First and second upper premolar in the treatment of an orthodontic patient

Abstract Aim: The study deals with differences in the size of anatomical crowns of first and second maxillary pemolars, and discusses the correlation between the crowns size and sex and skeletal classes of patients. Material and method: The non-randomized retrospective study worked with 152 plaster models of the maxilla. The models were scanned, and in these virtual models mesiodistal and buccolingual parameters of teeth anatomical crowns were measured. The models were divided into groups according to patients’ sex and skeletal class according to WITS. Results: Mesiodistal width was significantly bigger in first premolar (mean= 6.68 mm) than in the second one (mean = 6.43 mm). On the contrary, buccolingual dimension was statistically bigger in second premolars (mean value = 9.67 mm) that in the first one (mean value = 9.48 mm). Mean size of teeth was bigger in all parameters in males than females, i.e. mesiodistal dimension in first premolars (males = 6.75 mm; females = 6.61 mm) and in second premolars (males = 6.49 mm; females = 6.38 mm). The same holds true for buccolingual dimension in first premolars (males = 9,65 mm; females = 9.34 mm) and second premolars (males = 9,83 mm; females = 9.50 mm). In males with Class II the mesiodistal width of both first and second premolars is significantly smaller (mean value = 6.54 and 6.31 mm) than in males with Class I (mean value = 6.86 and 6.58 m) and with Class III (mean value = 6.85 and 6.56 mm). Conclusion: First upper premolar is bigger mesiodistally and smaller buccolingually than second upper premolar. Males’ teeth are bigger than females’. Men with Class II have statistically smaller mesiodistal width of first and second premolars than men with Class I and III.