- •Ideal golden proportion was absent in facial proportions of Clark's twin block treated patients.
- •Facial proportion ratios came closer to golden proportion after treatment with Clark's twin block.
- •Golden proportion can be used as a guide in treatment planning of patients.
This study aimed to determine the influence of Clark's twin block (CTB) appliance therapy on achieving golden proportion in post-treatment facial profiles in skeletal Class II patients.
A retrospective longitudinal study was conducted on a sample of 44 skeletal Class II subjects treated with CTB, followed by nonextraction mechanotherapy. Ricketts’ 13 dentoskeletal ratios were measured on pre- and post-treatment lateral cephalograms. Paired Student's t test was used to analyze the existence of golden proportion in the values of the pre- and post-treatment ratios. The influence of pretreatment variables was tested on post-treatment ratio 4 using simple and multiple linear regression analyses.
A statistically significant difference in pre- and post-treatment values was found for ratios 4 (P = 0.02), 9 (P = 0.04), 10 (P < 0.001), and 13 (P = 0.01). Ratios 4, 9, and 13 moved closer to the golden proportion, whereas ratio 10 moved away from the golden proportion after CTB therapy. Simple linear regression analysis showed a statistically significant association of post-treatment ratio 4 with pretreatment ratios 1, 4, 8, 9, and 12. Multiple linear regression analysis showed a statistically significant association of post-treatment ratio 4 with pretreatment ratios 4 and 12.
Treatment with CTB appliance may well move various facial ratios in individual patients toward the published Ricketts ideals. Ricketts’ published golden proportion may be used as one guide when planning for attempted dentofacial change in individual patients.
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Published online: August 30, 2022
Accepted: July 31, 2022
Received in revised form: July 29, 2022
Received: June 2, 2022
Funding: The authors have not declared a specific grant for this research from any funding agency in the public, commercial, or not-for-profit sectors.
Competing interests: Authors have completed and submitted the ICMJE Form for Disclosure of potential conflicts of interest. None declared.
Provenance and peer review: Non commissioned and externally peer reviewed.
© 2022 World Federation of Orthodontists. Published by Elsevier Inc. All rights reserved.