Comparison of occlusal inferences and guidance scheme in eccentric jaw movement in class I crowding malocclusion patients without orthodontic treatment history with those treated with or without tooth extraction

Abstract

Background and Aims Understanding that orthodontic treatment can affect the functional occlusal relationships to a great extent, and considering that unfavorable changes in functional jaw movements can make a person susceptible to TMJ pathological problems, therefore the aim of this study is to compare occlusal patterns and interactions in extra-central movements in people with Class I malocclusion without a history of orthodontic treatment, and people treated with or without tooth extraction. Methods and Materials Samples of 105 patients referred to Faculty of Dentistry, Tabriz University of Medical Sciences with a range of 18 to 30 years old, are divided in two groups of 35 patients with a history of Class I crowding malocclusion and orthodontic treatment with and without premolars extraction, whom are in 1 year period after debonding, another group of 35 patients with class I malocclusion without a history of orthodontic treatment are matched as a control group. In the sitting position, the patients were guided to bring the mandible forward until the incisal edges of the mandibular anterior teeth reaches the edges of maxillary anterior teeth. The patients were guided to move mandible from the maximum intercuspation position to the left and then to the right until he/she reaches the Cusp to Cusp position. Non-working side contacts be checked and recorded as the absence or presence of contact and its location. Maximum opening of the mouth is recorded using the measuring caliper as the distance between the edges of the upper and lower central incisors. Data be reported with descriptive statistics. In order to compare occlusal interferences and lateral movement and protrusion schemes between the three study groups Chi-square test be used and to compare the maximum opening of the mouth between three study groups, ANOVA or Kruskal-wallis test used. Data of this study reported using Spss 17, and descriptive statistics Statistical significance is considered as P-Value<0.05.

Result The contact of the non-working side on the right and left side was not significantly different between the study groups: (In the group with a history of tooth extraction, 71.65% of patients had right working occlusion and 71.65% of patients had left working occlusion in canine teeth. In the group with a history of treatment without tooth extraction, 54.29% had occlusion of the right worker and 51.43% had occlusion of the left worker in canine teeth. In the untreated group, 54.29% had right working occlusion in canine teeth and 60% of patients had left working occlusion in the post.g.f area. 80% of patients with a history of treatment with tooth extraction had the absence of all teeth related to anterior occlusion, which is 71.43% for patients with a history of treatment without tooth extraction. In 71.43% of patients with a history of treatment with tooth extraction, 80% of patients with a history of treatment without tooth extraction, and 82.86% of patients without treatment, there was no non-working interference. The average maximum mouth opening was the highest in the group with a history of treatment without tooth extraction and the lowest in the group without treatment.

Conclusion The results of the present study showed that in patients with a history of orthodontic treatment with or without tooth extraction and patients without a history of orthodontic treatment, there is no significant difference in lateral occlusion , protrusion, non-working side interferences and the maximum amount of mouth opening.