‌An investigation on the symmetry of total teeth size‌ in the right and left sides of dental arches among people‌ ‌with normal occlusion

Dr. M. Zarringhalam*

*- Assistant professor of Orthodontics Dept. Faculty of Dentistry Mashhad University of Medical Sciences.

Background and aim: Considering slight asymmetry between the left and right sizes of body along with the right and left sides of the face, the goal of this study was to measure and compare the total size of teeth in dental arches among highschool students with normal occlusion.

Materials and Methods: In this cross-sectional study,60 samples (30 females and 30 males), age ranging from 16 to 18 yaers old, were selected omong mashhad highschool students based on random cluster sampling method. Data were collected through direct observation, impressions, preparing and measuring study models using an informational form. Mesiodistal widths of 1440 teeth, from the first molar in one side to the other in another side, were measured and collected in each quadrant. Data were subjected to SPSS sofware, Paired t-test and t-test for independent groups.

Results: The average of total teeth size was as follows: 1. Upper right side in boys was smaller than the left but the difference was not significant (P.V=0.82). 2. Upper right side in girls, the same as boys, was smaller than the left but the difference was not significant (P.V=0.125). 3. Lower jaw of boys was larger in the right side than the left but the difference was not significant (P.V=0.456). 4. Lower jaw of girls was larger in the right side than the left but the difference was not significant (P.V=0.125) 5. Total size of teeth of the upper right side in boys was larger than girls and the difference was significant (P.V=0.003). 6. Total size of teeth of the upper left side in boys was larger than girls and the difference was significant (P.V=0.002). 7. Total size of teeth in the lower right side in boys was larger than girls and the difference was significant (P.V=0.039). 8. Total size of teeth in the lower left side in boys was larger than girls and the difference was significant (P.V=0.021). 9. Total size of teeth in the upper jaw (right & left) in boys (91.37mm) was larger than girls (88.65mm) and the difference was significant (P.V=0.005). 10. Total size of teeth in the lower jaw (right & left) in boys (84.4mm) was larger than girls (81.17mm) and the difference was significant (P.V=0.000).

Conclusion: Total size of teeth, in the right and left sides, was not symmetric in both genders but the differences were not significant. e of teeth - Normal occlusion.

Key word :Symmetry, Total size pf teeth, Normal occlusion.