Intraspecific variability in human maxillary bone modeling patterns during ontogeny.

Area of Science:

• Anthropology
• Human Osteology
• Developmental Biology

Background:

• Human populations exhibit distinct macroscopic morphological variations.
• Understanding the ontogenetic basis of this variability is crucial for evolutionary studies.
• The maxilla's development offers insights into micro- and macroscopic changes during growth.

Purpose of the Study:

• To compare ontogenetic bone modeling patterns of the maxilla with morphological changes in three distinct human populations.
• To investigate how micro- and macroscopic variability is established during human ontogeny.
• To elucidate population-specific developmental trajectories of the human maxilla.

Main Methods:

• Histological analysis of maxillary bone formation and resorption in 145 subadult and adult individuals.
• 3D geometric morphometrics to quantify morphological changes using semilandmark techniques.
• Multivariate statistical analysis and heat map visualization of age-group shape differences.

Main Results:

• Significant differences in the degree of maxillary shape change during ontogeny were observed among the three populations.
• Subtle population-specific differences in bone modeling patterns were detected and maintained throughout development.
• Bone resorption patterns in adults mirrored those in subadults but at reduced intensities.

Conclusions:

• Maxillary morphological differences between human populations are reflected at the microscopic bone modeling level.
• Variations are primarily driven by differences in the rates and timing of cellular activities, not the location of resorption.
• A general bone modeling pattern for the maxilla appears characteristic of Homo sapiens and is consistent throughout ontogeny.