ABSTRACT
Numerous ritual acts involving the skull result in orofacial changes. The present study focuses on ritual acts of Brazilian Zoé Indians. A distinct deformation effect of the ritual act (wearing a lip-plug) on the morphology of the orofacial system is demonstrated and documented using jaw models. The studies show that the lip-plug significantly influences tooth position and jaw growth. While the maxilla displays palatal displacement of the lateral incisors and elevation of the palate, retraction occurs in the mandible depending upon plug size. Additionally, both the plug and the nutritional habits of the Indians induce marked abrasion of all teeth. Moreover, it is shown that the duration of lip-plug wear is an essential determinant of sustained orofacial changes.
Subject(s)
Face/abnormalities , Indians, South American , Mouth Abnormalities/pathology , Aging , Brazil , Face/anatomy & histology , Humans , Lip/anatomy & histology , Male , Mandible/anatomy & histology , Mandible/growth & development , Maxilla/anatomy & histology , MorphogenesisABSTRACT
Two arm and two leg nerves in each of a group of healthy subjects were stimulated electrically and the muscle action potentials were taken from the corresponding regions by surface electrodes. Volumetrically conducted potentials appeared in almost all cases, and other nerves were stimulated at the same time in many cases. The resultant errors in the calculation of the speed of pulse transmission are considerable. The use of a concentric needle electrode is recommended for recording evoked muscle action potentials.
