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VOLUME 22 , ISSUE 9 ( September, 2021 ) > List of Articles


Orthodontic Treatment Effect on Inclination of Maxillary Incisors and Growth Axes in Adult Patients with Various Mandibular Divergent Patterns

Samar Bou Assi, Ziad Salameh, Antoine Hanna, Josephine Aybout, Anthony Macari

Keywords : Facial axis, Growth axis, Incisors, Mandibular divergence, Posttreatment

Citation Information : Assi SB, Salameh Z, Hanna A, Aybout J, Macari A. Orthodontic Treatment Effect on Inclination of Maxillary Incisors and Growth Axes in Adult Patients with Various Mandibular Divergent Patterns. J Contemp Dent Pract 2021; 22 (9):1008-1013.

DOI: 10.5005/jp-journals-10024-3191

License: CC BY-NC 4.0

Published Online: 06-01-2021

Copyright Statement:  Copyright © 2021; The Author(s).


Aim: To evaluate, in an adult population, the effect of orthodontic treatment on the inclination of maxillary incisors, facial, and growth axes in different mandibular divergence pattern. In addition, we aimed to determine if there is an association between the inclination of the maxillary incisors and facial and growth axes and if this association will change after orthodontic treatment. Materials and methods: Two-hundred and thirty-eight consecutive lateral cephalograms (119 at T1 and 119 at T2) of adult patients with an average age of 26.45 ± 9.11 years at T1 and 29.58 ± 9.36 at T2 were selected and digitized. Cephalometric maxillary incisors (I) inclination was measured to cranial base (SN), palatal plane (PP), nasion-A point (NA), nasion-basion (NBa), and true horizontal (H). Facial (FA) and growth (GA) axes’ inclinations were measured relative to NBa and H. The sample was stratified in three subgroups based on cephalometric mandibular divergence to anterior SN (MP/SN). A—Hypodivergent = MP/SN ≤27° (n = 28); B—Normodivergent = 27 < MP/SN < 37° (n = 49); C—Hyperdivergent = MP/SN ≥37° (n = 42). Associations were tested using Chi-square tests for categorical data. Paired sample t-tests and Pearson\'s correlation were computed for continuous data. Results: At T1, there was a tendency to have more proclined I in group A (I/SN = 105.59 ± 10.8°) and more retroclined in group C (I/SN = 99.06 ± 12.04°) with no statistical significance. However, at T2, maxillary incisors were statistically significant different between groups A and C (p = 0.002). Pre-treatment FA and GA were statistically significantly different among the three divergence groups (p <0.0001) with more increased angles in the group A (FA/Nba = 92.77 ± 5.07°) vs group C (FA/Nba = 86.28 ± 5.08°). This angle increases around 2° on average at posttreatment assessment (group A—p = 0.033; group B—p = 0.002). Correlations between I and facial/growth axes were not statistically significant at T1, whereas at T2 those correlations were higher and statistically significant between I/PP to FA/NBa (r = 0.408; p ≤0.0001). Conclusion: Correlations between the maxillary incisors’ inclination and the facial/growth axes were not statistically significant initially whereas after orthodontic treatment, those correlations were higher and statistically significant. Differences in FA existed between pre- and postorthodontic groups in all divergence groups. Clinical significance: Orthodontists should assess the inclination of the maxillary incisors, not only to the maxilla and anterior SN but also to FA and take it into consideration in their treatment objectives.

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  1. Doshi P, Kalia A, Patil W, et al. Evaluation of the effect of maxillary incisor labiolingual inclination and anteroposterior position on smiling profile esthetics: A computer aided photographic study. Sci J Res Dentistry 2017;1(2):043–049.
  2. Cao L, Zhang K, Bai D, et al. Effect of maxillary incisor labiolingual inclination and anteroposterior position on smiling profile esthetics. Angle Orthod 2011; 81(1):121–129. DOI: 10.2319/033110-181.1.
  3. Richmond S, Klufas ML, Sywanyk M. Assessing incisor inclination: a non-invasive technique. Eur J Orthod 1998;20(6):721–726. DOI: 10.1093/ejo/20.6.721.
  4. Jacobson A, Jacobson R. Radiographic cephalometry from basics to 3-D imaging. 2nd ed. Chicago, London: Quintessence Pub.; 2006.
  5. Ellis E 3rd, McNamara JA Jr. Cephalometric evaluation of incisor position. Angle Orthod 1986;56(4):324–344. DOI: 10.1043/0003-32 19(1986)056<0324:CEOIP>2.0.CO;2.
  6. Naini FB. Facial aesthetics: concepts and clinical diagnosis. London: Wiley-Blackwell; 2011.
  7. Singh G. Textbook of Orthodontics. 2nd ed. New Delhi: Jaypee; 2007. p. 517.
  8. Arnett W, McLaughlin R. Facial and dental planning for orthodontists and oral surgeons. London: Mosby; 2004.
  9. Ricketts RM. Cephalometric analysis and synthesis. Angle Orthod 1961;31(3):141–156. Available from<0141:CAAS>2.0.CO;2
  10. William B Downs. Analysis of the dentofacial profile. Angle Orthod 1956;26(4):191–212. DOI: 10.1043/0003-3219(1956)026 <0191:AOTDP>2.0.CO;2.
  11. Chirivella P, Singaraju GS, Mandava P, et al. Comparison of the effect of labiolingual inclination and anteroposterior position of maxillary incisors on esthetic profile in three different facial patterns. J Orthod Sci 2017;6(1):1–10. DOI: 10.4103/2278-0203.197387.
  12. Mollabashi V, Kazemisaleh A, Seyedtabib M. Final maxillary incisor inclination in Class II Div 1 malocclusion treated with standard edge wises or straight wire appliances. J Clin Diagn Res 2019;13(9):44–49. DOI: 10.7860/JCDR/2019/41541.13173.
  13. Burns N, Musich D, Razmuz T, et al. Class III camouflage treatment: what are the limits? Am J Orthod Dentofacial Orthop 2010;137(1):9–13. DOI: 10.1016/j.ajodo.2009.05.017.
  14. Troy B, Shanker S, Fields H, et al. Comparison of incisor inclination in patients with Class III malocclusion treated with orthognathic surgery or orthodontic camouflage. Am J Orthod Dentofacial Orthop 2009;135(2):146–147. DOI: 10.1016/j.ajodo.2008.07.012.
  15. Zou B, Zhou Y, Lowe A, et al. Changes in anteroposterior position and inclination of the maxillary incisors after surgical-orthodontic treatment of skeletal Class III malocclusions. J Craniomaxillofac Surg 2015;43(10):1986–1993. DOI: 10.1016/j.jcms.2014.12.013.
  16. Amjad N, Mahmood A, Masood RT, et al. Comparison of incisors inclination in hyperdivergent and hypodivergent patients. Pakistan O Dent J 2019;39(2):125–128.
  17. Bou Assi S, Macari A, Hanna A, et al. Cephalometric evaluation of maxillary incisors inclination, facial, and growth axes in different vertical and sagittal patterns: an original study. J Int Soc Prevent Communit Dent 2020;10(3):292–299. DOI: 10.4103/jispcd.JISPCD_60_20.
  18. Nouri M, Abdi AH, Farzan A, et al. Measurement of the buccolingual inclination of teeth: Manual technique vs 3-dimensional software. Am J Orthod Dentofacial Orthop 2014;146(4):522–529. DOI: 10.1016/j.ajodo.2014.06.018.
  19. Houston WB. The analysis of errors in orthodontic measurements. Am J Orthod 1983;83(5):382–390. DOI: 10.1016/0002-9416(83)90322-6.
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