Bruxism is a controversial phenomenon. Both its definition and the diagnostic procedure contribute to the fact that the literature about the aetiology of this disorder is difficult to interpret. There is, however, consensus about the multifactorial nature of the aetiology. Besides peripheral (morphological) factors, central (pathophysiological and psychological) factors can be distinguished. In...

Received for publication October 2, 1954. intestine. These findings, which appear to imply an extraordinary mobility of thyroid tissue in normal and goitrous fish, are presented for both their in trinsic interest and their possible value in the in terpretation of atypically located thyroid tissue in man. When first noted in a number of genetic strains of the platyfish (Xiphophorus mactdatus), h...