Mohammad Hossein Toodeh zaim - Associate professor department of orthodontics, faculty Of Dentistry, Yazd university of medical sciences
Hossein Ahga Aghili - Associate professor department of orthodontics, faculty Of Dentistry, Yazd university of medical sciences
Zohre Tahatabaei - Assistant professor department of orthodontics, faculty Of Dentistry, Yazd university of medical sciences
Zahra Yousefzade - Dentist

Aim: Prediction of mesiodistal width of unerupted permanent canines and premolars in mixed dentition period is necessary for space analysis. Use of panoramic radiographs instead of periapical radiographs in space analysis decreases the cost and X-ray exposure. The aim of this study was prediction of mesiodistal width of unerupted permanent canine and premolars by panoramic radiographs.Materials and Method: Panoramic radiographs and dental casts of ۶۰ orthodontic patients were selected. The largest mesiodistal width of dental crown of upper and lower canines and premolars on the panoramic and dental cast and also mesiodistal width of lower incisors on dental cast were measured, SPSS was used and data were analyzed by Pearson's coefficient correlation between panoramic, cast and linear regression analysis and paired sample T-test.Results: R for predication of total unilateral mesiodistal width of permanent canine and premolars from cast and panoramic in upper jaw was ۰.۵۸۹ and in lower jaw was ۰.۶۹l. R for prediction of mesiodistal width for unerupted canine and premolars by use of lower incisors width from dental cast and radiographic width of upper permanent canine for upper jaw and lower second premolar far lower jaw were respectively ۰.۶۶۴ and ۰.۹۹۹.Conclusion: Based on introduced linear equation for prediction of mesiodistal width of canine and premolars, the best equation resulted from use of lower incisor width from dental cast and one radiographic agent which is canine in upper arch and second premolar in lower arch.

Mixed dentition, Linear regression analysis, Mesiodistal crown width, Panoramic Radiography