Aim: The purpose of this study was to evaluate the Bolton overall ratio in a north Indian population reporting for orthodontic treatment and to determine the effect of extractions on the Bolton ratios. Another aim of the study was to check the effects of different extraction patterns on the final Bolton ratio. Materials and Methods: One hundred and twenty pre-treatment dental casts (60 males and 60 females) of orthodontic patients were selected randomly. Mesio-distal dimensions of the mandibular and maxillary teeth were measured before treatment, and subjected to Bolton analysis. Hypothetical tooth extraction by the following combinations: All the first premolars, all the second premolars, upper first and lower second premolars and upper second and lower first premolars were performed for each patient. The measurement results were again subjected to Bolton analysis to see whether any tooth-size discrepancy had been created. Results and Conclusion: The tooth material ratio of the studied north Indian population shows a mild maxillary tooth material excess. Extraction of premolars in any combination causes the maxillary tooth material to further increase. There is no significant sex difference in the tooth material ratios with or without extractions. In patients requiring extraction; all first premolar extraction or maxillary first and mandibular second premolar extraction should be preferred. For deciding a treatment plan involving extraction of teeth, we need to consider that the maxillary tooth mass may increase after extraction. Furthermore, the normal or the clinically significant tooth size discrepancies may change following extraction of teeth.

Background: Commonly used parameters for anteroposterior assessment of the jaw relationship includes several analyses such as ANB, NA-Pog, AB-NPog, Wits appraisal, Harvold's unit length difference, Beta angle. Considering the fact that there are several parameters (with different range and values) which account for sagittal relation, and still the published literature for comparisons and correlation of these measurements is scarce. Therefore, the objective of this study was to correlate these values in subjects of Indian origin. Materials and Methods : The sample consisted of fifty adult individuals (age group 18-26 years) with equal number of males and females. The selection criteria included subjects with no previous history of orthodontic and/or orthognathic surgical treatment; orthognathic facial profile; Angle's Class I molar relation; clinical Frankfort Mandibular plane angle FMA of 30±5° and no gross facial asymmetry. The cephalograms were taken in natural head position (NHP). Seven sagittal skeletal parameters were measured in the cephalograms and subjected to statistical evaluation with Wits reading on the true horizontal as reference. A correlation coefficient analysis was done to assess the significance of association between these variables. Results: ANB angle showed statistically significant correlation for the total sample, though the values were insignificant for the individual groups and therefore may not be very accurate. Wits appraisal was seen to have a significant correlation only in the female sample group. Conclusions: If cephalograms cannot be recorded in a NHP, then the best indicator for recording A-P skeletal dimension would be angle AB-NPog, followed by Harvold's unit length difference. However, considering biologic variability, more than one reading should necessarily be used to verify the same.

Aims: To determine the cephalometric norm among Bangladeshi adults and to investigate the differences in craniofacial morphology compared with Japanese and Caucasian normative data. Materials and Methods: Cephalometric radiographs were obtained from 46 Bangladeshi males (mean age 23.8 years) and 52 Bangladeshi females (mean age 24.6 years). Inclusion criteria were the following: Both parents from the same ethnic group, class-I occlusion with an arch length discrepancy less than 2 mm, overbite and overjet from 2 to 4 mm, balanced face, all teeth present except third molar, no previous orthodontic treatment, and no prosthetic replacement of teeth. Nine angular and five linear measurements were constructed for skeletal hard tissue analysis, four angular and six linear measurements for dental hard tissue analysis, and two angular and seven linear measurements for soft tissue analysis. Mean and standard deviations of measurements were determined for each gender. Polygonal chart and profilogram were made. Independent t-test was used to determine differences. Results: The present Bangladeshi population has a smaller lower face height ( P<0.01) and the antero-posterior position of the maxilla and mandible was found to be significantly ( P<0.01) more protruded compared with the Japanese and the Caucasian norms. Significantly ( P<0.01) more protruded upper incisor, less steep occlusal plane, and thinner soft tissue chin were the characteristics in Bangladeshi adults. Conclusions: Relative to the cranial base (SN), the maxillo-mandibular complex was more anteriorly placed compared with the Japanese and Caucasian adults. Further, the effective length of the maxilla and mandible was shorter compared with the Japanese and Caucasian adults. These findings should be considered carefully during orthodontic treatment planning of Bangladeshi adults.

Objective: This study aimed to explore the prevalence of malocclusion and its distribution among 12-17 year old Urban Libyan schoolchildren. Materials and Methods: A total of 900 subjects were examined, of which 343 fulfilled the inclusion criteria; 169 males and 174 females. Molar relationship, overjet (OJ), overbite (OB), midline deviation, crossbite, and crowding/spacing were recorded. Sexual dimorphism was explored using descriptive statistics and the Chi-square tests. Results: The prevalence of malocclusion was 95.6%. Class I, Class II division 1, Class II division 2 and Class III malocclusions comprised 66.5%, 21.9%, 3.5%, and 3.7% respectively of the total sample. The OJ percentage of 51% (zero-3.5 mm), 48.4% (>3.5 mm), 0.6% (≤−3.5 mm to >zero) was recorded, with no significant sex differences ( P=0.225). A normal overbite, increased and open bites were observed in 39.9%, 55.1%, and 2.3% of the group respectively with no sexual dimorphism ( P=0.970). Crossbite was present in 13.1% of the group, with no significant sex difference ( P=0.469). Crowding in the maxillary and mandibular arches were observed in13.9%, and 12.2% respectively. Spacing occurred in 9.4% and 7.9% of the examined maxillary and mandibular arches respectively, with no significant sex difference regarding the presence of spacing/crowding in the maxillary arch ( P>0.05). Males, however, had significantly more spacing and less crowding in the mandibular arch ( P<0.05). Conclusions: The prevalence of malocclusion in Libyan schoolchildren is among the highest reported in the literature. Crowding is among the least reported manifestations of malocclusion.