[Asymptomatic third molars; To remove or not to remove?] / Een klachtenvrije derde molaar, verwijderen of niet?

Three adult patients, ages 28 (female), 36 (male) and 53 (male), respectively, were referred by their dentists to an orofacial surgeon concerning problems with their third molars. With the woman, teeth 38 and 48 were removed. After the removal of tooth 38, a permanent periodontal attachment loss of the adjoining second molar occurred. With the second patient, retention of tooth 48 caused serious damage to the adjoining second molar, resulting in the loss of the tooth. At the time of removal, there was a question of increased risk of inflammatory complications and nerve damage. With the third patient, removal of his impacted tooth 38 led to osteomyelitis and a fracture of the angle of the mandible. According to the newly published 'Third molar' in the Dutch Clinical Guidelines, the advice is to consider the removal of asymptomatic third molars in 17-year-old patients. In the case of impacted third molars with mesial or horizontal angulation and partial eruption, the risk of pathology is such that preventive removal is advised. An intraoral radiograph (periapical or bitewing) as a first screening is recommended here.

Data-Driven Haptic Rendering-From Viscous Fluids to Visco-Elastic Solids.

In this article we present extensions of our earlier work on data-driven haptic rendering. Haptic feedback is generated directly by interpolating measured data. The selection of appropriate data dimensions is guided by the structure of the generalized Maxwell model. Material elasticity and viscosity are reproduced, including transient material effects like stress relaxation. All these properties can be nonlinear and mutually dependent. Besides visco-elastic bodies, we also apply our method to viscous fluids. We present results for several materials and compare the errors of the interpolated forces with perceptual thresholds reported in the literature. Moreover, we examine how these errors behave if different subjects perform the recordings on which the data-driven haptic feedback is based.