evaluation of the accuracy of the different methods of determining maxillary dental midline

Abstract

Introduction: Facial esthetic assessment is an important part of the orthodontic treatment planning process. The determination of the maxillary dental midline plays an important role in the diagnosis and treatment plan of various dental treatments.The methods of determining the maxillary dental midline have not been systematically and comprehensively examined and compared in previous studies, Therefore, this study aimed to investigate the accuracy of different methods including photographic method,dental cast method and gold standard method for determining the maxillary dental midline in relation to the face. Materials and methods: In this descriptive-analytical study, the study population is 70 patients referred to the Faculty of Dentistry in Tabriz University of Medical Sciences, Tabriz, Iran. After receiving informed consent, the dental midline was determined by photographic method,dental cast method and gold standard method in patients. The data obtained from this study were analyzed using chi-square statistical test and the statistical level was set as 0.05. Results: Based on the results of photographic,dental cast and gold standard methods, 35.7%, 54.3% and 47.1% of the studied population had dental midline coincidence with the midline of the face, respectively. In addition, the maximum deviation was between 0.5 and 1 mm to the left, which was 34.3, 22.9 and 28.5 of the studied population in photography,dentl cast and gold standard methods, respectively. Compared to the gold standard method, the photographic method was correctly identified 84% of the cases and the dental cast method was 70% of the midline location. These two methods were not significantly different from the gold standard method(p-value>0/05). Examining the results of two experts with the judgment of a third expert was showed that there was no significant difference between the diagnosis of two experts and they correctly diagnosed dental midline(p-value>0/05).

Conclusion: Compared to the gold standard method, there was no significant difference in determining of midline location by the photographic method and the dental cast method. Therefore, the gold standard method is preferable to the other two methods due to its ease and no need for materials and tools.