Volume 94 Number 2

Reviews and abstracts 177

findings, such as the range of mandibular movements, joint sounds, and the evidence of degenerative joint disease, were strongly associated with specific internal derangements. However, other clinical findings, such as muscle palpation, the history of the patient’s pain, and many occlusal factors, could not be associated with a specific arthrographic diagnosis. By use of decision rules formulated from a stepwise discriminant analysis, we were able to predict arthrographic diagnoses with reasonable accuracy. From a simpler set of rules, rea- sonable predictions were possible, but not on the total patient population. With both sets of rules, the most difficult patients to predict were those with normal ar- thrographic findings. We concluded that Q reason&y accurate prediction of internal derangements of the temporomandibular joint can be made from clinical jindings. However, for the dejinitive diagnosis of intra- capsular disease, radiologic evaluation may be nec- essary.

Dimensional Changes of the Human Face as Related to Skeletal Maturation Indices Edward P. Snyder Eastman Dental Center, Rochester, N.Y., 1987

Records of 20 female and 18 male subjects collected at the Denver Child Research Council were used. These were taken on a regular schedule from infancy to adult- hood and included lateral cephalograms and hand-wrist x-ray films. Tra.cings were made and 29 cephalometric points were marked by means of the definitions estab- lished in the Michigan Atlas of Craniofacial Growth by Riolo and associates. These were digitized and 31 linear and 30 angular measurements derived. The skel- etal maturity index (SMI) of Fishman was used to es- tablish the skeletal maturity age (SMA) of the subjects at the time each lateral cephalogram was taken.

Data from each subject at the age closest to 14 years were collected and compared with the Downs standards. Although differences were rated between the two, they were well within the limits of normal variation, espe- cially for skeletal features. The sample was therefore considered representative of a normal population as de- fined by Downs.

Subjects were separated according to sex and com- bined into three skeletal maturity levels that represented accelerating peak growth and decelerating phases of the adolescent growth spurt-SMI 1-3, SMI 4-7, and SMI 8-11, respectively. The SMA method was compared with the Michigan standards and found to be a more consistent way of determining growth changes than

chronologic age. The percentage change between these groups was determined and the male and female growth rates found to be essentially the same, indicating that the biologic process controlling growth during the pu- bertal growth spurt is common to both sexes. Male and female subjects grew the same; they just grew at dif- ferent chronologic ages.

Collagen Typing of the Human Temporomandfbular Joint Meniscus Paul D. Regan Eastman Dental Center, Rochester, N.Y., 1987

Configuration of the TMJ meniscus is dependent on its collagenous fiber network, which can change in re- sponse to stress. Internal derangements may cause or be caused by alteration of the collagen. This research was directed toward development of a reliable method for identifying collagen type in human meniscus as a means of studying the problem.

The samples were analyzed via SDS slab gel elec- trophoresis using acrylamide gel. A stacking gel placed on top of a gradient gel gave greatly improved reso- lution. Quantitative analysis of the gels was carried out with a Beckman DU-50 spectrophotometer. Type I col- lagen was identified; but also identified was another substance that may have been Type II or Type III col- lagen. Work continues to determine whether collagen type in the meniscus varies by region.

Computer Tomographic Evaluation of the Density of the TMJ Meniscus Mario E. Paz, Richard W. Kstzberg, Ross H. Talknts, and J. Daniel Subtelny Eastman Dental Center, Rochester, N.Y., 1987

Pathologic alteration of the attic&r disk including moderate calcification within the disk proper reportedly occurs in as many as 75% of the TMJ dysfunction cases with chronic anterior meniscal displacement. The pur- pose of this investigation was to measure by direct sagittal computed tomographic (CT) scanning technol- ogy, the density (x-ray attenuation) of the meniscus. Fifty-two patients, shown to have meniscus displace- ment with or without reduction (MD/MDR), and 24 symptomatic patients with normal CTs were evaluated using a GE 8800 CT scanner. Mean attenuation values were extrapolated by use of a symmetrical (1 to 9 pixels) region of interest (ROI) cursor. Density gradients of retromeniscal tissue, lateral pterygoid fat pad, and lat-