Issues‎ > ‎Vol 7, issue 1‎ > ‎


Dental Arch Dimension of Mixed Dentition of Kurdish Orthodontic Patients with Class I and Class II Division 1 Malocclusion (In-Vitro Comparative Study)

Rebin A. Mohammed Amin* , Mahmoud K. Mohsin* , Bayan A. Hassan*

*Department of Pedodontic, Orthodontic and Preventive Dentistry, College of Dentistry, Hawler Medical University, Erbil, Iraq.

Submitted: 24/11/2019; Accepted: 19/01/2020; Published 01/06/2020



Objective: To assess dental arch dimensions (width, depth) in mixed dentition in a sample of Kurdish orthodontic patients.   

Methods: A sample of 58 dental casts (28 class I, 30 class II division 1 malocclusions) from 8 years and two months to 10 years and nine months were collected. Measurement of arch dimensions was taken, including width and depth. Differences between males and females and between class I and class II division 2 malocclusion were tested using independent t-test.

Results: With gender pooled, class I group has larger UC, UE, U6, LE, L6 width than class II group, whereas class II group has larger LC width than class I group with no significant difference. The class II group has larger arch depth for maxillary measurements than the class I group, with no significant difference. While the class I group has larger arch depth for mandibular measurements than the class II group, with no significant difference except for LC. In gender dimorphism, class I group, all arch width measurements, females have a larger width than males except L6; all differences were no significant. While in all arch depth measurements, males have larger depth than females. In the class II group, all measurements of width and depth were larger in males than females, the difference in UE and U6 were significant.

Conclusions: Class I malocclusion has larger width and depth than class II division 1 malocclusion, except in the maxillary depth of class II division 1 malocclusion. Males had larger arch dimensions than females.


Keywords: Arch dimension, Orthodontic, Kurdish, Mixed dentition.                                                                                                                                                                                              Full Article - PDF                                                                                                                                                                                                                                   


1. Burdi AR. Morphogenesis of mandibular dental arch shape in human embryos. J Dent Res. 1968;47(1):50-8.
2. Bishara SE, Jakobsen BP . Longitudinal comparisons of dental arch changes in normal and untreated class II, division 1 subjects and their clinical implications. Am J Orthod Dentofacial Orthop. 1996;110(5):483-9.
3. Bishara SE, Bishara SE, Staley RN. Maxillary expansion: clinical implications. Am J Orthod Dentofacial. 1987;91(1):3-14.
4. Hassanali J, Odhiambo JW. Analysis of dental casts of 6–8- and 12-year-old Kenyan children. Eur J Orthod. 2000;22(2):135-42.
5. Al-Khateeb SN, Abu Alhaija ESJ. Tooth Size Discrepancies and Arch Parameters among Different Malocclusions in a Jordanian Sample. Angle Orthod. 2006;76(3):459-65.
6. Sillman JH. Dimensional changes of the dental arches: longitudinal study from birth to 25 years. Am J Orthod. 1964;50(11):600-16.
7. Knott VB. Longitudinal study of dental arch width at four stages of dentition. Angle Orthod. 1972;42(4):387-95.
8. Moorrees CFA. The dentition of the growing child. (Cambridge, Harvard University Press, 1959).
9. Lavelle CL, Flinn RM, Foster TD, Hamilton M. An analysis into age changes of human dental arch by a multivariate technique. Am J Phys Anthropol. 1970;33(3):403-12.
10. Moorrees CFA, Reed RB. Correlation among crown diameters of human teeth. Arch Oral Biol. 1964;9(6):685-97.
11. Jung M. Evaluation of the effects of malocclusion and orthodontic treatment on self-esteem in an adolescent population. Am J Orthod Dento facial Orthop. 2010;138(2):160-6.
12. Carter GA, McNamara JA Jr. Longitudinal dental arch changes in adults. Am J Orthod Dentofacial Orthop. 1998;114(1):88-99.
13. Cassidy KM, Harris EF, Tolley EA, Keim RG. Genetic influence on dental arch form in orthodontic patients. Angle Orthod. 1998;68(5):445-54.
14. Moorrees CF, Reed RB. Changes in dental arch dimensions expressed on the basis of tooth eruption as a measure of biologic age. J Dent Res. 1965;44:129-41.
15. Knott VB. Longitudinal study of dental arch widths at four stages of dentition. Angle Orthod. 1972;42(4):387-94.
16. Bishara SE, Jakobsen JR, Treder J, Nowak A. Arch width changes from 6 weeks to 45 years of age. Am J Orthod Dentofacial Orthop. 1997;111(4):401-9.
17. Defraia E, Baroni G, Marinelli A. Dental arch dimensions in the mixed dentition: a study of Italian children born in the 1950s and the 1990s. Angle Orthod. 2006;76(3):446-51.
18. Louly F, Nouer PRA, Janson G, Pinzan A. Dental arch dimensions in the mixed dentition: a study of Brazilian children from 9 to 12 years of age. J Appl Oral Sci. 2011;19(2):169-74.
19. Vanichvatana S. Comparison of Dental arch dimension of untreated mixed dentition patients with Class II division 1, Class II division 2, and Class III malocclusion.(2015; PhD Thesis, Saint Louis University).
20. Staley RN, Stuntz WR, Peterson LC. A comparison of arch widths in adults with normal occlusion and adults with class II, Division 1 malocclusion. Am J Orthod. 1985;88(2):163-9.
21. Raberin M, Laumon B, Martin JL, Brunner F. Dimensions and form of dental arches in subjects with normal occlusions. Am J Orthod Dentofacial Orthop. 1993;104(1):67-72.
22. Moyers RE, van der Linden FPGM, Roiolo ML, McNamara JA Jr. Standards of human occlusal development, monograph no. 5, craniofacial growth series. ann arbor, michigan: center for human growth and development, University of Michigan; 1976.
23. Dung TM, Ngoc VT, Khoi TD, Chu DT, Dung DT, Khue LN et al. The dental arch dimensions in Vietnamese children at 7 years of age, and their variation by gender and ethnicity. J Oral Biol Craniofac Res. 2019;9(3):236–40.
24. Ling JY, Wong RW. Dental arch widths of Southern Chinese. Angle Orthod. 2009;79(1):54– 63.

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