ABSTRACT
Background: Palatal rugae are unique for an individual and remain unchanged during individual's lifetime. Application of palatal rugae analysis as a method in gender identification needs to be confirmed with more scientific studies. The objectives of the present study were to assess the distribution of the palatal rugae patterns in Kerala population and compare the distribution of these parameters between males and females. Materials & Methods: A retrospective cross-sectional study was conducted by evaluating the casts of 100 dentate individuals, between the age of 18 and 30 years. The rugae were divided into two halves and patterns were then assessed as per Thomas and Kotze classification. Independent sample t-test was used to assess the significant difference of each type of palatal rugae between males and females. Results: Wavy rugae (mean – 5.6 ± 0.7) was predominant among males whereas curved (mean – 4.6 ± 0.6) and circular rugae (mean – 0.9 ± 0.3) were more in females, and were found to be statistically significant (p<0.05). The mean number of secondary rugae in females (1.5 ± 0.5) was greater than that of males (1.3 ± 0.4), and was found to be statistically significant (p<0.05). The diverging type was commonly found in females compared to males. Conclusion: Our findings showed statistically significant differences in the shapes and patterns of rugae between males and females among Kerala population. Thus, morphological analysis of palatal rugae can be considered as an additional aid in forensic odontology for gender differentiation.
ABSTRACT
BACKGROUND: In the human species, twin is a type of multiple birth in which the mother gives birth to two offspring from the same pregnancy. The occurrence and frequency of twinning, however, varies across human populations. The maternal age, socio-environmental factors, increase in the use of contraceptives, the race of human population, increase in the spontaneous abortion rate, and seasonal variations are among the factors that could influence twinning rate. Information on twinning rates in southwest Nigeria is limited. AIMS: This study presents information on the frequency of twinning, as well as its analysis by maternal age, in four urban settings in southwest Nigeria. This is with the aim of extending current knowledge on the frequency of twinning in southwest Nigeria and contributing to the demographic studies in the country. MATERIALS AND METHODS: Data on single births and twin births from January 1995 to December 2004 were collected from the Oyo State General Hospital (OSGH), Wesley Guild Hospital (WGH), Obafemi Awolowo University Teaching Hospital (OAUTH), and Ekiti State Specialist Hospital (ESSH) in Ogbomoso, Ilesa, Ile-Ife, and Ado-Ekiti respectively. These were analyzed by year and maternal age groups of 15-19, 20-24, 25-29, 30-34, 35-39, 40-44, and 45-49 years according to the standard method. RESULTS: A frequency of twin births of 46.5 per 1000 deliveries and 46.2 per 1000 deliveries was recorded for Ilesa and Ile-Ife respectively. The frequency recorded for Ogbomoso and Ado-Ekiti was 38.5 and 22.1 per 1000 deliveries respectively. The overall average frequency of 40.2 per 1000 deliveries for the four hospitals ranks among the highest recorded rates of twin births in the world. The maternal age group of 25-29 years had the highest occurrence of twin births, while the lowest was recorded in the 45-49 years age group. CONCLUSION: This analysis reveals high incidence of twinning in the studied areas and supports previous assertion that the southwestern part of Nigeria has the highest twinning rate in the country and in the whole world. It is our opinion that diet, maternal history of twinning, and some socio-environmental factors may have influenced the results.
ABSTRACT
BACKGROUND: Human sex ratio at birth differs from one population to the other. This variation has been attributed to cultural practices, seasonal variation, small-family size policy and sex selective technology. Information on secondary sex ratio in Nigeria is limited. AIMS AND OBJECTIVE: To analyzed human sex ratio at birth for samples of the Nigerian population in 4 urban settings in Southwest Nigeria, in order to know the trend and to compare the findings with those of previous reports. MATERIALS AND METHODS: Data were collected from Obafemi Awolowo University (OAU) teaching hospital at Ile Ife and Wesley Guild hospital at Ilesa, Osun state; General hospital at Ogbomoso, Oyo state and Ekiti state specialist hospital at Ado-Ekiti, Ekiti state. The data consisted of 35 209 live single births recorded between 1995 and 2004. Each set of data was analyzed to determine the sex ratio by year, month and quarterly values. Chi-square analysis was used to determine the deviation of the sex ratios for the years from the average value. RESULTS: The annual average ratios of 104.7:100, 102.8:100, 98.9:100 and 100.8:100 were recorded for OAU teaching hospital, Wesley Guild Hospital, General Hospital and Ekiti State specialist hospital, respectively. When pooled together, the average ratio was 102.7:100. This shows some bias for male births. Data also indicates more male birth in the rainy season, suggesting a seasonal variation of sex ratio. CONCLUSION: These findings are representative of the populations in southwest Nigeria and are comparable to values obtained for other regions in Nigeria and other populations of African origin.