MEASUREMENT OF CEPHALIC AND FACIAL INDICES AMONG STUDENTS OF KUSMS

Nepal is a nation with complex and varied ethnic composition of population where the shape of human face and head is often used for identification of individual. The shape of human face and head is affected by several factors like age, gender, race, ethnicity, climate and genetic factors.1 Cephalo-facial morphometry reviews the anatomical complexes of the head and face of human being living within a similar geography.2


INTRODUCTION
Nepal is a nation with complex and varied ethnic composition of population where the shape of human face and head is often used for identification of individual. The shape of human face and head is affected by several factors like age, gender, race, ethnicity, climate and genetic factors. 1 Cephalo-facial morphometry reviews the anatomical complexes of the head and face of human being living within a similar geography. 2 It provides considerable information about physical conditions and development during growth. The cephalo-facial indices are generally considered as indicators of shape of human head and face respectively which may provide a clue to genetic transmission of inherited characters. 3,4 It has also a great importance for the evaluation of genetic transmission, congenital and traumatic deformities. 1,5 It would also provide information on inheritance patterns such as dolicocephalic type of head are less prone to Otitis media and in the individuals with Apert's syndrome are hyperbrachycephalic type. 4,6 The researchers are very much interested in studying of cephalo-facial morphology of individual among different population 7 which has been shown variations based on ethnicity, races and geographical location. 8 Hence, the aim of the present study was to evaluate the shape and size of head and face among Nepalese population which may provide useful data to the clinicians and researchers during their applications. Calculated sample size was 196 and then study was conducted in 222 individuals (115 female and 107 male) from various program under KUSMS. The individuals with physically fit and age group 18-25 years were included for this study. The individuals with any traumatic and congenital cephalo-facial deformities were excluded from the study.

METHODS
The facial length was measured as the distance from nasion to gnathion and breadth was measured as the distance between two zygomatic prominences with the spreading caliper in centimeter. The cephalic head was measured as the distance from glabella to inion and breadth was measured as the distance between two parietal prominences with the spreading caliper in centimeter. All the measurements have been taken following the techniques of Martin and Saller. Facial Index was measured as the ratio of facial length to facial breadth multiplied by 100 and cephalic Index was measured as the ratio of head breadth to head length multiplied by 100. 9 All the measurements were taken with the individual sitting in a relaxed condition and head in Franfort's horizontal plane. The collected data was entered in excel and analyzed with SPSS version 22.0.
The type of head and face were classified as given by Martin

RESULTS
The study was done in 222 individuals (115 female and 107 male) from various program under KUSMS. The present study revealed the facial index and cephalic index cephalic index as 96.95±4.29 and 72.52±3.9 respectively ( Table 1).
The study evaluated the length of face of male was found to be significantly higher than that of female whereas the breadth of female face was found to be significantly higher than that of male as shown in table 2. There was a highly significant (0.00) difference in the mean value of facial index between male and female.  The average length and breadth of female head was found to be lower than that of male as shown in table 2. There was a highly significant (0.00) difference in the mean value of cephalic index between male and female.
The present study observed that that the most common type of face phenotype was hyperleptoprosopic with a prevalence of 75.68% (70.43% female and 81.31% male), which was followed by leptoprosopic with a prevalence of 19.37% (20.87% female and 17.76% male), mesoprosopic with a prevalence of 4.50% (8.70% female only) and euryprosopic with a prevalence of 0.93% (0.45% male only). It was also noted that hyperleptoprosopic facial type was more common in male as compared to female. In contrast, leptoprosopic type was more common in female than that of male. Furthermore, mesoprosopic facial type was seen only in female but not in male and euryprosopic facial type was observed only in male but not in female as illustrated in Table 3. According to the value of cephalic index, dolicocephalic was found to be the dominant type of head in which male was 74 (69.16%) and female was 91 (79.13%). It was followed by mesocephalic in which male was 20 (28.97%) and female was 30 (17.39%) and brachycephalic in which male was 2 (1.87%) and female was 4 (3.48%). It was also found that the dolicocephalic and brachycephalic type of female head were higher than that of male but mesocephalic type of female head was lower than that of male as shown in Table 4. The most common type of face among Nepalese population was found to be the hyperleptoprosopic in both genders. Likewise, the most common of type of face was recorded hyperleptoprosopic among Iranian population 15 and Albanians of Kosovo population. 16 A study done in Kathmandu reported the hyperleptoproscopic to be the second most common type of face. 17 However, a study done in the mid-part of Nepal concluded that it was the least common occurrence among both genders. 18 Similarly, Yesmin et al studied among Malaysian population and observed the hyperleptoprosopic type to be least common which accounted for 5% for both genders. 19 A study done among Gujarati (Indian) female also reported the hyperleptoprosopic (8.3%) type of face to be least common which was also disagreed with this study. 2 The leptoproscopic was recorded as the second common type of face in the present study. Whereas a study recently done in Nepal reported that it was the most common among dental students. 17 Similarly, it was also the second common type of face for male among Malaysian population. 19 In contrast, Mamun et al noted that the most common type of face was leptoproscopic for Japanese male (26.1%) and female (30.7%). 3 A study among Chinese ethnic population of Indonesia demonstrated leptoproscopic type in male to be most common which was inconsistant to the present study. 11 The mesoproscopic type of face was found to be the least common among Nepalese female with a prevalence of 8.70%. However, it was the most common type among Tibeto-Nepalese, and indigenous population of Eastern Nepal. 20 It was also the most common type of face for Malaysian as well as Iranian population (Sistani and Baluch groups). 18,19 Euryproscopic type of face was found only among male (0.93%) but not among female in the present study. In contrary, a study done by Ghosh et al reported the hypereuryproscopic and euryproscopic present in the highest and equivalent percentages in Santhals. 7 Heidari et al 21 conducted a study in southeast of Iran and reported the most common type of face was euryproscopic among female which was different from the present study. Similarly, hypereuryproscopic was the most common type of face followed by euryproscopic in Gujarati (Indian) population. 2 Variations in these findings may be due to environmental affect on their facial morphology.
Variations in cephalic index of different populations have been certified to a complex interaction between genetic and environmental factors. 22 Of course, the index varies from individual to individual but its amplitude can remain within certain limits in a given population. This peculiarity made the index suitable as a racial character. 10 A study done by Eroje et al 23 reported cephalic index for Obia male and female as 73.7 and 72.2 respectively which were almost similar to the present study. In contrast, the mean cephalic index for the male and female were 81.81 and 82.99 respectively among Thai population. 24 Dolicocephalic was found to be the most common type of head in the present study. A study done in indigenous Tharu community of Biratnagar, Nepal reveled dolicocephalic head to be the most common which was comparable to the present study. 25 A study done by Saini et al in North Indian state, Uttar Pradesh also reported dolicocephalic type of head to be the most common type. 10 In contrast it was recorded as the least common type among Nepalese Medical students of all the three ethnic groups namely Brahmin, Newar and Chettri. 26 It was the least common among (4.32%) Thai 24 and Japanese populations as well. 3 A study done among Colombian population found that the mesocephalic was the second common type of head 27 which was comparable to the present study. But a study conducted in Romanian population and reported the dominant cranial type in their study as mesocephalic. 28 A study in Nepal also claimed the mesocephalic type of head to be the most common among Medical students. 29 A study was conducted by Rao et al in Gujarat (India) reported the least type of head was the brachycephalic among their population which was in accordance to the present study. 30 Similarly, Setiya et al 31 did a study in Madhya Pradesh (India) and the reported the least type to be brachycephalic in male (1.11%) and female (4%). In contrast, it was recorded the most common type among Brahmin, Newar and Chettri of Nepalese population. 26 It was also the most common among Albanians of Kosovo 16 and Srilankan population. 32 The present study did not record hyperbrachycephalic type of head which was similar to the study done by Setiya et al. 31 So it is obvious that hereditary factor is primarily responsible for this variability in head shape in various ancestries, ethnicities and geographical regions, however environment has secondary effect on it. 33 There is an established relationship between the variation in cranial phenotypes and geographical distances. 34 The individuals chosen for study were from different parts of Nepal. However, due to a relatively small sample size it cannot be generalized. This study has just focused on the measurement of anthropometric data but has not focused on the factors which might be responsible for this anthropometric presentation.

CONCLUSION
The present study concluded that the majority of people of Nepal having hyperleptoproscopic type of face followed by leptoprosopic. Similarly, common type of head was found to be dolicocephalic followed by mesocephalic. The data obtained in this study may be useful in clinical and medico-legal practices; and further researches of anthropology and genetics.