Bernabé Eduardo, Flores-Mir Carlos
Associate Professor, Department of Social Dentistry, Universidad Peruana Cayetano Heredia, Lima, Peru.
Angle Orthod. 2006 Jan;76(1):20-5. doi: 10.1043/0003-3219(2006)076[0020:DMAC]2.0.CO;2.
The objective of this study was to compare, combined and individually, the mesiodistal (MD) and buccolingual (BL) tooth sizes as well as their respective crown proportions in the permanent dentition in dental arches with moderate, mild, and no crowding. Dental casts from two-hundred 12 to 16-year-old school children from a typical high school from Lima, Peru, were used. The MD and BL tooth sizes of all permanent teeth except second and third molars were measured, and their crown proportion (MD/BL ratio) was estimated. Each dental arch was classified as presenting moderate (-5.1 mm or more of discrepancy), mild (-0.1 and -5 mm of discrepancy), and no crowding (zero or a positive discrepancy). Combined and tooth-specific comparisons among the crowding groups for the tooth sizes as well as crown proportions were performed with a multivariate analysis of variance (MANOVA, using Wilks lambda). Combined MD tooth sizes and crown proportions differed among crowding groups. Subsequent individual comparisons indicated differences for MD tooth size of all upper teeth and for lower premolars and central incisors. Differences were also detected for crown proportions of the upper second premolar, canine, and both incisors; as well as for the lower first premolar, canine, and central incisor. No differences were found for the BL tooth sizes among crowding groups. MD tooth sizes and crown proportions from specific teeth are significantly different between dental arches with moderate, mild, and noncrowded arches. This study helps to understand the odontometric component of the dental crowding multifactorial origin.
本研究的目的是比较在牙弓中存在中度、轻度拥挤以及无拥挤情况的恒牙列中，近远中（MD）和颊舌（BL）牙尺寸及其各自的冠部比例，包括联合比较和单独比较。使用了来自秘鲁利马一所典型高中的200名12至16岁学童的牙模。测量了除第二和第三磨牙外所有恒牙的MD和BL牙尺寸，并估算了它们的冠部比例（MD/BL比值）。每个牙弓被分类为呈现中度（差异为-5.1毫米或更多）、轻度（差异为-0.1至-5毫米）和无拥挤（差异为零或正值）。使用多变量方差分析（MANOVA，采用威尔克斯λ）对拥挤组之间的牙尺寸以及冠部比例进行联合和特定牙齿的比较。联合的MD牙尺寸和冠部比例在拥挤组之间存在差异。随后的单独比较表明，所有上颌牙齿以及下颌前磨牙和中切牙的MD牙尺寸存在差异。在上颌第二前磨牙、尖牙以及两颗切牙的冠部比例方面也检测到差异；在下颌第一前磨牙、尖牙和中切牙方面也有差异。在拥挤组之间未发现BL牙尺寸存在差异。在中度、轻度拥挤和无拥挤的牙弓之间，特定牙齿的MD牙尺寸和冠部比例存在显著差异。本研究有助于理解牙列拥挤多因素起源中的牙测量学成分。
