The aim of this study was to investigate functional changes in occlusion during retention. Data on occlusal force (OcFr) and occlusal contact area (OcAr) was obtained using the pressure-sensitive sheet, from a treated group (20 female patients) who had had four premolar extractions and treatment with standard edgewise appliances, and a control sample who matched the treated group of retainer for sex, age and Angle classification at 1 year after removal. A repeated measures analysis of variance showed that the mean values of total OcFr and OcAr in the treatment group gradually increased during retention and were 669.3 N and 15.1 mm2, respectively, at 1 year after removal of retainer. The increases of OcFr and OcAr were larger in the molar region, especially at the second molar. At 1 year after removal of retainer, OcFr and OcAr in the second molar were significantly larger in the treatment group than in the control sample, and a similar distribution pattern of OcFr and OcAr to those in normal occlusion was seen. These results suggested that balanced OcFr and OcAr might be obtained during and after retention, due to the settling of molars that had been discluded by active orthodontic treatment.

The aim of this study was to investigate the relation between frontal craniofacial morphology and the distribution of occlusal force in orthodontic patients with and without TMD. Experimental data were obtained from 45 female orthodontic patients (TMD-free group: 22 subjects; TMD group: 23 subjects) using the pressure-sensitive sheet. The following results were obtained: (1) There were significant differences in the gonial angle width and the mandibular deviation of the postero-anterior cephalogram between the two groups. (2) There were significant differences in occlusal force, occlusal contact area and average occlusal pressure between the two groups. (3) On the relation between the frontal craniofacial morphology and the occlusal data, the asymmetry indices of occlusal force and occlusal contact area showed significant positive correlations to the mandibular deviation and the ratios of maxillary and gonial angle widths in the TMD group. The TMD-free group showed the smaller mandibular deviation and the smaller asymmetry indices of occlusal force and occlusal contact area than those in the TMD group. It could be concluded that orthodontic patients with TMD may have not only the morphological disharmony but also the imbalance of occlusal force.

Objectives: To evaluate the frequency, severity and extent of Oral Impact on Daily Performances (OIDP) in the patients wearing orthodontic appliances in relation to type of orthodontic appliances and sex of patients. Materials and method: This was a descriptive cross sectional study with 287 participants by convenient sampling aged 10-25 years, undergoing orthodontic treatment at the department of Orthodontics & Dentofacial Orthopedics of Dhaka Dental College & Hospital. Face-to-face structured interviews and clinical examination were done to collect information about impacts on quality of life related to wearing orthodontic appliances, using the OIDP. Results: Two hundred and eighty seven patients (31% male and 69% female) undergoing orthodontic treatment participated in the study. The prevalence of condition-specific impacts related to wearing orthodontic appliances was 30.7%. Among adolescents with impacts related to wearing orthodontic appliances, 16.8% reported impacts of severe intensity and 90.5% reported impacts on only one daily performance, commonly eating or speaking or cleaning mouth. The prevalence and the extent, but not the intensity of condition-specific impacts differed by type of orthodontic appliance (P =.023* and .0426* respectively). Conclusion: Less than one third participants undergoing orthodontic treatment reported side effects, specific impacts on daily living, related to wearing orthodontic appliances. Such impacts were higher among patients wearing fixed type of orthodontic appliances than removable type. This information could help to inform patients about the frequency, intensity & extent of sociodental impacts during the course of their treatment and thereby increase the treatment compliance. Ban J Orthod & Dentofac Orthop, April 2016; Vol-6 (1-2), P.6-12

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