Context: The detrimental effect of moisture on orthodontic bonding has long been known. Hydrophilic bonding materials have been introduced suggesting the possibility of obtaining successful orthodontic bonding to a moisture contaminated enamel surface. Aims: This study has been performed with an aim to compare the in vitro shear bond strength (SBS) and debonding characteristic of moisture-insensitive primer (MIP) (Transbond MIP) (3M Unitek, South Peck Road, Monrovia, California, USA) and self-etching primer (SEP) (Transbond Plus SEP) (3M Unitek, South Peck Road, Monrovia, California, USA) in combination with a color changing adhesive system (Transbond Plus Color Change) (3M Unitek, South Peck Road, Monrovia, California, USA) under both dry and contaminated condition. Settings and Design: Randomized controlled clinical study. Subjects and Methods: One hundred and twenty freshly extracted teeth for the purpose of orthodontic treatment were collected. Teeth were randomly assigned into four groups, each consisting of 30 specimen and stainless steel brackets were bonded using each primer-adhesive combination under different enamel conditions, that is, dry and enamel contaminated with natural saliva. SBS and adhesive remnant index were calculated for each group. Results: Analysis of variance of SBS for both MIP and SEP under dry and contaminated condition showed no statistical significance (P = 0.5). Chi-square test showed significant difference in debonding characteristics among the test groups (P < 0.001). All the groups showed typical debonding characteristics of separation either at the bracket-adhesive interface or within the adhesive itself. Conclusions: Moisture contamination did not affect the SBS and adhesive remaining on tooth for both MIP and SEP.

Aim: The aim of this study was to evaluate angulation and inclination of teeth from the study models of individuals with normal occlusion and evaluation of actual expression of torque expressed by three different bracket systems. Materials and Methods: In this study, the inclination and angulation were measured on 30 study models of North Indian individuals. A self-developed instrument (torque angle gauge) was used for the measurement. Fifteen study models were duplicated for the evaluation of torque expression in the bracket of three different manufacturers with different shape and size of bases. Results: The results give the mean, minimum and maximum, standard deviation of the normative data individually for each tooth. A significant correlation was noted in the angulation of maxillary canine and first premolar, and between premolars; and between mandibular central incisor with lateral incisor and canine, and between premolars. Conclusions: There was a highly significant correlation of teeth angulation and inclination in the maxillary and mandibular arch. Though the error in expression of torque was not significant, but it showed a large range, indicating the need to vary the position of brackets in different bracket systems for achieving optimum torque.

Objective : To investigate the role played by the cranial base flexure in influencing the sagittal and vertical position of the jaws in Indian population. Materials and Methods : Lateral cephalograms of 108 subjects were divided into three categories (Group A: NSAr > 125°, Group B: NSAr-120°-125°, Group C: NSAr < 120°) according to value of NSAr. Measurement of eight angular (SNA, SNB, NPg-FH, ANB, NAPg, SN-GoGn, Y-Axis, ArGo-SN) and seven linear (N-S, S-Ar, Ar-N, Ar-Pt A, Ar-Gn, Wits appraisal, N- Pt A) variables were taken. Results : Pearson correlation coefficient test was used to individually correlate angular and linear variables with NSAr for the whole sample as well as in individual group. Unpaired t-test was used to analyze the difference in the means of all the variables between the three groups. Significance was determined only when the confidence level was P < 0.05. Several parameters (SNB, NAPg, ANB, Y-Axis, GoGn-SN) showed significant positive correlation while others showed negative correlation (SNA, NPg-FH, N-S) with NSAr. Conclusions : This study show cranial base angle has a determinant role in influencing the mandibular position and it also affects both the mandibular plane angle and y-axis. Flattening of the cranial base angle caused a clockwise rotation of the mandible. The jaw relation tends to change from class III to class II, with progressive flattening of the cranial base and vice-versa.

Objective: The aim was to formulate a prediction regression equation for Yemeni and to compare it with Moyer's method for the prediction of the size of the un-erupted permanent canines and premolars. Subjects and Methods: Measurements of mesio-distal width of four permanent mandibular incisors, as well as canines and premolars in both arches were obtained from a sample of 400 school children aged 12-14 years old (13.80 ± 0.42 standard deviation) using electronic digital calliper. The data were subjected to statistical and linear regression analysis and then compared with Moyer's prediction tables. Results: The result showed that the mean mesio-distal tooth widths of the canines and premolars in the maxillary arch were significantly larger in boys than girls (P < 0.001), while, in the mandibular arch, only lateral incisors and canines were also significantly larger in boys than in girls (P < 0.001). Regression equations for the maxillary arch (boys, Y = 13.55 + 0.29X; girls, Y = 14.04 + 0.25X) and the mandibular arch (boys, Y = 9.97 + 0.40X; girls, Y = 9.56 + 0.41X) were formulated and used to develop new probability tables following the Moyer's method. Significant differences (P < 0.05) were found between the present study predicted widths and the Moyer's tables in almost all percentile levels, including the recommended 50% and 75% levels. Conclusions: The Moyer's probability tables significantly overestimate the mesio-distal widths of the un-erupted permanent canine and premolars of Yemeni in almost all percentile levels, including the commonly used 50% and 75% levels. Therefore, it was suggested with caution that the proposed prediction regression equations and tables developed in the present study could be considered as an alternative and more precise method for mixed dentition space analysis in Yemeni.

Objective: The aims of this study were to determine the prevalence of hypodontia in the permanent dentition in a sample of Sudanese patients who sought orthodontic treatment and to compare the results with the reported findings of other populations. Materials and Methods: Orthodontic files including orthopantomographs of 1069 patients (760 females and 309 males - more than 8 years old) were examined and inspected for evidence of hypodontia. Results: The prevalence of hypodontia of the present sample was 5.1%. Hypodontia was found considerably more frequently in the mandible than in the maxilla. The distribution of missing teeth was noticed in the left side more than in the right side. The most frequently missing teeth were the maxillary lateral incisors, followed by the mandibular second premolars, maxillary second premolars and mandibular left lateral incisor. The majority of patients had two or three teeth missing, but rarely more than 5 teeth missing. Conclusions: The prevalence of hypodontia of this study was within the range of that reported in the literature. The incidence of hypodontia in the anterior segment requires great need for orthodontic and prosthodontic treatment. With early detection of hypodontia, alternative treatment modalities can be planned and performed with a multidisciplinary team approach restoring the esthetic and function.