Intermaxillary tooth size discrepancies among different malocclusion classes: a comparative study

The purpose of this study is to determine whether a difference exists in intermaxillary tooth size among different malocclusion groups in Saudi patients. The study consisted of 240 pretreatment orthodontic casts (Sixty cases in each malocclusion class, in addition to normal occlusion). The results of the study shows no significant difference in the incidence of tooth size discrepancies for the overall ratio and ante-rior ratio between the different malocclusion groups, except for the anterior ratio in class III malocclu-sion. Further, no statistical significant difference was observed between males and females. When the mean values of the present study were compared to that of Bolton’s, a significant difference was found in all the malocclusion classes.We can conclude from this study that Bolton tooth size analysis is an impor-tant diagnostic tool, and should be taken into consideration before initiation of orthodontic treatment.

1. When tooth size ratios were compared, there was a statistical significant difference between normal occlusion and Class III malocclusion for the anterior ratio, whereas, no significant difference was found between the other malocclusion classes for the over-all ratio and anterior ratio.

2. Significant sexual dimorphism existed only for the anterior ratio in Class III malocclusion.

3. The means for anterior and overall ratios for the normal occlusion and other malocclusion classes in the present study were statistically significant com-pared to those of Bolton.

1. Fields HW. Orthodontic restorative treatment for relative mandibular anterior excess tooth size problems. Am J Orthod Dentofacial Orthop 79: 176-183, 1981.

2. Moorrees CFA, Reed RB. Biometric of crowding and spacing of the teeth in the mandible. Am J Phys Antrhop 12: 77-88, 1954.

3. Sperry TP, Worms FW, Isaacson RJ, Speidel TM. Tooth size dis-crepancy in mandibular prognathism. Am J Orthod Dentofacial Orthop 72: 183-90, 1977.

4. Proffit W. R. Contemporary orthodontics. 2nd edn. St Louis: Mosby, 1993.

5. Heusdens M, Dermaut L, Verbeeck R. The effect of tooth size discrepancy on occlusion: An experimental study. Am J Orthod Dentofacial Orthop 77: 189-91, 2000.

6. Kesling, HD. Philosophy of tooth positioning appliance. Am J Orthod Dentofacial Orthop 31: 297-340, 1954.

7. Bolton WA. Disharmony in tooth size and its relation to the analysis and treatment of malocclusion. Angle Orthod 28: 113-130, 1958.

8. Stifter J. A study of Pont’s, Howes’, Rees’, Neff’s and Bolton analysis on Class I adult dentitions. Angle Orthod 28: 215-225, 1958.

9. Lavelle CL. Maxillary and mandibular tooth size in different racial groups and in different occlusal categories. Am J Orthod Dentofacial Orthop 61: 29-37, 1972.

10. Arya BS, Savara BS, Thomas D. Relation of sex and occlusion to mesiodistal tooth size. Am J Orthod Dentofacial Orthop 66: 479-86, 1974.

11. Crosby DR, Alexander CG. The occurrence of tooth size discrep-ancies among different malocclusion groups. Am J Orthod Dentofacial Orthop 95: 457-61, 1989.

12. Hashim HA, Murshid Z. Intermaxillary tooth width ratio in a Saudi sample with different malocclusions. Alex Den J 19: 45-52, 1994.

13. Nie Q, Lin J. Comparison of intermaxillary tooth size discrepan-cies among different malocclusion groups. Am J Orthod Dento-facial Orthop 116: 539-544, 1999.

14. Tamimi TS. An odontometric study of tooth size ratio and arch dimensions in a Saudi population with normal occlusion. Master Thesis, 2000. College of Dentistry, King Saud University. Saudi Arabia.

15. Hunter WS, Priest WR. Error and discrepancies in measurements of tooth size. J Dent Res 39: 405-14, 1960.

16. Binder RE, Cohen SM. Clinical evaluation of tooth size discrep-ancy. J Clin Orthod 9: 544-546, 1998.