Lecture 2 - Oral Cavity-1.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 2 Oral Cavity Landmarks & Features Presented by Dr Filip Vujovic DDS, PhD School of Medical Sciences Slides courtesy of Dr Jonathan D. Hakim The University of Sydney Page 2 Anatomy Descriptive and Surgical by Henry Gray (1858)  Lecture Outline – Boundaries of oral cavity – Lips and cheeks – Gingiva – Tongue – Palate – Teeth The University of Sydney Page 3  Learning Objectives – Describe the boundaries of the oral cavity. – Identify and describe the function of teeth. – Identify the gingiva found within the oral cavity. – Identify the structures of the hard and soft palate. – Identify the structures of the tongue. – Identify and describe the function of the intrinsic and extrinsic muscles of the tongue. The University of Sydney Page 4 Oral Cavity The University of Sydney Page 5  Oral Cavity - Function – Mastication (chewing) – Swallowing – Taste – Speech – Jaw bones – Mandible – Maxilla – Temporomandibular joint (TMJ) The University of Sydney Page 6 Nasal & Oral Cavities & Pharynx Nose Nasopharynx - posterior to nasal cavity Mouth Oropharynx - posterior to oral cavity Laryngopharynx - posterior to larynx Larynx The University of Sydney Page 7 Nasal & Oral Cavities & Pharynx VESTIBULE – Inside lips and cheeks – Superficial to teeth, gingivae and Nose alveolar arches of mandible & Nasopharynx maxilla Hard palate Soft p alate ORAL CAVITY PROPER Mouth – Anterolateral: dental arches Oropharynx – Roof/Superior: hard and soft Vestibule Oral Cavity palate Proper – Posterior: oropharyngeal isthmus Laryngopharynx (fauces), bounded laterally by Larynx palatoglossal folds, leads to oropharynx – Inferior: floor of mouth The University of Sydney Page 8  Oral Cavity Palatoglossal arch Palatopharyngeal arch Oropharynx (opening to this region is called oropharyngeal isthmus or fauces) The University of Sydney Page 9  Oral Cavity Oral mucosa – Mucous membrane – Stratified squamous epithelium – Keratinsed = tongue, gingivae and hard palate (pink) – Non-keratinsed = cheek, sublingual and alveolar mucosa (shiny, red) Keratin: a protein found on epithelial cells which line the inside and outside surfaces of the body. Helps form hair, nails and your skin’s outer layer (epidermis) The University of Sydney Page 10 Oral Cavity Proper & Oropharynx Oral Cavity Proper Oropharynx Soft Palate Uvula Palatine tonsil Palatopharyngeal arch Palatoglossal arch o Posterior border of oral cavity proper o Anterior border of oropharynx The University of Sydney Page 11 Lips, Cheek, Gingiva The University of Sydney Page 12  Cheeks – Form the side of the face, continuous with the lips – Externally: skin, Internally: mucosa – Bones – Maxilla – Zygomatic bone (cheek bone) – Mandible – Muscles – Masseter – Buccinator – Buccal (cheek) fat pads: superficial and overlie buccinator muscle – Parotid gland (extrinsic salivary gland) – Buccal glands in mucosa The University of Sydney Page 13  Lips Musculo-fibrous fold Functions – Grasping food – Sucking liquids – Speech – Osculation (kissing) Muscle – Orbicularis oris Covered – Exterior = skin – Interior = mucous membrane – Transitional zone = vermillion The University of Sydney Page 14  Gingiva (Gums) Gingiva proper – Covers the alveolar processes of the maxilla and mandible and finish at the neck of each tooth – Facing lips (labial) – Facing cheek (buccal) – Facing tongue (lingual) – Colour: light coral pink to heavily pigmented. Exhibits first signs of inflammation through redness, bleeding or swelling. Alveolar mucosa – Area of tissue beyond the gingiva proper, less firmly attached and redder. It is non- keratinized and proxides flexible area for movement of cheeks & lips The University of Sydney Page 15  Gingiva (Gums) Gingiva proper – Two types: – Free gingiva: forms a collar around the tooth and is not attached to bone (normally 1- 3mm depth). Gingival margin is the border region that touches the tooth. – Attached gingiva: adjacent to free gingiva and is firmly attached to bone structure (can range 3-12mm in height) The University of Sydney Page 16 Tongue The University of Sydney Page 17  Tongue – Mobile muscular organ – Two parts: Oral (moveable part) and Pharyngeal (nonmovable) – Covered in mucous membrane – Functions – Speaking – Mastication – Taste – Swallowing The University of Sydney Page 18  Tongue Structure – Dorsal (upper) surface: Oral (anterior 2/3) Pharyngeal Pharyngeal (posterior 1/3) are divided by: Palatoglossal arch – Palatoglossal arch Foramen caecum – Sulcus terminalis: V-shaped Sulcus terminalis groove – Foramen caecum: remnant of embryological duct associated with thyroid gland – Ventral (inferior) surface Oral – Body: oral part of tongue – Apex: tip of tongue Dorsal surface – Root: connected to the hyoid bone via hyoglossus and genioglossus muscles Apex The University of Sydney Page 19  Oral Tongue – Dorsal – Lingual papilla: – Dorsal surface: fungiform (white circle), filiform (fur), vallate (7- 12, mushroom) Vallate Foliate – Sides: Foliate (ridges) – Taste buds associated with Filiform all except filiform Oral Fungiform The University of Sydney Page 20  Palatine Tongue Foramen caecum Sulcus terminalis Vallate Foliate Fungiform Filiform Dorsal surface The University of Sydney Page 21  Oral Tongue – Ventral – Frenulum – Deep lingual veins – Fimbriated folds (slight fold of mucous membrane) – Sublingual folds with openings and sublingual papilla (prominence of mucous membrane that overlies sublingual gland, has openings Deep lingual veins for sublingual and submandibular glands) The University of Sydney Page 22  Extrinsic Muscles of Tongue (Position the tongue) Genioglossus – Upper genial tubercle to hyoid bone and base of tongue – Protrusion/deviation Hyoglossus – Hyoid bone to side of tongue – Depresses side of tongue (sucking, retraction) Styloglossus – Styloid process to side of tongue (intermingles with hyoglossus) – Lifts tongue up and back Palatoglossus – Palatal aponeurosis to side of tongue – Tongue up The University of Sydney Page 23  Intrinsic Muscles of Tongue (Shape the tongue) Superior longitudinal muscles – Elevate, assist in retraction Transverse and vertical muscles – Narrowing of the tongue, and pull tongue towards floor of mouth Inferior longitudinal muscles – Deviating tongue to the side and pulls tip of tongue downwards – Also assists in retraction The University of Sydney Page 24 Palate The University of Sydney Page 25  Palate – Roof of mouth/floor of nasal cavity – Hard palate (anterior) – Soft palate (posterior) – Respiratory mucosa in nasal cavity – Oral mucosa in oral cavity The University of Sydney Page 26  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 The University of Sydney Page 27  Hard Palate with overlying mucosa Incisive papilla Rugae Median Raphe Palatine glands Rugae Asymmetric ridges of connective tissue located behind incisive papilla over the anterior hard palate. Palatine glands Intrinsic salivary glands The University of Sydney Page 28  Soft Palate – Contains: – Muscles and aponeuroses of palatine muscles – Fat and glands Soft Palate The University of Sydney Page 29  Palatine Aponeurosis – Thin, firm, fibrous sheet – Formed by expanded tendon of tensor palati muscle – Provides support to the other palatine muscles that attach to it and gives strength to soft palate Palatine Aponeurosis The University of Sydney Page 30  Muscles Of Palate Tensor palati There are five paired palatal muscles: 1. Levator Palati Levator palati – Lifts palate up & back 2. Tensor Palati – Tightens palate, pulls auditory tube open 3. Palatoglossus Uvula 4. Palatopharyngeus 5. Uvula Palatoglossus Palatopharyngeus Together: – Depress soft palate – Narrows & shorten isthmus & pharynx The University of Sydney Page 31 Teeth The University of Sydney Page 32  Teeth – Function – Incise, reduce and mix foods with saliva – Protect themselves via supporting structures – Participate in speech The University of Sydney Page 33  Teeth 20 Primary (milk) teeth 32 Permanent (adult) teeth – 2 incisors, 1 canine, 2 premolars & 3 molars in each of the 4 quadrants of the oral cavity anterior teeth posterior teeth Labial: surface of anterior teeth closest to the lip Buccal: surface of posterior teeth closest to the lip Lingual: opposite the tongue in mandibular arch and opposite the hard palate of the maxillary arch (also referred to as “palatal”) Mesial: closest to the midline of the dental arch Distal: farthest from the midline of the dental arch Occlusal: used for chewing in posterior teeth Incisal: the cutting edge of anterior teeth The University of Sydney Page 34  Anatomy of Teeth Regions – Crown – includes cusps (elevations) on occlusal surface – Neck – Root – includes root canal, and apex Tooth tissues – Enamel: hardest portion – Dentine: second hardest tissue in body – Cementum: thin layer on surface of root, similar in composition to bone – Pulp: neurovascular tissue contained in pulp cavity and canal Alveolar bone of maxilla & mandible – Alveolar processes – Interalveolar septa – Interradicular septum The University of Sydney Page 35