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Purpose: The purpose of this study was to produce a clinically useful, patient-derived, minor oral surgery outcome scale. Patients and Methods: Seventy-seven consecutive patients scheduled for minor oral surgery were interviewed using semistructured interview techniques to identify those areas of life (domains) that patients believed will be affected by minor oral surgery. These interviews were analyzed by a multidisciplinary panel and a scale based on 5 domains, each with 4 outcome statements was constructed. The domains and outcome statements were weighted in terms of importance by a further consecutive sample of 100 patients using resource allocation and visual analog tasks. An additive mathematical formula was applied to the mean weights for each domain and outcome states to produce the final weighted scale. Results: Five domains were identified from the interviews and weighted according to their order of importance (0 to 100 scale; 0 = least important). These were general health and well-being (24.6); impact on home/social life (20.8); health and comfort of the mouth, teeth, and gums (20.0); appearance (18.8); and impact on job/studies (15.8). Conclusion: A clinically applicable, multi-attribute outcome scale has been produced that takes into account all determinants of health outcome as perceived by the patient in the context of minor oral surgery. It is completed by selecting a weighted statement from each domain, the sum of which constitutes the patient's health state utility score. The scale has potentially extensive application to both clinical care and research. © 2000 American Association of Oral and Maxillofacial Surgeons

Objectives : To outline the key concepts of neural network based systems and to evaluate the potential applications of such systems in dentistry. Data sources : Published work on neural networks. Conclusions : Neural networks may initally seem complex and computer intensive, but actually integrate well with a clinical environment. Neural network expert systems may be trained with only clinical data and as such can be used where ‘rule based’ decision making is not possible. This is the case in many clinical situations. Neural networks may therefore become important decision making tools within dentistry and have applications both in improving clinical care and in maximizing the cost benefit of care.

The objective of the study was to identify those factors that should affect treatment planning for patients who have lower third molars, using decision-analytic techniques. Utility values based on data from 104 patients indicated that the respondents considered that postoperative complications (except mild pain and temporary paresthesia) reduced health to a greater degree than did complications following non-intervention. A decision analysis indicated that the maximum expected utility of prophylactic third-molar surgery (60.25) was lower than that for non-intervention (76.96). The decision was sensitive to changes in the probabilities of occurrence of recurrent pericoronitis (threshold = 0.52), resorption of an adjacent tooth (threshold = 0.29), loss of an adjacent tooth (threshold = 0.32), and cystic change (threshold = 0.34). These thresholds are much higher than the incidence of problems affecting the lower third molar shown by a concurrent clinical audit and literature review. This study therefore suggests that lower third molars should not be removed prophylactically. Key words: decision analysis; utility values; third molar surgery. (Med Decis Making 1995;15:143-151)

A definite energy threshold is found for the appearance of doubly and triply charged ions when N+ions are elastically scattered from surface atoms in a clean silicon surface. These threshold energies directly confirm the model in which multiply charged ions are created in binary encounters by molecular-orbital electron promotion, and then are partially neutralised as they leave the surface. Characteristic velocities for neutralisation of scattered N 2+ , N + and recoiled Si 3+ , Si 2+ , Si + ions in silicon are in the same range as have been found for rare gas and metal ions. For each element they seem to scale roughly as the square root of ionisation potential of each charge state, but there appears to be no other systematic dependence