Distribution-free approach to the evaluation of reliability of complex systems

In the industrial community it is well known that the failure rate of the manufactured units vary with time due to a variety of causes, namely, engineering design, manufacturing process, maintenance and quality inspection procedures and various assignable and non-assignable factors. Such failure rates invariably exhibit changes in both level and slope and at times exhibit periodic patterns as well. Therefore it would be quite inappropriate and erroneous to analyze such stochastic series of observations using the usual failure distribution approach. Since such data can be construed as time series, we suggest in this paper the time series techniques including the Kalman filter for their analysis. Other advantages of using the latter techniques are that the periodicities, if any, can be taken into account and short-term forecasts can be made which otherwise would not have been possible

Surgical management of intraosseous compound odontome preserving permanent incisors - report of two cases

Odontomas are considered to be hamartomatous malformations rather than tumours. Compound odontomas are mostly found in anterior maxilla and complex odontomas are more prevalent in posterior mandible. Although the pathology is benign, early intervention is required to avoid the subsequent complications and ensure a better prognosis. Two case reports are presented where compound odontomas were associated with impacted teeth. In the first case, an unusually giant odontome caused impaction of both central and lateral incisor. Combined surgical and orthodontic treatment was required for eruption of central incisor whereas lateral incisor erupted after surgical exposure. In the second case surgical removal of the odontome and exposure of the incisal edge led to eruption of the impacted incisor.Key words: compound odontome, anterior maxilla, impacted inciso