Harris E F
Department of Orthodontics, College of Dentistry, University of Tennessee, Memphis 38163, USA.
Am J Orthod Dentofacial Orthop. 1997 Apr;111(4):419-27. doi: 10.1016/s0889-5406(97)80024-8.
Adulthood-the lengthy phase following attainment of biologic maturity-often is perceived as a period of "no change" or one of slow deterioration. Recent skeletodental studies discount this stereotype. Changes in arch size and shape were studied here in a longitudinal series of 60 adults with intact dentitions. Full-mouth study models were taken at about 20 years of age and again at about 55 years. Some variables-particularly those between arches (incisor overbite and overjet, molar relationship) and mandibular intercanine width-remained age-invariant. In contrast, all other measures of arch width and length changed significantly (P < 0.01): Arch widths increased over time, especially in the distal segments, whereas arch lengths decreased. These changes significantly altered arch shape toward shorter-broader arches. The data suggest that changes during adulthood occur most rapidly during the second and third decades of life, but do not stop thereafter. Possible mechanisms driving these changes in tooth position are discussed.
成年期——生物成熟之后的漫长阶段——通常被视为一个“无变化”的时期或缓慢衰退的时期之一。最近的骨骼牙齿研究对这种刻板印象提出了质疑。在此，对60名牙列完整的成年人进行了纵向系列研究，以观察牙弓大小和形状的变化。在大约20岁时取全口研究模型，大约55岁时再次取模型。一些变量——特别是那些牙弓间的变量（切牙覆合和覆盖、磨牙关系）以及下颌尖牙间宽度——保持与年龄无关。相比之下，牙弓宽度和长度的所有其他测量值均有显著变化（P < 0.01）：随着时间的推移，牙弓宽度增加，尤其是在远中段，而牙弓长度减少。这些变化显著改变了牙弓形状，使其朝着更短更宽的方向发展。数据表明，成年期的变化在生命的第二个和第三个十年最为迅速，但此后并不会停止。文中讨论了驱动牙齿位置这些变化的可能机制。
