Risk Assessment and Oral Diagnostics in Clinical Dentistry

Part A

Guidelines for Risk Assessment of Systemic Conditions that may Complicate or be Complicated by Dental Treatment

1  Basics of the Health History, Physical Examination, and Clinical Investigations

1.0 INTRODUCTION

This chapter sets the foundation for this clinical guide by describing the basic principles and processes of clinical evaluation of the patient. Risk assessment first and foremost depends on obtaining a comprehensive medical history. In addition to physical examination, the ­clinician must determine whether any other clinical investigations are indicated prior to providing oral health care. These elements provide an essential basis for the clinical guide.

1.1 Obtaining a complete medical history

A wide variety of medical conditions and their treatments have the potential to affect oral health and may require specific considerations prior to providing dental care. In order to adequately assess a patient’s health and determine risk for developing complications, a complete medical history must be obtained and updated on a regular basis. Whether paper or electronic medical records are utilized, this information should be clear and easy to locate. Contact information for the patient’s primary care physician and any relevant medical specialists should also be recorded and accessible. Details of all telephone, email, or mail correspondences with the patient or his/her medical providers, as well as laboratory reports, should be included in the patient’s chart.

While a self-completed health history form can be useful in screening for certain medical conditions and risks, this should be used to guide, rather than replace, the medical interview. The oral health care provider and patient should be facing each other in a comfortable and relaxed manner during the interview, and translators should be used when necessary. When there are any questions or items in the medical history requiring greater detail or clarification, the patient’s primary care physician should be consulted.

1.1.1 Chief complaint

The chief complaint is the patient’s primary reason for seeking medical/dental consultation and should be recorded in his/her own words. Sometimes, a patient’s chief complaint when he/she presents to his/her oral health care provider will be some type of oral pain or a ­complication of a recent dental procedure. In some cases, the chief complaint may be directly related to an underlying medical condition. Examples include a patient with salivary gland hypofunction and rampant dental caries, or a patient with acute leukemia and acute onset of gingival bleeding.

1.1.2 History of present illness

The history of present illness relates directly to the chief complaint and is told from the perspective of the patient. This is essentially the story describing the chief complaint and should be collected in sufficient detail. Basic elements should include, as relevant to the nature of the chief complaint: history of onset; the duration, nature, quality, and timing of symptoms; complications; pain score; modifying factors; any treatment provided; and whether symptoms are stable, improving, or deteriorating.

1.1.3 Past medical history

The past medical history includes all relevant aspects of a patient’s health history both past and present. Medical conditions for which a patient has received treatment, or is actively being treated, and overall continuity of medical care should be included. Pertinent details of treatment and overall management should be obtained, such as timing of chemotherapy cycles in a patient undergoing cancer therapy, hemodialysis schedule in a patient with renal failure, or glycated hemoglobin (HbA1c) levels in a diabetic patient.

1.1.4 Medications and allergies

All current medications, prescription and non-prescription (over-the-counter, herbal supplements), taken on a regular basis must be listed. The dose, schedule, and most recent dose taken should also be noted, in particular if the medication is immunosuppressive/immunomodulatory, antihypertensive, antiglycemic, antithrombotic, or anticoagulatory. Previous exposure to specific medications, such as antiresorptive agents (e.g., bisphosphonates), is also important and should be selectively collected. If there appear to be any inconsistencies between the patient’s medical history and the list of medications, clarification should be requested. All reported drug allergies must be clearly noted, including the specific allergic reaction. Expected adverse side effects, such as gastrointestinal upset with opioid analgesics, should not be misclassified as an allergy, even if reported as such by the patient (adverse drug reactions).

Certain medications have the potential to interact with one another through competitive binding, or through induction or inhibition of the hepatic cytochrome p450 pathway. Some common examples, such as antibiotics, antifungals, and analgesics, are shown in Table 1.1.

1.1.5 Review of systems

The review of systems is an extension of the past medical history that serves more or less as a checklist of a patient’s overall health by assessing specific symptoms within each system in a comprehensive manner. Systems include neurologic/psychiatric; ears, eyes, nose, and throat (EENT); cardiovascular/respiratory; musculoskeletal; hematologic; endocrine; gastrointestinal; and genitourinary (Table 1.2). Any positive responses should be followed with additional questioning and the patient should be referred to his/her primary care physician for further evaluation when indicated.

Table 1.1 Cytochrome P450-associated drug interactions.

Table 1.2 Potentially serious drug interactions that may interact with medications prescribed by oral health care providers.

1.1.6 Family and social history

The family history should include any significant known medical conditions in first-degree relatives or that have been present in multiple generations. The social history should include whether the patient is single, previously married and/or divorced, or in a long-term relationship, and if s/he has children, as well as any other pertinent details that might impact his/her overall health. In addition, the patient’s occupation is important. For those who are not working, it is important to understand why, as this may be related to an underlying ­medical condition. Tobacco history should be obtained in pack-years (packs per day times the number of years), and if the patient has discontinued use, for how long; regular use of ­marijuana should also be ascertained. Alcohol and recreational drug use history should include amount and frequency and whether there is any history of treatment for abuse, addiction, or dependency. These aspects of the social history are important as stress, lifestyle, and ­psychosocial factors may contribute to disease presentation and may impact management.

1.1.7 Past dental history

A patient’s past dental history provides a great deal of information with respect to future risk of developing dental disease and associated complications. This should include whether care has been routine and preventive, or sporadic and problem-driven, and if so, why. Oral hygiene practices, home care, and diet should be reviewed.

1.2 Physical examination

Vital signs, including at minimum blood pressure and pulse, should be collected on all new patients and on an annual basis for general health screening, with appropriate referral when findings are abnormal (see chapter 2). For oral health care providers, the physical examination is largely limited to the head and neck and the oral cavity, intraorally extending from the labial mucosa anteriorly, to the soft palate, tonsils, and visible oropharynx posteriorly. Limited dermatologic examination, for example, can often be informative, especially when there is a chief complaint of oral lesions and concurrent skin lesions. Similarly, a limited neurologic examination may be warranted in a patient with signs and symptoms suggestive of a central nervous system disorder (Figure 1.1; see Figure 9.2). For proper conduct of a comprehensive examination, nothing more is needed than a good light source, a mouth mirror and gauze, which can be useful for manipulating the tongue and assessing salivary gland function. Normal findings should be summarized and for all positive findings, the size must be recorded as well as a description of color, consistency and contours of tissues.

1.2.1 Extraoral examination

Extraoral examination begins with careful visual inspection for skin changes and any head/neck asymmetry or swelling (Figure 1.2). The head and neck is then palpated for swelling, tenderness, lymphadenopathy, thyromegaly, and any other abnormalities. Temporomandibular joint examination includes observation of opening, closing, and lateral excursions of the jaw, palpation of the muscles of mastication, and evaluation of the joints for sounds and tenderness (see chapter 12). Depending on the chief complaint and history of present illness, a limited or more extensive cranial nerve examination may be included to evaluate for neuromuscular and neurosensory deficits.

1.2.2 Intraoral examination

The intraoral soft tissues should be examined thoroughly, including the upper and lower labial mucosa, right and left buccal mucosa, vestibules, gingiva, ventrolateral and dorsal surfaces of the tongue, floor of mouth, hard and soft palate, and the tonsils and oropharynx. Normally keratinized sites include the gingiva, hard palate, and tongue dorsum; these sites have a thicker, paler appearance than the rest of the non-keratinized mucosa that tends to be more pink or red in color. The mucosa should be assessed for red and/or white changes, pigmentation, ulceration, or any other abnormalities (Figure 1.3). These tissues should then be palpated for any subtle inconsistencies or masses. The major salivary glands should be bimanually palpated, and then saliva should be expressed from the glands to assess duct patency and flow, and saliva should be evaluated for amount, consistency, color, and floor of mouth pooling (Figure 1.4). Saliva is expressed and observed by drying the duct orifice and then palpating the gland distally to proximally until saliva flows from the orifice. The dentition and periodontium should be examined, and any removable prostheses inspected for fit and function. The oropharyngeal anatomy, and in particular the tonsils, should be assessed for symmetry, size, color, and the presence of exudates or other abnormalities that might prompt referral to an otolaryngologist for further evaluation (Figure 1.5).

Figure 1.1 62-year-old male with metastatic prostate cancer involving the clivus (affecting cranial nerves IX and XII on the right side) with progressive right-sided tongue and constrictor muscle weakness. Straight protrusion of the tongue (a) demonstrates right-sided muscle flaccidity, whereas excursion to the right side (b) demonstrates minimal movement.

Figure 1.2 68-year-old male with notable extraoral asymmetry and swelling (a), that upon intraoral examination (b), demonstrated a large poorly differentiated carcinoma of the right maxilla.

1.3 Ordering and performing laboratory tests

Laboratory investigations may be necessary to determine a diagnosis or to evaluate for risk prior to dental treatment. How to order laboratory tests and, importantly, what test to order, when, why, and how to interpret the results are critical to the understanding of laboratory medical procedures. Retesting to confirm abnormal findings should always be considered, in particular when the ­findings are unexpected.

Figure 1.3 Well-defined area of leukoplakia of the anterior mandibular alveolar mucosa, with a distinct white appearance, against a background of normal-appearing pink mucosa.

Figure 1.4 Clear aqueous saliva expressed by palpating the parotid gland extraorally.

Figure 1.5 Squamous cell carcinoma of the right palatine tonsil (arrow), appearing enlarged and erythematous with extensive ulceration.

1.3.1 Basics of ordering laboratory tests

1.3.1.1 Identifying a clinical laboratory

Before a laboratory test can be ordered, a clinical laboratory must be identified. Options include a local hospital or commercial laboratory, such as Quest Diagnostics (www.questdiagnostics.com). The laboratory should be contacted regarding procedures for ordering tests, necessary supplies (e.g., culture kits), and where/how to order the recommended kits.

Alternatively, most testing can be coordinated through a patient’s primary care physician. In many cases, especially for the typical oral health care provider practicing outside of a larger health care facility, collaboration with the patient’s primary care physician may be the easiest option. Specific orders should be sent in writing to the physician’s office and a copy of the results should be requested.

1.3.1.2 Completion of forms

When ordering laboratory tests, the correct requisition forms must be used and fully completed. It can be very frustrating for the provider and patient when an incorrect test is run by accident. Typically an ICD-9 code (see section 1.3.1.3) is required for each test being ordered. By law, all submitted specimens must be accompanied by two patient identifiers (e.g., name and date of birth, on both the labeled specimen and the requisition form), and when appropriate (i.e., with a biopsy or culture) the site should be specified. Questions regarding the completion of requisition forms should be directed to the clinical laboratory.

1.3.1.3 ICD-9 codes

The International Classification of Diseases (ICD) is a coding system created and maintained by the World Health Organization that is used for a number of purposes, including medical billing. The ICD provides a standardized classification of disease by etiology and anatomic localization. In the United States, the version that is used is the Ninth Revision, Clinical Modification, or ICD-9-CM; and this can be found on the internet or is available for purchase in print and electronic formats. Current Procedural Terminology codes, or CPT codes, are created and maintained by the American Medical Association and are used for medical billing of procedures, such as an oral biopsy. Laboratory tests and CPT codes need to have associated ICD-9 codes.

1.3.2 Serologic studies

Blood tests are used routinely in medicine, and in many cases may be required for evaluation of patients requiring dental care or for the work-up of patients with medical conditions affecting the oral cavity. Blood tests can be used to assess bleeding or infection risk, organ function, glucose management, and the presence of autoimmune or inflammatory diseases. The volume of blood required depends on the type and number of tests that are ordered and will be determined by the phlebotomist performing the blood collection. The main risk associated with blood collection is slight pain and bruising at the site of venipuncture. Serologic testing for specific diseases/conditions is described in greater detail throughout the clinical guide.

1.3.3 Microbiology studies

Microbiology studies are often necessary when evaluating a patient with suspected infection. In some cases, it may be important to identify a specific pathogen or to test for antimicrobial susceptibility so that appropriate therapy can be prescribed. The ordering clinician must understand when to order a test, which kit to use, and any transport considerations (i.e., ice for a viral specimen). While blood, urine, and cerebrospinal fluid can all be tested microbiologically, it would be rare for an oral health professional to submit anything other than an oral specimen.

Figure 1.6 Persistent purulence despite broad-spectrum antibiotic therapy in a 50-year female with metastatic breast cancer and Stage 0 medication-associated osteonecrosis of the jaw.

1.3.3.1 Performing cultures

There are several culture techniques, each with a very specific indication. Failure to use the correct technique will generally result in non-interpretable findings. As already discussed, whenever there is any question as to what test to order, and how to properly obtain and submit the sample, the clinical laboratory should be consulted directly. In addition to correctly completing the appropriate laboratory requisition form, the culture specimen should be clearly labeled with the patient’s name, date of birth, date of service, and site.

1.3.3.2 Bacterial cultures

Bacterial culture of the oral cavity is rarely indicated except in cases of purulence (Figure 1.6). Swabbing of non-purulent mucosa will invariably demonstrate normal oral flora. In most cases, a culture is ordered after failing initial empiric antibiotic therapy; therefore, to ensure thoroughness, both aerobic and anaerobic culture and susceptibility (sensitivity) testing should be requested. The purulence should be sampled directly, collected either by swabbing with the kit’s cotton-tipped applicator, or by aspiration (in particular for anaerobic culture samples), and placed directly (cotton tip first) into the appropriate culture medium, then sealed. The susceptibility test results should ultimately guide appropriate antimicrobial therapy selection.

1.3.3.3 Fungal cultures

Candida albicans is the most common fungal organism in the oral cavity and is a normal component of the oral microflora in a significant proportion of the general population. It is therefore not uncommon to have a positive fungal culture in the absence of infection. Fungal cultures should only be ordered when confirmation of a diagnosis of infection is essential, or in situations where antifungal susceptibility testing is necessary following failure of standard empiric therapy. Using the same type of culture kit as that used for aerobic bacterial culture, the area of infection is gently swabbed with the cotton-tipped applicator provided in the kit, placed tip first into the culture medium, and sealed. Culture results should always be interpreted critically, and if a lesion has not responded to what should otherwise be adequate therapy, further susceptibility testing and/or biopsy may be indicated.

Figure 1.7 Viral culture kit.

1.3.3.4 Viral cultures

Viral culture is highly specific, indicating that a positive result is almost always reflective of active infection. Both herpes simplex virus (HSV) and varicella zoster virus (VZV) can be readily cultured from the oral cavity. Importantly, false negatives are common; therefore, treatment for a suspected HSV infection should almost always be initiated empirically, regardless of confirmation of the diagnosis. Less commonly, false positives can be ­encountered due to subclinical physiologic oral shedding of virus in the absence of signs of infection.

Viral culture medium must be used and the specimen should be immediately transported to the laboratory or kept on ice when on-site facilities are not available to ensure submission of a viable specimen. Ulcerative lesions are lightly swabbed with the sterile cotton tip, which is then placed tip down into the medium and sealed (Figure 1.7). When positive, results are typically identified by the laboratory technician within the first 48 hours of culture. The direct fluorescence antibody (DFA) test is a rapid HSV test that can be useful when an immediate (same-day) diagnosis is required. DFA may also be used to confirm positive culture results, which otherwise show non-specific viral cytopathic changes, and to type HSV-1 or HSV-2. Polymerase chain reaction (PCR) is an extremely sensitive assay that is primarily used for testing of the cerebrospinal fluid in cases of viral encephalitis, and tests are available for most of the human herpes viruses. PCR is not typically used to evaluate suspected oral infections.

Cytomegalovirus (CMV) is a very rare cause of oral ulcers in immunocompromised patients. This virus cannot be cultured from the surface exudate of ulcers, as the virus is located in the endothelium and other mesenchymal cells of the connective tissue. If CMV infection is suspected, an incisional biopsy of ulcerated tissue should be obtained.

Figure 1.8 Cytology kit (a) and cytology specimen (b) demonstrating virally infected multinucleated cells, consistent with a diagnosis of herpes simplex virus infection.

1.3.3.5 Cytopathology studies

When an immediate diagnosis is necessary, the following cytology-based tests can be performed and interpreted in a very short period of time, depending on available resources and/or laboratory support. Cytology specimens are obtained using either a cytology brush or wooden spatula (Figure 1.8). The lesion of interest, typically clinically suspicious for either fungal or viral infection, is gently scraped so that cellular material is collected that can be transferred onto a glass slide. For diagnosis of fungal infection, a potassium hydroxide (KOH) preparation may be done within minutes with the patient still in the office, while the periodic acid Schiff stain highlights fungal organisms under light microscopy (Figure 1.9). For diagnosis of herpes infection, the Tzank test, or Tzank smear, is a cytology specimen that is treated with Papanicolaou, Wright’s or Giemsa stain and evaluated under a microscope for balloon-like multinucleated giant cells that are indicative of herpes virus infection.

Figure 1.9 Oral cytology specimen demonstrating Candida hyphae (linear organisms; solid arrow) and conidiae (ovoid budding organisms; broken arrow).

Photomicrograph courtesy of Mark Lerman, DMD, Boston, MA.

1.3.4 Histopathology studies

Histopathologic analysis of a tissue biopsy is essential for definitive diagnosis of many hard and soft tissue lesions. The ability of the pathologist to interpret the histopathologic findings is limited by the tissue sample provided, so site selection and quality of the specimen are both critical factors. Since many general pathologists are not familiar with oral pathologic conditions, it is ideal to have all biopsy specimens interpreted by a board-certified oral and maxillofacial pathologist. If a local oral pathology laboratory is not available, most services will provide