The prevalence of malocclusion and orthodontic treatment need of school children in Northern Saudi Arabia.

OBJECTIVE: To evaluate the incidence of malocclusion and requirement for orthodontic treatment in the Saudi region of Hail city. MATERIALS AND METHODS: 520 Saudi participants between 7 and 12 years from Hail city were used in the research, all of whom were selected using a simple randomization method. For every participant, various malocclusion variables such as molar, canine, and incisor relationship, overjet, overbite, open bite, cross bite, scissor cross bite, and the score for the orthodontic treatment need [Index of Orthodontic Treatment Need (IOTN)] were recorded. A light source was used for examination, in addition to mouth mirrors, a calibrated ruler, and a portable dental chair. RESULTS: The prevalence of class I molar relationship was 70.4%, with class II being 21.3% and class III being 8.3%. As for the incisor relationships, class I was found at a prevalence of 72.5%, class II at 19.8%, and class III at 7.7%. Additionally, the following malocclusion characteristics were also found: deep overbite (>4 mm) (16.2%), increased overjet (>4 mm) (14.4%), posterior cross bite (13.3%), anterior open bite (7.7%), anterior cross bite (5.2%), scissor bite (4%), and posterior open bite (0.6%). A total of 4.4% were identified as requiring orthodontic treatment. Grades 1 and 2 were 25.5% and 58.5%, respectively. There was a significant relationship found between grades 3 and 4, and the anterior open bite, cross bite, and scissor bite. CONCLUSION: This research showed that class I malocclusion was most dominant, followed by classes II and III, respectively. When the Hail city school pupils in the study were assessed for IOTN index, grades 3 and 4 were found to be highly related to anterior open bite, cross bite, and scissor bite.

Effect of the dental arches morphology on the masticatory muscles activities in normal occlusion young adults.

OBJECTIVES: The aim of this study was to assess the relationship between the morphology of dental arches and the activity of the masticatory muscles activities in healthy volunteers with full natural dentition. METHODS: Two-hundred youthful Class I volunteers (113 females, 87 males) were clinically investigated. Alginate impressions of dental arches were taken, and plaster casts were prepared and measured. EMG data from eight masticatory muscles was recorded to assess their activities in central occlusion, lateral and protrusive movements. RESULTS: Clinical measurements and plaster casts analyses confirmed normal values of parameters investigated. Most of the arch measurements were significantly larger in the males than in the females. Weak positive correlations were found between overbite and masseter activity in centric occlusion (the right Mm R = 0.151, P ≤ 0.05; the left Mm R = 0.191, P ≤ 0.05). Also, the range of protrusive movement positively correlated with masseter activities in central occlusion (the right Mm R = 0.194, P ≤ 0.05; the left R = 0.201, P ≤ 0.05). CONCLUSIONS: The null hypothesis that morphology of dental arches does not affect the masticatory muscles' activities was rejected. The findings of this investigation indicate that systemic, longitudinal analyses of morphology of occlusion and muscular response, even in normal subjects, are needed.

Influence of functional head postures on the dynamic functional occlusal parameters.

BACKGROUND: The dentist utilizes supine position during therapeutic procedures, while the patients assumes extended head posture during mastication. It is critical for the restorative dentist to evaluate and understand the possible effect of change in head posture on occlusal contacts. An understanding of the possible effect will help in better restorative rehabilitation. AIM: The aim of the following study is to evaluate the influence of head postures on the dynamic occlusal parameters. SUBJECTS AND METHODS: Study group consisted of 50 students from College of Dentistry, King Khalid University. The students were selected randomly from the college student body; they were in the age group of 18-25 years. The head posture evaluated were supine position, upright sitting position and alert feeding position. The head postures were standardized by goniometer and dynamic occlusal contacts were analyzed with Tscan. The data obtained was subjected to statistical analysis with repeated measures of ANOVA to identify the changes in occlusal contacts. RESULTS: The occlusion time was 1.366 (0.484), 1.226 (0.562) and 0.997 (0.429) s for supine, upright and alert feeding position respectively. Disclusion time was for right lateral movement was 0.872 (0.372), 0.629 (0.290) and 0.831 (0.369) s for corresponding head postures. Left lateral disclusion time was 0.621 (0.274), 0.274 (0.345) s for upright and alert feeding posture. Repeated measures of ANOVA showed statistically significant difference between occlusal contacts in different head postures. CONCLUSION: Within the limitation of the study, it was concluded that there were significant changes in initial occlusal contact, occlusion and disclusion time at all the head postures evaluated in the study.