Journal of Dental Medicine

Background and Aims: Since there is a relationship between the tooth size and race, it seems that having statistical information about the tooth size in a society in which the orthodontic treatments are done, is very important. The aim of this study was to determine the relationship between the mesiodistal width of permanent incisors and first molars in both jaws with unerrupted permanent canine and premolars. New regression equations for prediction of the sum of mesiodistal width of canine and premolars were established.

Materials and Methods: A total of 715 dental casts (526 female, 189 male) were recruited from the department of orthodontics of Shiraz dental school and private offices of orthodontists for this cross sectional study. The greatest mesiodistal widths of all teeth were measured with digital caliper with accuracy of 0.01 mm. All data were analyzed with SPSS software and Pearson Correlation, independent T-test, paired sample T-test and multiple linear regression tests.

Results: Tanaka-Johnston equations and Moyer’s prediction tables had significant difference with mesiodistal dental width of south Iranian population, so new regression equations (based on incisors and first molars) for different jaws and sexes were presented in this study for south Iranian population. The best suggested regression is the regression that is based on all maxillary and mandibular incisors and first molars and has 12 variables. The suggested regression for prediction of maxillary canine and premolars based on the summation of mesiodistal width of all incisors and first molars in both jaws was Y=0.177X+4.227 and for prediction of mandibular canine and premolars was Y=0.188X+2.730, which a the greatest in r2 prediction of unerrupted teeth in comparison with the regressions based on incisors alone or incisors and first molars in one jaw.

Conclusion: Tanaka-Johnston and Moyer’s prediction tables are overestimated the actual size of south Iranian’s teeth width. So new regression equations based on incisors alone and incisors and first molars are suggested to increase the accuracy of space analysis in both jaws.

Background and Aims: Selecting an appropriate treatment plan is one of the most critical aspects of dental treatments. The purpose of this study was to compare multimedia system and conventional method in patients' selecting prosthetic treatment and the time consumed.
Materials and Methods: 90 patients randomly divided into three groups. Patients in group A, once were instructed using the conventional method of dental office and once multimedia system and time was measured in seconds from the beginning of the instruction till the patient had came to decision. The patients were asked about the satisfaction of the method used for them. In group B, patients were only instructed using the conventional method, whereas they were only exposed to soft ware in group C. The data were analyzed with Paired-T-test (in group A) and T-test and Mann-Whitney test (in groups B and C).
Result: There was a significant difference between multimedia system and conventional method in group A and also between groups B and C (P<0.001). In group A and between groups B and C, patient's satisfaction about multimedia system was better. However, in comparison between groups B and C, multimedia system did not have a significant effect in treatment selection score (P=0.08).
Conclusion: Using multimedia system is recommended due to its high ability in giving answers to a large number of patient's questions as well as in terms of marketing.