Bhaskar, in his textbook on radiographic interpretation, listed 38 radiolucent lesions and other abnormalities of the jaws. Three of these lesions, dental granuloma, radicular cyst, and abscess, are categorized as being related to necrotic pulps.

The dentist must therefore differentiate between the endodontic and the nonendodontic lesions, ruling out those that trace their origin from non–pulp-related sources. Additional confusion in radiographic diagnosis relates to normal radiolucent and radiopaque structures that lie within or over apical regions. Differential diagnosis of periradicular pathosis is essential and, at times, confusing. There is a tendency for the clinician to assume that a radiolucency is an endodontically related lesion and that root canal treatment is necessary without performing additional confirmatory tests. Avoid this pitfall!

The dentist must therefore be astute as well as knowledgeable when diagnosing bony lesions. It is important that teeth with sound pulps not be violated needlessly because of the mistaken notion that radiolucencies in the apical region always represent endodontic pathema. The reverse is also true; endodontic lesions may mimic nonendodontic pathosis.

Significantly, mostradiolucent lesions do indeed trace their origin to pulpal disease. Therefore, the dentist is likely to encounter many more endodontic lesions, because of their sheer numbers, than other types of pathosis. However, many of the nonendodontic lesions mimic endodontic pathema, with similar symptoms and radiographic appearance. On the other hand, many of the nonendodontic lesions are symptomless (as endodontic lesions frequently are) and are detected only on radiographs. To avoid errors, the dentist must approach all lesions with caution, whether symptomatic or not. Differentiating between lesions of endodontic and nonendodontic origin is usually not difficult. Pulp vitality testing, when done with accuracy, is the primary method of determination; nearly all nonendodontic lesions are in the region of vital teeth, whereas endodontic lesions are usually associated with pulp necrosis, giving negative vitality responses. Except by coincidence, nonendodontic lesions are rarelyassociated with pulpless teeth. Other significant radiographic and clinical signs and symptoms, however, aid in differential diagnosis.

Primarily, a dentist must depend on himself, not the laboratory. Therefore, knowledge is the most important asset the dentist must possess. This includes familiarity with all local orofacial causes of pain, as well as numerous systemic, neurogenic, and psychological causes. In addition, the dentist must be aware of the many physical, perceptual, emotional, and behavioral changes brought about by chronic pain. He must know that constant overwhelming pain can affect the function of every organ of the body. Chronic pain patients can develop increased blood pressure, heart rate, kidney function, decreased bowel activity, and hormone levels. They can have many symptoms, such as nausea, vomiting, photophobia, tinnitus, and vertigo. The astute clinician gathers knowledge about the patient and his problem through a thorough history and an examination. The history and examination include evaluating the physical, emotional, behavioral, and perceptual aspects of the patient’s pain experience.

Under knowledgemust also be listed the important asset of knowing when and where to refer the patientfor additional consultation. This comes with experience and the help of physicians, psychologists, and fellow dentists who may be depended on to assist in diagnosis. Often the patient is referred because examination reveals a problem clearly in the province of the neurologist or otolaryngologist. Sometimes the patient is referred because the examiner has exhausted his knowledge and needs help in diagnosis. The recognition of fallibility and limitation—knowing when to yell for help—is also a major asset to the dentist.

Anamnesis,“recollection” or “calling to memory,” is the first step in developing a diagnosis. The importance of obtaining and recording this “history” goes beyond medicolegal protection. A complete history will not determine treatment but may influence modifications in endodontic treatment modalities. It will seldom deny treatment. A complete medical history should contain, as a baseline, the vital signs; give early warning of unsuspected general disease; and define risks to the health of the staff as well as identify the risks of treatment to the patient. The medical history must be updated regularly, especially if there have been any changes in the patient’s health status.

Once the status of the patient’s general health has been established, a dental diagnosis is best developed by following the time-honored formula of determining the chief complaint,enlarging on this complaint with questions about the present dental illness,relating the history of past dental illness to the chief complaint, and combining this with information about the patient’s general health (medical history)and the examination results.