Pericoronal radiolucencies with and without radiopacities.

Pericoronal radiolucencies are common entities of the jaws that account for about 15% to 20% of all biopsy specimens. They are usually slow-growing, benign entities that involve odontogenic epithelium and the crown of a nonerupting tooth. Many lesions develop early in life and are detected during routine radiographic examination. Others are found in later years when a patient presents with a slow-growing swelling. The dentist is often the first provider to encounter these conditions. Thus, he or she must be familiar with their appearance and understand the proper management required.

Radiolucent halos associated with radiopaque composite resin restorations.

Since the introduction of radiopaque composite resins, clinicians and researchers have occasionally noticed radiolucent halos adjacent to composite restorations. Such halos have frequently been thought to be recurrent caries or voids in the material. Fifteen of 45 radiopaque composite resin restorations placed by students enrolled in a first-year preclinical operative dentistry course exhibited such halos. Micrographs showed that a thick layer of unfilled resin bonding agent was present. These halos were reproduced in other teeth when excess bonding was not blown off. The results indicate the importance of meticulous technique.

Significance of condylar positions in patients with temporomandibular disorders.

Radiographs of closed condylar positions in subjects with symptoms of temporomandibular joint disorders are compared with those in subjects without symptoms. Of the condyles in asymptomatic subjects, 30% had anterior or posterior deviations of more than 1 mm in either direction. Of the condyles in symptomatic subjects, 27% had anterior or posterior deviations of more than 1 mm. As the findings are almost the same for both groups, it appears that condylar position in the fossa, as determined by transcranial radiographs, is of questionable significance as it relates to the symptoms of temporomandibular disorders.

Intraoral or panoramic radiography?

When panoramic radiographs are used to replace full-mouth radiographic series for the pediatric patient, certain advantages and disadvantages of this technique should be understood. The panoramic exposure offers ease of operation, shorter working time, and greater coverage than does the intraoral full-mouth series. However, certain shortcomings are noted. Rotations of maxillary premolars appear where there are none, and confusion exists in the anterior region about rotated teeth. Supernumerary teeth are frequently missed on the panoramic film in the anterior region. Because of this it is wise to supplement the panoramic image with anterior periapical films. Posterior bitewing films are a necessary supplement to the panoramic examination and with them interproximal caries, periapical lesions, and other details not visualized on the panoramic film are noted. It is imperative that the dentist understand confusing panoramic images that result from motion, superimposed structures, and apparent rotations, so that missed diagnoses do not occur.

Entrepreneurial science and the university.

KIE: The relationship between universities and the free enterprise system has become increasingly controversial as researchers and universities reap profits from scientific investigations. A review is given of developments in this relationship and issues which have been raised at symposia of university leaders and researchers, and by individual professors and students. These issues include conflict of interest, secrecy, patent ownership, research priorities, the role of graduate students, public confidence, and the traditional norms of scientific research. It is concluded that future university deliberations about these concerns should represent a broad range of disciplines and viewpoints, and be open to students, the public, and the press.^ieng

A clinical study of cysts arising from mucosa of the maxillary sinus.

Panorex radiographs taken during the past 5 years at the University of Kentucky College of Dentistry were reviewed for evidence of mucosal cysts of the maxillary sinus. Thirteen patients with this lesion were recalled for re-evaluation of their status. Ten of the patients had symptoms that could be related to the involved sinus. These included stuffiness, fullness, postnasal drip, gushing of yellow fluid from the nose, and headache. Radiographic examination revealed that three of the cysts had increased is size, three had decreased in size, three had not changed in size, and two had disappeared; no evaluation could be made on two. On the basis of radiographic, transillumination, history, and clinical findings, the nine cysts that could be evaluated were diagnosed as being of the nonsecretory type of mucosal cyst. We recommended periodic radiographic examination for this type of lesion. Surgical intervention is necessary only if destruction of surrounding bone has occurred or recurrence of disturbing symptoms is reported.