Overview of Oral Tissues PDF

Overview of Oral Tissues By. Dr.R. Amsterdam  What is in the oral cavity? The oral cavity is found in the mouth. It consists of a mix of hard as well as soft structures. Are the structures hard or soft? Both types of structures a...

Overview of Oral Tissues By. Dr.R. Amsterdam  What is in the oral cavity? The oral cavity is found in the mouth. It consists of a mix of hard as well as soft structures. Are the structures hard or soft? Both types of structures are found in the mouth. Soft structures are found lining of the mouth and salivary glands. Hard structures are found on bones of the jaw and on teeth. Oral Cavity divides into two main portions/sections ORAL CAVITY VESTIBULE PROPER external to teeth Internal to teeth ORAL CAVITY The oral cavity extends from the lips and cheeks externally to the pillars of the fauces internally, where it continues into the oropharynx. The palate forms the roof of the mouth and separates the oral and nasal cavities. The floor of the oral cavity consists of a mucous membrane covering the mylohyoid muscle and is occupied mainly by the tongue. The lateral walls of the oral cavity are defined by the cheeks and retromolar regions. THE LIP The lips are composed of a muscular skeleton, connective tissue, and is covered externally by skin and internally by a mucous membrane. The red portion of the lip (the vermilion) is a feature characteristic of humans. The sharp junction of the vermilion and the skin is termed the vermilion border THE ORAL VESTIBULE The oral vestibule is a slit-like space between the lips and cheeks, and the teeth and alveolus. The mucosa covering the alveolus is reflected on to the lips and cheeks, forming a trough or sulcus called the vestibular fornix. Distinct sickle-shaped folds running from the cheeks and lips to the alveolus in both maxillary and mandibular areas. These are referred to as labial frena or  THE CHEEKS The cheeks extend intraorally from the labial commissures anteriorly to the ridge of mucosa overlying the ascending ramus of the mandible posteriorly and bounded superiorly and inferiorly by the upper and lower vestibular fornices. The mucosa is nonkeratinised and being tightly adherent to the buccinator muscle, is stretched when the mouth is open and wrinkled when closed. Ectopic sebaceous glands called Fordyce spots are seen as small, yellowish- white spots, occurring singly or in clusters, and may also be seen on the margin of the lips. In the retromolar region, in front of the pillars of the fauces, a fold of mucosa What salivary gland is found in the cheek? The parotid gland! The parotid duct drains into the cheek opposite the maxillary second molar tooth. Its opening may be covered by a small fold of mucosa termed the parotid papilla  THE PALATE It is divided into the immovable hard palate anteriorly and the movable soft palate posteriorly. The hard palate is covered by a masticatory, keratinized mucosa that is firmly bound down to underlying bone and also contains some taste buds. A distinct prominence immediately behind the maxillary central incisors, the incisive papilla overlies the incisive fossa through which the nasopalatine nerves enter on to the palate. Extending posteriorly in the midline from the papilla runs a ridge termed the palatine raphe. Palatine rugae are elevated ridges in the anterior part of the hard palate that radiate transversely from the incisive papilla and the anterior part of the palatine raphe.  THE SOFT PALATE The boundary between the soft palate and the hard palate is readily palpable and may be distinguished by a change in colour, the soft palate having a yellowish tint. Extending laterally from the free border of the soft palate on each side are the palatoglossal and palatopharyngeal folds (pillars of the fauces), the palatoglossal fold being more anterior. The free edge of the soft palate in the midline is termed the palatal uvula. The oropharyngeal isthmus is where the oral cavity and the oropharynx meet. It is delineated by the palatoglossal folds. Two small pits, the fovea palatini, may be seen on either side of the midline; these represent the orifices of ducts from some of the minor mucous glands of the palate.  Add a subheading  Gingiva is the tissue that covers the roots of teeth. It divides into two main portions/sections GINGIVA ALVEOLAR PROPER MUCOSA extends from the neck of teeth covers upper part of bone and to the vestibule up to neck of teeth Attachd gingiva Free gingiva  THE GINGIVA The attached gingiva is firmly bound to the periosteum of the alveolus and to the teeth, and the free gingiva lies unattached around the cervical region of the tooth. A groove (the free gingival groove) may be seen between the free and attached gingivae. This groove corresponds approximately to the floor of the gingival sulcus that separates the inner surface of the attached gingiva from the enamel itself The interdental papilla is that part of the gingiva that fills the space between adjacent teeth.  A – alveolar mucosa B- Free gingival groove C – mucogingival junction D – attached gingiva E – free gingiva F – interdental papilla G – labial frenu  FLOOR OF THE MOUTH The moveable floor of the mouth is a small, horseshoe-shaped region above the mylohyoid muscle and beneath the movable part of the tongue. It is covered by a lining of nonkeratinized mucosa. In the midline, near the base of the tongue, a fold of tissue called the lingual frenum extends onto the inferior surface of the tongue. The sublingual papilla, on to which the submandibular salivary ducts open into the mouth, is a large centrally positioned protuberance at the base of the tongue. On either side of this papilla are the sublingual folds, beneath which lie the submandibular ducts and sublingual salivary glands. a : lingual frenum b fimbriated fold c deep lingual vein d. sublingual papilla e. sublingual fold  THE TOOTH The portion that is visible in the mouth is referred to as clinical crown and the root portion is covered by bone and gingiva. It consists of four main layers each playing a specific role on the tooth.  Layers of the tooth ENAMEL CEMENTUM Hardest tissue in the human body. It is 96% It is covers the roots of teeth and meets inorganic mainly made up hydroxyapatite the enamel at the neck of the tooth. It is crystals. It is formed before teeth erupt and also rich in inorganic crystals and helps lacks nerves or formative cells to protect the tooth from injury DENTINE PULP This tissue forms the bulk of the tooth. It This is soft tissue of the tooth which is consists of dentinal tubules which house protected by dentine. It contains live the extension of cytoplasmic process of cells and will respond to painful stimuli odontoblast. Dentine is avascular. PERIODONTAL LIGAMENT Fibrous connective tissue that anchors tooth to bone.Allows for easy perception of pressue sround the tooth space and has 5 types located in different areas of the tooth. ALVEOLAR BONE Forms sockets which house teeth firmly in the mouth. Buccal and lingual plates form dense plates with spongy bone lying in the inner most area. PRIMARY DENTITION This refers to teeth which are first to erupt. They will fully erupt by age 2 and will remain in the mouth until age 6. It consists of incisors, canines and molars. PERMANENT DENTITION This refers to teeth which will be present up until the time of death. These teeth are larger and begin eruption from age 5/6. Premolars are only found in permanent dentition. FUNCTIONS OF THE MOUTH INGESTION MASTICATION SWALLOWING SPEECH VENTILATION