Applicability of Tanaka and Johnston mixed dentition analysis in a contemproary Pakistani population

Mixed dentition analysis is carried out to predict the size of unerupted canine and premolar in the developing occlusion. The aim of this study was to assess the applicability of Tanaka and Johnston method of mixed dentition analysis in predicting the size of permanent canines and premolars in patients visiting Islamic International Dental Hospital, Islamabad. The sample consisted of 80 dental casts [40 male and 40 female], obtained from patients reporting at the department of orthodontics, Islamic International Dental College, Islamabad with the age range between 12 to 21 years. Mesiodistal tooth widths were measured with a digital vernier caliper. A paired student t test was used to compare the predicted and actual sum of the maxillary [PUCPM and AUCPM] and mandibular permanent Canines and Premolars [PLCM and ALCPM] for both genders combined and separately. Significant difference was found between PUCPM and AUCPM in maxilla for both male and female together [M + F: 0.000] and when both genders were compared separately [M: 0.032, F: 0.001]. Tanaka and Johnston method was only applicable in predicting the space for unerupted canine and premolars in mandible in both male and female sample

Comparative evaluation between cervical vertebrae and hand-wrist maturation for assessment of skeletal maturity orthodontic patients

The aim of the study was to find a correlation between the evaluation of skeletal maturation performed by the study of cervical vertebrae maturation indicators and the evaluation obtained by the hand and wrist maturation indicators. A radiographic hand-wrist bone analysis and cephalometric cervical vertebral analysis of 100 patients [36 males and 64 females] ranging from 9 to15 years were examined. The hand-wrist bone analysis was evaluated by the Bjork index, whereas the cervical vertebral analysis was assessed by the cervical vertebral maturation stages method of Bacetti. To define vertebral stages, morphological evaluation of three cervical vertebrae [2nd to 4th] was done. Bjork's nine stages were reduced to five growth intervals [A-E] to relate to five stages [I-V] of cervical vertebral maturation method. The spearman correlation coefficient was 0.944 [P<.01] between cervical vertebral maturation and hand-wrist maturation for sexes combined and 0.936 [P<.01] for males and 0.912 [P<.01] for females respectively. The result shows that cervical vertebrae can be used with the same confidence as hand-wrist radiographs to evaluate skeletal maturity, thus avoiding the need for an additional radiograph

Tooth size discrepancy in various malocclusion groups

To compare tooth size discrepancy among dental class I, class II div 1, class II div 2 and class III malocclusions. This study was conducted during 2006-2007 at the Orthodontic department of Islamic International Dental Hospital, Islamabad. It was a cross sectional study conducted with sampling technique of non-probability [purposive]. Sample sizes were 200 patients with different malocclusion classes. Age ranged between 13 to 20 years. Bolton's ratio was used to determine the overall and anterior tooth size ratio amongst the various malocclusion groups. Bolton's anterior and overall ratios showed statistically significant differences among malocclusion groups. The mean anterior and overall Bolton's ratios for the different groups was in the order of Class III > Class I > Class II division 2 > Class II division 1. In our study statistically significant differences were found among different malocclusion groups and Class III group was found to have greater tooth size discrepancy than other malocclusion groups

In vitro comparison of shear bond strength of transbond XT and heliosit orthodontic as direct bracket bonding adhesives

Heliosit Orthodontic was developed to ease the bonding procedure of orthodontic attachments by eliminating the need for primer application both on the bracket base and the etched tooth surface. The aim of this study was to determine the shear bond strength of Heliosit Orthodontic and then compare it with the control group of Transbond XT. The study consisted of two groups A and B of 80 human premolar teeth each bonded with mesh based metal brackets. The bonding agent used in group A was Transbond XT and that of group B was Heliosit Orthodontic, Every effort was made to control the cofounding variables including light tip distance, force of application of bracket, storage of teeth before and after bonding and orientation of bracket in the acrylic block this was followed by debonding of the brackets by shearing in a universal testing machine. It was found that the mean shear bond strength of Transbond XT was 25.5 MPa and that of Heliosit orthodontic was 10.54 MPa. The t-test revealed that there was a significant difference between the shear bond strength of the two groups. In conclusion the bond strengths of both the composites tested were greater than the recommended values of Reynolds for the composites to be clinically useful. It is recommended that the bond strength and the viscosity of the Heliosit Orthodontic be increased for it to be clinically as efftctive as Transbond XT