volumea7 Number
Reviews
was much more variable, possibly of reduced magnitude, and occurred at a slower pace. However, a response qualitatively similar to that in juveniles was observed in one third of the experimental sample. It is suggested that the osteogenic response may be triggered by periosteal tension transmitted by fibers of the posterior portion of the articular disk (retrodiskal pad). As skeletal adaptations reduce the need for habitual anterior posturing of the mandible by the lateral pterygoid muscles after 8 weeks, tension on the disk fibers diminishes to levels present during normal jaw excursions and the stimulus for further osteogenesis is eliminated. T. M. Graber
Effect of Increased Upward Displacement of the Glenoid Fossa on Mandibular Growth Tuomo Kantomaa Eur.
and
abstracts
85
1
J. Orthod.
6: 183-91,
1984
What is the exact role of the condyle, as compared to the temporal bone fossa, in the accomplishment of vertical mandibular growth? Does the Moss h:ypothesis of condylar subservience to functional forces (that is, downward pull by muscles) explain this phenomenon? In this study, the vertical growth of the mandibular condyle was studied by inducing an artificial increased upward displacement of the glenoid fossa in twentynine young rabbits. Twenty-nine untreated animals served as controls. The reactions of the craniofacial structures were studied biometrically, histologically, roentgenographically, and from photographs of the temporomandibular joint. The ramus of the mandible was significantly higher in the experimental animals at 50 days but not at 100 days, and the mandible showed a tendency toward an increase in length. The condyles of the 15- and 25-dayold experimental rabbits were located further downward and forward in relation to the fossa than in the control animals. The whole mandible had shifted forward and tilted upward posteriorly in relation to other structures, such as the skull base, pterygoid processes, and the maxillary molars. In the lOO-days-of-age group, an edge-to-edge or inverse incisor relationship was observed. The results indicate that the adaptability of the condylar cartilage expresses itself mainly in a change in direction of growth. However, they do not support the hypothesis that the vertical growth of the condyle is the result of a downward pull of the mandible. The author
suggests that, rather, it might be that the growth of the cartilage pushes the mandible downward. T. M. Graber
Chronic Pain and TMJ Syndrome Gerald D. Smernoff Bethesda, 1983. Ark1 Price, $4.00
Enterprises.
12 pages.
illustrated.
The profusion of articles on temporomandibular joint problems and the greatly enhanced interest in clinical aspects and treatment have spawned a number of patient-education manuals. Recently the well done, color-illustrated Higdon book was reviewed. This little paperback manual, written by an ABO Diplomate, is more general and is directed specifically at the prospective or new patient, explaining the “great imposter,” TMJ syndrome. The author refers to it as a “spectrum of syndromes” and then enumerates and describes the symptoms, unique character of the TMJ complicating factors, diagnostic considerations, and treatment possibilities. With five black and white drawings and only twelve pages, the booklet can only skim the surface. But it is surprisingly complete and would make a good handout to all TMJ patients, both new and already in treatment. The writing style is interesting, and the details are sufficiently general to cover most therapeutic rationales. Since patient communication is the name of the game with TMJ patients, particularly, booklets of this type can help significantly to make the patient better understand the problems and possible solutions, and valuable chair time can be reduced. The publisher has a quantity discount for those desiring more than ten copies. T. M. Graber
Prostaglandins and Tooth Movement J. FL Sandy and M. Harris Eur.
J Orthod.
6: 175-182,
1984
The exact mechanism of tooth movement still is an enigma, despite extensive animal research, largely of a histologic nature. More recently, intracellular biochemistry has been examined, specifically with regard to the role of secondary cell messengers such as cyclic adenosine monophosphate (CAMP). Research in the past 5 years has shown that prostaglandins are short-acting, locally produced modulators of bone resorption and possibly bone formation. In this study, the effect of flurbiprofen, a prosta-