Gender Determination in Pakhtun Pakistani Population Using Dental Arch Dimensions: A Digital Model Study

@#Introduction: In circumstances where the ante mortem list is unknown, gender determination would exclude onehalf of the population, aid in a more precise search of the ante mortem records. This study aims to formulate gender prediction models in the Pakhtun Pakistani population using digital dental arch dimensions. Methods: Data collection and analysis of the dental casts were conducted on 128 subjects, 64 males and 64 females from the Pakistani population. The mean age of the subjects was 19.2 years old. Several linear dental arch dimensions were measured and recorded for both upper and lower arches. Results: It was found that gender differences in linear arch dimensions were statistically significant for both males and females (p<0.05); in which the arch dimensions for the males were larger than the arch dimensions for the females. Stepwise discriminant function analysis found that the highest discriminant power of the variables was present within the inter-second premolar width for the upper arch and inter-molar width for the lower arch. These variables significantly contributed to gender variance. Moreover, the prediction of 67.2% of original grouped cases for the upper arch and 66.4% of cross-validated group cases was correct. Similarly, the correct prediction was made on 64.8% of original grouped cases for the lower arch and 64.1% of cross-validated group cases. Conclusion: The dental arch dimensions were larger among the males compared to the females. Prediction models obtained in this study were moderately strong predictors which may be used as an adjunct to predict gender.

Association between genetic polymorphisms and external apical root resorption: A systematic review and meta-analysis / 대한치과교정학회지

OBJECTIVE: To date, only a few studies have investigated the relationships between genetic polymorphisms and external apical root resorption (EARR). Hence, the aim of this systematic review was to explore the relationship between different gene polymorphisms and their association with EARR. METHODS: A complete literature search was conducted by two independent reviewers. The PubMed, Science Direct, and Scopus databases were searched. In addition, the bibliographies of all textbooks and relevant articles were searched manually. A meta-analysis was performed using data entered into the electronic databases until February 28, 2017. RESULTS: On the basis of the search, we identified 17 and 7 publications for the systematic review and meta-analysis, respectively. Odds ratio (OR) was used to evaluate the association of the interleukin 1B (+3954) polymorphism and the risk of EARR. The overall OR from the studies was used to estimate the risk of EARR. However, no association was found and no publication bias was apparent for the risk of EARR in patients receiving orthodontic treatment. CONCLUSIONS: More research on the relationship between gene polymorphism and EARR is necessary to determine better specificity of possible interactions.

Assessment of gender dimorphism on sagittal cephalometry in Pakistani population

Objective: To determine and compare the cephalometric values among Pakistani males and females using commonly used sagittal skeletal measurements [ANB, Wits appraisal, Beta-angle] and newly developed cephalometric analyses [Yen-angle and W-angle]

Study Design: Observational, cross-sectional study

Place and Duration of Study: Orthodontic Department of Baqai Medical University, Karachi, Pakistan, from August to October 2013

Methodology: A total of 209 pre-treatment lateral cephalometric radiographs of orthodontic patients were selected from departmental records, comprised of 92 males and 117 females. Radiographs were traced for measurements of ANB, Wits appraisal, Beta-angle, W-angle and Yen-angle. Patients were categorized into skeletal classes I, II, and III on the basis of performed measurements, incisor classification, and profile recorded from their records. Descriptive analysis was used to obtain median interquartile range in both the genders and Mann-Whitney U-test was used to observe gender dimorphism

Results: Skeletal class II was the most prevalent type of malocclusion. There were no difference in the obtained measurements between males and females except the Wits appraisal and Beta-angle in class II patients, which showed significant difference in values [p < 0.05]

Conclusion: Pakistani population has no significant different difference in the craniofacial morphology of males and females, with the exception of Wits-appraisal and Beta-angle in class II cases

New prediction equations for the estimation of maxillary mandibular canine and premolar widths from mandibular incisors and mandibular first permanent molar widths: A digital model study / 대한치과교정학회지

OBJECTIVE: The primary aim of the study was to generate new prediction equations for the estimation of maxillary and mandibular canine and premolar widths based on mandibular incisors and first permanent molar widths. METHODS: A total of 2,340 calculations (768 based on the sum of mandibular incisor and first permanent molar widths, and 1,572 based on the maxillary and mandibular canine and premolar widths) were performed, and a digital stereomicroscope was used to derive the the digital models and measurements. Mesiodistal widths of maxillary and mandibular teeth were measured via scanned digital models. RESULTS: There was a strong positive correlation between the estimation of maxillary (r = 0.85994, r2 = 0.7395) and mandibular (r = 0.8708, r2 = 0.7582) canine and premolar widths. The intraclass correlation coefficients were statistically significant, and the coefficients were in the strong correlation range, with an average of 0.9. Linear regression analysis was used to establish prediction equations. Prediction equations were developed to estimate maxillary arches based on Y = 15.746 + 0.602 × sum of mandibular incisors and mandibular first permanent molar widths (sum of mandibular incisors [SMI] + molars), Y = 18.224 + 0.540 × (SMI + molars), and Y = 16.186 + 0.586 × (SMI + molars) for both genders, and to estimate mandibular arches the parameters used were Y = 16.391 + 0.564 × (SMI + molars), Y = 14.444 + 0.609 × (SMI + molars), and Y = 19.915 + 0.481 × (SMI + molars). CONCLUSIONS: These formulas will be helpful for orthodontic diagnosis and clinical treatment planning during the mixed dentition stage.