Estudio de la relación entre la mordida cruzada y alteración en la trayectoria de los caninos superiores, inclinación del plano oclusal e inclinación de la comisura labial

Abstract

The objectives of this work were to study whether the presence of a unilateral posteior crossbite can produce alterations in the inclination of the canines, the inclination of the occlusal plane or the inclination of the labial commisure. In addition, we compared the inclination of the canines on the side with a crossbite with respect to the canines on the side with no crossbite. Methodology: The sample was dicided according to their transverse malocclusion, age and sex, and 106 patients with unilateral posterior crossbite and 41 control group patients were obtained. All patients have been done an orthodontic study, from which we used panoramic radiograpphy to measure the inclination of the canines and the occlusal plane; and the frontal photograph to measure the inclination of the labial commisure. Measurements were made with a computer program (tpsDig2) by two observers and the data obtained were analyzed with the SPSS 22.0 program for windows, using parametric tests (ANOVA) and non-parametric tests (Kruskal-Wallis) for descriptive statistical analysis. Results: No statistically significant differences were observed in the inclination of the right and left canines in patients with a right crossbite compared to patients in the control group (p 0.475). The same occurrs when analyzing the canines when we refer to the left crossbite (p.0.30). However, it was observed that the left canine has a greater inclination than the right in the control group of patients (p.0.010). We were able to verify that sex did not influence the inclination of the canines but age did influence, with the greatest difference between the 6-year-old group, with a lower inclination, and the 8-year-old, with a greater inclination (p.0.05). This occurred equally in the canines on the crossbite side, the canines on the non-crossbite side and those of the control group. Regarding the occlusal plane, it was observed that there is a relationship between the presence of a crossbite and the inclination of the occlusal plane (p.0.037). However, according to our results, age and sex do not influence the inclination of the occlusal plane. Finally, we analyze the inclination of the lip cprner. In this study, no statistically significant differences were observed in the inclination of the labial comissure in patients with right or left crossbite compared to patients in the control group (p.0.220). We also did not obtained differences based on age or sex. Discussion: In the bibliographic review, we did not find similar studies to compare our results, so we focused on comparing the study methodology and the analysis of the results with the studies most similar to ours. Conclusions: According to the results of the present study, we can conclude:1) There is no relationship between the presence of a unilateral posterior crossbite and the alteration in the eruptive trajectory of the permanent upper canines.2) It seems that there would be a relationship between the presence of a unilateral posterior crossbite and the alteration in the inclination of the occlusal plane.3) There is no relationship between the presence of a unilateral posterior crossbite and an alteration in the inclination of the labial commissure.4) There are no statistically significant differences when comparing the mesiodistal inclination of the upper canines on the side without crossbite with the inclination of the upper canines on the side crossbite.