Mastication Effects on Craniofacial Development of Prehistoric and Contemporary Humans

Objectives: Changes in craniofacial morphology, particularly in the masticatory structures can be analyzed by comparing bone materials representing the man from prehistoric times up to the modern civilized man. This study aimed to conduct a comparative assessment of skulls and jaws of the human sambaqui (prehistoric population that lived around 6500 BP) and the contemporary man, with respect to selected craniometric indexes: the right and left mandibular angles; occlusion and dental crowding; maxillary and mandibular arch forms and dental wear.
Methods: The study used both qualitative and quantitative methods, in which 48 sambaqui man skulls aged between 18 and 40, from the Sambaqui Archaeological Museum of Joinville (MASJ), have been analyzed along with 78 modern man skulls from the Federal University of São Paulo - Paulista School of Medicine (UNIFESP – EPM). For the descriptive statistics, frequency distribution of qualitative variables has been obtained, whilst average and standard deviation measures have been calculated for the numeric variables. For the inferential statistics, Mann-Whitney and Pearson‘s chi-square tests have been performed. Fisher's exact tests have been applied in cases that the conditions required by chi-square tests were not present.
Results: The results show that the skull-mandibular skeletal structure of contemporary man is similar to sambaqui man according to the craniometric indexes analyzed. In turn, the mandibular angle, dental crowding, maxillary and mandibular arch forms, degree of dental wear and growth profile categories showed a significant difference between the two groups.
Conclusions: It was possible to verify a more harmonious masticatory development profile for sambaqui man.