A retrospective study evaluating the use of the panoramic radiograph in endodontics

Military Medicine, Jul 2003 by Bodey, Timothy E, Loushine, Robert J, West, Lesley A

Patients are referred to the endodontist to have root canal therapy performed to treat pulpal and periradicular diseases. Routinely, the only radiograph to accompany the patient is the periapical radiograph. This radiograph is inadequate in the detection of asymptomatic pathosis that may be present in other areas of the maxilla and mandible. The military's readiness mission requires that a panoramic radiograph be part of the patient's dental record. In addition to its use for personal identification purposes, the panoramic radiograph is an excellent diagnostic tool that can give the clinician an overall view of the dentoalveolar structures. This retrospective study evaluated randomly selected panoramic radiographs and recorded the presence of radiolucent and radiopaque areas not evident on a referral periapical radiograph. The results of this study found a 4.2% occurrence of undiagnosed pathosis following additional radiographs and clinical examinations.

Introduction

Radiography is used today to provide information about hard and soft tissue anatomic structures and to detect pathosis that may not be clinically evident. Wilhelm Roentgen discovered X-rays in 1895. During these experiments, he concluded that X-rays could have diagnostic value in the medical field. After he reported his findings, many medical researchers recognized the significance of using the newly discovered rays. The use of X-rays in dentistry began in 1896 when radiographs were made of the teeth and jaws.1

Great advances have been made in the field of radiology during the past century. Today, we not only have the basic periapical radiographs (PAX) and bitewing radiographs (BWX) but also the panoramic radiographs (PR), conventional and computed tomography, and digital radiography. These different types of radiographs in addition to imaging processes such as magnetic resonance imaging, ultrasound, and thermography allow the dentist to view both the hard and soft tissues of the maxilla and the mandible. Unfortunately, much of this equipment is cost-prohibitive for routine use in the dental office and, therefore, many practitioners depend upon the PAX or PR to assess the dentoalveolar structures of the maxilla and mandible.

The standard PAX film (1 1/4 inches x 1 1/2 inches) has a limited area of diagnostic value. The clinician is restricted to viewing the anatomy of a few teeth and supporting structures. Even with a full-mouth series of PAX films, there are areas of the hard tissues not visualized that may contain undetected pathosis. The BWX film (2 1/8 inches x 1 1/8 inches) is an excellent diagnostic aid for detecting caries in the clinical crown, abnormalities found in the pulp chamber, and moderate to advanced periodontal disease. However, it has limited value for detecting pathosis associated with the root and supporting bony structure. The PR film (5 inches x 12 inches) serves as a valuable adjunct to the PAX and BWX. Although the image of a PR film does not have the resolution of an intraoral film, it is excellent for general survey purposes. A suspicious area on the PR can give the clinician justification for ordering more specific radiographs and diagnostic testing.

The purpose of this retrospective study was to evaluate 1,000 randomly selected PRs and to record nonanatomic radiolucent and radiopaque areas. Additional clinical examinations and radiographs were used to evaluate these suspicious areas to determine the percentage of undiagnosed pathosis in these patients.

Materials and Methods

PRs from 1,000 randomly selected records from the Dental Activity, Fort Gordon, Georgia, representing individuals from all regions of the United States, were reviewed. All PRs were evaluated on a view box2 by one clinician in a dental operatory over a 15-month period. If any pathosis was detected, then a second clinician would confirm its presence on the PR.

The PR was placed on the view box over a black construction paper frame fabricated to eliminate any peripheral light. The PR was then scanned visually using a plastic eye mask designed for dental radiography that incorporates a magnifying lens, X-Produker (Johansson Och Co, Malmo, Sweden). Any radiolucent or radiopaque abnormalities that were not detected on previous routine examinations were recorded.

An informal telephonic survey was conducted with 3 endodontists and 35 general dentists in the Augusta, Georgia, area to obtain a better understanding of the radiographs sent by the referring dentists. The endodontists were asked the following questions: (1) Do you have a PR machine in your office? (2) What kind of radiograph do you usually receive from the referring dentist? The general dentists were asked the following questions: (1) When you refer a patient to an endodontist, what kind of radiograph do you routinely send? (2) Do you have a PR machine in your office?

Results

The data obtained from 1,000 PRs revealed that 4.2% of the PRs had undiagnosed radiolucent or radiopaque pathosis. Both odontogenic and nonodontogenic pathosis were included in this category.