No abstract

The aim of this summary of a longitudinal investigation on temporomandibular disorders (TMD) was to present the prevalence figures of signs and symptoms of TMD and certain other examined variables, and the correlations between these variables, over a 20-year period. Originally, 402 randomly selected 7-, 11-, and 15-year-olds were examined clinically and by means of a questionnaire. The same examination procedure was repeated three times: after 4-5 years and after 10 and 20 years, respectively. Signs and symptoms of TMD were mainly mild, but common already in childhood. They increased up to young adulthood, after which they leveled out. Progression to severe pain and dysfunction was rare, and spontaneous recovery from more pronounced symptoms was also rare. Significant correlations between reported bruxism and TMD symptoms were found, and a baseline report of tooth-grinding was a predictor of TMD treatment during the 20 years covered by the investigation. Occlusal factors were only weakly associated with TMD signs and symptoms. However, a lateral forced bite between the retruded contact position (RCP) and the intercuspal contact position (ICP) and a unilateral crossbite deserve further consideration as possible local risk factors for development of TMD. In conclusion, a substantial fluctuation of TMD signs and symptoms was observed in this sample of Swedish subjects followed for 20 years from childhood to adult. The demand for TMD treatment was low at all examinations, while the estimated treatment need was larger. One-third of subjects who had some kind of orthodontic treatment did not run a higher risk of developing TMD later in life.

Note This research was financed by the Harry Ca-rothers Wiess fund of the department of geology of Rice Institute. We thank John M. Whitfield for helping to assemble the collection studied. November 1957On the Presence of 3-Hydroxytyramine in BrainThe compound 3-hydroxytyramine has attracted interest as a probable intermediate in the biosynthesis of noradrenaline and adrenaline and also as a possible neurohumoral agent. It has been shown to occur in the urine (1), in the adrenals (2, 3), and in the heart (2) of sheep and in the splenic nerve of the ox (4). The study of this compound has been hampered by lack of sensitive and specific assay methods. Apart from bioassay techniques, only the fluorimetric ethylenediamine condensation method of Weil-Malherbe and Bone (5) appears to be sufficiently sensitive for biological purposes. However, with this method the fluorescence spectra obtained from 3-hydroxytyramine and adrenaline are almost identical (6). In the fluorimetric method of Euler and Floding (7), the fluorescence obtained from 3-hydroxytyramine is very weak and amounts to only a few percent of that obtained from noradrenaline or adrenaline.Recently we observed, however, that if the pH of samples prepared essentially according to this method was adjusted to about 5 by means of acetic acid, a fairly strong fluorescence developed. Furthermore, the activation and fluorescence peaks (345 and 410 m,g, respectively, as read in an Aminco-Bowman spectrophotofluorimeter) were at much shorter wavelengths than those obtained from noradrenaline and adrenaline, so that these compounds did not interfere, even if they were present in comparably large amounts.Using this technique in combination with ion-exchange chromatography (Dowex 50), we have started to investi-also possible that early crystallization of plagioclase grains causes them to be isolated from each other by later forming minerals such as quartz and potassium feldspar. Quartz, however, does not seem to affect the development of neighboring grains, and it also appears that no mineral affects the development of other mineral species (1). Note 1. This research was financed by the Harry Carothers Wiess fund of the department of geology of Rice Institute. We thank John M. Whitfield for helping to assemble the collection studied.13 November 1957

The aims were to study the development over 20 years of reported temporomandibular disorders (TMD) symptoms in an epidemiologic sample and to analyze possible correlations between these symptoms and some other variables. Four hundred and two randomly selected 7-, 11- and 15-year-old subjects were originally examined by means of a questionnaire with regard to symptoms of TMD. The investigation was repeated after 4 5, 10, and 20 years, using the same method. After 20 years, when the original group had reached the age of 27 to 35 years, 378 individuals (94%) could be traced, and they were sent a questionnaire. Three hundred and twenty subjects (80% of the original sample, 85% of the traced subjects) completed and returned the questionnaire. There was a substantial fluctuation of reported symptoms over the 20-year period. Progression to severe pain and dysfunction of the masticatory system was rare. On the other hand, recovery from frequent symptoms to no symptoms was also rare. At the last examination 13% reported one or more frequent TMD symptom. The prevalence of bruxism increased with time, but other oral parafunctions decreased. Women reported TMD symptoms and headache more often than men. Correlations between the studied variables were mainly weak. The highest correlations found (rs = 0.4-0.5) were those between reported tooth clenching and tooth grinding and jaw fatigue. It can be concluded that in this epidemiologic sample, followed over 20 years from childhood to adulthood, a substantial fluctuation of TMD symptoms was found. Severe symptoms were rare, but 1 of 8 subjects reported frequent TMD symptoms at the last exam.