Orofacial Anatomy Exam III Review PDF

OROFACIAL ANATOMY EXAM III REVIEW Chapters 6, 8, 32, 33, 34, and 35  TABLE 33.1 Salivary Glands TABLE 33.1 Salivary Glands Name Location Type of Secretion Major Salivary Glands Parotid Anterior...

OROFACIAL ANATOMY EXAM III REVIEW Chapters 6, 8, 32, 33, 34, and 35  TABLE 33.1 Salivary Glands TABLE 33.1 Salivary Glands Name Location Type of Secretion Major Salivary Glands Parotid Anterior ear Serous Submandibular Angle of mandible Mixed serous Sublingual Anterior floor of mouth Mucous Minor Salivary Glands Labial Lips Mixed Buccal Cheeks Mixed Palatine Hard and soft palates Mucous Lingual Anterior tongue Mixed Middle tongue Serous Posterior Mucous  Major Salivary Glands Threepaired glands: parotid, submandibular, and sublingual Produce the bulk of the saliva in the mouth Saliva mixes with food to make it easy to swallow. Begins to break down starches into smaller carbohydrate units Keeps mucosa in the oral cavity from drying out Aids in swallowing and speech Copyright © 2019 by Elsevier, Inc. All rights reserved. 3  Salivary Glands—Generally Controlled by the parasympathetic nervous system Sympathetic nervous system controls blood flow, important in saliva production. Stimulation of the sympathetic nervous system decreases the flow of blood to the glands and slows the production of saliva. Thesmell of food or the presence of something in the mouth will start the glands secreting saliva. Normal amounts of saliva production vary greatly; 4 cups is average Nerve Supply: primarily the seventh cranial nerve Copyright © 2019 by Elsevier, Inc. All rights reserved. 4  Clinical Considerations Salivary stones or a “sialolith” are calcium products formed within salivary glands. Most of these are flushed out by saliva, but if a stone gets too large, it can block the salivary gland. This results in a painful condition wherein when the patient tries to eat, saliva is produced but cannot come out of the blocked salivary duct, so it backs up into the salivary gland. This causes pain when eating or even looking at food. The salivary gland is swollen and painful upon palpation. Surgery may be required if the stone cannot be extracted by milking the duct.  Clinical Considerations Xerostomia (dry mouth) is caused by reduction in saliva production Commonly seen in older individuals and patients “taking certain medications and undergoing cancer treatments (radiation or chemotherapy).” It results in the mouth being dried out and makes eating and swallowing difficult. Teethbecome prone to decay because they have lost the protection afforded by saliva, which cleans their surfaces and dilutes the acids produced by bacteria. Major Salivary Glands— Submandibular (Submaxillary) Gland Provides about 60% to 65% of the total resting salivary volume Mixed gland: Includes both serous and mucous cells. Mucous secretion thicker than serous, slightly viscous Located below and toward the posterior part of the mandible Wrapped around the mylohyoid muscle in the neck Duct extends from deep part of the gland and opens onto the sublingual caruncle, at the base of the lingual frenum. Copyright © 2019 by Elsevier, Inc. All rights reserved. 7  Minor Salivary Glands Similar structure to the major glands Much smaller and less branching Primary differences: size, number of secretory units or acini, and number of ducts Function of the minor glands: to secrete minor amounts of saliva onto the surface to keep the mucosa moist Some are pure serous, most are pure mucous, some are mixed Short ducts, many clusters each with own duct Located: labially, buccally, palatally, glossopalatally, lingually Copyright © 2019 by Elsevier, Inc. All rights reserved. 8 Lymphatic System— Submandibular Nodes Found grouped around submandibular gland, near the angle of the mandible Areas that drain into these nodes: Maxillary teeth (except third molars), maxillary sinus, mandibular canines and all mandibular posterior teeth, floor of mouth, most of the tongue, cheek area, hard palate, anterior nasal cavity, and submental nodes Copyright © 2019 by Elsevier, Inc. All rights reserved. 9  Node Groups Affected by Disease An infection of the third molars may involve these nodes first—the primary group involved. If the infection were in a second mandibular molar, the initial sign of infection would be in the submandibular nodes. If it were not successfully combated there, it would spread secondarily to the superior deep cervical nodes. Copyright © 2019 by Elsevier, Inc. All rights reserved. 10  Lymphatic System A component of the immune system of the body Accumulation of tiny channels or tubules with small nodular structures called lymph nodes interconnecting them Thesystem functions by returning fluids to the bloodstream from the various tissues of the body. Copyright © 2019 by Elsevier, Inc. All rights reserved. 11  Lymphatic System (Cont.) A filtrate of blood plasma flows out of capillaries into surrounding tissues, where it becomes extracellular fluid. It is picked up by lymphatic vessels or tubules: now lymphatic fluid. Flows through tubules into lymph nodes Leavesthe nodes, empties into the venous system, and travels back to the heart Copyright © 2019 by Elsevier, Inc. All rights reserved. 12  Lymphatic System (Cont.) Lymph nodes: filters for the fluids Lymphocytes produced within the lymph nodes combat infections. Most tissues, including the pulp of teeth, have lymph vessels. Copyright © 2019 by Elsevier, Inc. All rights reserved. 13  Lymphatic System— Submental Nodes Found beneath the chin Draininto submandibular nodes or directly into the lower deep cervical nodes Copyright © 2019 by Elsevier, Inc. All rights reserved. 14 Lymphatic System—Diagram Copyright © 2019 by Elsevier, Inc. All rights reserved. 15  Spread of Infection in Fascial Spaces Fascial spaces: Spaces between muscle and tissue layers Infections spread through here. This kind of infection follows certain predictable pathways, depending on its location. Mostdental infections start at apex of a tooth or in the periodontal space around a tooth. Copyright © 2019 by Elsevier, Inc. All rights reserved. 16  Maxillary Infections Maxillary infections react slightly differently. Ifthe infection does not open into the maxillary buccal vestibule or palate, it may spread toward the nasal cavity (rare). maxillary sinus (rare). soft tissue of the cheek (posterior tooth) or below the eye (anterior tooth). Copyright © 2019 by Elsevier, Inc. All rights reserved. 17 Spread of Infection in Fascial Spaces (Cont.) Molar infection: tends to spread to the submental space Willcause Ludwig’s angina: swelling beneath the chin Causes swelling on the side of the neck, if left untreated May spread around the pharynx to its posterior border Copyright © 2019 by Elsevier, Inc. All rights reserved. 18  Ludwig’s Angina Angina means tortured, twisted, or painful. In the case of Ludwig’s angina, it refers to the fact that patients can die from asphyxiation Before the advent of antibiotics Ludwig’s angina was 50% fatal. Even now with antibiotics and surgical intervention the mortality rate is 8%. Ninetypercent of the time Ludwig’s angina is caused by infections from just two teeth, the mandibular second and third molars  Common Carotid Artery (2 of 3) Anterior branches Superior thyroid artery  thyroid gland and larynx Lingual artery  tongue and floor of mouth Facial artery  submandibular salivary gland Medial branches Ascending pharyngeal artery  pharyngeal wall and tonsil area  Common Carotid Artery (3 of 3) Posterior branches Occipital artery  occipital region Posterior auricular artery  area behind ear Final branches Maxillary artery Superficial temporal arteries FIGURE 32.8 The pterygoid plexus of veins just behind the maxillary tuberosity. It may be injured during injection of that area of maxillary molars.  Jugular Veins: Maxillary Vein Formed by intertwining network of veins: the pterygoid plexus of veins Very close to the maxillary tuberosity Riskof piercing the veins exists if the needle is at an improper angle during a posterior superior alveolar nerve block If so, blood escapes into tissues, causing a hematoma Hematoma: swelling and discoloration of area  Maxillary Artery (4 of 10) Inferior alveolar artery with mental branch Runs down to enter the mandibular foramen into the mandibular canal Sends off branches to the mandibular teeth, the periodontal ligaments, and bone Premolar region sends the mental artery branch, then exits from the mandible through the mental foramen Supplies the mandibular buccal gingiva and mucosa from the premolars to the incisors Supplies the mucosa of the mandibular lip and chin  Maxillary Artery (8 of 10) Posterior superior alveolar artery Comes out of the pterygopalatine fossa through the pterygomaxillary fissure, descends onto the maxillary tuberosity, and enters the bone behind the third molar Supplies blood to all maxillary posterior teeth and to part of the maxillary sinus, as well as the posterior buccal mucosa of the upper posterior teeth  Facial Artery (1 of 2) Ascends the side of the neck, runs into the submandibular gland, supplying it, and crosses the lower border of the mandible Atthis point, the artery gives off a submental branch, which runs along the inferior border of the mandible to the chin Aftergiving off this branch, the facial artery and vein cross the mandible It is at this point that you can compress the vessels to act as a pressure point for facial bleeding  Peripheral Nervous System: Cranial Nerves (1 of 6) 12 cranial nerves: attach directly to brain I. Olfactory: sensory, provides sense of smell II. Optic: sensory, provides sense of sight III. Oculomotor: motor, supplies most muscles that move eye in different directions and one that raises the upper eyelid  Peripheral Nervous System: Cranial Nerves (2 of 6) IV. Trochlear: motor, supplies superior oblique muscle, muscle that moves eye downward and laterally V. Trigeminal; motor and sensory Sensory from all teeth, oral cavity, anterior two thirds of tongue, maxillary sinus, nasal cavity, and most of the skin of the front part of the face and head Motor to muscles of mastication, a soft palate muscle (tensor veli palatini), and tensor tympani muscle of middle ear  Peripheral Nervous System: Cranial Nerves (3 of 6) VI. Abducens: motor, supplies the lateral rectus muscle, which moves the eye laterally VII. Facial: motor and sensory Motor to the muscles of facial expression, stylohyoid, posterior belly of digastric muscles, stapedius muscle of the middle ear Bell’s palsy is an unexplained episode of facial muscle weakness or paralysis that results from damage to the facial nerve (the 7th cranial nerve) Parasympathetic to the submandibular and sublingual glands, lacrimal gland of the eye Sensory from areas behind the ear, taste from the anterior two thirds of the tongue  Trigeminal Nerve: Maxillary Division V2 (1 of 4) Branches go to upper teeth, oral cavity, nasal cavity, cheek, midface, and temporal region Has the same names and pathways as the arterial supply to that area Divides into posterior superior alveolar nerve Supplies maxillary buccal gingiva of the premolars and molars Enters bone to supply second and third maxillary molars and the distobuccal and lingual roots of the first maxillary molar Also supplies part of the maxillary sinus  Trigeminal Nerve: Mandibular Division V3 (4 of 5) Inferior alveolar nerve Supplies all lower teeth and their periodontal ligaments Mylohyoid nerve branch: supplies the mylohyoid muscle and the anterior belly of the digastric muscle Mental nerve branch: supplies the mucosa of the lip and the labial gingiva in the anterior mandible area, and the skin of the lower lip and chin  Trigeminal Nerve: Maxillary Division V2 Infraorbital nerve Supplies the skin of the nose, lower eyelid, skin and mucosa of the upper lip, and maxillary labial gingiva Sends two branches to supply rest of maxillary teeth Middle superior alveolar, supplies: Premolars; part of maxillary sinus Mesiobuccal root of maxillary first molar Anterior superior alveolar, supplies: Maxillary anterior teeth Other branches of the maxillary division supply the nasal pharynx  Trigeminal Nerve: Mandibular Division V3 (3 of 5) Lingual nerve Supplies sensation to the floor of the mouth, the lingual mandibular gingivae, and the anterior two thirds of the tongue Chorda tympani: branch from cranial nerve VII Supplies the submandibular and sublingual salivary glands Carries taste perception from the anterior two thirds of the tongue Attachment Unit—Cementum Formed by cementoblasts Has Sharpey’s fibers embedded Bone-like structure Growsby apposition of new layers like bone Copyright © 2019 by Elsevier, Inc. All rights reserved. 34 Attachment Unit— Periodontal Ligament (PDL) Surrounds the tooth Helps to hold it in alveolar bone Suspends the tooth like a hammock in the socket Tinymeshwork of collagenous connective fibers Prevents tooth from being pushed into bone Minimizes the trauma of teeth being pushed together Adaptability and versatility of the PDL make orthodontics possible. Awidened PDL on a radiograph could indicate tooth mobility and/or trauma Copyright © 2019 by Elsevier, Inc. All rights reserved. 35  Position and Sequence of Eruption (Cont.) Diastemae—spaces created when the dental arches grow but teeth stay the same size Normal part of growth process Primate spaces—large spaces sometimes found mesial to maxillary primary canines and distal to mandibular canines Copyright © 2019 by Elsevier, Inc. All rights reserved. 36  Centric Occlusion Determinedby the way teeth fit together when the jaws are closed Allowsthe greatest interdigitation of teeth Related to tooth occlusion Not determined by muscle or bone Other names: Acquired centric occlusion Habitual occlusion Convenience occlusion Intercuspal position Copyright © 2019 by Elsevier, Inc. All rights reserved. 37  Skeletal Classification Three classes Class I: The maxilla and mandible are in normal relationship to each other. Class II: The mandible is retruded. Distal relationship with the maxilla Class III: The mandible is protruded. Mesialrelationship with the maxilla Copyright © 2019 by Elsevier, Inc. All rights reserved. 38 Overjet, Overbite, and Crossbite Crossbite When one or more teeth in the mandibular arch are located facial to their maxillary counterparts Copyright © 2019 by Elsevier, Inc. All rights reserved. 39 Dental Classification (Cont.) Molar Classification Class I: Occlusal Relationship (Neutroclusion) Facial profile: mesognathic Copyright © 2019 by Elsevier, Inc. All rights reserved. 40 Dental Classification (Cont.) Molar Classification Class II: Occlusal Relationship (Distoclusion) Facial profile: retrognathic Division I: Permanent first molars in Class II, maxillary central incisors in normal position Division II: Permanent first molars in Class II, maxillary central incisors retruded and inclined lingually Copyright © 2019 by Elsevier, Inc. All rights reserved. 41 Dental Classification (Cont.) Molar Classification Class III: Occlusal Relationship (Mesioclusion Facial profile: prognathic Copyright © 2019 by Elsevier, Inc. All rights reserved. 42 Vertical Alignment Mandibular posterior teeth Crowns tip lingually Roots tip laterally Copyright © 2019 by Elsevier, Inc. All rights reserved. 43 Overjet, Overbite, and Crossbite Overjet The amount of facial horizontal overlap of maxillary teeth Copyright © 2019 by Elsevier, Inc. All rights reserved. 44  Buccoverted -displacement of a tooth from the normal line of occlusion toward the cheek. Infraverted - Lower than rest of teeth Linguoverted-displacement of a tooth to the lingual side of its proper occlusal position. Supraverted - Higher than rest of teeth Torsoversed (torsiversion) - the rotation of a tooth on its long axis