title: Age dynamics and secular changes of indices characterizing the neurocranium and facial cranium in ethnic Bulgarian 7-17-year-old children from the region of the Eastern Rhodopes.
abstract: BACKGROUND
  It is impossible to give an objective anthropologic assessment of the overall physical development of a child's body during the time of intensive growth (7-17 years) without taking into account the age and gender changes in the absolute and relative head and face measurements. Head growth has specific characteristics that makes it different from the growth of other parts of the body. The head of a child differs from the head of an adult not only by metric characteristics but also by the proportions between the different head measurements. Growth and proportionality of the head comply with the general growth pattern, but there are also certain regional, populational and temporal differences. That was the reason why we conducted a study targeted at children and adolescents from the region of the Eastern Rhodopes. The aim Of the present study was to determine the growth dynamics in between-gender and between-age aspects of the variables characterizing the neurocranium and facial cranium, and establish the tendency and direction of the secular changes,
  
  
  METHODS
  The study included 1481 children and adolescents (699 boys and 782 girls) aged 7 to 17 years that were examined using the classical methodology of Martin-Saller (1957). Head length, width, height and circumference, as well as face width, mandible width, morphological and physiognomic height of the face were measured. Head index, morphological face index and jugulormandibular index were calculated using standard formulas. The secular changes were analyzed comparing data from 1907 and 1960 with the data of the present study.
  
  
  RESULTS
  The head index classified the children from both genders and all age groups as mesocephals. The girls from the study region had a relatively greater mandible width and boys - relatively greater face width. In the beginning of the growth period wider face forms prevailed especially in the girls, while narrower face forms were more characteristic for the adolescence and postadolescence and better manifested in the boys.
  
  
  CONCLUSIONS
  Throughout the entire study period the boys presented with greater measurements of the neurocranium and facial cranium than the girls. For both genders the increase in the neurocranium measurements anticipates that in the facial cranium measurements. In the examined children and adolescents the width cephalometric variables complete their growth earlier than the height variables. The head circumference and head width decrease, while the differences in the head length and facial height increase in both genders and all age groups in the end of the 20th and beginning of the 21st century.
authors.affiliation: Department of Human Anatomy and Physiology, Faculty of Biology, Plovdiv University Paisii Hilendarski, Bulgaria. slavi02@uni-plovdiv.bg
authors.forename: Slavi At
authors.initials: SA
authors.lastname: Tineshev
mesh_terms: D000293:Adolescent; D000367:Age Factors; D002031:Bulgaria / Q000453:epidemiology; D002508:Cephalometry / Q000379:methods*; D002648:Child; D005006:Ethnicity; D005260:Female; D006801:Humans; D008297:Male; D012016:Reference Values; D012737:Sex Factors; D012886:Skull / Q000254:growth & development*