Protecting All Children’s Teeth Basic Oral Anatomy www.aap.org/oralhealth/pact

Introduction Paper permission on file by Diona Reeves Knowledge of the structures of the mouth, their locations, and nomenclature is important in helping children maintain good oral health. The ability to recognize normal from abnormal and to communicate that information to families and other health professionals will aid in education and provision of care. This PowerPoint will review key anatomic structures in the mouth and typical and atypical development of these structures. www.aap.org/oralhealth/pact

Learner Objectives Paper permission on file by Diona Reeves Upon completion of this presentation, participants will be able to: Recognize and properly label oral anatomic sites. Describe the location of a tooth lesion using the correct tooth name, letter or number designation, and surface label. Recall the layers of a tooth and their basic functions. www.aap.org/oralhealth/pact

Lips The lips form the entryway of the mouth. The following structures underlie the epithelium of the skin of the lips: Vasculature Sweat glands Hair follicles Muscles that function to move the lips Notes: The lips are also known as labia. There are 2 different surfaces of the lip: Skin and the mucous membrane (vermilion border and internal surface). www.aap.org/oralhealth/pact

Lips, continued The mucous membrane of the lips is non-keratinized with many capillary vessels close to the surface, giving it the pinkish/red color. Examination of the lips is valuable in recognizing signs of illness, such as cyanosis, herpetic lesions, or trauma. Glossary: Cyanosis: A bluish or purplish discoloration due to deficient oxygenation of the blood. Used with permission from Martha Ann Keels, DDS, PhD; Division Head of Duke Pediatric Dentistry, Duke Children's Hospital www.aap.org/oralhealth/pact

Cheeks The cheeks form the sides of the mouth. Like the lips, the cheeks are muscles covered with skin on the outside and mucous membranes on the inside. Examination of the oral mucosa is especially important in adolescents who chew tobacco to screen for oral cancer. www.aap.org/oralhealth/pact

Cheeks, continued Along with trauma, you may also note the following: Glossary: Aphthous ulcers: Disintegration and necrosis of epithelial tissue on a mucous membrane. Mucoceles: Swelling like a sac due to distension of a hollow organ or cavity with mucus. Permission from Martha Ann Keels, DDS, PhD; Division Head of Duke Pediatric Dentistry, Duke Children's Hospital Permission from Martha Ann Keels, DDS, PhD; Division Head of Duke Pediatric Dentistry, Duke Children's Hospital Aphthous ulcers Mucoceles www.aap.org/oralhealth/pact

Gums The gingiva (gums) is the mucosal membrane that covers the periodontal ligaments, the alveolar sockets, bones of the jaw, and borders the teeth at their neck. The periodontal ligament is made up of bundles of connective tissue fibers that anchor the teeth within the jaws. As the teeth erupt, ridges of bone called alveolar processes develop around the teeth to provide support. Notes: Within the bones of the jaw are small craters known as the alveolar sockets. www.aap.org/oralhealth/pact

Gums, continued Examination of the gingiva can help reveal gingivitis. If untreated, gingivitis can progress to bone involvement, or periodontitis. Severe periodontitis can lead to tooth loss. Notes: There is increasing medical evidence that periodontal disease can adversely affect other disease processes, such as heart disease and diabetes. Glossary: Gingivitis: Inflammation of the gums. Periodontitis: Inflammation of the periodontium and especially the periodontal membrane. Permission from Noel Childers, DDS, MS, PhD; Department of Pediatric Dentistry, University of Alabama at Birmingham www.aap.org/oralhealth/pact

Palate The palate is the area in the roof of the mouth that starts behind the upper teeth and extends to the uvula. A normal hard palate consists of the fusion of bones in the upper jaw and the palatine bones. The soft palate is mostly muscle and has an important role in swallowing and speech. Examination of the hard and soft palate may uncover thrush. Notes: The palate has 2 discreet sections: the hard palate (anterior two-thirds of the palate) and the soft palate (posterior one-third of the palate). When complete fusion of the hard palate does not occur, a cleft palate results. Because examination of the palate may uncover thrush, it is important to examine these areas in infants. www.aap.org/oralhealth/pact

Tongue The tongue is composed entirely of muscle and connective tissue and has ventral and dorsal surfaces. The ventral surface (underside) is smooth. The dorsal surface (top) is most visible on examination. Notes: The dorsal surface of the tongue is covered with hair-like projections called filiform papillae. Glossary: Fungiform: Any of numerous papillae on the upper surface of the tongue that are flat-topped and noticeably red from the richly vascular stroma and usually contain taste buds. Foliate: Any of the paired oval papillae of the lateral aspect of the posterior part of the tongue that are rudimentary or missing in humans but form the chief organs of taste of some other mammals (eg, rabbits). Circumvallate papillae: Any of approximately 12 large papillae near the back of the tongue; supplied with taste buds responsive especially to bitter flavors. Used with permission from shutterstock.com The dorsal surface includes the fungiform, foliate, and circumvallate papillae, which are associated with the sense of taste. www.aap.org/oralhealth/pact

Floor of the Mouth Beneath the tongue is the floor of the mouth. The frenulum connects the floor of the mouth to the tongue. Notes: The lingual frenulum, or frenum, is normally made up of a thin strip of tissues. In infants, ankyloglossia can lead to difficulty with feeding, especially breastfeeding and this may be an indication for release. Glossary: Ankyloglossia: A congenital defect characterized by limited mobility of the tongue due to shortness of its frenulum. Frenectomy: Excision of a frenulum. Used with permission from Rocio B. Quinonez, DMD, MS, MPH; Associate Professor Department of Pediatric Dentistry, School of Dentistry University of North Carolina A thick frenulum that limits the movement is called ankyloglossia. In cases where breastfeeding is inhibited, a frenectomy may be done to release the tongue. www.aap.org/oralhealth/pact

Salivary Glands Near the frenulum are the tiny openings of the submandibular salivary glands. These openings are called Wharton’s ducts. There are 2 large salivary glands, known as the Parotid glands. These glands empty through tiny holes called Stenson’s ducts. Failure of the Parotid glands to produce saliva leads to xerostomia, an abnormal dryness of the mouth. Notes: The ducts of the sublingual salivary glands are present on either side of the Wharton’s ducts. The Parotid glands are located along the sides of the jaw, just below and in front of the ears, between the masseter muscle and the skin. Stenson's ducts appear as small bumps on the inside of the cheeks near the maxillary second molars. Examination of the Parotid glands might lead to the discovery of inflammation, known as parotitis. www.aap.org/oralhealth/pact

Teeth There are 4 kinds of teeth: 1. Incisors 2. Canines 3. Premolars Used with permission from the American Dental Association www.aap.org/oralhealth/pact

Teeth, continued The 4 front teeth are the central and lateral incisors. Next to the incisors are the cuspids. Next to the cuspids are the 8 premolars, or bicuspids. The final 12 teeth are the molars. The molars have pits and fissures that can harbor cariogenic bacteria and are a common site of dental caries. Notes: There are 2 central and lateral incisors on the top and 2 on the bottom. Cuspids is another name for the canine teeth. The molars are numbered first (6 year), second (12 year), or third (wisdom teeth) molars, depending on their location. Along with naming the primary teeth, dentists give them letters for identification. Permanent teeth are assigned numbers. In children, the tooth farthest back on the upper (maxillary) right is "A" and the last tooth on the lower (mandibular) right is "T". In the permanent teeth, tooth number 1 is the tooth farthest back on the right side of the mouth in the upper (maxillary) jaw and tooth number 32 is farthest back on the bottom (mandibular) right side of the mouth. Used with permission from the American Dental Association www.aap.org/oralhealth/pact

Sides of the Tooth These terms describe the sides of the tooth: Buccal/labial/facial – Side that faces outward, toward the cheeks or lips Lingual/palatal – Inside surface facing the tongue or the palate Mesial - Sides of the teeth that face the front of the mouth Distal - Surfaces of the teeth that face the back of the mouth Occlusal - Surface of the back teeth where biting and chewing takes place  Incisal - Biting surface of the front teeth www.aap.org/oralhealth/pact

Anatomy of a Tooth The tooth consists of a crown and a root. The crown is visible above the gums. The root is covered with cementum, which anchors it to the periodontal membrane. Glossary: Cementum: A specialized external bony layer covering the dentin of the part of a tooth normally within the gum. Used with permission from Miller Medical Illustration & Design www.aap.org/oralhealth/pact

Anatomy of a Tooth, continued The hard, outer surface of the crown is the enamel. The enamel is mostly composed of hydroxyapatite. Binding of fluoride to the hydroxyapatite leads to the formation of fluoroapatite, which makes the enamel harder and more resistant to decay. Notes: The enamel is the hardest substance in the human body. Glossary: Enamel: Intensely hard calcareous substance that forms a thin layer partly covering the teeth; the hardest substance of the animal body; consists of minute prisms arranged at right angles to the surface and bound together by a cement substance. Fluoroapatite: Hard crystalline substance with the formula Ca5(PO4)3F; structural element of tooth enamel. www.aap.org/oralhealth/pact

Anatomy of a Tooth, continued The enamel protects the dentin, a hard, thick substance containing thousands of tubules that surround the nerve. These tubules contain tiny projections of the nerve and are sensitive to exposure to air, acid, and touch. The pulp is the soft core of the tooth that contains blood vessels, connective tissue, and the nerve itself. Glossary: Dentin: A calcareous material similar to bone but harder and denser that composes the principal mass of a tooth; consists of a matrix containing minute parallel tubules which open into the pulp cavity and during life contain processes of the cells of the pulp. Used with permission from the American Dental Association

Question #1 The most common indication to perform a frenectomy (ankyloglossia release) is: A. Prematurity B. Inability to handle introduction of solid foods C. Interference with breastfeeding D. Dysarticulation/speech impediment E. Development of cavities www.aap.org/oralhealth/pact

Answer The most common indication to perform a frenectomy (ankyloglossia release) is: A. Prematurity B. Inability to handle introduction of solid foods C. Interference with breastfeeding D. Dysarticulation/speech impediment E. Development of cavities www.aap.org/oralhealth/pact

Question #2 Which teeth are the most common site for caries? A. Pre-molars B. Incisors C. Molars D. Canines E. None of the above www.aap.org/oralhealth/pact

Answer Which teeth are the most common site for caries? A. Pre-molars B. Incisors C. Molars D. Canines E. None of the above www.aap.org/oralhealth/pact

Question #3 The hard, thick substance of the tooth that surrounds the nerve is known as the: A. Enamel B. Dentin C. Hydroxyapatite D. Cementum E. Pulp www.aap.org/oralhealth/pact

Answer The hard, thick substance of the tooth that surrounds the nerve is known as the: A. Enamel B. Dentin C. Hydroxyapatite D. Cementum E. Pulp www.aap.org/oralhealth/pact

Question #4 Which term describes the sides of the teeth that face the front of the mouth? A. Mesial B. Distal C. Buccal D. Occlusal E. Incisal www.aap.org/oralhealth/pact

Answer Which term describes the sides of the teeth that face the front of the mouth? A. Mesial B. Distal C. Buccal D. Occlusal E. Incisal www.aap.org/oralhealth/pact

Question #5 Which type of papillae is responsible for the sense of taste? A. Fungiform B. Conventrial C. Circumvallate D. Foliate E. Flavial www.aap.org/oralhealth/pact

Answer Which type of papillae is responsible for the sense of taste? A. Fungiform B. Conventrial C. Circumvallate D. Foliate E. Flavial www.aap.org/oralhealth/pact

References 1. Anatomy of orofacial structures. 7th edition. RW Brand and DE Isselhard eds. St Louis. Mosby. 2003. 2. Netter's head and neck anatomy for dentistry. NS Norton. Philadelphia. Saunders Elsevier. 2007. 3. Wheeler's dental anatomy, physiology and occlusion, 8th Edition. MM Ash and SJ Nelson eds. Philadelphia. Saunders. 2003. www.aap.org/oralhealth/pact