Retention of a maxillary primary canine: fifty years above and beyond the call of duty.

A case is reported of a retained maxillary primary canine that functioned effectively over fifty years. At the time of exfoliation the tooth was still of normal length and was lost not because of ankylosis and root resorption, but because of periodontal disease. Excellent histological preservation of the specimen at the time of exfoliation, together with a very complete clinical history, permitted the development of a detailed description of a tooth and its dying pulp while under function over a long period of time.

Healing of periapical radiolucencies after nonsurgical endodontic therapy.

Eighty-nine periapical radiolucencies treated by nonsurgical endodontic therapy were evaluated to better understand the healing rates of these lesions. After at least 3 months after treatment, radiographs revealed that 46.1% of the lesions had resolved, 48.

Effect of environmental factors on film badge dosimetry readings of dental office personnel.

Inadvertent exposure of film badges to environmental factors may produce fogging of the film and yield higher radiation exposure readings. Common environmental factors in everyday living were studied to assess their effect on film badge readings. Only heat appeared to have any significant effect, because moisture, chemicals, pressure, cold temperature, and non-work-related electromagnetic radiation did not substantially alter film badge readings.

Pathological sequelae of "neglected" impacted third molars.

An NIH conference on "Removal of Third Molars" debated the need for removal of asymptomatic impacted teeth with no evidence of pathology but stressed the need for long-range studies. The assumption is that "neglected" impacted third molars (ITMs) will sometime cause serious pathology. Examination of panoramic radiographs of 11,598 patients revealed 1,756 patients with 3,702 impacted teeth; average age 47 years, and an average retention period approximately 27 years.