Regression Equations for Prediction of Permanent Canine and Premolar Mesiodistal Width in Thai Population: A Cross-sectional Study

Jirawan Chartpitak, Nalinporn Kamsiriphiman, Paniti Prasomphol, Pitchaya Saksurasub, Phansuk Nilniyom, Natchaphon Jakkathammanukul, Punrit Thongmaeng, Paween Tangchitphisut, Suttichai Krisanaprakornkit, Boontida Changkhaokham

Published Online: May 29, 2025 DOI 10.12982/OSR.2025.047

Objectives: This study aimed to formulate regression equation(s) for predicting human permanent canine and premolar mesiodistal (MD) widths of Thai population.

Methods: 176 Mae Fah Luang University students with Thai nationality were selected for this study. Based on their domicile, participants were grouped by four different regions of Thailand, including central, northern, southern, and northeastern. An intraoral scanner was used to record digital dental models, and the tooth MD widths were measured using SolidWorks 2020 EP1 software. Significant differences were tested by two-sample t-test or one-way ANOVA. By Pearson’s correlation coefficient, the relationships between the maxillary and/or mandibular incisor MD width and the upper and/or lower canine and premolar MD widths were determined for prediction equations.

Results: There were statistically significant differences in a sum of the maxillary and mandibular incisor and in that of the upper and lower canine and premolar MD widths between males and females (p<0.001). Statistically significant differences in the sum of the mandibular incisor MD width and in that of the maxillary and mandibular central incisor MD width were found among four different regions (p<0.05). By linear regression analysis, correlation coefficients of eight prediction equations were between 0.62 and 0.75 with the percentages of prediction accuracy from 47.16 to 53.41. These percentages were significantly greater than those predicted by previous models for the upper canine and premolar MD widths (p<0.01).

Conclusions: Our novel regression equations may predict the MD width of unerupted canine and premolars of Thai population precisely enough to be applicable for mixed dentition space analysis.

intraoral scanner canine premolar mixed dentition regression equation tooth size prediction
  1. Al-Bitar ZB, Al-Omari IK, Sonbol HN, Al-Ahmad HT, Hamdan AM. Mixed dentition analysis in a Jordanian population. Angle Orthod. 2008;78:670-5.
  2. de Paula S, Almeida MA, Lee PC. Prediction of mesiodistal diameter of unerupted lower canines and premolars using 45 degrees cephalometric radiography. Am J Orthod Dentofacial Orthop. 1995;107:309-14.
  3. Moyers RE. Handbook of orthodontics. 4th ed. Chicago, IL: Year Book; 1988
  4. Tanaka MM, Johnston LE. The prediction of the size of unerupted canines and premolars in a contemporary orthodontic population. J Am Dent Assoc. 1974;88(4),798-801.
  5. Hixon EH, Oldfather RE. Estimation of the sizes of unerupted cuspid and bicuspid teeth. Angle Orthod. 1958;28:236-40.
  6. Dempsey PJ, Townsend GC. Genetic and environmental contributions to variation in human tooth size. Heredity (Edinb). 2001;86(6):685-93.
  7. Yuen KK, Tang EL, So LL. Mixed dentition analysis for Hong Kong Chinese. Angle Orthod. 1998;68(1):21-8.
  8. Jaroontham J, Godfrey K. Mixed dentition space analysis in a Thai population. Eur J Orthod. 2000; 22:127–34.
  9. Sherpa J, Sah G, Rong Z, Wu L. Applicability of the Tanaka–Johnston and Moyers mixed dentition analyses in Northeast Han Chinese. J Orthod. 2015;42(2):95-102.
  10. Giri J, Pokharel PR, Gyawali R, Timsina J, Pokhrel K. New regression equations for mixed dentition space analysis in Nepalese mongoloids. BMC Oral Health. 2018;18(1):214.
  11. Shahid F, Alam MK, Khamis MF. New prediction equations for the estimation of maxillary mandibular canine and premolar widths from mandibular incisors and mandibular first permanent molar widths: a digital model study. Korean J Orthod. 2016;46(3):171-9.
  12. Aragón ML, Pontes LF, Bichara LM, Flores-Mir C, Normando D. Validity and reliability of intraoral scanners compared to conventional gypsum models measurements: a systematic review. Eur J Orthod. 2016;38(4):429-34.
  13. Rossini G, Parrini S, Castroflorio T, Deregibus A, Debernardi CL. Diagnostic accuracy and measurement sensitivity of digital models for orthodontic purposes: a systematic review. Am J Orthod Dentofacial Orthop. 2016;149(2):161-70.
  14. Galvão M, Dominguez GC, Tormin ST, Akamine A, Tortamano A, de Fantini SM. Applicability of Moyers analysis in mixed dentition: A systematic review. Dental Press J Orthod. 2013;18(6):100-5.
  15. Chong SY, Aung LM, Pan YH, Chang WJ, Tsai CY. Equation for tooth size prediction from mixed dentition analysis for Taiwanese population: a pilot study. Int J Environ Res Public Health. 2021;18(12):6356.
  16. Merz ML, Isaacson RJ, Germane N, Rubenstein LK. Tooth diameters and arch perimeters in a black and a white population. Am J Orthod Dentofacial Orthop. 1991;100(1):53-8.
  17. Abaid S, Zafar S, Kruger E, Tennant M. Size estimation of unerupted canines and premolars using various independent variables: a systematic review. J Orofac Orthop. 2023;84(3):164-77.
  18. Altherr ER, Koroluk LD, Phillips C. Influence of sex and ethnic tooth-size differences on mixed-dentition space analysis. Am J Orthod Dentofacial Orthop. 2007;132(3):332-9.
  19. Luu NS, Mandich MA, Tieu LD, Kaipatur N, Flores-Mir C. The validity and reliability of mixed-dentition analysis methods: a systematic review. J Am Dent Assoc. 2011;142(10):1143-53.
  20. Jaber ST, Hajeer MY, Alkhouli KW, Al-Shamak RM, Darwich KMA, Aljabban O, et al. Evaluation of three-dimensional digital models formulated from direct intra-oral scanning of dental arches in comparison with extra-oral scanning of poured dental models in terms of dimensional accuracy and reliability. Cureus. 2024;16(2):e54869.

Chartpitak J, Kamsiriphiman N, Prasomphol P, Saksurasub P, Nilniyom P, Jakkathammanukul N, et al.. Regression Equations for Prediction of Permanent Canine and Premolar Mesiodistal Width in Thai Population: A Cross-sectional Study: Original articles. Oral Sci Rep [Internet]. 2025 May 29 [cited 2025 May 31];46(2):69-76. Available from: https://www.dent.cmu.ac.th/cmdj/frontend/web/?r=site/viewarticle&id=502

Chartpitak, J., Kamsiriphiman, N., Prasomphol, P., Saksurasub, P., Nilniyom, P., Jakkathammanukul, N., Thongmaeng, P., Tangchitphisut, P., Krisanaprakornkit, S. & Changkhaokham, B. (2025). Regression Equations for Prediction of Permanent Canine and Premolar Mesiodistal Width in Thai Population: A Cross-sectional Study. Oral Sci Rep, 46(2), 69-76. Retrieved from: https://www.dent.cmu.ac.th/cmdj/frontend/web/?r=site/viewarticle&id=502

Chartpitak, J., Nalinporn Kamsiriphiman,Paniti Prasomphol,Pitchaya Saksurasub,Phansuk Nilniyom,Natchaphon Jakkathammanukul,Punrit Thongmaeng,Paween Tangchitphisut,Suttichai Krisanaprakornkit and Boontida Changkhaokham. 2025. "Regression Equations for Prediction of Permanent Canine and Premolar Mesiodistal Width in Thai Population: A Cross-sectional Study." Oral Sci Rep, 46(2), 69-76. https://www.dent.cmu.ac.th/cmdj/frontend/web/?r=site/viewarticle&id=502

Chartpitak, J. et al. 2025. 'Regression Equations for Prediction of Permanent Canine and Premolar Mesiodistal Width in Thai Population: A Cross-sectional Study', Oral Sci Rep, 46(2), 69-76. Retrieved from https://www.dent.cmu.ac.th/cmdj/frontend/web/?r=site/viewarticle&id=502

Chartpitak, J., Kamsiriphiman, N., Prasomphol, P., Saksurasub, P., Nilniyom, P., Jakkathammanukul, N., Thongmaeng, P., Tangchitphisut, P., Krisanaprakornkit, S. and Changkhaokham, B. "Regression Equations for Prediction of Permanent Canine and Premolar Mesiodistal Width in Thai Population: A Cross-sectional Study", Oral Sci Rep, vol.46, no. 2, pp. 69-76, May. 2025.

Chartpitak, J., Kamsiriphiman, N., Prasomphol, P., et al. "Regression Equations for Prediction of Permanent Canine and Premolar Mesiodistal Width in Thai Population: A Cross-sectional Study." Oral Sci Rep, vol.46, no. 2, May. 2025, pp. 69-76, https://www.dent.cmu.ac.th/cmdj/frontend/web/?r=site/viewarticle&id=502