Craniofacial malformations and the orthodontist.

This review article presents an overview of craniofacial malformations and the role of the orthodontist in their management. The first part of this article focuses on cleft lip and palate, followed by more complex deformities including craniosynostosis and craniofacial microsomia. The main features of these anomalies are discussed as well as the clinical problems seen in this group of patients. The emphasis is on the role of the orthodontist in the multi-disciplinary management of these cases.

A retrospective study of two-stage treatment outcomes assessed with two modified PAR indices.

This retrospective study was undertaken to evaluate the long-term outcome of two-stage (functional/fixed) Class II treatment. A modified peer assessment rating (PAR) was applied to the records of 27 patients who had been recalled an average of 9 years after the completion of the second phase of treatment. UK and US weightings were applied. Analysis of variance identified significant differences among treatment stages. The greatest change in PAR score occurred during the first (functional) phase of treatment. By the end of the second phase, there had been an 83% reduction in PAR score. At recall, however, the PAR scores had increased significantly, due largely to relapse in overjet and in the lower labial segment. These results call into question the ultimate utility of early, two-stage treatment regimens. Although the differences between the UK and USA weightings were smaller than anticipated, the nature of the relapse seen here argues against the American exclusion of the lower labial segment.

Are gatekeepers necessary?

Primary care physicians, acting as gatekeepers, are being used in an attempt to better control rising healthcare costs. However, the success of gatekeepers is difficult to measure because of the lack of data. The purpose of this article is to outline the function of gatekeepers, address the complications in measuring the benefits, and propose methods for further studies. In addition, we hope to foster a sense of responsibility and emphasize the importance of sharing data among organizations involved in the delivery of healthcare.

Direct bonding to typodont teeth.

Three methods of bonding orthodontic brackets to acrylic teeth were investigated for use with a typodont. One-hundred-and-twenty Dentaurum 0.018 x 0.025 inch standard Edgewise brackets were bonded to Crylopax cross-linked acrylic teeth using three cements: Concise composite, Concise with acrylic primer, and GAC acrylic cement on a previously roughened tooth surface. Half the specimens in each group was immersed in a thermostatically controlled water bath for 15 min on 20 occasions over a 5-day period, to simulate the conditions of a typodont, prior to measuring tensile bond strength on an Instron machine. Under dry conditions Concise composite was significantly stronger than either Concise with acrylic primer or GAC cold cure acrylic resin. Under wet conditions, however, the mean bond strength of the acrylic resin increased significantly compared to the other cements. The bond strength of both Concise and Concise composite with primer deteriorated following water immersion. It is suggested that when setting up typodont teeth with brackets bonded with GAC acrylic resin, immersion of the bonded teeth in hot water prior to positioning of the teeth in the typodont may greatly reduce the risk of subsequent bracket loss.

A study to compare the effects of simulated torquing forces on pre-adjusted orthodontic brackets.

The transmission of torquing forces between three types of preadjusted bracket was investigated. 0.022-inch Roth prescription 'A'-Company (stainless steel), Silkon (reinforced polycarbonate), and Allure III (polycrystalline ceramic) brackets were used. A selection of stainless steel archwires were chosen, 0.018 x 0.025, 0.019 x 0.025, and 0.021 x 0.025 inch. The brackets were torqued with respect to the archwire and force v. angular deflection was recorded on an Instron machine. The dimension of angular change was in part dependent on the ability of the bracket to elastically or plastically deform. There were no significant differences between bracket types with the 0.018 x 0.025-inch archwire. 'A'-Company brackets demonstrated a significantly lower resistance to loading compared to Silkon brackets in the 0.019 x 0.025-inch group. The greatest amount of distortion was seen in Silkon brackets with an 0.021 x 0.025-inch archwire. Allure III brackets demonstrated the greatest resistance to loading in all groups. As no apparent distortion under loading is seen in Allure III brackets, it is assumed that the load is largely transmitted to the tooth. Full thickness stainless steel rectangular wires should be avoided with these brackets, in order to prevent overloading.