ABSTRACT
INTRODUCTION: The cervical vertebrae maturation (CVM) method is used to determine the timing of treatment of Class II malocclusion. Because its performance has not been tested in patients with Class II, the objective of this study was to evaluate the effectiveness of the CVM method in predicting craniofacial growth in Class II malocclusion. METHODS: Twenty-nine untreated girls with Class II malocclusion were identified among participants of the Nijmegen Growth Study. Each girl had a series of cephalograms taken semi-annually from 9 to 14 years of age. The CVM status was established by five observers on a cephalogram taken at 9 years; mandibular and maxillary length and anterior face height were assessed on all available cephalograms. Method error was evaluated with kappa statistics and Bland-Altman (BA) plots. Regression analysis was used to determine if CVM grade can predict the amount of facial growth. RESULTS: The mean kappa for intra-rater agreement during grading with CVM was 0.36 (fair agreement). BA plots demonstrated acceptable agreement for cephalometric measurements. The regression analysis demonstrated that the only chronologic age was associated with the facial growth. The largest effect of age was for condylion-gnathion (Cd-Gn) and articulare-gnathion (Ar-Gn)-for every additional 6 months the Cd-Gn increases by 1.8mm [95 per cent confidence interval (CI): 1.7, 1.9, P < 0.001] and Ar-Gn increases by 1.59mm (95 per cent CI: 1.52, 1.67, P < 0.001). The CVM grade could not predict the change of cephalometric variables. CONCLUSIONS: There is no evidence to support the hypothesis that the CVM method can predict the amount of craniofacial growth in girls with Class II malocclusion.
Subject(s)
Cervical Vertebrae/growth & development , Malocclusion/therapy , Aging/pathology , Aging/physiology , Cephalometry/methods , Child , Female , Follow-Up Studies , Humans , Malocclusion/pathology , Malocclusion/physiopathology , Mandible/growth & development , Mandible/pathology , Maxilla/growth & development , Maxilla/pathology , Maxillofacial Development/physiology , Observer Variation , Predictive Value of Tests , Reproducibility of ResultsABSTRACT
The World Wide Web is increasingly important for medical education. Internet served pages may also be used on a local hard disk or CD-ROM without a network or server. This allows authors to reuse existing content and provide access to users without a network connection. CD-ROM offers several advantages over network delivery of Web pages for several applications. However, creating Web pages for CD-ROM requires careful planning. Issues include file names, relative links, directory names, default pages, server created content, image maps, other file types and embedded programming. With care, it is possible to create server based pages that can be copied directly to CD-ROM. In addition, Web pages on CD-ROM may reference Internet served pages to provide the best features of both methods.
Subject(s)
CD-ROM , Education, Medical , Internet , HumansABSTRACT
Computer simulation models can be extremely valuable for teaching and for understanding real world processes. The discipline of creating a model forces the investigator to carefully define each relationship and test the result. Even simple models can be fundamentally unpredictable. Models are typically comprised of systems of differential equations and are solved by numerical integration with computer programs. Spreadsheets, simulation software and custom programs may be used to calculate the numerical solution, draw graphs and animate the result.
