356 Reviews and abstracts Am. J. Orthod. Dentofac. Orthop. October 1986

groups. Although the correlation coefficients were only moderate, the orthodontists’ ratings concurred with pa- tient responses more often than the dental students or either group of laypersons.

A careful initial consultation is necessary between the patient and orthodontist to determine the true chief complaint and sincere motivations for treatment. Cli- nicians should recommend the appropriate treatment, including surgery if necessary, to meet the patient’s functional or esthetic objectives, but an effort must be made not to make patients overly aware of minor es- thetic deficiencies that were not part of their initial complaints.

Clinical, Radiographical and Electromyographical Study of Patients With Internal Derangement of the TMJ A. Isberg, S.-D. Widmalm and FL lvarsson Dept. of Oral Radiology, Stomatology, and Physiology, School of Dentistry, Karolinska Institute, Stockholm, Sweden (From J. Dent. Res. 64: 764, 1985.)

Patients with clinically and radiographically diag- nosed internal derangement of the TMJ were elec- tromyographically examined. Ongoing nonfunctional muscle contraction was found to be directly related to a faulty disc position. The contraction ceased every time the disc position became normalized in association with opening clicking. Nonfunctional muscular activity was also registered before the condyle passed the posterior band of the disc during both mouth opening and closing. This muscle activity was interpreted as a protective arthrokinetic reflex to prevent traction of joint com- ponents. However, it contra-acted the downward move- ment of the condyle which is a prerequisite for the condyle to pass the posterior band of the disc and slide into a normal position again. One patient was registered during both clicking, transient locking, and in a closed lock situation. During progress from clicking to closed

lock, the nonfunctional muscle activity increased. When the disc was permanently displaced (closed lock), spasm occurred in the temporal muscle area on the ipsilateral side. The result showed that nonfunctional muscle activity in the temporal and masseter areas can occur secondary to TMJ disc displacement and cease when the disc position becomes normalized.

This study was supported by grants from the Swed- ish Medical Research Council, proj. no. 6877 and Rag- nar Siiderbergs and Torsten Soderbergs Foundations, Stockholm. Sweden.

Profile Changes in the Child and Young Adolescent J. H. Hoskin Department of Orthodontics, University of Pretoria, Republic of South Africa (From J. Dent. Res. 64: 775, 1985.)

It is reported in most standard orthodontic textbooks that the profile flattens with growth of the face. The purpose of this study was to determine the profile changes between 6 and 18 years of age.

Black-and-white photographs of the lateral view of the face were taken. Pictures were standardized and printed life-size. The sample was selected purely for age; no facial characteristics were considered. Three angular and four linear measurements were used to study the vertical and horizontal changes in the profile. The soft-tissue N-PO line was used as reference plane.

The thickness of the upper and lower lips in both sexes remained constant. There was a signijcant in- crease in nose size in the horizontal plane: males in- creased from 16.4 to 22.3 mm and females from 16.1 to 21.6 mm at I8 years of age (P -C 0.025).

The total vertical measurement of the face also showed a signijicant increase in both sexes: males from 94.8 to 123.3 mm and females 92.6 to 113.9 mm (P < 0.025). The angular direction of facial growth remained constant at 54” in both sexes.