Pretreatment Evaluation in Dentistry
A complete guide to patient history, examination, diagnostic testing, oral disease recognition, and safe treatment planning.
- Establishment of a diagnosis.
- Determination of underlying medical conditions that may modify the oral condition or the patient’s ability to tolerate treatment.
- Discovery of concomitant illnesses.
- Prevention of medical emergencies associated with dental treatment.
- Establishment of rapport with the patient.
- Chief complaint
- History of the present illness
- Past medical history
- Social history
- Family history
- Review of systems
- Dental history
The chief complaint is the reason that the patient seeks care, as described in the patient’s own words.
The history of the present illness is a chronologic description of the patient’s symptoms. It should include information about duration, location, character, and previous treatment.
- Current status of the patient’s general health
- Medications
- Hospitalizations
- Allergies
- Present and past occupations
- Occupational hazards
- Smoking, alcohol, or drug use
- Marital status
The family history often provides information about diseases of genetic origin or diseases that have a familial tendency. Examples include clotting disorders, atherosclerotic heart disease, psychiatric diseases, and diabetes mellitus.
The medical history is most often obtained with a written questionnaire supplemented by a verbal history. The verbal history is imperative because patients may leave out or misinterpret questions on the written form.
For example, some patients may take daily aspirin and yet not consider it a “true” medication. The verbal history also allows the clinician to pursue positive answers on the written form and, in doing so, establish rapport with the patient.
Inspection is the most commonly used technique and is based on visual evaluation of the patient.
Palpation involves touching and feeling the patient. It is used to determine the consistency and shape of masses in the mouth or neck.
Percussion involves differences in sound transmission of structures. It has little application to the head and neck.
Auscultation is the technique of listening to differences in the transmission of sound, usually with a stethoscope. In dentistry, it is most typically used to listen to changes in sounds from the temporomandibular joint and to take a patient’s blood pressure.
- Blood pressure
- Pulse
- Respiratory rate
- Temperature
- Blood pressure: 120/80 mmHg
- Pulse: 72 beats per minute
- Respiratory rate: 16–20 respirations per minute
- Temperature: 98.6°F or 37°C
A complete blood count consists of a determination of the patient’s hemoglobin, hematocrit, white blood cell count, and differential white blood cell count.
| Test | Normal range |
|---|---|
| Hemoglobin | Men: 14–18 g/dL; Women: 12–16 g/dL |
| Hematocrit | Men: 40–54%; Women: 37–47% |
| White blood cell count | 4,000–10,000 cells/mm³ |
| Neutrophils | 50–70% |
| Lymphocytes | 30–40% |
| Monocytes | 3–7% |
| Eosinophils | 0–5% |
| Basophils | 0–1% |
The most effective screen for diabetes mellitus is fasting blood sugar.
With few exceptions, biopsy is the diagnostic technique of choice for virtually all soft-tissue lesions of the mouth.
Exfoliative cytology may be used as a screening technique for oral lesions. This technique is analogous to the Papanicolaou smear used to screen for cervical cancer.
Unfortunately, a high rate of false negatives makes exfoliative cytology a dangerous practice in the screening of suspected oral cancers. It has value mainly in the diagnosis of certain viral, fungal, and vesiculobullous diseases.
Immunofluorescent techniques are of value in the diagnosis of a number of autoimmune diseases that affect the mouth, including pemphigus vulgaris and mucous membrane pemphigoid.
- Past dental visits, including frequency, reasons, previous treatment, and complications
- Oral hygiene practices
- Oral symptoms other than those associated with the chief complaint, including tooth pain or sensitivity, gingival bleeding or pain, tooth mobility, halitosis, and abscess formation
- Past dental or maxillofacial trauma
- Habits related to oral disease, such as bruxing, clenching, and nail biting
- Dietary history
Bacterial infection
Because the overwhelming majority of oral infections are sensitive to treatment with penicillin, routine bacteriologic culture of primary dental infections is not generally indicated.
However, cultures are indicated in patients who are immunocompromised or myelosuppressed for two reasons: they are at significant risk for sepsis, and the oral flora often change in such patients. Cultures should also be obtained for infections that are refractory to the initial course of antibiotics before changing antibiotics.
Viral infection
Immunocompromised patients who present with mucosal lesions may be manifesting herpes simplex infection, and a viral culture is warranted. Other viruses in the herpes family, such as cytomegalovirus, may also cause oral lesions in immunocompromised patients and should be isolated if possible.
Routine culturing for primary or secondary herpes infections is not warranted in healthy patients.
Fungal infection
Candidiasis is the most common fungal infection affecting the oral mucosa. Because its appearance is often varied, especially in immunocompromised patients, fungal cultures are often of value.
In addition, because candidal infection is a frequent cause of burning mouth, culture is often indicated in immunocompromised patients even in the absence of visible lesions.
It is easy to obtain laboratory tests for patients, even outside a hospital setting. Community hospitals provide virtually all laboratory services that patients may require.
Usually, the laboratory provides order slips and culture tubes. The clinician indicates the test needed and sends the patient to the laboratory. Patients who need a test at night or on a weekend can generally be accommodated through the hospital’s emergency department.
Commercial laboratories may also be used. They supply order forms, and if a practice is located in a medical building with physicians, it is useful to determine which laboratory they use. If they use a commercial laboratory, a specimen pick-up service may be available.
| Test | Approximate cost |
|---|---|
| Complete blood count | $18 |
| Platelet count | $18 |
| Prothrombin time | $29 |
| Fasting glucose | $13 |
| Bacterial culture | $32 |
| Fungal culture | $42 |
Halitosis may be caused by local factors in the mouth and by extraoral or systemic factors.
Local factors
- Food retention
- Periodontal infection
- Caries
- Acute necrotizing gingivitis
- Mucosal infection
Extraoral and systemic causes
- Smoking
- Alcohol ingestion
- Pulmonary or bronchial disease
- Metabolic defects
- Diabetes mellitus
- Sinusitis
- Tonsillitis
- Infectious and inflammatory diseases of all types. Common oral conditions causing lymphadenopathy include herpes infections, pericoronitis, aphthous or traumatic ulceration, and acute necrotizing ulcerative gingivitis.
- Immunologic diseases, such as rheumatoid arthritis, systemic lupus erythematosus, and drug reactions.
- Malignant disease, such as Hodgkin’s disease, lymphoma, leukemia, and metastatic disease from solid tumors.
- Hyperthyroidism.
- Lipid storage diseases, such as Gaucher’s disease and Niemann-Pick disease.
- Other conditions, including sarcoidosis, amyloidosis, and granulomatosis.
- Onset and duration: Inflammatory nodes tend to have a more acute onset and course than nodes associated with tumor.
- Identification of an associated infected site: An identifiable site of infection associated with an enlarged lymph node is probably the source of the lymphadenopathy. Effective treatment of the site should result in resolution of the lymphadenopathy.
- Symptoms: Enlarged lymph nodes associated with an inflammatory process are usually tender to palpation. Nodes associated with tumor are not.
- Progression: Continuous enlargement over time is associated with tumor.
- Fixation: Inflammatory nodes are usually freely movable, whereas nodes associated with tumor are hard and fixed.
- Lack of response to antibiotic therapy: Continued nodal enlargement in the face of appropriate antibiotic therapy should be viewed as suspicious.
- Distribution: Unilateral nodal enlargement is a common presentation for malignant disease. In contrast, bilateral enlargement is often associated with systemic processes.
The most appropriate technique for lymph node diagnosis is biopsy or needle aspiration. Needle aspiration is preferred but is technique-sensitive.
The most frequent causes of intraoral swelling are infection and tumor.
Too many crackers.
Infection of viral or bacterial origin is the most common cause of parotitis in humans. Viruses causing parotitis include mumps, Coxsackie virus, and influenza.
Staphylococcus aureus, the most common bacterial cause of parotitis, results in the production of pus within the gland. Other bacteria, such as Actinomyces, streptococci, and gram-negative bacilli, may also cause suppurative parotitis.
- Advanced age
- Certain medications
- Radiation therapy
- Sjögren’s syndrome
The typical patient with a parotid gland tumor presents with a firm, fixed mass in the region of the gland. Involvement of the facial nerve is common and results in facial palsy.
Fine-needle biopsy is a commonly used technique for diagnosis. However, the small sample obtained by this technique may be limiting. CT and MRI are also often helpful in evaluating suspected tumors.
Tobacco and alcohol use are the major risk factors for the development of oral cancer.
Toluidine blue is a metachromatic nuclear stain. It has been reported to be preferentially absorbed by dysplastic and cancerous epithelium.
Consequently, it has been used as a technique to screen oral lesions. The technique has a reported false-positive rate of 9% and a false-negative rate of 5%.
The two most common clinical presentations for oral cancer are a nonhealing ulcer or an area of leukoplakia, often accompanied by erythema.
Approximately 10% of such oral lesions are dysplastic or cancerous.
Necrotic lesions of the mucosa, such as those caused by burns or candidal infections, scrape off when gently rubbed with a moist tongue blade.
Keratotic lesions result from epithelial changes, so scraping fails to dislodge them.
Virtually all ulcers caused by trauma or aphthous stomatitis heal within 14 days of presentation. Consequently, any ulcer that is present for two weeks or more should be biopsied.
- Traumatic ulcer
- Aphthous stomatitis
- Cancer
- Tuberculosis
- Chancre of syphilis
- Noma
- Necrotizing sialometaplasia
- Deep fungal infection
Pigmented lesions may be vascular in nature. Prebiopsy aspiration is prudent to prevent hemorrhage.
Pigmented lesions are due to either endogenous or exogenous sources.
Endogenous sources
- Melanoma
- Endocrine-related pigmentation, such as occurs in Addison’s disease
- Perioral pigmentation associated with intestinal polyposis or Peutz-Jeghers syndrome
Exogenous sources
- Heavy metal poisoning, such as lead
- Amalgam tattoos
- Changes caused by chemicals or medications
A common example of medication-related change is black hairy tongue associated with antibiotics, particularly bismuth-containing compounds such as Pepto-Bismol.
Numerous diseases can cause simultaneous lesions of the mouth and skin. Among the most common are lichen planus, erythema multiforme, lupus erythematosus, bullous pemphigoid, and pemphigus vulgaris.
The skin lesion of erythema multiforme looks like an archery target, with a central erythematous bullseye and a circular peripheral area. Hence, the lesions are called bullseye or target lesions.
Spontaneous bleeding, especially in the face of good oral hygiene, is most likely of systemic origin. Gingival bleeding is among the most common presenting signs of acute leukemia, which should be high on the differential diagnosis.
A complete blood count and platelet count should provide data to help establish a preliminary diagnosis. Definitive diagnosis most likely requires a bone marrow biopsy.
The combination of polyuria, polyphagia, polydipsia, and suppurative periodontal disease should raise strong suspicion of diabetes mellitus.
A fasting blood glucose test is the most efficacious screen.
The mandible is not an infrequent site for metastatic breast cancer. As the metastatic lesion grows, it puts pressure on the inferior alveolar nerve and causes paresthesia.
Radiographic evaluation of the jaw is a reasonable first step to make a diagnosis.
Pigmented lesions of the oral mucosa may suggest Addison’s disease.
- Phenytoin
- Cyclosporine
- Nifedipine
The oral lesions of tuberculosis are thought to result from organisms brought into contact with the oral mucosa by sputum.
A nonhealing ulcer, which is impossible to differentiate clinically from carcinoma, is the most common presentation in the mouth. Ulcers are most consistently present on the lateral borders of the tongue and may have a purulent center. Lymphadenopathy may also be present.
Diagnosis is made by histologic examination and demonstration of organisms in the tissue.
The most common target site in the mouth is the tongue, which presents with a smooth dorsal surface denuded of papillae. Angular cheilitis is a frequent accompanying finding.
Angular cheilitis, or cheilosis, is fissuring or cracking at the corners of the mouth.
The condition typically occurs because of a localized mixed infection of bacteria and fungi. Cheilitis most commonly results from a change in the local environment caused by excessive saliva due to loss of the vertical dimension between the maxilla and mandible.
Systemic conditions, such as deficiency anemias and long-term immunosuppression, may also predispose to the condition.
Mucosal lesions with a cobblestone appearance are associated with Crohn’s disease.
- Xerostomia
- Cervical and incisal edge caries
- Osteoradionecrosis
- Mucositis
Cancer chemotherapy nonspecifically affects the bone marrow, so the patient is likely to be myelosuppressed after treatment.
Therefore, both the patient’s white blood cell count and platelet count must be known before initiating treatment.
Lichen planus has been associated with hydrochlorothiazide.
Because of its acidity, topical application of aspirin to the mucosa frequently causes a chemical burn. This appears as a white, necrotic lesion in the area corresponding to aspirin placement.
- Dry mouth
- Nutritional deficiencies
- Diabetes mellitus
- Psychogenic factors
- Medications
- Acid reflux from the stomach
- Hormonal imbalances
- Allergy
- Chronic infections, especially fungal infections
- Blood dyscrasias
- Anemia
- Iatrogenic factors
- Inflammatory conditions, such as lichen planus
The most important goal in evaluating a taste disorder is the elimination of an underlying neurologic, olfactory, or systemic disorder as the cause of the condition.
- Metronidazole
- Benzocaine
- Ampicillin
- Tetracycline
- Sodium lauryl sulfate toothpaste
- Codeine
- Bell’s palsy
- Multiple sclerosis
- Head trauma
- Cancer
- Chronic renal failure
- Cirrhosis
- Niacin deficiency
- Adrenal insufficiency
- Cushing’s syndrome
- Diabetes mellitus
- Sjögren’s syndrome
- Radiation therapy to the head and neck
- Viral infections
- Hypertension
Glossodynia, or burning tongue, is relatively common. Although the problem is frequently related to local irritation, it may be a manifestation of an underlying systemic condition.
- What is the likelihood that the disease is present, given the history, clinical findings, and known risk factors?
- How serious is the condition? What are the consequences of a delay in diagnosis?
- Is an appropriate diagnostic test available? How sensitive and accurate is it?
- Are the costs, risks, and ease of administering the test worth the effort?
Reference: Matthews et al., “The use of diagnostic tests to aid clinical diagnosis,” Journal of the Canadian Dental Association 61:785, 1995.
Accuracy is a measure of the overall agreement between the test and a gold standard. The more accurate the test, the fewer false-negative or false-positive results.
Sensitivity measures the ability of a test to show a positive result when the disease is present. The more sensitive the test, the fewer false negatives.
For example, one problem with cytologic evaluation of cancerous keratotic oral lesions is that, of 100 patients with cancer, 15 will test negative. This is an unacceptable false-negative rate; consequently, cytology for this diagnosis is not highly sensitive.
Specificity measures the ability of a test to show a negative finding in people who do not have the condition. Higher specificity means fewer false positives.
Reference: Matthews et al., “The use of diagnostic tests to aid clinical diagnosis,” Journal of the Canadian Dental Association 61:785, 1995.
FNA refers to a diagnostic technique called fine-needle aspiration, in which a needle, typically 22-gauge, on a syringe is used to aspirate cells from a suspicious lesion for pathologic analysis.
Many otolaryngologists use the technique to aid in the diagnosis of cancers of the head and neck. It is particularly valuable in the diagnosis of submucosal tumors, such as lymphoma, and parapharyngeal masses that are not accessible to routine surgical biopsy.
Like many techniques, the efficacy of FNA depends on the skill of the operator and the experience of the pathologist reading the slide.
Reference: Cramer H et al., “Intraoral and transoral fine needle aspiration,” Acta Cytologica 39:683, 1995.
- Cystic fibrosis
- HIV infection
- Diabetes mellitus
- Affective disorder
- Metabolic disturbances, including malnutrition, dehydration, and vitamin deficiency
- Renal disease
- Cirrhosis
- Thyroid disease
- Autoimmune disease, including Sjögren’s syndrome, myasthenia gravis, and graft-versus-host disease
- Sarcoidosis
- Autonomic dysfunction
- Alzheimer’s disease
- Cancer
Polymerase chain reaction is a technique developed by researchers in molecular biology for enzymatic amplification of selected DNA sequences.
Because of its exquisite sensitivity, PCR appears to have marked clinical potential in the diagnosis of viral diseases of the head and neck.
- Viral disease
- Lichen planus
- Pemphigoid
- Pemphigus vulgaris
- Erythema multiforme
The posterior lateral and ventral surfaces of the tongue are the most common sites of intraoral cancer.
Staging is a method of defining the clinical status of a lesion and is closely related to its future clinical behavior. It is related to prognosis and helps provide a basis for treatment planning.
The staging system used for oral cancers is called the TNM system and is based on three parameters:
Size of the tumor, on a scale from 0 to 3. T0 indicates no evidence of primary tumor; T3 indicates a tumor greater than 4 cm in greatest diameter.
Involvement of regional lymph nodes, on a scale from 0 to 3. N0 indicates no clinically palpable cervical nodes; N3 indicates clinically palpable lymph nodes that are fixed and metastases are suspected.
Presence of distant metastases, on a scale from 0 to 1. M0 indicates no distant metastases; M1 indicates clinical or radiographic evidence of metastases to nodes other than those in the cervical chain.
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