A craniofacial growth maturity gradient for males and females between 4 and 16 years of age.

Differential growth of the craniofacial complex implies variation in ontogenetic patterns of development. This investigation quantifies the relative maturity--as defined by percent adult status--of nine cephalometric dimensions and stature. Analysis is based on 663 lateral cephalograms from a mixed longitudinal sample of 26 males and 25 females between 4 and 16 years of age. Graphic comparison of maturity status across the age range shows that variation is intergraded between the neural and somatic growth maturity patterns, as described by head height and stature, respectively. The maturity gradient moves from head height through anterior cranial base, posterior cranial base and maxillary length, upper facial height, corpus length, and ramus height to stature. After 9 years of age ramus height is less mature than stature. Anterior maxillary and mandibular heights diminish during transitional dentition and thereafter exhibit maturity patterns that compare to corpus length. Although females are consistently more mature than males, the gradient of variation between dimensions is sex independent.

Craniofacial growth and size patterns during postnatal development.

Patterns of craniofacial growth and size relationships are described for a mixed longitudinal sample of 26 males and 25 females, followed serially from four years of age through adult status. The seven dimensions examined, derived from 663 lateral cephalograms, show differential patterns of negative allometric growth relative to statural increase. Relative growth is greatest for mandibular traits, followed by upper facial and neurocranial traits, respectively. Males exhibit greater relative growth than females. Craniofacial variation residual to allometry follows three independent patterns of association defined by principal component analysis. The components are age and sex independent, suggesting that after proportional changes related to absolute size or scale are controlled for, anterior facial, cranial height, and masticatory associations follow separate but proportionate patterns during growth.

Principal components of craniofacial growth for white Philadelphia males and females between 6 and 22 years of age.

Three principal components, explaining 83 percent of the common variation for 999 males and females between 6 and 22 years of age, describe ontogenetic patterns of relationship for seven facial dimensions, including sella-nasion, sella-basion, nasion-prosthion, infradentale-menton, articulare-gnathion, gonion-gnathion, and articulare-gonion. Accounting for 65 percent of the variation, a general component associated with both size and shape defines size-required changes in proprotion during growth. Independent patterns of regional variation associated with alveolar remodeling (second component) and condylar growth (third component) describe specific sources of facial modification. Mean multivariate component scores reveal that sexual dimorphism, which progressively favors males over females with age, results from accumulating differences in size and related proportional changes in shape. The timing of the condylar growth spurt, as evident from variation in ramus height, produces secondary dimorphism which diminishes following the adolescent phase in males. Significant age effects are indicated for alveolar remodeling and mandibular growth of the condyle.

Intra-group variations in the dental eruption sequence of Macaca fuscata fuscata.

The purpose of this investigation was to establish general trends of intra-group variations in the dental eruption sequence of a semi-wild troop of Maca fuscata fuscata. Dental impressions were taken on 128 animals of varying ages. The analysis of the dental casts revealed sexual dimorphism in sequence and timing of eruption.