Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Aug 24:11:40.
doi: 10.4103/jos.jos_174_21. eCollection 2022.

Factors that affect lip changes following incisor retraction in Vietnamese adults with a convex facial profile

Trang Le  1 , Phi Tran  2 , Vy Tran  3
Affiliations

Factors that affect lip changes following incisor retraction in Vietnamese adults with a convex facial profile

Trang Le et al. J Orthod Sci. .

Abstract

Objective: This study aimed to evaluate the factors that influence lip change through the results of tooth anterior retraction by fixed orthodontic treatment in Vietnamese adult patients with a convex facial profile.

Materials and methods: This prospective study included 32 Vietnamese adults who have convex facial profiles. Digital software measurements according to Arnett's analysis and the superimposition method were performed to evaluate the changes in dentoskeletal structures, and soft tissue variables included lip change. A multiple logistic regression model was applied with various explanatory variables to analyze the correlation.

Results: The study revealed a strong correlation of lip change at the site of the cervical point and incisal edge of the upper incisors, and the cervical position demonstrated a stronger correlation. The ratio between lip change and incisor retraction in patients is approximately 1:2.3 at the incisal edge and 1:1.3 at the cervical point.

Conclusion: Lip change was associated with incisor retraction at the cervical and incisal edge, but it did not correlate with the rotation axis of the upper incisors.

Keywords: Convex profile; incisor retraction; lip changes.

PubMed Disclaimer

Conflict of interest statement

There are no conflicts of interest.

Figures

Figure 1
Figure 1
Hard tissue and soft tissue measurement on cephalometric analysis. Abbreviation: Mx1, maxillary incisor tip; Md1, mandibular incisor tip; MxOP, maxillary occlusal plane; MdOP, mandibular occlusal plane
Figure 2
Figure 2
Changes in lip morphology. (a–g) Statistical analysis of the change of soft tissue variables before and after treatment. Data are presented as mean ± SD; *P < 0.05, **P < 0.001, ***P < 0.0001 indicates significant change after treatment
Figure 3
Figure 3
Multiple logistic regression analysis of the correlation between upper lip change and influential factors
Figure 4
Figure 4
Correlation between lip retraction and incisor retraction after treatment. (a–c) A correlation between upper lip retraction and other factors. (d) A correlation between lower lip retraction and lower incisor retraction
See this image and copyright information in PMC

References

    1. Downs WB. Variations in facial relationships; their significance in treatment and prognosis. Am J Orthod. 1948;34:812–40. - PubMed
    1. Chan EK, Soh J, Petocz P, Darendeliler MA. Esthetic evaluation of Asian-Chinese profiles from a white perspective. Am J Orthod Dentofacial Orthop. 2008;133:532–8. - PubMed
    1. Farrow AL, Zarrinnia K, Azizi K. Bimaxillary protrusion in black Americans--An esthetic evaluation and the treatment considerations. Am J Orthod Dentofacial Orthop. 1993;104:240–50. - PubMed
    1. Gu Y, McNamara JA, Jr, Sigler LM, Baccetti T. Comparison of craniofacial characteristics of typical Chinese and Caucasian young adults. Eur J Orthod. 2011;33:205–11. - PubMed
    1. Basciftci FA, Uysal T, Buyukerkmen A, Demir A. The influence of extraction treatment on Holdaway soft-tissue measurements. Angle Orthod. 2004;74:167–73. - PubMed