Sharma Ridhima, Srivastava Anurag
Department of Oral Medicine and Radiology, Government Dental College and Hospital, Jaipur, India.
J Forensic Dent Sci. 2010 Jan;2(1):22-6. doi: 10.4103/0974-2948.71053.
It is a well-known fact that the assessment of the dental development can be related to an individual's age, but after the age of 21 years when the wisdom teeth also complete their development, there arises a need for an optimal age estimation procedure. With advancing age, there is a reduction in the size of the pulp due to secondary dentin deposition and a measurement of this reduction can also be used as a parameter to assess the age of the individuals, both in the living and dead.
The purpose of the present study was to evaluate the feasibility of this approach in the estimation of age of adults, using Kvaal's method in the set sample.
The material consisted of the digital long-cone intraoral periapical radiographs from 50 subjects of either sex in the age group of 15-60 years, who were selected after evaluation for the set inclusion and exclusion criteria. The pulp width and length from radiographs of 6 selected teeth, namely, maxillary central incisor, lateral incisor, and second premolar and mandibular lateral incisor, canine, and first premolar of either right or left side were measured using the RVG trophy software [Trophy® Windows is a software program supplied by Trophy Radiologie (Trophy Windows Version 5.03, Copyright 1993-2002,Trophy RVG patented by Trophy, Chicago)]. In order to compensate for the differences in magnification and angulation, various ratios were calculated and the mean of all ratios (M) was taken as the first predictor, while the difference between the mean of 2 width ratios and the mean of 2 length ratios (W - L) was taken as the second predictor. Different regression formulae for all 6 teeth, 3 maxillary teeth, 3 mandibular teeth, and each of the individual teeth were derived and the age was assessed. The assessed age was then co-related with the actual age of the patient using the Student's t test.
The results showed that the coefficient of determination (R(2)) was the strongest (0.198) for the mandibular first premolar indicating that age can be estimated better with this particular tooth. No significant difference was observed between the estimated age and the actual age for all (P>0.05) except in mandibular lateral incisor and maxillary lateral incisor, where a significant difference was observed.
To conclude, the results of the present study suggest the feasibility of Kvaal's method for age estimation in the set sample.
众所周知,牙齿发育的评估可以与个体年龄相关,但在21岁以后,当智齿也完成发育时,就需要一种最佳的年龄估计方法。随着年龄的增长,由于继发性牙本质沉积,牙髓腔的大小会减小,这种减小的测量也可以用作评估个体年龄的一个参数,无论个体是在世还是已故。
本研究的目的是在设定样本中使用Kvaal方法评估这种方法在估计成年人年龄方面是否可行。
材料包括50名年龄在15 - 60岁之间、性别不限的受试者的数字化长锥口腔内根尖片,这些受试者是根据设定的纳入和排除标准评估后选取的。使用RVG trophy软件 [Trophy® Windows是由Trophy Radiologie提供的软件程序(Trophy Windows版本5.03,版权所有1993 - 2002,Trophy RVG由Trophy在芝加哥申请专利)] 测量6颗选定牙齿(即上颌中切牙、侧切牙、第二前磨牙以及下颌侧切牙、尖牙和第一前磨牙,左右侧均可)根尖片上的牙髓宽度和长度。为了补偿放大率和角度的差异,计算了各种比率,并将所有比率的平均值(M)作为第一个预测指标,而2个宽度比率的平均值与2个长度比率的平均值之差(W - L)作为第二个预测指标。得出了所有6颗牙齿、3颗上颌牙齿、3颗下颌牙齿以及每颗单独牙齿的不同回归公式,并对年龄进行了评估。然后使用学生t检验将评估年龄与患者的实际年龄进行相关性分析。
结果表明,下颌第一前磨牙的决定系数(R²)最强(0.198),这表明用这颗特定牙齿可以更好地估计年龄。除下颌侧切牙和上颌侧切牙观察到显著差异外,所有牙齿的估计年龄与实际年龄之间均未观察到显著差异(P>0.05)。
总之,本研究结果表明Kvaal方法在设定样本中进行年龄估计是可行的。