In order to evaluate the relationship of age with the developmental stage on mandibular second molars in female, the author examined the radiographs in standard films taken by intraoral paralleling technic and analysed the development of 620
roots
of
310 females ranged from 10 to 18 years.
@ES The development was divided into 7 states:
@EN Crown complete(Cr.C.), Root lengthed 1/4(R.1/4), Root length 1/2(R.1/2), Root length 3/4(R.3/4), Root length complete(R.C.), Apex 1/2 closed(A.1/2), Apical closure complete(A.C.)
@ES The obtained results were as follows;
@EN 1. The formation of roots in full length of mandibular second molars was completed at 14.21-year-age in mesial root and at 14.96-year-age in distal root.
2. The formation of apical foramen of mandibular second molars was completed at 17.11-year-age in mesial root and at 17.53-year-age in distal root.
3. The mesial root of mandibular second molar was generally developed earlier than distal root(p<0.01).
4. Coefficients of correlation and regression equations between for age(Y) and the developmental stage of mandibular second molar(X) were "Y=1.53X+6.54, n=0.91 (p<0.01)" in mesial root and "Y=1.52K+7.11, n=0.92(p<0.01)" in distal root
respectively.
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