Transverse development of the craniofacial skeleton and dentition between 7 and 15 years of age--a longitudinal postero-anterior cephalometric study

The aim of this study was to identify the transverse growth pattern of the craniofacial skeleton and dentition from 7 to 15 years of age. The database for this longitudinal study comprised the postero-anterior (PA) cephalograms and dental casts at 7, 9, 11, 13 and 15 years of age of 18 untreated Class I subjects with good occlusion from the Belfast Growth Study. Differential magnification of the PA cephalograms was corrected using the method of similar triangles. Most of the craniofacial widths were larger in males than in females. At 15 years of age, the gender differences in craniofacial widths were more pronounced than at 7 years of age. The majority of the skeletal dimensions showed a progressive increase in width. In contrast, there was a deceleration in the increase in maxillary and mandibular intermolar widths after 11 years of age in males and even a slight decrease in the intermolar width beyond 11 years of age in females. Growth curves were calculated where the values of the respective variables were expressed in terms of percentage of attainment at 7, 9, 11 and 13 years of age when compared with 15 years of age. For mid-facial, bizygomatic and skeletal maxillo-mandibular widths, percentile attainments in the range of 84-91 per cent indicated a greater remaining growth potential at 7 years of age than for the cranial width where growth was almost complete. By the age of 7 years, over 95 per cent of the growth in the intermolar width had occurred.