid