Date of Award
Master of Arts
William M. Bass
P.S. Willey, Richard Jantz
The palatal processes of the adult human maxilla consist of two horizontally directed bones of quadrilateral shape situated posterior of the nasal fossae. In the early stages of morphogenesis, these palatal folds are vertically oriented and separated by the developing tongue. Between the eighth and eleventh weeks the fetal tongue descends allowing alignment and midline fusion of the palatal processes of the maxilla. At birth the palate is composed of four bones joined by broad serrated sutures. With increasing age the suture gaps narrow, fuse, and ultimately obliterate.
The purpose of this study is to develop a method of estimating the age of an individual from obliteration of the four maxillary sutures. The sample consisted of 46 White males, 32 White females, 64 Black males, and 44 Black females of known age, race, and sex. In the initial stages of analysis, two hypotheses were tested. The first hypothesis was that there would be no differences in the rate of suture obliteration between the races (Black versus White). Statistical analysis revealed that significant race differences do not exist, so the null hypothesis was accepted and the races were pooled in subsequent analysis.
The second hypothesis was that there would be no difference in the rate of suture obliteration between the sexes. Statistical analysis revealed that significant sex differences do exist.
It was found that males of both races exhibit more suture obliteration than females at the same age. The four maxillary sutures show significant differences in the rate and/or onset of obliteration. During the early adult years, both sexes progress at nearly the same rate while older females with a combined obliteration score approaching 4.0 may be over-aged by as much as 59 years.
The biological explanations for the observed sexual dimorphism in the rate of suture obliteration remain elusive. However, it is probable that differences result primarily from hormal influences as well as nutritional, pathological, and other environmental factors producing increased obliteration in the males or decreased obliteration in the females.
Although this method does not estimate exactly the age of an individual, it is valuable in estimating the age range of an individual, sorting commingled remains and estimating the skeletal age when only the maxilla is present. In addition, this method offers valuable information concerning sex dimorphism in the human skeleton.
Mann, Robert Walter, "Maxillary Suture Obliteration: A Method for Estimating Skeletal Age. " Master's Thesis, University of Tennessee, 1987.