Report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

Comparison of three radiographic methods in screening of temporomandibular joint involvement in patients with psoriatic arthritis

Fifty-three randomly selected subjects with psoriatic arthritis (PA) were examined radiographically by means of orthopantomography, transcranial radiography, and transmaxillary radiography. Two examiners graded the radiographic signs of flattening, osteophytes, erosion, and sclerosis. The findings obtained were then compared, to determine the best technique for screening of temporomandibular joint (TMJ) bone changes. Together the techniques showed definite (24%) and possible (6%) changes suggesting TMJ involvement in 31 (30%) of 106 joints. In all projections radiographic signs suggesting TMJ involvement were most frequent in the condyle. Erosion in the condyle was the most frequent finding. Agreement with regard to definite changes in the condyle was found in only one-third to half of the cases. It is concluded that in radiography of the TMJ in subjects with PA a combination of radiographic techniques should be used to obtain maximum information. However, orthopantomography is well suited for screening of TMJ involvement in subjects with PA.

A dynamic model of etiology in temporomandibular disorders

A dynamic model is proposed to depict the etiology of temporomandibular disorders. A balance is described between destructive factors in the masticatory system that result in dysfunction, and adaptive factors that tend to return it homeostatically to normal. Five factors that cause or potentiate muscle hyperfunction are included on one side of the model with five other factors that affect the ability of the system to adapt on the other side. Relationships among the etiologic factors are discussed, and literature support for each is cited.

Simple application of anterior jig or leaf gauge in routine clinical practice

Utilization of either of the two described methods by dentists is recommended as a simple means to routinely record or provide centric relation closures. The leaf gauge (1 to 6 mm thick) can be made from plastic or x-ray film or it can be purchased. The anterior acrylic resin jig can be made in a few minutes directly in the mouth by the dentist or an assistant or by a technician using mounted casts. Both methods avoid adaptive mandibular closure patterns and dentist-guided jaw closure as well as other commonly unrecognized errors in assessing occlusal contacts.

New device for accurately recording centric relation

A new system for recording jaw relations has been described. It is easy to learn to use correctly, is pleasant to the patient while assisting the patient's neuromusculature into the desired retruded closure at the specific vertical dimension preselected by the dentist, and its uses minimal amounts of recording media. Duplicate records can be quickly made for verification, various recording media may be used, improved stability during mounting is obtained, and the method is applicable in most dentulous and partially edentulous situations. Two elements are used, a dental arch-shaped, partially performed, thin, waterproof wafer and a disposable paper leaf gauge. The paper leaf gauge is narrower and more solid than the plastic leaf gauge and thus forms a better anterior leg of the tripod with the two condyles on patient-guided terminal hinge closures. The leaf gauge of preselected thickness is inserted into a slot in the wafer that has been deformed exactly like the occlusal plane by a previous centric occlusion closure. The system is quick, economical, and less complex than most methods presently used. Even so, it accurately reproduced six check-bites on one patient according to comparisons on the Veri-check instrument (Denar Corp., Anaheim, Calif.).

Report of Committee on Scientific Investigation of the American Academy of Restorative Dentistry

A few personal points seem appropriate in summary. It is axiomatic that while research solves problems, it also creates them. As an example, it is an accepted fact that dentistry more than any other profession has made serious inroads into putting itself out of business through research. Each year this report takes note of the reduction in dental caries in children, which has thus triggered a change in the nature of general practice. Be this as it may, it is well to acknowledge that major dental diseases are not disappearing, but their patterns in the population are changing, accompanied by an expansion of other services. Despite the optimistic picture painted earlier in this report, it is grossly premature to acclaim the elimination of caries, and thereby a significant segment of restorative dentistry. Of course the younger age groups have been the major beneficiaries of caries reduction. As the child ages from 9 to 16 years, the percentage of mouths free of caries drops by one half. In addition, the disease pattern in the adult population is being altered because of a longer life span and loss of fewer teeth. Unquestionably what we will, and are already seeing, is not an elimination of restorative dentistry but a different target and changes in procedures because of new materials, therapy, and expanded scope of services. There is yet another subtle change in the trend of dental research and it deals with the reduction in the number of dental schools worldwide and smaller class sizes in those schools. Dental research thereby suffers because of the traditional link between education and research. Thus the potential pool of researchers becomes smaller and research monies for training programs for dental investigators, particularly in clinical research, decreases. This year a surprising number of articles are concerned with manpower as it relates to research priorities. So, it is indeed a time that both the profession and the scientific community find filled with controversy and frustration. Yet never has there been a time that offers more in challenges and rewards.