J. Mahmodian , A. Kowsary , Sh. Javadi-Nejad ,
Volume 11, Issue 4 (8-1998)
Abstract
Eruption is a kind of development move of tooth from the place of its formation to its functional position in the mouth.Time and sequence of permanent's teeth eruption from the point of health diagnosis and orthodontic treatments is very important.Because of this, we decided to evaluate and determine the mean eruption time of canine and premolars from gum penetrations toward occlusion and also their sequence of eruption.The average time of eruptions in this study was higher than other similar studies.Our findings showed that the mean eruption time of canine and premolars in girls is earlier than boys lower canines erupt earlier than upper ones and maxillary premolars erupt before mandibular premolars in boys.
V. Talebi , H. Mahmood Hashemi , H. Gahani Hashemi ,
Volume 16, Issue 2 (5-2003)
Abstract
Statement of Problem: One of the easiest and most practical methods to predict the size of permanent canines and premolars, is of Tanaka-Johnston, but their research has been only performed on white skin North Europeans and it should be noted that the size of teeth, in various races, differ from each other.
Purpose: The aim of this study was to determine the validity of Tanaka-Johnston method, in a sample population taken from Ghazvin city.
Materials and Methods: The numbers of 235 pairs of study casts, prepared before any kind of treatment, were selected. The size of lower permanent incisors and permanent canines and premolars of both arches were measured. To analyze the results, "regression analysis" and "t test" were used.
Results: Based on the findings obtained from this study, new prediction equations as Y=12.9+0.4(X) and Y=]0.6+0.5(X) were presented for maxilla and mandible, respectively. However, these equations did not differ from Tanaka-Johnston equations statistically.
Conclusion: Tanaka- Johnston equations can be acceptably applied for the sample population taken from Ghazvin city, if the predictions are not overestimated.
