Can electrical stimulation be used to establish a physiologic occlusal position?

An electromyographic study was undertaken to discover the mechanism by which the Myo-monitor instrument causes muscle contraction. Our data, which strongly suggest that the distal axons of the motoneurons are directly stimulated, lend support to previous studies showing that the stimulus does not cause reflex activation of the jaw closing muscles. Inasmuch as the stimulus acts only in the periphery without the participation of the central nervous system, the ability of the instrument to produce a reflexly controlled occlusal position is highly questionable. Furthermore, we believe that there is no evidence that reflex jaw closure could ever be used to establish a physiologic occlusal position.     

Correlation of scanning and transmission electron microscopy of human dentinal tubules

Areas of human dentine were examined first with the scanning electron microscope (SEM) and subsequently with the transmission electron microscope (TEM). Structures observed in dentinal tubules from outer dentine by SEM were identified by TEM as electron-dense structures lining the tubules and not as odontoblast processes. These structures, termed lamina limitans, correspond to the previously described inner hypomineralized lining of dentinal tubules.     

The curve of Spee in Stone Age man

The purpose of this research was to test Spee's predictions on a sample of skulls with well-worn occlusions. Thirty-nine Shell Mound Indian skulls with marked attrition of the teeth were x-rayed in the Margolis cephalostat. Following Spee's suggested landmarks, three curves were obtained which included the condyle. A fourth curve was investigated--not using the condyle but based from three landmarks of the occlusal surface. All curves, radii, and centers were generated by a computer using the landmarks digitized from each skull's film. When only the molars and the condyle were used, the length of the radius and the location of the center came closest to Spee's predictions. In most of the sample, however, Spee's inclusion of the incisor along that arc could not be verified. Prosthodontic experiments which might give clues to finishing curves for orthodontic patients are suggested.     

The basic proline-rich proteins in human parotid saliva from a single subject.

Eleven Chromatographic fractions of basic proline-rich proteins isolated from parotid saliva from a single donor showed similar but not identical chemical compositions; proline, glycine and glutamic acid-glutamine accounted for 70–80 per cent of the total residues in the proteins. The basic amino acids, lysine and arginine, accounted for a further 10 per cent. All the proteins were in freshly-collected saliva and did not result from post-secretory proteolysis. The most basic of the proline-rich proteins, I-B9, was purified and characterized. The amino terminal residue was serine and the carboxyl terminal residue arginine. The molecular weight determined by quantitative end-group analyses was 9000–9500. Protein I-B9 was resistant to hydrolysis by collagenase and Staphylococcus aureus protease, whereas papain and subtilisin extensively degraded it. I-B9 fragments from clostripain and elastase digestions were isolated for use in sequence determination. Basic proline-rich proteins, acidic proline-rich proteins and proline-rich glycoprotein accounted for 23, 30 and 17 per cent, respectively of the total protein in the parotid saliva.