Volchansky A, Cleaton-Jones P, Fatti L P
J Clin Periodontol. 1979 Aug;6(4):231-7. doi: 10.1111/j.1600-051x.1979.tb01925.x.
The position of the gingival margin of the incisor and canine teeth, indicated by clinical crown height, was measured using a standardised photographic technique, in 30 dental students over a 3-year period. There was a progressive increase in mean clinical crown height during this period, suggesting that continual passive eruption of the teeth was occurring. There was a significant slowing in the rate of change over the period 1975-1977 for tooth 33, the reason for which is unknown.
在3年时间里，使用标准化摄影技术测量了30名牙科学生中切牙和尖牙牙龈边缘的位置，以临床冠高度表示。在此期间，平均临床冠高度逐渐增加，表明牙齿在持续被动萌出。1975年至1977年期间，33号牙的变化速率显著放缓，原因不明。
