Association between ABO, Rh blood groups, lip and dermatoglyphic patterns, and nonsyndromic oral clefts: A case-control study

OBJECTIVE

The objective of the study is to determine the association between nonsyndromic oral clefts (OC) in children and ABO, Rh blood groups, lip, and dermatoglyphic patterns of their unaffected parents.

METHODS

This case-control study was conducted at a tertiary cleft center in Chennai, India, among 240 individuals comprising 80 units (40 cases and controls, respectively). Each unit (triad) was constituted by a child (0-12 years of age) either born with nonsyndromic OC (cases) or with no diagnosed congenital anomaly (control) and their unaffected parents (mother and father). ABO and Rh blood groups, specific lip print, fingerprint pattern, and palmar asymmetry were recorded for each individual. Strength of association of related factors was assessed by multivariable logistic regression reported as adjusted odds ratios and 95% confidence interval.

RESULTS

A₁-positive blood group was found to be considerably higher among case mothers (14.39 [1.57-32.27]). A higher odds of OCs were observed among case mothers with whorl lip pattern (1.51 [1.16-3.17]) and radial loop pattern in fingers (1.44 [1.09-2.31]) relative to controls. In addition, palmar asymmetry was distinctively higher among case parents compared to controls (P < 0.01).

CONCLUSION

Findings indicate that A₁-positive blood group, higher frequency of whorl lip, and radial loop finger patterns in mothers and higher ulnar loop pattern in fathers and palmar asymmetry in both parents increases odds of occurrence of OC among their offspring. These identifiable traits offer potential scope for better service planning among resource-constrained disadvantaged communities in India.

Age estimation using development of third molars in South Indian population: A radiological study

AIM

To assess the estimation of chronological age based on the stages of third molar development following the eight stages (A-H) method of Demirjian et al. in Chennai population of South India.

MATERIALS AND METHODS

A sample consisting of 848 individuals (471 males and 377 females) aged between 14 and 30 years was randomly selected for the clinical evaluation and 323 orthopantomograms with clinically missing third molars were taken for radiological evaluation using Demirjian's method from a Chennai population of known chronological age and sex. Statistical analysis was performed using Pearson's Chi-square test and mean values were compared between the study groups using t-test or analysis of variance (ANOVA) followed by Tukey's highly significant difference (HSD). In the present study, P < 0.05 was considered as the level of significance.

RESULTS

The results showed that the mean age of having clinically completely erupted maxillary third molars was 22.41 years in male subjects and 23.81 years in female subjects and that of mandibular third molars was 21.49 years in male subjects and 23.34 years in female subjects. Mandibular third molars were clinically missing more often in females than in males. Eruption of mandibular third molars was generally ahead of the emergence of maxillary third molars into the oral cavity. Third molar development between male and female subjects showed statistically significant differences at calcification stage F and stage G in maxillary third molars and stage F in mandibular third molars (P < 0.05).

CONCLUSION

There are differences indicating that maxillary and mandibular third molar eruption reached Demirjian's formation stages earlier in males than in females. It is suggested that in future studies, to increase the accuracy of age determination, indications of sexual maturity and ossification should also be evaluated in addition to third molar mineralization.