1: Problem Solving in the Diagnosis of Odontogenic Pain

Chapter 1

Problem Solving in the Diagnosis of Odontogenic Pain

Problem-Solving List

Problem-solving challenges and dilemmas in diagnosis addressed in this chapter are:

Taking an Accurate Dental History
Interpretation of Historical Data and Subjective Findings
Clinical Examination: Objective Findings

    Visual inspection
    Use of the explorer
    Bite pressure test
    Periodontal probing
Radiographic Interpretation
Differential Tentative Diagnosis
Sensibility (Vitality) Testing

Applicable and Pertinent Testing Techniques

    Cold test
    Heat test
    Dental (rubber) dam application for thermal pulp testing
    Electric pulp test
    Anesthetic test
    Test cavity
Clinical Diagnostic Scheme Based on Test Responses

    Reversible pulpitis
    Irreversible pulpitis
    Irreversible pulpitis not localized
    Necrotic pulp
Putting It All Together: the Final Pulpal Diagnosis

“A few moments’ consideration of the original cause of trouble at the apex of roots enables us to realize what is required to be accomplished in the way of successful treatment. If the original cause is admitted to be irritation from decomposing pulp, its removal will in most cases affect a cure.”< ?xml:namespace prefix = "mbp" />27

W. Whitehouse, 1884

Making an accurate endodontic diagnosis is a problem for many dentists. The solution to this problem is neither easy nor lends itself to a method that can be reduced to a series of simple steps. A further complication is that most clinicians find it difficult to challenge long-held concepts and practices and resist the notion that these beliefs may be biased. Their experience, under examination, may be limited. There is also a tendency to place trust in authorities without asking how these authorities came to be dominant influences in clinical thinking and practice. When attending a continuing education course, it is not unusual to have thoughts, such as “I already know this,” or “I have heard this before,” or “There is nothing new to be learned here.”

Dentists attend continuing education courses or read professional literature with the intent to improve their knowledge and abilities. In reality, most of the information in a course may not be new to an experienced clinician. What is often missed by clinicians, however, is the importance of detail, relative significance of concepts, and how this unique information can enhance their diagnostic acumen and clinical data gathering. Upon returning to the practice of dentistry, the information presented in the educational experience is often forgotten, and the clinician is destined to repeat the same errors they have been perpetuating for years. In an attempt to minimize this nonproductive process, and in the hope that ingrained patterns of erroneous thinking in the diagnosis of pulpal and periapical pathosis states will be clarified, simplified, and enhanced for the dental clinician, this chapter will provide detailed diagnostic methods used by the authors and most endodontic specialists.

Most concepts may already be familiar; the intent of this chapter is to provide a context for each method or test that will emphasize its unique importance in a problem-solving format. Not all diagnostic tests, examination methods, weighing of historical information, or patient subjective data are relevant to every case. Through clinical examples, the value of each approach will be emphasized to assist the clinician in reevaluating the entire diagnostic process and the incorporation of a realistic and meaningful approach to making a final diagnosis.

Taking an Accurate Dental History

The most common complaint that brings people to the dentist is pain. It is usually an acute problem termed “an emergency” by the patient, who typically characterizes it as being swollen, having pain to biting, being unable to tolerate temperature changes, or the statement, “I have an infection in my tooth.” Occasionally the dental problem is the result of trauma that is usually obvious by appearance; or the patient arrives with complaints of vague or nonlocalized pain. In some cases, pain may not be a reason for the dental consultation at all. The specific nature of the problem is sorted out during the consultation interview, where patient statements and other critical information are collected. In addition to revealing much information about the dental problem, this initial contact, if done in an open and nonthreatening manner, will usually disclose patients’ expectations, previous experiences, fears, and their understanding of the nature of their dental problem.

Because pain is so variable and its perception so subjective, history taking will require gathering and interpreting appropriate information. Patients frequently have strongly held preconceptions that may not be true or relevant. For example, often they believe they know which tooth is causing the problem. The clinician must be able to distinguish information that is useful, such as “I cannot bite on this tooth,” from that which is subjective, such as “The pain hurts me in these three teeth.” It is highly unlikely there are three teeth creating the patient’s problem, but it is quite common for pain to be referred to an area larger than the area of the offending tooth. A few pertinent questions to obtain greater insight into the patient’s specific problem may include:

“Is there a tooth that is bothering you at this time?”
“Are you experiencing pain?”
“How would you rate the pain on a scale of 1 to 10?”
“How long has the pain been present?”
“When did you first experience pain?”

In some cases, pain has continued after another clinician has attempted to manage the patient’s problem. In these cases, the following questions may be appropriate.

“Is the pain you are now experiencing any different from the pain you had before the previous treatment?”
“Can you recall what you were experiencing prior to the treatment performed by the other dentist?”

Hearing the patient describe their pain is essential to understanding their problem, interpreting the information gathered, and asking additional probing questions when necessary. Some patients may be accompanied by a spouse, parent, or friend who wishes to contribute to the interview. Generally, this is not very helpful. It is best to address the patient for this information.

“When do you feel this pain?”
“Is it a constant pain? If not, describe when or how it occurs and how long it might last.”
“Has the pain occured more frequently or lasted longer in the past few days or weeks?”
“Is the pain stimulated by something hot or cold?”
“Is there a time of day when the pain seems to be worse?”
“Does the pain awaken you at night?”
“How would you describe the pain? Is it dull? Is it sharp, like an electric shock?”

At this point, it is appropriate to ask the patient about any physical perceptions or concerns.

“Have you noticed any swellings, or do you feel swollen in any specific area?”
“Is there an area of your face that is tender to touch?”
“Are there any teeth that hurt or are uncomfortable when you chew or after you have eaten?”
“Do any of your teeth feel loose, or are you biting on any tooth sooner than other teeth?”

Interpretation of Historical Data and Subjective Findings

Interpreting historical data and subjective findings usually occurs simultaneously as they are secured, and these initial impressions usually direct the subsequent questioning. As a broad overview, let us consider these questions in the order they have been presented. Responses to the initial questions about the basic dental complaint can often lead directly to a clinical examination and a rapid diagnosis. If the problem were an acute abscess, for example, the patient would probably give enough information in the first two or three sentences to make a tentative diagnosis of abscess. Subsequent questioning would then concentrate on the presence of physical signs and symptoms of infection. It would remain to be determined if the abscess is of pulpal, periodontal, or other etiology.

Patients who have been experiencing chronic pain problems may not be feeling any pain at the moment of examination but can describe the chronic nature of it in detail. Endodontic problems can develop episodically over a period of time but will most often show a pattern of decreasing periods of comfort and increasing periods of discomfort. This may even be followed by periods of complete comfort.

The overall time frame for tooth problems is much shorter than for myofascial pain problems, which often come and go over a period of years. It is helpful to find out if there have been periods of complete resolution. This kind of history is also consistent with myofascial pain related to nocturnal bruxing or clenching, which is discussed in Chapter 6 on nonodontogenic pain. Within this diagnostic theme, it is common to awaken in the morning with facial pain. Both endodontic problems and myofascial pain problems can awaken patients from sound sleep, which is one of the few relatively objective measures of the severity of pain. Other typical symptoms of myofascial pain problems may mimic endodontic pathosis as well. As will be discussed in detail in Chapter 6, patients who have developed trigeminal neuralgia may experience severe and debilitating episodes of electric shock–type pain but are curiously never awakened from sleep with pain.

If the patient has not experienced appreciable pain, responses to the probing questions during data gathering often focus on a nodule or “bump” noticed on the mucosal surface or an area that is noticeably tender to touch. These findings may indicate a developing periapical lesion or a draining sinus tract. Other possibilities could include a wide range of possibilities, from a normal but previously unrecognized exostosis to a small swelling associated with blocked ducts of minor or major (Stensen’s duct) salivary glands. Diagnosis and treatment of many of these etiologies is beyond the intended scope of this book. Our purpose here is to rule these out as having a pulpal or periapical origin or focus.

Finally, some patients who come for a routine examination are found to have a clinical lesion of possible pulpal or periapical origin or a radiographic lesion discovered on the routine radiographic survey (see Chapters 2 and 3). It is still important to inquire about any history associated with these lesions. Many people may recall episodes of pain or local swelling in the past that may assist in clarifying these findings and providing a more accurate diagnosis. On the other hand, the radiographic lesion or interpretation of such may not be of pathologic origin.

Clinical Examination: Objective Findings

Visual Inspection

Clinical examination specifically for an endodontic diagnosis will focus on two areas: causative factors in the teeth (pulpal inflammation, infection, etc.) and signs of periapical pathosis in the soft tissues due to spread of an inflammatory/infectious process from the pulp.1,2 All of the teeth on the side of pain should be visually inspected. Gross caries is an obvious etiology for painful symptoms. Occasionally in a case of spontaneous pain, gross caries may be observed in a tooth, almost invariably a molar, in the opposing arch from where the pain has been felt. Further testing in such a case often indicates that the teeth in the area of felt pain are normal, whereas the opposing carious tooth is the source of the referred pain.




A 52-year-old male was seen on an emergency basis. His chief complaint was of acute, spontaneous pain episodes in the mandibular left molar area (Fig. 1-1, A). Visual examination revealed no caries or fracture lines in either the left maxillary or mandibular teeth. There was a very large amalgam restoration in the mandibular first molar, which was the area where the patient felt the pain was originating. Thermal sensibility (pulp) tests, however, elicited normal responses from all teeth in this area.


FIGURE 1-1 A, Left mandibular molars respond normally to thermal tests. B, Maxillary second molar with evidence of gross caries.


Failure to reproduce the patient’s chief complaint during the examination of this quadrant of teeth resulted in conducting further tests in other areas of the left side. Further tests were then conducted on the opposing teeth. The heat test elicited an acute, severe painful response on the maxillary second molar. A radiograph of this area revealed gross caries (see Fig. 1-1, B). Although there was no visual evidence of caries clinically, on removal of the occlusal composite resin, gross marginal leakage was apparent. Root canal treatment was indicated only on the maxillary second molar.


Another important process in the clinical examination is to search for the presence of coronal fracture lines.5 The majority of fractures occur in a mesial-distal direction, and frequently these are obscured by coronal restorations (Fig. 1-2). It is often possible to observe them only on the intact marginal ridges, but they may extend to or below the level of crestal bone on the interproximal surface (Fig. 1-3). Fractures may also be observed on the buccal or lingual surfaces.26 Two fracture lines on different surfaces may be evidence of a complete cusp fracture. For example, the combination of a deep lingual fracture line in the lingual groove of a mandibular molar and a fracture line on the distal marginal ridge distal could indicate the fracture of the distal lingual cusp, which is a common factor in the initiation of pulpal inflammation (Fig. 1-4).


FIGURE 1-2 Coronal fracture evident on intact marginal ridges. The mesial fracture line is obvious (black arrows). The distal extension of the same fracture is not as apparent but is visible (red arrow).


FIGURE 1-3 A, Coronal fracture extending over distal marginal ridge. B, Periodontal defect from extension of crack below crestal bone (arrows).


FIGURE 1-4 A, Fracture lines evident on distal marginal ridge and lingual developmental groove of mandibular second molar. B, In this case, the fracture resulted in complete separation of the cusp from the crown.

The soft tissues should be examined for physical signs of redness and swelling that may indicate that the periapical tissues have become inflamed or infected. Typically these specific physical signs would be evidence of a sinus tract, local swelling over the apices, or regional swelling (Fig. 1-5). Discoloration and edema may also be clues in a site of recent acute infection. In view of the original complaint of the patient, the clinician must be careful to avoid being misled by the accidental discovery of additional problems. For example, if the original complaint included a current history of acute thermal sensitivity, the visual observation of a sinus tract in the alveolar mucosa or attached gingiva on a single-canal tooth may be evidence of a pulpal problem, but it would probably not be the source of the symptoms for which the patient is seeking treatment. In this situation, the patient may have at least two distinct problems.


FIGURE 1-5 Swelling resulting from an acute periapical abscess.

Occasionally there may be signs of infection that are likely to be the source of the patient’s complaint but unlikely to be of pulpal or periapical origin. Pericoronitis around a partially erupted third molar is usually recognizable owing to its location; an endodontic problem with the second molar may have to be ruled out (Fig. 1-6). Much more common are periodontal abscesses, which may be more difficult to differentiate from periapical abscesses if periodontal disease is evident throughout the dentition.3,14 This diagnostic problem will be discussed further in the subsequent section on periodontal probing.


FIGURE 1-6 Pericoronitis associated with a partially erupted third molar (arrow).

The clinical examination is conducted with a series of instruments and techniques that might be considered the “tools of problem solving.” Each test or assessment technique can reveal a clue that may impact or confirm the ultimate diagnosis. Seldom will it be necessary to do all of the tests or techniques listed, but it is equally important not to jump to conclusions too early in difficult diagnostic cases. The process of clinical examination is intended to both identify the source of the symptoms or observed pathosis and to rule out pathosis on adjacent teeth. It may be difficult in some cases to reproduce reported symptoms, but it often will be possible to reach a confident opinion about the normality of certain teeth, thereby reaching a diagnosis through the process of elimination.

During a clinical examination, data are gathered using a multitude of tests and evaluative procedures. While some tests will focus on the status of the pulp, others will be used to ascertain the extent of the spread of pulp inflammation or infection to the supporting periodontium. At times, it is difficult to separate information that is pulpally related from information related to extension of the disease process or periapically related. It is the intent of this first chapter to focus on the gathering of key information that will initially provide evidence of pulpal status. Other findings gleaned in this problem-solving process must be correlated and integrated with a thorough examination of the supporting periodontium, along with quality radiographs. These data will then be integrated into a periapical diagnosis that will be addressed in Chapter 3.

Use of the Explorer

For diagnostic purposes, the No. 23 explorer or the DG16 endodontic explorer (both explorers can feature a No. 17 tip when the instruments are double ended) are useful for the detection of caries, open restorative margins, fractures, loose cusps, and fracture lines (Fig. 1-7). Interproximally, the extent of caries buccal lingually can be ascertained. If a cracked tooth is located in the area of pain, it is useful to explore the interproximal surface of the tooth with a fine No. 17 explorer (Fig. 1-8). Often it is possible to feel the presence of a deep fracture line and follow it vertically along the proximal surface. Obviously, the more apical the fracture is felt, the more likely there is pulpal involvement. If the fracture extends below crestal bone, periodontal breakdown may also occur, a finding with serious prognostic implications. This will be discussed in more detail in the section on periodontal probing and also in Chapter 3 on radiographic interpretation.


FIGURE 1-7 No. 23 explorer (left) and DG 16 endodontic explorer (right).


FIGURE 1-8 A, No. 17 explorer. B, Use of the No. 17 explorer to detect vertical fractures in the crown. C, Use of the No. 17 explorer interproximally for the detection of fractures.


One of the most informative but often overlooked evaluative procedures of the clinical examination is palpation. While not crucial for a pulpal diagnosis, for teeth with pulpal necrosis, palpation soreness or pain may reveal the presence of inflammation associated with periapical periodontitis.10 Reflecting on the anatomy of this environment is important in the interpretation of findings in this examination. Teeth with roots that lie close to the surface of the alveolar process will more likely exhibit palpation sensitivity or tenderness. Roots covered by relatively thin labial plates of bone or no bone at all are usually in the maxilla, with the apices of the central incisors, the canines, the buccal root of the first premolar, and the buccal roots of the molars often located anatomically superficial to the bony surface.12 Examination of teeth in human skulls indicates that fenestration of the apex or sections of the root surface is common in the absence of pathosis (Fig. 1-9).8 Periapical lesions of teeth in other areas are less likely to exhibit palpation tenderness, owing to the thickness of the buccal plate or the external oblique ridge in the case of the mandibular molars (Fig. 1-10).12 Nevertheless, in conditions of an acute periapical abscess, palpation tenderness, local swelling, and drainage through the gingival sulcus are not unusual even where the buccal bone is very thick.


FIGURE 1-9 Fenestration is a normal anatomic finding.


FIGURE 1-10 Apices of mandibular molars covered with thick, dense cortical bone. Palpation signs are less common in this area.


Pain or tenderness to tapping on a tooth (percussion) is not crucial to a pulpal diagnosis but is symptomatic of three other conditions. It may be a sequela of trauma, which applies to virtually all anterior teeth and is easy to identify by the history. A root canal procedure may not be indicated, because there may be no pulpal damage. Sensibility testing (formerly known as vitality testing) would be indicated. There may or may not be concomitant palpation tenderness with traumatized teeth, but if palpation tenderness is found, it will usually not be confined to the region over the apex.

Second, tenderness to percussion may be the result of periapical inflammation due to either a necrotic or an acutely inflamed pulp.1,10 In these cases, concomitant palpation tenderness may or may not be found only over the apices. Depending on the acuteness or chronicity of the underlying pathosis, both the percussion tenderness and concomitant palpation tenderness can be either mild or extremely acute. Included in this category are teeth that have coronal fractures, since it is the pulp that becomes painful from the flexing of the cracked cusp. However, sensibility tests would be necessary to establish a pulp diagnosis.

Third, tenderness to percussion may be a symptom of occlusal trauma, most often the result of nocturnal clenching or bruxing.1 The presence of a concomitant tenderness to palpation with this condition is rare. Furthermore, the pulps of affected teeth respond normally to sensibility testing. It is common to find more than one tooth equally sensitive and a history of episodes of discomfort separated by intervals of complete comfort. The reader is referred to Chapter 6 for additional information on this topic.

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Jan 2, 2015 | Posted by in Endodontics | Comments Off on 1: Problem Solving in the Diagnosis of Odontogenic Pain
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