Tooth ankylosis. Clinical, radiographic and histological assessments

Ankylosis is a serious condition for the affected teeth as such teeth form part of the remodelling process of the alveolar bone and are therefore progressively resorbed. There are, however, very few clinical studies on tooth ankylosis and the reason for this may be due to the difficulties that are encountered in the diagnosis of minor areas of ankylosis. In the present study, the radiographs, percussion sound and mobility of experimentally extracted and replanted monkey incisors were compared with a morphometric histological study of ankylosis. Ankylotic areas were evident radiographically when the ankylosis was located on the proximal surfaces of the root, but were not evident when the ankylosis occurred on the lingual and labial surfaces. The percussion sound was dull and the mobility normal in all non-ankylotic teeth as well as in those teeth which histologically demonstrated ankylosis on less than 10% of the root surface. When the ankylosis affected 10-20% of the root surface, 2 out of 4 teeth changed their percussion sound from dull to high and these teeth no longer possessed normal mobility. When more than 20% of the root surface was affected with ankylosis, the percussion sound was characteristically high in all teeth and no mobility was present.

Patient-selection criteria for panoramic radiography

The purpose of this study was to determine whether selection criteria could be developed for the use of panoramic radiographs in the treatment planning of patients seeking dental care. A total of 1,424 patients were included in this 10-month study. Clinicians were asked to indicate what signs or symptoms caused them to order a panoramic radiograph. After the radiograph was taken, the referring clinician was asked to indicate the extent that the panoramic radiograph influenced the patient's care. The panoramic examination was found to be most productive in dentulous patients when no other radiographs were ordered and least productive in dentulous patients who had already had a full-mouth set of radiographs. Considering all patients, it is possible to reduce the number of panoramic examinations by 73% while missing 6% of the findings that influence patient treatment. The most important selection criteria for the panoramic examination are whether the radiograph was ordered for a "general screening examination" (a negative predictor) and whether the radiograph was ordered for any specific examination (a positive predictor).

A critical evaluation of panoramic radiography as a screening procedure in dental practice

One thousand consecutive panoramic radiographs were assessed to determine the risk/benefit relationship involved when this technique is used to screen patients for previously undiagnosed pathologic processes. The results of the investigation do not support the use of this technique as a routine procedure in general dental patient assessment.

Effective exposure level and diagnostic performance in endodontic radiography

Image quality is limited by the information capacity of the image-forming system and can be computed from three parameters: contrast, resolution, and noise. These parameters can be combined to yield a single measure which determines the maximum amount of information obtainable from any x-ray system and is called the noise-equivalent number of quanta (NEQ) per unit area. The effects of image quality, expressed as noise-equivalent number of quanta (NEQ) per unit area, on the radiographic performance by dentists reading the position of an endodontic file in a root canal were studied. Three different speed films were used in conjunction with a fixed screen. NEQ values ranged between 0.64 x 10(4) and 14.3 x 10(4) per square millimeter. Components of variance associated with the position of the tooth apex and the tip of an endodontic file in a root canal were compared for the effect of different NEQs and observers. Results show that the standard deviation in locating a file tip and tooth apex may be a linear function of log NEQ. The estimated standard deviation associated with changes in NEQ was found to be relatively small compared to that observed among dentists. These findings indicate that a significant reduction in exposure would have a relatively small effect on the precision of endodontic distance measurements.

Observations of dental disease and anomalies in 9- to 11-year-old Norwegian children

Sets of intraoral radiographs consisting of ten periapicals and, in most cases, two posterior bitewings, from 99 girls and 101 boys aged 9-11 years were examined by four dentists. The study was undertaken to quantitate the disease and anomalies present in the sample and investigate the inter-examiner variability of the diagnosis. Each of the examiners independently recorded the disease and anomalies from the radiographs. Knowledge of previous dental treatment and abnormalities noted by the community dental officers were obtained from the children's dental records. The prevalence of disease and anomalies in the sample was low. Considerable examiner variability revealed a need for more objective criteria for the radiographic diagnosis of some of the dental anomalies. Girls had a significantly higher DMFT than boys. Hypodontia was found in 13 children, and dens invaginatus class III/IV (9) was observed on radiographs from 5 children.

Hypercementosis--an important clue to Paget disease of the maxilla

Paget disease of the maxilla and mandible is not rare. There appears to be a significant correlation between skull involvement in the form of osteoporosis circumscripta and maxillofacial changes. The maxillary component can be of the typical form of Paget disease or be in the form of hypercementosis. The latter change is not well recognized and we present two cases with such involvement.