evaluating medically complex patientsevaluating medically compromised patients to occur during the...

Evaluating Medically Complex Patients

Chapter 19

2001 William H. Crawford, Jr. D.D.S., M.S. All rights reserved. Copying for commercial purposes is prohibited.

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Outline Objectives

A. Introduction

B. Risk Classification of Dental Procedures (after Sonis)

1. Nonsurgical Procedures2. Surgical Procedures

C. Classification of Risk (ASA)

1. ASA I (Med Type I)2. ASA II (Med Type II)3. ASA III (Med Type III)4. ASA IV (Med Type IV)5. ASA V (Med Type V)

D. Consulation with a Physician

E. Consultation with Dental Specialists

F. Laboratory Tests

1. Oral Biopsy2. Oral Exfoliative Cytology3. Other Laboratory Tests of Importance to Dentists

a. Culture and Sensitivity Testingb. Complete Blood Countsc. Blood Glucosed. Blood Coagulation Studiese. Infectious Disease Testing

4. Other Laboratory Tests of Less Importance to Den-tists

G. Evaluation of Medications

H. Summaries

1. Topic Sentence Summary2. Risk Classification of Dental Procedures (after

Sonis)3. ASA (MED) Risk Classification of Dental Patients4. Dos of Biopsy (after Melrose); Don’ts of Biopsy

(after Melrose)5. Biopsy and Cytology Fixatives6. Grading of Oral Cytology Specimens7. Indications and Containdications for Oral Cytology8. Some Information that Can Be Learned froma

Complete Blood Count9. Using the Physician’s Desk Reference (PDL)10. Components of Discovery and Evaluation of Medi-

cally Complex Patients

I. Study Questions

After completion of this chapter, the student should be able to

1. write and identify definitions for the following: activa-teed partial thromboplastin time, biopsy, bleeding time, CBC, complete blood count, excisional biopsy, exfolia-tive cytology, fasting blood glucose, glucose tolerance test, hematocrit, incisional biopsy, leukocytosis, leuko-penia, prothrombin time, and thrombocytopenia.

2. list, define, and identify the six Sonis categories for risk of dental procedures.

3. identify which of the Sonis categories the following pro-cedures fall: oral hygiene instruction, supragingival pol-ishing, subgingival scaling and root planing, and periodontal surgery.

4. list, define, and identify the five ASA/MED categories for determining patient risk.

5. write and identify why the “Pap” smear is not used much in dentistry.

6. list and identify which two types of lesions may occa-sionally be candidates for the “Pap” smear.

7. write and identify three reasons evaluating patient’s medications is important.

8. list and identify five things a “complete blood count” measures.

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Introduction

Evaluate: “…to judge or determine the significance, worth, or quality of; assess: to evaluate the results of an experiment.”

Once identified, risks must be evaluated in light of the planned treatment.Identifying patients who are medically complex and, therefore, at risk of being harmed by cer-tain dental procedures, is accomplished by the interviewing and examining procedures covered in the last chapter. Once the nature of the risk is established, it is necessary to evaluate it in relationship to the dental procedures that are contemplated. This evaluation is aided by 1) patient and procedure classifications, 2) evaluation of medications 3) physician and dentist consultations, and 4) laboratory tests. Whatever the steps taken, it is necessary to evaluate each patient individually in the context of their unique medical history and in the context of the type of dentistry to be performed. Patients should be party to the evaluation of her/his medical sta-tus; they need to be kept informed and invited to participate in the process.

Risk Classification of Dental Procedures (after Sonis)

Dental procedures vary in the risk they pose to the patient.One author has constructed a useful classification of dental procedures according to increasing levels of risk. This classification recognizes that procedures that involve surgery are inherently of higher risk than those that do not. Extraction of teeth, periodontal surgery, and endodontic surgery involve the potential for stress, bleeding, and infection. On the other hand, oral exami-nations, routine fillings, and dental prophylaxis usually do not produce such complications. Accordingly, the Sonis classification subdivides procedures into the nonsurgical and surgical ones and assigns each procedure group a number (I-VI). It is presented with slight modifica-tions below.

Nonsurgical Procedures—No Purposeful Incisions

None of the procedures included in classes I-III involve a purposeful incision in the oral soft tissues. Only in type III is the integrity of the oral tissues breached.

Type I—Nonsurgical, noninvasive, no wounds, no stress

Noninvasive examinations, study cast impressions, oral hygiene instructions are Type I.Procedures in this class do not involve surgery or purposeful invasion of the underlying tissues; there is virtually no possibility for these procedures to produce wounds of any size. These pro-cedures are usually not associated with patient fear or stress. Such procedures include exami-nations, study cast impressions, and oral hygiene instructions. Most examinations (vital signs, soft tissue, and caries detection) are rated as Type I. It is possible, however, that probing of deep periodontal pockets may induce bleeding and therefore may be rated as Type III. As can be seen, this classification places those procedures that induce bleeding and/or wound produc-tion at a higher level.

Type II—Nonsurgical, noninvasive, no wounds, low stress

Fillings, supragingival prophylaxis, and orthodontic therapy are Type II procedures.Type II procedures are also nonsurgical. They are intended to be noninvasive and produce no wounds. However, there may be mild stress and pain associated with some procedures in the group. These procedures include simple operative dentistry, supragingival prophylaxis, and orthodontic therapy.

Type III—Nonsurgical, invasive, few superficial wounds, low stress

Nonsurgical procedures producing bleeding (e.g. subgingival scaling) are Type III.In the last group of nonsurgical procedures there is the potential to produce bleeding or inva-sion of the underlying tissues. While these outcomes are not purposeful, they may be expected

Evaluating Medically Compromised Patients

to occur during the course of treatment. Type III procedures include advanced operative den-tistry, subgingival scaling/root planing (subgingival), and nonsurgical endodontic therapy. Minimal bleeding and invasion of underlying structures may occur in advanced restorative dentistry and nonsurgical periodontic procedures (root planing). In nonsurgical endodontic procedures, invasion of the periapical tissues may occur. By their very nature, these procedures may produce a few minor wounds and may be painful and stress producing.

Surgical Procedures—Purposeful Incisions

“Closed” and “open” surgical procedures producing wounds.Surgical procedures involve purposeful invasion of the underlying tissues and production of wounds. Those surgical procedures that do not involve incisions and sutures are known as “closed procedures.” Many tooth extractions are closed surgical procedures. Procedures that involve incisions and sutures are known as “open procedures.” The baring of underlying bone by laying back a flap of mucosa is one example of an open surgical procedure. Both closed and open surgical procedures produce invasion of underlying tissues and wounds. They vary in the extent of invasion and the size and number of wounds produced. The potential for pain, stress, and complicated recovery increases between Type IV-VI procedures.

Type IV—Closed surgical, invasive, single deep wounds, low stress

Simple tooth extraction and periodontal curettage are Type IV procedures.Type IV procedures involve closed surgery. While there is invasion of underlying tissues and single deep wounds may result, healing is rapid and complications few. Simple extractions, periodontal curettage, and periodontal gingivoplasty qualify as Type IV procedures. “Simple extractions” employ only forceps; no flaps, no bone removal, and no sutures are required. Sim-ilarly, periodontal curettage and gingivoplasty do not require flaps or sutures. While these pro-cedures may seem stressful, patients in good health can be expected to cope with them well.

Type V—Open surgical, invasive, several deep wounds, moderate stress

Multiple extractions, impacted tooth extraction, flap surgery are Type V procedures.With Type V procedures, a number of deep wounds may result. Surgical flaps may be elevated and bone may need to be removed. Because bone is removed, there may be post-operative pain. The potential for infection, while low, is higher than for lower procedure categories. The num-ber of wounds, the involvement of bone, and the length of time that the surgery requires will produce significant patient stress; this factor, considered as Type V surgery, is contemplated for medically complex patients. Multiple extractions, flap surgery, single bony extraction of impacted teeth, and endodontic apicoectomy qualify as Type V procedures.

Type VI—Open surgical, invasive, many deep wounds, high stress

Full arch extractions, extraction of many impacted teeth, orthognathic surgery are Type VI.Procedures in the highest risk category produce many deep wounds, flaps, and/or major head and neck surgery. Significant bleeding may be encountered during surgery. Post-operative complications may include hemorrhage and infection; they may need intervention to be con-trolled. Depending on the patient’s general health, it may be wise (and necessary) to conduct Type VI procedures in a hospital operating room. Type VI procedures include full arch/mouth extractions, extraction of multiple bony impactions, and orthognathic surgery.

Classification of Risk (ASA)

ASA patient classification rates a patient’s ability to withstand surgical procedures.Many years ago, members of the American Society of Anesthesiologists (ASA) devised a patient classification based on increasing risk. The original intent of this ASA classification was to evaluate the ability different patients with different health problems have in withstand-ing the rigors of general anesthesia. Because the safety of general anesthesia to a great degree depends on the health of the cardiovascular and respiratory systems, the ASA classification

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emphasizes them.

The ASA classification has been adapted to dentistry: MED classification.In more recent times, authors of dental texts have written about the ASA classification in the context of managing the medically complex patient. One of these authors adapts the original ASA classification to dental needs. What follows is a composite classification combining McCarthy’s and the more recent adaptation by Little and Falace. Because the ASA classifica-tion relates specifically to general anesthesia, it is appropriate to indicate its modification to dentistry by using “MED” instead of “ASA.”

American Society of Anesthesiologists—ASA (after McCarthy and Little)

The ASA (or MED) classification rates patients from healthy to dying.This classification starts with a normal healthy patient and ends with a dying one. The signifi-cance of ASA I and V is obvious: An ASA I patient can tolerate any dental procedure (Types I-VI) while an ASA V patient literally cannot. An ASA status in between these extremes often require modification of dental treatment in order to cause the patient no harm.

ASA I (MED Type I)

A normal healthy patient who can withstand any treatment without modifications.

These patients are those for whom no significant findings were uncovered from the medical history and examination. They should be able to tolerate any dental procedure without treat-ment modification.

ASA II (MED Type II)

A patient with mild to moderate systemic disease that does not interfere with day-to-day activity; with stress reduction, these patients should be able to withstand all dental proce-dures.

If some mild systemic disease is uncovered on the medical history and examination, treatment may or may not need to be modified. Mild hypertension and some forms of diabetes mellitus are two conditions that warrant an ASA II status. It is usually not necessary to consult with the patient’s physician if treatment is modified appropriately.

ASA III (MED Type III)

A patient with severe systemic disease that limits activity but is not incapacitating; treatment modification and physician consultation is mandatory; with appropriate modifications, this patient should be able to withstand most dental procedures.

The numbers of patients in this category seeking dental care will increase in the coming years. Providing safe dental care for them will be one of dentistry’s challenges. ASA III conditions may be reported by the patient or observed by the dentist. Once discovered, modification of dental treatment (beyond Type I) is essential. Moderate hypertension, angina pectoris, and con-gestive heart failure are but three conditions that place a patient in the ASA III category. Con-sultation with the patient’s physician prior to treatment (Types II-VI) is wise.

ASA IV (MED Type IV)

A patient with severe systemic disease that limits activity and is a constant threat to life; these patients need to be treated in a special facility staffed with specially trained personnel (e.g. a hospital); even with modifications, they may not be able to withstand the most stress-ful and most invasive dental procedures.

Sicker ASA IV patients will surely need modification of dental treatment. It may be necessary to provide any treatment other than Type I, in a special facility (hospital, specially equipped dental clinic). Consultation with the patient’s physician prior to treatment (Types II-VI) is vir-tually mandatory.


ASA V (MED Type V)

A moribund patient not expected to survive 24 hours with or without operation; dental care is not at issue with these patients.

It is unlikely that ASA V patients will be seeking dental care while they are moribund. These patients have problems in maintaining vital signs; dental care is not a priority for them.

Consultation with a Physician

Physician consultation will become an increasingly common activity in dental practices.It may be necessary to seek guidance from a physician concerning the dental management of patients with identified medical problems. As already indicated, it is virtually mandatory to do so with ASA IV and recommended with ASA III patients.

The logistics of physician consultation may vary in its difficulty.Depending on the circumstances, seeking physician consultation may be simple or difficult. In smaller communities physicians may be easily accessible; in large cities they may not be. Unlike dentists who typically practice in a single facility, physicians are mobile. Depending on their specialty, physicians may spend little time at their desks responding to correspondence and telephone messages. Those who practice in large institutions (medical centers, academic health centers, and hospitals) may be particularly hard to reach. More often than not, it is the physician’s staff that will set the stage for the consultation. The recent wide use of FAX tech-nology and E-mail has begun to alleviate the difficulty in reaching physicians by telephone.

The dental practitioner must be prepared for physician consultation.Once the physician’s office is contacted, the dentist needs to explain the request succinctly and clearly. First, the patient must to be identified so that her/his record can be retrieved. Second, the medical condition that is of concern must be presented and third, the nature of the proposed dental treatment has to be discussed.

Physicians may not know much about dental procedures.In this regard, it cannot be assumed that a physician knows of the full range of services that a dentist provides. Too often, the physician’s image of dentistry is limited to single tooth restora-tions—he/she may not be at all aware that invasive procedures are commonly and safely per-formed in dental offices. The physician may not, for example, realize a procedure as common as the dental prophylaxis might be classified as “invasive.” Given this situation, it is important that the dentist not merely name the procedure(s) to be performed, but to indicate if, for exam-ple, bleeding will occur, local anesthesia will be used, and the level of patient stress that is anticipated.

Oral consultation (personal, telephone) is desirable.Direct personal or telephone contact with a physician is probably the easiest and most satisfy-ing consultation method. Usually, this form of consultation is conducted by telephone. When the dentist initiates the call, he/she should have a clear idea what is to be covered: 1) patient identification, 2) health problem of concern, 3) procedure to be performed, 4) modification of therapy proposed. The patient’s dental record should be in front of the dentist during the call so that information can be retrieved and notes taken. It is unlikely that contact will be established with the initial call. More often than not the physician will return the call within a day or so. Given this reality, it is important that the office staff be ready with the patient record when the dentist takes the return call. A little organization in this regard will make physician consulta-tion a more pleasant experience.

Records of physician consultation must be kept.Some urge that the dentist follow up the telephone with a formal letter or FAX confirming the conversation and the physician’s recommendations. While this procedure cannot hurt, in most cases is it unnecessary if adequate notes are made in the patient’s record. These notes should

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include 1) the date and time of the call, 2) the physician’s name, and 3) and the modifications in treatment decided upon.

Written consultation (letter, form, FAX, E-mail) may be necessary.If more formality is needed, a letter may be directed from dentist to physician. This is common in the dental school setting. In fact, some schools have developed preprinted consultation letter forms that the student (with faculty supervision) can prepare. While the written consultation has certain medical-legal appeal, it is usually too cumbersome, and too time consuming to be of much value in the usual dental practice. However, the wide-spread use of FAX machines have made written consultation much more practical.

Consultation with Dental Specialists

Consultation with others about medically complex patients is common in dental schools.Soliciting the advice of other dentists about the modification of treatment for medically com-prised patients is a common practice in dental schools. In fact, most dental schools have for-malized such consultations by developing forms that make the consultation process efficient and uniform.

Outside dental schools, oral surgeons are knowledgeable about the medically complex.In dental practice, referral of patients for evaluation and treatment, usually by specialists, is a common occurrence. Referring a patient for consultation only (without treatment) is less com-mon. Given the specialized training oral surgeons receive in physical diagnosis, patient evalua-tion, and monitoring of vital signs, these specialists may serve as a excellent consultative resource in the identification, evaluation, and management of the medically complex patient.

Laboratory Tests

Dental practitioners can and should request laboratory tests for their patients.As a health professional, a dentist can legitimately request virtually any laboratory test that a physician can. As a matter of practical fact, however, only a few basic tests are helpful in the evaluation of medically complex patients or in management of patients with oral disease.

Oral Biopsy

Submission of tissue for microscopic examination is an important procedure.Of the laboratory tests most commonly used in dentistry, the submission of a patient’s tissue for histologic examination is arguably the most important. The term “biopsy” refers to the “removal of tissue from a living patient for the purpose of microscopic examination.” While biopsy is usually thought of as a surgical procedure, it may be performed with instruments other than a scalpel (needles, punches, etc.). In fact removal of blood and bone marrow for his-tologic examination also qualify as biopsy procedures.

While biopsy is used to diagnose cancer, it is used to diagnose other diseases too.The word “biopsy” is associated in the minds of the public as “a test for cancer.” While it is often used to rule out the presence of a malignancy, it can be used for the diagnosis of a num-ber of conditions where cancer is not an issue—a liver biopsy in hepatitis is but one example. In spite of the fact that suspected cancers are not the only reason biopsies are performed, patients often equate the two. To many of them, “biopsy” means “cancer.” If cancer is not sus-pected, the patient may need to be reassured as to why a biopsy is necessary; in these cases, the term might best be avoided.

Removal of an entire lesion is known as an “excisional biopsy.”With excisional biopsy, the entire lesion is removed and submitted for microscopic examina-tion. If removal of the entire lesion is confirmed by microscopic examination, the patient is cured—no further treatment may be necessary. Furthermore the microscopic diagnosis will be

Biopsy

Removal of tissue for the purpose of arriving at a diagnosis through micro-scopic examination.

Excisional Biopsy

Removal of an entire lesion for microscopic examination.


based on examination of the entire lesion; therefore, it is more accurate. As ideal as excisional biopsies are, they are limited to small lesions located in areas that do not require specialized surgery.

Removal of part of a lesion is known as “incisional biopsy.”When excision of a lesion cannot be accomplished easily, the next best thing is to remove and submit a section of it for microscopic examination; this procedure is known as “incisional biopsy.” Candidates for incisional biopsy are lesions too large to be entirely removed, lesions that are in inaccessible locations, and lesions that are close to important anatomic structures. Because only a portion of a lesion is removed, the microscopic diagnosis will be based upon the submitted sample. If the most representative portion of a lesion is missed, an erroneous “negative” result may be returned. This unfortunate circumstance is known as a “false nega-tive” result. While it is sometimes difficult to determine where the most representative sample should be taken, those experienced in the clinical appearance of oral lesions can make a fairly accurate educated guess. With large lesions, they may make several incisions to increase the likelihood of submitting a representative sample. There is another problem with incisional biopsies: Incising vascular or pigmented lesions may cause excessive hemorrhage or introduc-tion of cells into the blood stream. However, these complications do not justify not performing a biopsy.

Tissue removed at biopsy must be “fixed” immediately.Once the lesion (or a portion of it) is removed it must be immediately placed in a solution that will immediately kill (or “fix”) the cells in an effort to maintain their appearance as close to liv-ing as possible. The standard solution is 10% formalin; it is provided by the oral pathology lab-oratory to which the specimen is to be sent. It is also important that enough formalin is used: it is impossible to use too much. Use of at least 20 times the volume of formalin to the tissue removed is a good rule of thumb. Most laboratories now put their formalin in wide-mouth bot-tles so that the tissue can be dropped directly into the solution and not stick to the walls.

Oral Exfoliative Cytology (Papanicolaou Technique)

The “Pap” smear has reduced dramatically deaths from cervix cancer.The method of removing and examining individual cells from the surface of a lesion was per-fected by Papanicolaou decades ago. The use of the “Pap smear” to evaluate lesions of the uterine cervix has profoundly reduced the death rates from cervical cancer. It was, therefore, natural to use the technique for evaluation of oral lesions; however, the use of the oral Pap smear has had little impact on oral cancer death rates. The reasons for this paradox will become clear soon.

With a “Pap” smear, surface cells are examined under the microscope.Exfoliative cytology is defined as “microscopic examination of individual cells removed from the surface of a lesion.” The sample of cells is submitted to a pathology laboratory and is read by an oral pathologist or, in the medical setting, by a cytotechnician.

The technique for obtaining a “Pap” smear is easy and non-invasive.The technique of obtaining an oral cytology specimen is much simpler than that of obtaining a biopsy specimen. There is usually no need for anesthesia and there certainly is no need for scalpels and sutures. Because the technique is so simple and because it is nonsurgical, it has at least two significant advantages. First, it can be performed on most patients regardless of their health status (ASA I-IV) and second it can be performed by ancillary health personnel. All that is needed to obtain an oral cytology specimen is: 1) a ground glass slide, 2) fixative, 3) a pencil, and 4) a cement spatula or tongue blade. The glass slide and fixative are provided by the oral pathology laboratory to which the specimen will be sent.

Step 1—First of all, it is essential that the patient’s name and the date be written in pencil on the ground glass surface at one end of the slide.

Step 2—With the labeled slide nearby, pick up a cement spatula or a wooden tongue

Incisional Biopsy

Removal of a portion of a lesion for microscopic examination.

Papanicolaou

The developer of the stain-ing procedure that lead to the use of exfoliative cytol-ogy.

Exfoliative Cytology

Removal of surface cells and their examination under the microscope; the “Pap smear.”

Cytotechnician

A health-care auxiliary trained to examine “pap smears.”

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blade. (A metallic or plastic instrument is recommended of a wooden tongue blade for at least two reasons: First, it is possible to exert more pressure with a metal or plastic instrument. Second, these materials do not absorb water; therefore, they will not pre-maturely dry out the cells prior to fixation.)

Step 3—Holding the instrument at about a 45o angle to the lesion, firmly scrape the surface of the lesion. The scraping action will cause white material to accumulate on the instrument edge; this material is composed of cells. As will be explained soon, it is necessary to scrape the lesion surface firmly enough to occasionally require local anesthesia, brutal scraping causing tearing, undue pain, and bleeding is not appropri-ate. If that action were required, a biopsy should be performed instead.

Step 4—Smear white scrapings in the middle of the ground glass slide. The deposi-tion area should be the middle one-third of the slide leaving the ends free.

Step 5—Open the container of fixative and flood the scraping’s deposit on the slide. Usually, the oral pathology laboratory provides fixative in a small plastic vial; cutting off the tip will allow fixative to be squeezed out. The slide is now allowed to dry before placing it in the shipping container provided. Occasionally a larger container of fixative will be provided; in these cases the entire slide is inserted and sent off to the laboratory in the container. Formalin is not used to fix cytology smears; the appro-priate fixative is 70% alcohol, a fluid found in many dental offices. Only cytology specimens should be fixed with 70% alcohol. It is inappropriate to submit biopsy specimens in alcohol; they must be submitted in formalin.

It is essential to obtain “deep cells” for a Pap smear to be diagnostic. The accuracy of oral cytology in the diagnosis of oral surface lesions depends entirely on obtaining cells that show the features of disease. Usually, serious surface mucosal diseases show their first cellular changes in the layers closest to the underlying tissues; these changes rise to the surface only late in the disease course. As a result of these histologic facts, it is essential to obtain cells from the lower as well as the upper layers. It is necessary, therefore, to apply firm pressure on the lesion during scraping to have a chance of obtaining these deeper cells.

It is possible to tell if deep cells are obtained by examining a Pap smear.The cytotechnician (health worker who examines Pap smears) can determine whether or not deeper cells have been obtained because oral mucosa cells have different properties at different depths. Cells of the stratum basale (the deepest layer) have larger nuclei and green-staining cytoplasm (with Pap stain). On the other hand, cells nearer the surface (strata spinosum and corneum) have increasingly smaller nuclei and increasingly orange-staining cytoplasm. Cells of the stratum corneum usually have no nuclei and stain bright orange. As a consequence of these features, if the cytotechnician studies a smear that is composed of only orange anucleated “squames,” he/she knows that the scraping was very superficial and may, therefore, be inade-quate. If, however, the smear has a number of green-staining nucleated cells the technician knows that cells from the deeper layers are present.

It is impossible to reach deep cells if excessive surface keratin in present.It should now be clear that the operator must scrape firmly to get to the deeper layers where the early changes in many oral mucosal disease, including cancer, occur. It is much more difficult to reach these deeper layers if a heavy stratum corneum is present. Putting it in clinical terms it may be difficult to reach deeper layers if the lesion is white (keratotic) or if it is dry and crusted (lip lesions).

The Pap smear “works” only for surface lesions; it will not “work” for submucosal masses.Obviously, oral cytology is only of value when a surface lesion is observed. It has no value at all for assessing submucosal lesions (such as minor salivary gland tumors).


Red, not white, and blistering lesions are candidates for Pap smears.Cytology is usually used to identify early malignancies of the surface epithelium. If the lesion is not white, but red, it may possible to obtain cells from the deeper layers. If the lesion, how-ever, is white, it is likely that the surface keratin will prevent obtaining deeper cells. When in doubt, it is recommended that biopsy, not cytology, be performed. Cytology may be more help-ful in establishing the diagnosis of vesiculobullous lesions like pemphigus vulgaris. Even in these cases, biopsy is more accurate, more reliable, and more discriminate (can tell one lesion from another). When all is said and done, biopsy is preferable to cytology in almost all instances.

Other Laboratory Tests of Importance to Dentists

Dentists may use the services of laboratories to process tests for patients.Dentists may order laboratory tests for their patients. They may either obtain sample them-selves (usually blood) or, more commonly, refer the patient to a clinical laboratory (often in a hospital) to have the sample taken. The laboratory processing the patient’s sample will report its findings directly to the dentist.

It is no longer necessary to memorize normal values for laboratory tests.In the past it was common to subject students to the memorization of normal values against which the laboratory findings are measured. Happily with the emergence of computerized lab-oratory tests, it is no longer necessary to do so. The report sent to the dentist is generally pre-pared by a computer. The computer analyzes the findings in the patient sample and compares it to normal values stored in its memory. It prints the patient’s value and the expected normal value along side each other. Most of these forms also indicate which of the patient’s values are abnormal and how far from normal they are. Given this technology and given the listings of normal values in many textbooks, there is no longer any reason to commit them to memory.

Culture and Sensitivity Testing

Identifying an offending microorganism and effective antibiotics against it is “C&S.”If an oral infection is present, it is prudent to obtain a sample of exudate from an abscess or other lesion and submit it for identification of the causative organism (microbial culture). Dur-ing the culture of the offending organism it is common to subject the microbial colonies to a number of antibiotics to determine which is the most effective at killing them. Given this infor-mation, the dentist can prescribe the antimicrobial drug that will be the most effective in curing the infection.

Complete Blood Counts

A “CBC” returns much information about the status of a patient’s blood cells.A tremendous amount of information can be derived from examination of blood—information on the numbers of cells, the ratios of various cells, the amount of certain materials within cells, and the amount of certain materials in the serum. When a dentist orders a complete blood cell

count (cbc) be performed he/she will learn the numbers of rbcs, wbcs, and platelets per mm3 of blood, the proportion of wbc types, the size and shapes of rbcs and wbcs, the amount of hemoglobin in 100 ml. of blood, and the volume of rbcs in 100 ml of blood.

Many specific diseases may be suggested or identified with a CBC.Elevation of the white blood cell count is known as leukocytosis; WBC depression is known as leukopenia. Decreased numbers of platelets is known as thrombocytopenia. These and a host of other conditions may be uncovered by a CBC: anemia to infections, immune deficiencies to leukemias.

Blood Glucose

Measuring the amount of glucose in the blood stream may uncover diabetes mellitus.Often it is important to know if a patient has diabetes of not. Since the disease manifests by inadequate utilization of glucose, one way of assessing this is to measure the amount of glu-

Complete Blood Cell Count (cbc)

Common blood test in which the numbers and proportions of rbc’s, wbc’s, and platelets are reported.

Hematocrit

The volume of rbc’s in 100 ml of blood; useful in determining the presence of anemias.

Leukopenia

Decreased numbers of cir-culating wbc’s; may indi-cate susceptibility to infection.

Leukocytosis

Increased numbers of cir-culating wbc’s; may indi-cate presence of infection of leukemia.

Thrombocytopenia

Decreased numbers of cir-culating platelets; may indicate susceptibility to hemorrhage.

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cose in the serum—a measurement of blood glucose. Usually this is done before the patient eats in the morning (fasting blood glucose). It is also common to measure the rate at which a known amount of glucose is metabolized in the body. This is done by the patient drinking a known amount of glucose and then measuring the blood glucose levels at intervals over a cou-ple of hours. This is known as a glucose tolerance test.

Blood Coagulation Studies

Studying the ability to clot after injury is necessary for patients on anticoagulant therapy.There are a number of laboratory studies that can be performed to assist physicians in deter-mining the cause of blood clotting disorders. A few of these are of value to dentists in assessing the suitability of treating patients with these disorders. Also, many patients are taking medica-tions that prevent abnormal blood clotting (thromboembolism). Some of the laboratory tests discussed below will provide information on such patients’ ability to stop bleeding following invasive procedures.

Measuring the time bleeding stops after a small needle prick is “the Bleeding Time” (BT).The time it takes for bleeding from a small wound to stop is called the “bleeding time.” In nor-mal individuals (including those not taking anticlotting medications), bleeding stops in less than 10 minutes (usually between 2–8 minutes).

Clotting ability along the extrinsic pathway is measured by a “Prothrombin Time” (PT).Determination of the time it takes for blood to coagulate through the extrinsic and common pathways is called the “prothrombin time.” It is measured in-vitro using certain chemical reagents. Normal PT is from 10 to 15 seconds. Because the extrinsic pathway is necessary for clotting after tissue injury, the PT is a measure of the patient’s ability to clot after surgical pro-cedures.

Clotting along the intrinsic pathway is “Activated Partial Thromboplastin Time” (APTT).This test measures clotting along the intrinsic and common pathways. As the intrinsic pathway is activated by platelets after endothelial injury, the APTT assists in assessing platelet function. Because factors VIII and IX are activated along the intrinsic pathway, the APTT is also helpful in assessing blood clotting in patients afflicted with hemophilia.

The effectiveness of fibrin formation by thrombin is measured by a “Thrombin Time” (TT).The thrombin time measures the time necessary for fibrin to be formed from fibrinogen. Since thrombin is necessary for the conversion of fibrinogen to fibrin, this test is a measure of throm-bin activity. The normal TT is between 15–25 seconds.

Infectious Disease Testing

Determining the presence of infectious diseases is increasingly common.Infectious diseases, once thought conquered, are back with a vengeance. The HIV epidemic has changed the practice of dentistry forever. While HIV infections are of most concern today, hepatitis, tuberculosis, and syphilis are becoming increasing problems in dentistry. There are, of course, tests that can be performed to identify the presence of these diseases.

Hepatitis B

The presence of HBsAg indicates that a patient carries the hepatitis B virus (HBV).The infectious agent of hepatitis B (HBV) is identified by the presence of the virus coat in the serum—if coat is detected, the rest of the virus must be there too. Coat is recognized by the presence of one its antigens, the hepatitis B surface antigen (HBsAg). If a patient is positive for HBsAg, it means that he/she has an active infection and will develop symptoms, or, in the absence of symptoms, that the patient is an asymptomatic carrier. The presence of the antibody against the surface hepatitis B virus (anti HBs) indicates that the patient 1) has or had an infec-tion with HBV and 2) that the patient is developing, or has developed, immunity to the organ-ism.

Fasting Blood Glucose

Measure of blood glucose before eating; helpful in determining the presence of diabetes mellitus.

Glucose Tolerance Test

Measurement of blood glu-cose after drinking a known quantity of glucose; determines the body’s abil-ity to metabolize glucose; helpful in determining the presence of diabetes melli-tus.

Bleeding Time (BT)

Determination of the time necessary for bleeding to stop from a finger-prick wound; 2–8 minutes is nor-mal.

Prothrombin Time (PT)

Determination of the time necessary for blood to clot along the extrinsic-com-mon pathways; measure of ability to stop bleeding after surgery.

Activate Partial Thromboplastin Time

(APTT)

Determination of time nec-essary for blood clotting along the intrinsic-com-mon pathways; assesses platelet function; also assesses activity of factors VIII and IX.

Thrombin Time (TT)

Determination of time nec-essary for blood clotting along the common path-way; assesses thrombin activity.

HBsAg

Designation for the surface antigen displayed by the hepatitis B virus; it is only present when infected with this virus.


Hepatitis C

The presence of HCAg or antiHC indicates a patient is carrying the hepatitis C virus (HCV).Hepatitis C is a type of hepatitis once known as “nonA-nonB” because it couldn’t be detected with the serologic markers of hepatitis A or B. Now it is known that the condition is caused by yet another virus that has come to be known as hepatitis C. The virus that causes it, naturally, is HCV. The presence of this virus is marked by identification of the hepatitis C antibody (anti-HCV).

HIV

A positive ELIAS and Western Blot Analysis indicates a patient is carrying the HIV. It is, of course, possible to detect the present of the human immunodeficiency virus (HIV) in patients. The usually performed procedure is called the ELIAS test (for enzyme-linked immu-nosorbent assay). If a patient has a positive ELIAS test, another procedure, the Western Blot Analysis if performed to confirm the presence of the virus. More recently the ELIAS proce-dure has successfully been adapted to identifying HIV in human saliva. As routine as these tests have become it must be remembered that there are Federal, State, and local laws that guide the disclosure of a patient’s HIV status.

Tuberculosis

A positive Mantoux test indicates a patient has been exposed to the tubercle bacillus.Because of the huge influx of immigrants to the U.S., the increased numbers of HIV+/AIDS patients, and the emergence of drug-resistant strains of the TB organism, tuberculosis is on the rise again. The presence of this disease is determined by an easily conducted and inexpensive test—the tuberculin skin test or Mantoux test. If a patient proves to be Mantoux positive, it only means that he/she has once been infected with the tubercle bacillus (Mycobacterium tuberculosis); it does not necessarily mean that the patient currently has tuberculosis and there-fore is infective.

Syphilis

Positive reagin and FTA tests indicates a patient has been exposed to the syphilis organism.Syphilis is an infectious disease that can be identified by two kinds of tests. The first are the reagin tests (VDRL, Kahn, Wassermann, etc.) that identify a non-specific antibody-like sub-stance. Because this test is non-specific, a positive result does not necessarily mean the patient is infected with Treponema pallidum, the causative agent of syphilis. The other tests are much more specific. One is known as the fluorescent treponema antibody (FTA) test and the other the treponema immobilizing test (TPI). These tests identify specific antibodies to T. pallidum; their presence indicates that either the patient is currently infected or has recovered from a pre-vious infection.

Other Laboratory of Less Importance to Dentists

Less commonly used tests are sometimes helpful in assessing medically complex patients. Dentists can order virtually any study a laboratory offers; however, with the exception of biopsy and culture/sensitivity tests, it is uncommon that they do so. Even the other tests pre-sented above under “common” (e.g. CBC, coagulation studies) are not used as commonly as they might be. The following are several other relevant tests that could assist some dentists from time to time; however, they are presented here mainly to help dentists communicate with their medical colleagues.

Bone Studies

Assessing serum calcium and/or alkaline phosphatase may help with bone diseases.Occasionally, biopsy of a lesion central in bone is equivocal (e.g. some fibrosseous and giant

cell lesions); in these cases measurement of calcium (Ca+2) and alkaline phosphatase levels may provide much needed information.

Anti-HCV

The designation of the antibody to the hepatitis C virus (HCV); presence indicates present or past infection with HCV.

ELIAS Test

A screening test used for identification of the human immunodeficiency virus (HIV).

Western Blot Analysis

A more specific test used for confirmation of the presence of HIV.

Tuberculin Skin Test

A procedure used to iden-tify past or present infec-tion with the tuberculosis organism.

Mantoux Test

Another name for the “tuberculin skin test.”

Reagin Tests

A series of screen tests used for identification of the syphilis organism (VDRL, Kahn, Wasser-mann).

Fluorescent Treponema Antibody Test (FTA)

A test used to confirm the presence of the syphilis organism (Treponema pal-lidum).

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Elevation in serum calcium may indicate that bone resorption is abnormally high.The serum calcium level is a closely guarded constant. When elevated, it means that bone is

being resorbed to generate the excess Ca+2. Such bone resorption may be caused by the excess secretion of parathyroid hormone (hyperparathyroidism) or by some more destructive process (e.g. some cancers).

Elevation in serum alkaline phosphatase may indicate that bone turnover is abnormally high.Alkaline phosphatase is an enzyme important in calcification of bone. Because bone is contin-ually formed and resorbed (“turnover”), some alkaline phosphatase is always needed. How-ever, if levels of this enzyme rise to abnormally high levels, it may mean that bone is being formed at abnormally high levels too. Bone destruction and deposition is generally equal. This means that if bone is abnormally destroyed (e.g. cancer), bone will be deposited at abnormally high levels too. In such circumstances the alkaline phosphatase levels will rise to abnormally high levels. In sum, high alkaline phosphatase levels may be abnormally high bone deposition or abnormally high bone destruction.

Urinalysis

Urine examination can assist in uncovering diabetes mellitus and certain kidney diseases.Examination of urine is one of the most commonly used tests in medicine. While it was sug-gested that a urinalysis be performed on every patient registering for treatment in dental schools, the interest in this test waned when it turned out that more pertinent information can be derived from a CBC. In any case, the examination of the urine can provide information on presence of blood, proteins, nitrogenous wastes, and glucose. More will be said about blood, proteins, and nitrogenous wastes a little later.

Elevated urine glucose and ketone levels suggest presence of diabetes mellitus.Glucose is the urine is an indicator of diabetes mellitus. Patients under treatment for this dis-ease are trained to test their urine with commercially available kits. These kits also indicate the presence of ketones, abnormal products of glucose metabolism in diabetics, as well.

Determining Bilirubin Levels

Elevation in serum bilirubin indicates liver disease (e.g., hepatitis B).Bilirubin is a normal breakdown product of hemoglobin. It appears in normal individuals as a by-product of RBC turnover. When this material is delivered by the blood to the liver it is com-bined (“conjugated”) with a substance that renders it harmless. Once conjugated, bilirubin is excreted into the intestines where is it is eliminated in feces. Elevations in bilirubin are indica-tive of liver disease. If they rise high enough, the patient’s skin and sclera (eyes) may appear to be yellow (jaundice, icterus). Hyperbilirubinemia may occur with 1) excessive breakdown of RBCs (hemolytic jaundice), 2) blockage of the excretory passages out of the liver (obstructive jaundice), and 3) damage to liver cells (hepatocellular jaundice). Of the three, hepatocellular jaundice is the most pertinent to dental patients as this form is associated with hepatitis.

Renal Function Tests

Elevation in nitrogenous waste products in the serum indicates severe kidney disease.One kidney function is to transfer nitrogen-containing (nitrogenous) waste products from blood and eliminate them in urine. In certain serious systemic diseases, the excretion of these wastes is impaired; as a consequence, they accumulate in blood serum with very serious conse-quences. Abnormally high levels of nitrogenous waste products in the serum is known as “azotemia.” An important test of renal function is the measurement of non-protein nitrogenous waste products; this test is known as the “BUN” (blood urea nitrogen). Elevated BUN is indicative of azotemia and, therefore, of renal failure.

Other Blood Tests

Increased circulating immature red cells (reticulocytes) indicates red cell destruction.A reticulocyte is a juvenile red blood cell. It is recognized by retention of nuclear remnants

Alkaline Phosphatase

An enzyme important in the mineralization of bone; excessive amounts in blood plasma may indicate excessive bone resorption/deposition.

Jaundice (Icterus)

Yellow coloration of skin and sclera caused by excessive amounts of bilirubin in blood plasma.


with the RBC. As RBCs remain in circulation, the nuclear remnants disappear. Recognition of reticulocytes provide some measure of the numbers of young RBCs in circulation. Abnormally high reticulocyte counts may indicate an abnormally high RBC turnover; indicating, in turn, that RBC destruction is abnormally high.

Tissue destruction is suggested by an increased “erythrocyte sedimentation rate.”Certain diseases accompanied by tissue destruction (e.g. infections, infarcts) are identified by prolonged settling or RBCs in vitro. This is called an “increased sedimentation rate” (“sed rate” or “ESR”) If patient’s sed rate is prolonged, it suggests that tissue is being destroyed somewhere in the body.

Elevation in certain serum enzymes may indicate presence of specific diseases. Tissue destruction is also accompanied by appearance of certain enzymes in the serum. Some of these are 1) glutamic transaminase (GOT), 2) lactic dehydrogenase (LDH), 3) creatine phos-phokinase (CPK) and 4) glutamic-pyruvic transaminase (GPT). These (and other) enzymes are elevated in hepatitis, myocardial infarction, and other diseases associated with tissue injury.

Evaluation of Medications (PDR)

Most older patients are taking prescribed medications.The importance of understanding the nature and effects of medications a patient is taking can not be overstated. Taking prescribed medications suggest the presence of some underlying dis-ease otherwise they would not have been prescribed in the first place; medications may lead to some unfavorable treatment outcome; medications may interact unfavorably others used in dental treatment.

Some medications signify underlying diseases.Medications are only prescribed for good reason. If a patient is taking medications prescribed by a physician or if a patient is even taking self-prescribed over-the-counter (OTC) medica-tions, the chances are very good that patient has some disease (or is threatened by some dis-ease) that may require modification of some kinds of dental treatments. As but one common example, patients who are regularly prescribed a coronary vasodilator (like Isordil™), have angina pectoris.

Some medications may produce unfavorable dental treatment outcomes.Some medications may lead to complications if their presence isn’t known and proper treat-ment modifications taken. Patients taking an anticoagulant like Coumadin™ are likely to have prolonged bleeding during invasive dental procedures.

Some medications may react unfavorably with those used in dental treatment.Some medications a patient is taking may interact unfavorably with medications the dentist uses in treatment. One common example of this is the potential prolonged hypertension pro-duced by the interaction of certain antidepressant medications and epinephrine-containing local anesthetics.

The Physician’s Desk Reference (PDR)

With the large number of medications currently being physician-prescribed, and the untold number of over-the-counter medications being self-prescribed, it might seem that evaluating them would be impossible. That would be the case if were not for an important reference book—the Physician’s Desk Reference, or PDR as it is more commonly called.

The PDR (and other similar books) are readily available.This book is readily available at medical and dental school bookstores, at large commercial bookstores, and directly from the publisher (Medical Economics Data). It is virtually impossi-ble to practice dentistry without receiving advertisements and toll-free telephone numbers (from the publisher) that makes direct purchase of the PDR easy. Given the importance of this

Blood Urea Nitrogen (BUN)

Measurement of amounts of nitrogenous waste prod-ucts in blood plasma; may indicate kidney disease.

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volume, given its availability, and given its reasonable price, no dentist should be without a PDR. Accordingly there should be a copy of this book in every dental office. The useful life of this book is about 3-5 years. The year of publication is printed in large numbers on the cover and on the spine; therefore, it is easy to know when to buy a new one.

The PDR has descriptions of all commonly used medications.The PDR lists virtually every prescription and non-prescription medication available to the medical and dental profession. This information is included under the “Product Identification Section.” It is the largest portion of the book; its pages are white. There are other, smaller, sec-tions; the pages of most of these are printed on paper of different colors.

Descriptions of each medication is located in the Product Information (White) Section.As mentioned earlier, this section provides detailed descriptions of all medications, listed by manufacturer and brand name. The descriptions include 1) chemical composition, 2) clinical pharmacology, 3) pharmacokinetics, 4) indications/usage, 5) contraindications, 6) precautions, 7) adverse reactions, 8) overdosage, 9) dosage/administration, 10) how supplied, 11) cautions, 12) storage. In short, everything that a dentist needs to know about a medication is found in these descriptions.

If only the manufacturer is known, the Manufacturers’ Index (White) will be helpful.This is the first section in the PDR. In it, all manufacturers of pharmaceuticals and the brand name of medications they produce are listed. The page locations of the detailed descriptions of these products in the Product Information section are also listed here. It serves as an index to the descriptions if the manufacturer and drug brand name is known.

If only the medication’s name is known, the Product Name Index (Pink) may be helpful.This index lists all medications by their generic and brand names (e.g. “acetylsalicylic acid” and “aspirin”). The page of the complete description of the product is listed as well. The pink section, then, is an index to the descriptions if the name of the drug is known.

If only the medication’s category is known, the Product Category Index (Blue) may help.This index lists all medications by broad usage categories (e.g. “analgesics”, “antihistamines”, “deodorants”). Here again, page numbers locating the complete descriptions are presented opposite the drug name. The blue section is an index to the complete descriptions if the name of the drug is known.

If only the medication’s appearance is known, Product Identification Section (Gray) will help.This is a very helpful section. In it are pictures of many medications arranged by manufacturer. If a drug is identified from these pictures its name and manufacturer will then be known allow-ing access to the complete descriptions through either the Manufacturers’ Index (white) or the Product Name Index (blue).

If a diagnostic aid is sought, the Diagnostic Product Information (Green) may help.This section will not be used by dentists very often. It is located at the back of the PDR and lists substances and reagents used in various diagnostic procedures (e.g. tuberculin tine test) listed by manufacturers. If a particular diagnostic procedure is known but the name of a partic-ular reagent is not, consulting this section for the page of the complete description may be of value.


Summary

A. Introduction• Once identified, risks must be evaluated in light of the planned treatment.

B. Risk Classification of Dental Procedures1. Dental procedures vary in the risk they pose to the patient.2. Nonsurgical Procedures—No Purposeful Incisions

a. Type I—Nonsurgical, noninvasive, no wounds, no stressb. Type II—Nonsurgical, noninvasive, no wounds, low stress c. Type III—Nonsurgical, invasive, few superficial wounds, low stress

3. Surgical Procedures—Purposeful Incisionsa. “Closed” and “open” surgical procedures produce wounds.b. Type IV—Closed surgical, invasive, single deep wounds, low stress c. Type V—Open surgical, invasive, several deep wounds, moderate stressd. Type VI—Open surgical, invasive, many deep wounds, high stress

C. Classification of Risk (ASA)1. ASA patient classification rates patients ability to withstand surgical procedures.2. The ASA classification has be adapted to dentistry: MED classification.3. The ASA (or MED) classification rates patients from healthy to dying.

a. ASA I (MED Type I)—A normal healthy patient who can withstand any treatment without modifica-tions.

b. ASA II (MED Type II)—A patient with mild to moderate systemic disease that does not interfere with day-to-day activity; with stress reduction, these patients should be able to withstand all dental procedures.

c. ASA III (MED Type III)—A patient with severe systemic disease that limits activity but is not inca-pacitating; treatment modification and physician consultation is mandatory; with appropriate modifi-cations, they should be able to withstand most dental procedures.

d. ASA IV (MED Type IV)—A patient with severe systemic disease that limits activity and is a con-stant threat to life; these patients need to be treated in a special facility staffed with specially trained personnel (e.g. a hospital); even with modifications, they may not be able to withstand the most stressful and most invasive dental procedures.

e. ASA V (MED Type V)—A moribund patient not expected to survive 24 hours with or without oper-ation; dental care is not at issue with these patients.

D. Consultation with a Physician1. Physician consultation will become an increasingly common activity in dental practices.2. The logistics of physician consultation may vary in its difficulty.3. The dental practitioner must be prepared for physician consultation.4. Physicians may not know too much about dental procedures.5. Oral consultation (personal, telephone) is desirable.6. Records of physician consultation must be kept.7. Written consultation (letter, form, FAX, E-mail) may be necessary.

E. Consultation with Dental Specialists1. Consultation with others about the medically complex is common in dental schools.2. Outside dental schools, oral surgeons are knowledgeable about the medically complex.

F. Laboratory Tests1. Dental practitioners can and should request laboratory tests for their patients.2. Oral Biopsy

a. Submission of tissue for microscopic examination is an important procedure.b. While biopsy is used to diagnose cancer, it is used to diagnose other diseases too.c. There are two basic biopsy techniques: excisional and incisional.

(1) Removal of an entire lesion is known as an “excisional biopsy.”(2) Removal of part of a lesion is known as “incisional biopsy.”

d. Tissue removed at biopsy must be “fixed” immediately.3. Exfoliative Cytology

a. The “Pap” smear has reduced dramatically deaths from cervix cancer.b. With a “Pap” smear, surface cells are examined under the microscope.c. The technique for obtaining a “Pap” smear is easy and non-invasive.d. It is essential to obtain “deep cells” for a Pap smear to be diagnostic.

(1) It is possible to tell if deep cells are obtained by examining a Pap smear.(2) Red, not white, and blistering lesions are candidates for Pap smears.

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4. Other Laboratory Tests Important to Dentistsa. Dentists may use the services of laboratories to process tests for patients.b. It is no longer necessary to memorize normal values for laboratory tests.c. Culture and Sensitivity Testing

(1) Identifying an offending microorganism and effective antibiotics against it is “C&S.”d. Complete Blood Counts

(1) A “CBC” returns much information about the status of a patient’s blood cells.(2) Many specific diseases may be suggested or identified with a CBC.

e. Blood Glucose—Measuring the amount of glucose in the blood stream may uncover diabetes mel-litus.

f. Blood Coagulation Studies(1) Studying the ability to clot after injury is necessary for patients on anticoagulant therapy.(2) Measuring the time bleeding stops after a small needle prick is “the Bleeding Time” (BT).(3) Clotting ability along the extrinsic pathway is measured by a “Prothrombin Time” (PT).(4) Clotting along the intrinsic pathway is “Activated Partial Thromboplastin Time” (APTT).(5) The effectiveness of fibrin formation by thrombin is measured by a “Thrombin Time” (TT).

g. Infectious Disease Testing5. Other Laboratory Tests of Less Importance to Dentists

a. Bone Studiesb. Urinanalysisc. Bilirubind. Renal Function Testse. Other Blood Tests

G. Evaluation of Medications 1. Introduction2. The Physician’s Desk Reference

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Risk Classification of Dental Procedures (after Sonis)

Type I—Nonsurgical, Noninvasive, No Wounds, No Stress

•Examinations (soft tissue, vital signs, caries detection)

•Study cast impressions

•Oral hygiene instructions

Type II—Nonsurgical, Noninvasive, No Wounds, Low Stress

•Simple operative dentistry

•Supragingival prophylaxis

•Orthodontic therapy

Type III—Nonsurgical, Invasive, Few Superficial Wounds, Mild Stress

•Advanced operative dentistry

•Subgingival probing, scaling, root planing

•Nonsurgical endodontic therapy

Type IV—Closed Surgical, Invasive, Single Deep Wound, Mild Stress

•Simple extractions

•Periodontal curettage, gingivoplasty

Type V—Closed Surgical, Invasive, Several Deep Wounds, Moderate Stress

•Flap surgery

•Multiple extractions

•Single bony extraction of impacted tooth

•Endodontic apioectomy

Type VI—Open Surgical, Invasive, Many Deep Wounds, High Stress

•Full arch/mouth extractions

•Extraction of multiple impacted teeth

•Orthognathic surgery

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ASA (MED Type) Risk Classification of Dental Patients

ASA I (MED Type I)

•A normal healthy patient

•No treatment modifications are necessary

ASA II (MED Type II)

•A patient with mild to moderate systemic disease

•Does not interfere with daily activities

•Minimal treatment modifications (e.g., stress reduction) may be needed

ASA III (MED Type III)

•A patient with severe systemic disease

•Limits daily activity, but is not incapacitating

•Physician consultation recommended

•Treatment modification mandatory

ASA IV (MED Type IV)

•A patient with severe systemic disease

•Limits daily activity, and is a constant threat to life

•Physician consultation mandatory

•Treatment to be conducted in specialized facility

ASA V (MED Type V)

•A moribund patient

•Not expected to survive 24 hours without surgery

•Dental care contraindicated

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Dos of Biopsy (after Melrose)

•Do submit an accurate and complete history.

•Do remove sufficient tissue to ensure having representative material.

•Do submit x-rays of all bony lesions

•Do remove tissue from the periphery (or active area) rather than the center of a lesion.

•Do immerse the lesion immediately in sufficient volume of fixative.

•Do use a wide-mouth container for fixation.

•Do perform periodic biopsies if necessary to check for recurrence and to follow the course of the lesion.

•Do handle the lesion gently—crushing may render the specimen useless.

Don’ts of Biopsy (after Melrose)

•Don't incise a small lesion—excise it instead.

•Don't inject local anesthetic solution into the immediate area—it distorts the tis-sue making microscopic examination difficult.

•Don't use cautery or lasers—they cook tissues rendering specimens useless.

•Don't allow the tissue to dry out before fixation—place it in formalin immedi-ately.

•Don't remove a sample from necrotic areas as they may be difficult to interpret on microscopic examination.

•Don't cut into pigmented or vascular lesions as they may either seed blood ves-sels with malignant cells or cause profuse bleeding.

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Biopsy and Cytology Fixatives

Biopsy Specimens

•10% Formalin

Cytology Specimens

•70% Alcohol

Grading of Oral Cytology Specimens

•I No atypical cells seen

•II Some atypical cells; proba-bly inflammatory

•III Some atypical cells; may be malignant

•IV Many atypical cells; proba-bly malignant

•V Many malignant cells seen; outright malignancy

Indications for Oral Cytology:

•Evaluation of a lesion when the patient refuses biopsy

•Evaluation of a lesion in a patient who is a poor risk for office surgery

•Follow-up evaluation of a treated malignancy

•Evaluation of a vesiculobullous lesion (e.g., suspected pemphigus vulgaris)

Contraindications for Oral Cytology:

•Heavily keratotic surfaces (white lesions)

•Lesions with dry, crusted surfaces (lip lesions)

•Submucosal swellings with normal appearing overlying mucous membrane

•Lesions suspicious for malignancy—they must be biopsied

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Some Information that Can Be Learned from a Complete Blood Count

•Number of erythrocytes (rbcs) per mm3 of blood.

•Number of leukocytes (wbcs) per mm3 of blood.

•Number of platelets per mm3 of blood.

•Proportion of WBC types in percent (differential white count).

•Size and shape of rbcs and wbcs (peripheral smear).

•Amount (grams) of hemoglobin (Hb) in 100 ml of blood.

•Volume of rbc’s in 100 ml of blood (hematocrit).

•other information concerning erythrocytes (mean corpuscular volume, mean corpus-cular hemoglobin, and mean corpuscular hemoglobin concentration.

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Using the Physician’s Desk Reference (PDR)

If you know the manufacturer’s name:

•Look in the first white pages (Manufacturers’ Index)

If you know the drug’s generic name:

•Look in the pink pages (Product Name Index)

If you know the drug’s brand name:

•Look in the pink pages (Product Name Index)

If you know the drug’s appearance:

•Look in the gray pages (Product Identification Sec-tion)

If you know the drug’s category (e.g. vasodilators):

•Look in the blue pages (Product Category Index)

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Summary of Components of Discovery and Evaluation of Medically Complex Patients

Discovery

The Health History

• Questionnaire

• Interview

The Physical Examination

• Body

• Vital Signs

• Oral Soft Tissues

• Oral Hard Tissues

Evaluation

• Risk of dental procedure

• Patient’s medical risk (MED)

• Physician consultation

• Dental specialist consultation

• Laboratory tests

• Evaluation of medications

Treatment Modification

Oral Medicine

Study Questions:

1. Which of the following is an advantage of incisionalbiopsy?1. Removes the entire lesion2. Will produce a cure if benign3. May produce a “false negative” diagnosis4. No further treatment may be necessary5. May establish a diagnosis for a very large lesion

2. A cytology report returned from a pathologist indicatedthat the cells seen were “anucleated keratinized squa-mes.” What was the proper interpretation of this infor-mation?1. The lesion was probably benign2. The lesion was most definitely benign3. The lesion was probably malignant4. The lesion was most definitely malignant5. The sample was not diagnostic; only surface cells

were present

3. According to the treatment risk classification (Sonis)presented in the course syllabus, oral hygiene instruc-tions would be considered a 1. Type I procedure.2. Type II procedure.3. Type III procedure.4. Type IV procedure.5. Type V procedure.

4. Which of the following does NOT have to be revealedduring telephone consultation with a physician?1. Patient’s name2. Dental treatment to be performed3. Fee to be charged for dental treatment4. Health problem of concern5. Proposed treatment modification

5. A “differential count” reports1. the number of RBC’s. 2. the percentage of RBC’s to platelets.3. the percentage of hemoglobin to RBC volume.4. the percentage of various WBC’s.5. the number of WBC’s.

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Additional Readings:

6. The fundamental purpose of The Physician’s Desk Ref-erence is to provide1. the diagnosis for most diseases.2. medical emergency procedures.3. the telephone numbers of most physicians.4. facts about most medications.5. the indication for most laboratory tests.

evaluating medically complex patientsevaluating medically compromised patients to occur during the...

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