Regression analysis to predict total space required from mandibular first permanent molar

Umar Hussain; Ali Ayub; Afeef Umar Zia; Faizan Ul Hassan; Syed Suleman Shah; Ghulam Rasool

Regression analysis to predict total space required from mandibular first permanent molar

Authors

Umar Hussain BDS, FPCS, MS; Lecturer, Saidu College of Dentistry, Swat, Pakistan.
Ali Ayub BDS, FPCS; Associate Professor, Orthodontics, HBS Medical and Dental college, Islamabad.
Afeef Umar Zia BDS, FPCS, M.Orth RCS Ed; Professor & Head of department Orthodontics, Margalla institute of Health Sciences, Pakistan.
Faizan Ul Hassan BDS, FPCS; Assistant professor, Rehman College of Dentistry, Peshawar, Pakistan.
Syed Suleman Shah BDS, FPCS; Demonstrator, Khyber College of Dentistry, Peshawar, Pakistan.
Ghulam Rasool BDS, MCPS, FPCS, MPHE; Dean and Principal of Rehman College of Dentistry, Peshawar, Pakistan.

Keywords:

Mesiodistal widths, mandibular permanent first molar, regression equation, space analysis, total space required

Abstract

Introduction: Space analysis is an essential tool for treating crowded cases in Orthodontics. Accurate method for space analysis can help the clinician to obtain optimal results.

Material and methods: The mesiodistal width of teeth was measured for 120 plaster models. The correlation between MW of mandibular first molar (Md-6) and total space required (TSR) in both jaws was assessed with Pearson correlation test. Regression equations for both genders and jaws between Md-6 and TSR were derived through linear regression. Independent samples t test was used for comparison of MW of Md-6 and TSR between genders for each jaw. Paired t test was applied for comparing the MW of predicted and actual TSR.

Results: The mean MW of all 10 permanent teeth in mandible for males (68.30±4.41) was higher than females (66.44±3.337) statistically (P=.010). Correlation between MW of Md-6 and TSR were higher in females (maxillary arch r=0.84 and mandibular arch r=0.860) than males (maxillary arch r=0.79 and mandibular arch r=0.830). In mandible 69.2% of the variations in TSR can be explained due to MW of Md-6 in the model. Similarly, in maxilla 65% of the variations in TSR can be explained due to MW of Md-6 in the model. Regression equations were derived for both arches and genders using Md-6 as an explanatory variable and TSR as a dependent variable.

Conclusions: Md-6 can be utilized as a predictor for TSR in both arches and genders.