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
. 2012 Mar;82(2):209-17.
doi: 10.2319/051911-339.1. Epub 2011 Sep 20.

The impact of extraction vs nonextraction treatment on soft tissue changes in Class I borderline malocclusions

Dimitrios Konstantonis  1
Affiliations

The impact of extraction vs nonextraction treatment on soft tissue changes in Class I borderline malocclusions

Dimitrios Konstantonis. Angle Orthod. 2012 Mar.

Abstract

Objective: To obtain through the use of discriminant analysis a relatively bias-free sample of extraction and nonextraction, Class I, equally susceptible to both treatments' malocclusions and to analyze retrospectively the soft tissue changes between the two different treatment groups.

Materials and methods: The cephalometric, model, and demographic data of 215 patients (females and males) fueled a stepwise discriminant analysis that provided the borderline homogenous subsample (30 extraction and 32 nonextraction cases). The pretreatment and postreatment cephalograms of the borderline sample were then subjected to a thorough soft tissue cephalometric analysis.

Results: The results indicated that the three variables that played the most important role in the clinician's treatment decision were indicators of lower crowding, soft tissue convexity, and lower incisor protrusion. Significant differences (P < .001) regarding upper and lower lip protrusion, upper lip thickness (P < .05), and the nasiolabial angle (P < .05) occurred.

Conclusion: Extraction treatment of Class I borderline malocclusions led to significant soft tissue changes regarding the upper and lower lip position and thickness as well as the nasiolabial angle, whereas the nonextraction treatment resulted in significant upper lip retraction and lower lip protraction.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Parent sample: standardized discriminant scores.
Figure 2
Figure 2
Borderline sample: standardized discriminant scores.
Figure 3
Figure 3
(1) Upper lip to Sn-Pg′ line. (2) Lower lip to Sn-Pg′ line. (3) Upper lip to E-plane. (4) Lower lip to E-plane.
Figure 4
Figure 4
(1) Angle of facial convexity (G-Sn-Pg′). (2) Nasiolabial angle. (3) Maxillary sulcus depth (Max. Sulcus - Sn-Ls). (4) Mandibular sulcus depth (Mand. Sulcus - Li-Pg′).
Figure 5
Figure 5
(1) Upper incisor exposure (Is-Stm). (2) Upper lip thickness (Is-Ls). (3) Lower lip thickness (Ii-Li).
Figure 6
Figure 6
Average tracings at the start of treatment. Dashed line: extraction. Solid line: nonextraction.
Figure 7
Figure 7
Average tracings at the end of treatment. Dashed line: extraction. Solid line: nonextraction.
See this image and copyright information in PMC

References

    1. Marvin C. A. Regulating teeth. Dental Times. 1866;4:97–100, 105–108, 156–160.
    1. Peck H, Peck S. A concept of facial esthetics. Angle Orthod. 1970;40:284–315. - PubMed
    1. Riedel R. A. Esthetics and its relation to orthodontic therapy. Angle Orthod. 1950;20:168–178. - PubMed
    1. Burstone C. J. The integumental profile. Am J Orthod. 1958;44:1–25.
    1. Holdaway R. A. A soft tissue cephalometric analysis and its use in orthodontic treatment planning. Part I. Am J Orthod. 1983;84:1–28. - PubMed

LinkOut - more resources