A physician should always examine the mouth and be able to recognize oral pathology. However, consultation with a dentist is needed for patients with tooth problems and for those with xerostomia (see Approach to the Patient With Nasal, Oral, and Pharyngeal Symptoms: Xerostomia) or unexplained swelling or pain in the mouth, face, or neck. Children with abnormal facies (who may also have dental malformations requiring correction) should also be evaluated by a dentist. In FUO or a systemic infection of unknown cause, a dental disorder should be considered. A dental consultation is necessary before head and neck radiation therapy and is advisable before chemotherapy.

A dentist should consult a physician when a systemic disorder is suspected, when the patient is taking certain drugs (eg, warfarin), and when a patient's ability to withstand general anesthesia or extensive oral surgery must be evaluated. Patients with heart valve abnormalities typically require antibiotic prophylaxis before undergoing certain dental procedures.

Common dental disorders are discussed in Common Dental Disorders. Dental emergencies, including toothache, are discussed in Dental Emergencies.

Anatomy and Development

Teeth

The teeth are categorized as incisors, canines, premolars, and molars and conventionally are numbered beginning with the maxillary right 3rd molar (see Fig. 1: Approach to the Dental Patient: Identifying the teeth.).

Fig. 1
Identifying the teeth. The numbering system shown is the one most commonly used in the US.

Each tooth has a crown and a root. The canines have the largest and strongest roots. An inner pulp contains blood vessels, lymphatics, and nerves, surrounded by the hard but porous dentin, a very hard enamel coating above the root, and the bonelike cementum over the root, which is usually covered by gingiva (see Fig. 2: Approach to the Dental Patient: Section of a canine tooth.). Twenty deciduous teeth normally begin appearing at close to age 6 mo and should all be in place by age 30 mo (see Table 1: Physical Growth and Development: Tooth Eruption Times). These teeth are followed by 32 permanent teeth that begin to appear by about age 6. The period from age 6 to 11 is called the mixed dentition stage, in which both deciduous and permanent teeth are present. Timing of tooth eruption is one indicator of skeletal age and may identify growth retardation or establish age for forensic purposes.

Fig. 2
Section of a canine tooth.

Supporting tissues

The gingiva surrounds the teeth at the base of their crowns. The alveolar ridges are trabecular bone containing sockets for the teeth. The periodontium consists of the tissues that support the teeth—the gingiva, epithelial attachment, connective tissue attachment, periodontal ligament, and alveolar bone. The mandible and maxilla support the alveolar ridges and house the teeth. Saliva from the salivary glands bathes and protects the teeth. The tongue directs food between the grinding surfaces and helps clean the teeth. The maxilla receives innervation from the maxillary nerve, the 2nd division of the trigeminal nerve (the 5th cranial nerve). The mandibular nerve, which is the 3rd and most inferior division of the trigeminal nerve, innervates the mandible.

In the elderly, or in the case of some periodontal diseases, gingival recession exposes the dental root adjacent to the crown, making root caries common. If tooth destruction results, the mechanical stimulation necessary for maintaining bone integrity ceases. Consequently, atrophy of the alveolar ridge (senile atrophy) begins as soon as teeth are lost.

Gingival Recession

Evaluation

The first routine dental examination should take place by age 1 yr or when the first tooth erupts. Subsequent evaluations should take place at 6-mo intervals or whenever symptoms develop.

History

Important dental symptoms include bleeding, pain, malocclusion, new growths, and chewing problems.

Bleeding or pain with brushing usually suggests localized periodontal problems, such as gingivitis or, rarely, acute necrotizing ulcerative gingivitis. However, easily induced gingival hemorrhaging may also indicate a bleeding diathesis or leukemia.

Face, head, or neck pain can indicate infection, malocclusion, poorly fitting dental appliances, temporomandibular disorders, Eagle's syndrome (elongation of the styloid process or ossification of the stylohyoid ligament causing pain when the head is turned), spasm of the masticatory muscles (see Temporomandibular Disorders: Myofascial Pain Syndrome), or occult lesions with low-grade anaerobic infections spreading to the bone. Pain referred to the ear may arise from an inflamed gingival flap around a partly erupted mandibular 3rd molar (pericoronitis) or from a localized osteitis (dry socket) after a lower molar is extracted.

Facial numbness or paresthesias may be due to a tumor of the antrum or nasopharynx, stroke, tumors involving the brain stem, viral infection, or multiple sclerosis. Paresthesia of the lower lip may result from extraction of a mandibular molar causing damage to the inferior alveolar nerve. Rarely, it indicates an oral tumor.

Masticatory fatigue may be caused by a congenital muscular or neuromuscular disorder in younger people or by poorly occluding artificial dentures in older people. It is a cardinal symptom of myasthenia gravis. Pain with mastication (jaw claudication) may indicate polymyalgia rheumatica or giant cell (temporal) arteritis.

Weight loss can result from an oral or dental problem. For example, a person may be unable to chew food well because of too loose, too few, or painful teeth; poorly fitting dental appliances; stomatitis; or a temporomandibular disorder.

Physical examination

Inspection of soft tissues in the mouth (see Approach to the Patient With Nasal, Oral, and Pharyngeal Symptoms: Physical examination), including gingiva and mucous membranes, may reveal inflammation, exudates, vesicles, tumors, ulcers, or red or white patches as evidence of local or systemic disease.

Teeth are inspected for shape, alignment, defects, mobility, color, and presence of adherent plaque, materia alba (dead bacteria, food debris, desquamated epithelial cells), and calculus. They are gently tapped with a tongue depressor or mirror handle to assess tenderness (percussion sensitivity).

Tenderness to percussion suggests deep caries that has caused a necrotic pulp with periapical abscess or severe periodontal disease. Percussion sensitivity or pain on biting can also indicate an incomplete fracture of a tooth. Percussion tenderness in multiple adjacent maxillary teeth may result from maxillary sinusitis. Tenderness to palpation around the apices of the teeth may also indicate an abscess.

Loose teeth usually indicate severe periodontal disease but can be caused by bruxism or trauma that damages periodontal tissues. Rarely, teeth become loose when alveolar bone is eroded by an underlying mass (eg, ameloblastoma, eosinophilic granuloma). A tumor or systemic cause of alveolar bone loss (eg, diabetes mellitus, hyperparathyroidism, osteoporosis, Cushing's syndrome) is suspected when teeth are loose and heavy plaque and calculus are absent.

Calculus (tartar) is mineralized bacterial plaque—a concretion of bacteria, food residue, saliva, and mucus with Ca and phosphate salts. After a tooth is cleaned, a mucopolysaccharide coating (pellicle) is deposited almost immediately. After about 24 h, bacterial colonization turns the pellicle into plaque. After about 72 h, the plaque calcifies, becoming calculus. When present, calculus is deposited most heavily on the lingual (inner, or tongue) surfaces of the mandibular anterior teeth near the submandibular and sublingual duct orifices (Wharton's ducts) and on the buccal (cheek) surfaces of the maxillary molars near the parotid duct orifices (Stensen's ducts).

Caries (tooth decay—see Common Dental Disorders: Caries) appears as defects in the tooth enamel. Caries first appears as white spots, later becoming brown.

Attrition (wearing of biting surfaces) can result from chewing abrasive foods or tobacco or from the wear that accompanies aging, but it usually indicates bruxism (clenching or grinding of teeth—see Approach to the Dental Patient: Bruxism). Another common cause is abrasion of a porcelain crown against adjacent enamel. Attrition makes chewing less effective and causes noncarious teeth to become painful when the eroding enamel exposes the underlying dentin. Dentin is sensitive to touch and to temperature changes. A dentist can desensitize such teeth or restore the dental anatomy by placing crowns or onlays over badly worn teeth.

Deformed teeth may indicate a developmental or endocrine disorder. In Down syndrome, teeth are small. In congenital syphilis, the incisors may be small at the incisal third, producing a pegged or screwdriver shape with a notch in the center of the incisal edge (Hutchinson's incisors), and the 1st molar is small, with a small occlusal surface and roughened, lobulated, often hypoplastic enamel (mulberry molar). In ectodermal dysplasia, teeth are absent or conical, so that dentures are needed from childhood. Dentinogenesis imperfecta, an autosomal dominant disorder, produces abnormal dentin that is dull bluish brown and opalescent and does not cushion the overlying enamel adequately. Such teeth cannot withstand occlusal stresses and rapidly become worn. People with pituitary dwarfism or with congenital hypoparathyroidism have small dental roots; people with gigantism have large ones. Acromegaly produces excess cementum in the roots as well as enlargement of the jaws, so teeth may become widely spaced. Congenitally narrow lateral incisors occur in the absence of systemic disease. The most commonly congenitally absent teeth are the 3rd molars, followed in frequency by the maxillary lateral incisors and 2nd mandibular premolars.

Defects in tooth color must be differentiated from the darkening or yellowing that occurs from food pigments, with aging, and, most prominently, with smoking. A tooth may appear gray because of pulpal necrosis, usually due to extensive caries penetrating the pulp or because of hemosiderin deposited in the dentin after trauma, with or without pulpal necrosis. Children's teeth darken appreciably and permanently after even short-term use of tetracyclines by the mother during the 2nd half of pregnancy or by the child during odontogenesis (tooth development), specifically calcification of the crowns, which lasts until age 9. Tetracyclines rarely cause permanent discoloration of fully formed teeth in adults. However, minocycline darkens bone, which can be seen in the mouth when the overlying gingiva and mucosa are thin. Affected teeth fluoresce with distinctive colors under ultraviolet light corresponding to the specific tetracycline taken. In congenital porphyria, both the deciduous and permanent teeth may have red or brownish discoloration but always fluoresce red from the pigment deposited in the dentin. Congenital hyperbilirubinemia causes a yellowish tooth discoloration. Teeth can be whitened (see Table 1: Approach to the Dental Patient: Tooth Whitening Procedures).

Table 1
Tooth Whitening Procedures Who Performed by Ingredients Comments Dentist     In office Concentrated hydrogen peroxide is applied to teeth, to which a light or laser is applied Very effective. Gingiva, skin, and eyes must be protected At home Custom-made trays are used, to which the patient adds 6% carbamide peroxide (becomes 3% hydrogen peroxide when applied) and a thickening agent containing copolymers of acrylic acid cross-linked with a polyalkenyl polyether Very effective Patient (OTC products)     Commercial whitening strips Composed of carbamide peroxide Very effective Whitening toothpaste Usually contain carbamide or hydrogen peroxide Moderately effective Paint-on whitening Usually composed of titanium dioxide Not very effective

Defects in tooth enamel may be caused by rickets, which results in a rough, irregular band in the enamel. Any prolonged febrile illness during odontogenesis can produce a permanent narrow zone of chalky, pitted enamel or simply white discoloration visible after the tooth erupts. Thus, the age at which the disease occurred and its duration can be estimated from the location and height of the band. Amelogenesis imperfecta, an autosomal dominant disease, causes severe enamel hypoplasia. Chronic vomiting and esophageal reflux decalcify the dental crowns, primarily the lingual surfaces of the maxillary anterior teeth. Chronic snorting of cocaine can result in widespread decalcification of teeth, because the drug dissociates in saliva into a base and hydrochloride.

Swimmers who spend a lot of time in overchlorinated pools lose considerable amounts of enamel from the outer facial (buccal) sides of the teeth, especially the maxillary incisors, canines, and 1st premolars. If Na carbonate has been added to the pool water to correct pH, then brown calculus deposits form but can be removed by dental cleanings.

Fluorosis is mottled enamel that may develop in children who drink water containing > 1 ppm of fluoride during tooth development. Fluorosis depends on the amount of fluoride ingested. Enamel changes range from irregular whitish opaque areas to severe brown discoloration of the entire crown with a roughened surface. Such teeth are highly resistant to dental caries.

Testing

For a new patient or for someone who requires extensive care, a full mouth x-ray series is taken. This series consists of 14 to 16 periapical films to show the roots and bone plus 4 to 7 bite-wing films to check for caries between teeth. Modern techniques reduce radiation exposure to a near-negligible level. Patients at high risk of caries (ie, those who have had caries detected during the clinical examination, have many restorations, or have recurrent caries on teeth previously restored) should undergo bite-wing x-rays q 12 to 18 mo. Otherwise, bite-wings are indicated q 2 to 3 yr. A panoramic x-ray can yield useful information about tooth development, cysts or tumors of the jaws, supernumerary or congenitally absent teeth, 3rd molar impaction, Eagle's syndrome (less frequently), and, incidentally, carotid plaques.

Dental Care of Patients With Systemic Disorders

Certain medical conditions (and their treatment) predispose patients to dental problems or affect dental care.

Hematologic disorders

People who have disorders that interfere with coagulation (eg, hemophilia, acute leukemia, thrombocytopenia) require medical consultation before undergoing dental procedures that might cause bleeding (eg, extraction, mandibular block). Hemophiliacs should have clotting factors administered before, during, and after an extraction. Such oral surgery should be performed in the hospital in consultation with a hematologist. All patients with bleeding disorders should maintain a lifelong routine of regular dental visits, which includes cleanings, fillings, topical fluoride, and preventative sealants, to avoid extractions.

Cardiovascular disorders

After an MI, dental procedures should be avoided for 6 mo, if possible. Patients with pulmonary or cardiac disease who require inhalation anesthesia for dental procedures should be hospitalized.

Endocarditis prophylaxis is required for dental procedures in patients with congenital defects of the heart or great vessels, valvular disease (including mitral valve prolapse), hypertrophic cardiomyopathy, or a prosthetic cardiac valve. The heart is better protected against low-grade bacteremias, which occur in chronic dental conditions, when dental treatment is received (with prophylaxis) than when it is not received. Although probably of marginal benefit, antibiotic prophylaxis is sometimes recommended for patients with hemodialysis shunts and within 2 yr of receipt of a major prosthetic joint (hip, knee, shoulder, elbow).

Epinephrine and levonordefrin are added to local anesthetics to increase the duration of anesthesia. In some cardiovascular patients, these drugs cause arrhythmias, myocardial ischemia, or hypertension. Plain anesthetic is used for procedures lasting < 60 min, but in longer procedures or where hemostasis is needed, up to 0.04 mg epinephrine (2 dental cartridges with 1:100,000 epinephrine) is considered safe. Generally, no healthy patient should receive > 0.2 mg epinephrine at any one appointment. Absolute contraindications to epinephrine (any dose) are uncontrolled hyperthyroidism, pheochromocytoma, blood pressure > 200 systolic or > 115 diastolic, uncontrolled arrhythmias despite drug therapy, and unstable angina, MI, or stroke within 6 mo.

Some electrical dental equipment, such as an electrosurgical cautery, a pulp tester, or an ultrasonic scaler, can interfere with early-generation pacemakers.

Cancer

Extracting a tooth adjacent to a carcinoma of the gingiva, palate, or antrum facilitates invasion of the alveolus (tooth socket) by the tumor. Therefore, a tooth should be extracted only during the course of definitive treatment. In patients with leukemia or agranulocytosis, infection may follow an extraction despite the use of antibiotics.

Immunosuppression

People with impaired immunity are prone to severe mucosal and periodontal infections by fungi, herpes and other viruses, and, less commonly, bacteria. The infections may produce hemorrhage, delayed healing, or sepsis. Dysplastic or neoplastic oral lesions may develop after a few years of immunosuppression. People with AIDS may develop Kaposi's sarcoma, non-Hodgkin lymphoma, hairy leukoplakia, candidiasis, aphthous ulcers, or a rapidly progressive form of periodontal disease.

Endocrine disorders

Dental treatment may be complicated by the presence of some endocrine disorders. For example, people with hyperthyroidism may develop tachycardia and excessive anxiety as well as thyroid storm if given epinephrine. Insulin requirements may be reduced upon elimination of oral infection in diabetics; insulin dose may require reduction when food intake is limited because of pain after oral surgery. In people with diabetes, hyperglycemia with resultant polyuria may lead to dehydration, resulting in decreased salivary flow (xerostomia), which, along with elevated salivary glucose levels, contributes to caries.

Patients receiving corticosteroids and those with adrenocortical insufficiency may require supplemental corticosteroids during major dental procedures. Patients with Cushing's syndrome or who are taking corticosteroids may have alveolar bone loss, delayed wound healing, and increased capillary fragility.

Neurologic disorders

Patients with seizures who require dental appliances should have nonremovable appliances that cannot be swallowed or aspirated. Patients unable to brush or floss effectively may use chlorhexidine rinses in the morning and at bedtime.

Drugs

Certain drugs, such as corticosteroids, immunosuppressants, and antineoplastics, compromise healing and host defenses. When possible, dental procedures should not be performed while these drugs are being given.

Some antineoplastics (eg, doxorubicin, 5-fluorouracil, bleomycin, dactinomycin, cytosine, arabinoside, methotrexate) cause stomatitis, which is worse in patients with preexisting periodontal disease. Before such drugs are prescribed, oral prophylaxis should be completed, and patients should be instructed in proper tooth brushing and flossing.

Drugs that interfere with clotting may need to be reduced or stopped before surgery. Patients taking aspirin, NSAIDs, or clopidogrel should stop doing so 4 days before undergoing dental surgery and can resume taking these drugs the day after bleeding stops. Warfarin should be stopped 2 to 3 days before oral surgery. PT is obtained; INR of 1.5 is considered safe for surgery. For people receiving hemodialysis, dental procedures should be performed the day after dialysis, when heparinization has subsided.

Radiation Therapy

Caution: Extraction of teeth from irradiated tissues (particularly if the total dose was > 65 Gy, especially in the mandible) is commonly followed by osteoradionecrosis of the jaw. This is a catastrophic complication in which extraction sites break down, frequently sloughing bone and soft tissue. Thus, if possible, patients should have any necessary dental treatment completed before undergoing radiation therapy of the head and neck region, with time allowed for healing. Teeth that may not survive should be extracted. Necessary sealants and topical fluoride should be applied. After radiation, extraction should be avoided, if possible, with the use of dental restorations and root canal treatment.

Head and neck radiation often damages salivary glands, causing xerostomia, which promotes caries. Patients must therefore practice lifelong good oral hygiene. A fluoride gel and fluoride mouth rinse should be used daily. Rinsing with 0.12% chlorhexidine for 30 to 60 sec, if tolerated, can be done in the morning and at bedtime. Viscous lidocaine may enable a patient with sensitive oral tissues to brush and floss the teeth and eat. A dentist must be seen at 3-, 4-, or 6-mo intervals, depending on findings at the last examination. Irradiated tissue under dentures is likely to break down, so dentures should be checked and adjusted whenever discomfort is noted. Irradiated patients may develop oral mucosal inflammation and diminished taste as well as trismus due to fibrosis of the masticatory muscles. Trismus may be minimized by such exercises as opening and closing the mouth widely 20 times 3 or 4 times/day. If extraction is required after radiation, 10 to 20 treatments in a hyperbaric oxygen chamber may forestall or prevent osteoradionecrosis.

Last full review/revision November 2005