Soft tissue facial profile changes after orthodontic treatment with four premolars extracted

Extraction vs. Nonextraction on Soft-Tissue Profile Change in Patients with Malocclusion: A Systematic Review and Meta-Analysis

Objectives

We aimed to summarize the current evidence regarding the impact of extraction vs. nonextraction in orthodontic treatment on patients' soft-tissue profile with malocclusion.

Methods

Between April 30^th and November 30^th, 2020, we searched PubMed and SCOPUS for published papers from inception to November 2020 using "orthodontic," "extraction," "nonextraction," and "Malocclusion." Included studies were summarized, and relevant data were extracted and analyzed using Review Manager 5.4.

Results

Pooled data from four controlled trials demonstrated a nonsignificant difference between extraction and nonextraction in terms of SNA (MD = 0.50, 95% CI: -0.37, 1.38; p = 0.26), SNB (MD = 0.11, 95% CI: -1.23, 1.44; p = 0.88), FMA (MD = 1.82, 95% CI: -2.39, 6.02; p = 0.40), IMPA (MD = 0.06, 95% CI: -8.83, -8.94; p = 0.99), overjet (MD = -1.47, 95% CI: -6.21, 3.26; p = 0.54), and overbite (MD = 0.50, 95% CI: -1.40, 2.40; p = 0.60). On the other hand, the extraction method significantly increased the ANB compared with the nonextraction group (MD = 0.78, 95% CI: 0.25, 1.31; p = 0.004).

Conclusion

The current evidence demonstrated that nonextraction protocols for orthodontic treatment are a safe and effective alternative to extraction protocols; individually tailored treatment strategies should be applied. More randomized controlled trials are critically needed to safely make an evidence-based treatment conclusion.

Pretreatment dentoskeletal comparison between individuals treated with extractions in the 1970s and in the new millennium

OBJECTIVE

This retrospective study aimed to compare the occlusal and dentoskeletal initial features of patients treated with four first premolar extractions in the 1970s and after 2000.

MATERIALS AND METHODS

Group 70' was composed by 30 subjects with Class I malocclusion (mean age of 12.8 years, 10 male, 20 female) treated in the 1970s with four first premolar extractions and comprehensive orthodontic treatment. Group NM comprised 30 subjects with Class I malocclusion (mean age of 13.4 years, 13 male, 17 female) treated in the new millennium, similarly to Group 70'. Initial dental models and lateral cephalograms were digitized and measured using OrthoAnalyzerTM 3D software and Dolphin Imaging 11.0 software, respectively. Initial occlusal and dentoskeletal features were analyzed and compared. Intergroup comparison was performed using t tests (p < 0.05). Holm-Bonferroni correction for multiple comparison was applied.

RESULTS

Group NM showed significantly greater maxillary and mandibular effective lengths and greater maxillary and mandibular incisor protrusion in comparison with Group 70'. Group NM presented a significantly greater lower anterior facial height. Group NM also showed significantly smaller nasolabial angle and protruded inferior lip.

CONCLUSION

Patients with Class I malocclusion treated with four first premolar extractions in the new millennium present a greater degree of dental and labial protrusion, increased lower anterior facial height, and more acute nasolabial angle compared with patients treated similarly in the 1970s. Greater dental and labial protrusion determines first premolar extractions in the new millennium.

CLINICAL RELEVANCE

Despite the decrease of tooth extraction frequency, four first premolar extractions may be justified in cases with severe dental and skeletal protrusions.

Differential Benefit of Two Different Tooth-Borne Rapid Maxillary Expansion Appliances in Female Subjects

Objective

The aim of the present study was to evaluate the effects of tooth-borne acrylic-bonded rapid maxillary expansion (RME) appliances with or without the anterior teeth anchorage on the skeletal and dentoalveolar structures, as well as soft tissues.

Methods

This study included 44 patients who were treated with two different tooth-borne bonded acrylic RME appliances. Lateral cephalometric radiographs were taken before the treatment (T0) and in the post-retention (T1) phase of the RME treatment. The posterior-bonded RME appliance group and full-bonded RME appliance group were created as the two different groups of treatment. The following statistical analyses were performed: intra- and inter-group comparisons were made using the paired t-test, Wilcoxon test, independent t-test, and Mann-Whitney U-test for normal and non-normal distribution data.

Results

Significant increases were observed in R1-A, R1-ANS, R1-U1, R1-AR, R1-St, R1-Li, and R1-Pn in both groups. R1-PNS, R1-Ls, R1-Sn, and R1-B' were found to be significantly larger at T1 than at T0 in the posterior-bonded RME appliance group. R2-A, R2-ANS, R2-L1, R2-A', and R2-Pn were significantly larger at T1 than at T0 in the full-bonded RME appliance group. The R2-A' was significantly different between the groups.

Conclusion

The soft tissue A point appears to be the most important differing matter between the two different RME appliances, and a full acrylic-bonded RME appliance may be beneficial for subjects with a maxillary retrognathic profile.

Comparative evaluation of soft tissue changes in Class I borderline patients treated with extraction and nonextraction modalities

Objective:

To compare soft tissue changes in Class I borderline cases treated with extraction and nonextraction modalities.

Methods:

A parent sample of 150 patients with Class I dental and skeletal malocclusion (89 patients treated with premolar extraction and 61 patients without extraction) was randomly selected and subjected to discriminant analysis which identified the borderline sample of 44 patients (22 extraction and 22 nonextraction patients). Pretreatment and post-treatment cephalograms of the borderline subsample were analyzed using 22 soft tissue parameters.

Results:

Upper and lower lips were more retracted and thickness of the upper lip increased more in the borderline extraction cases (p < 0.01). The nasolabial angle became more obtuse and the interlabial gap was reduced in the borderline extraction cases (p < 0.01). Lower lip, interlabial gap and nasolabial angle showed no changes in the borderline nonextraction cases.

Conclusion:

The soft tissue parameters which can be used as guideline in decision making to choose either extraction or nonextraction in Class I borderline cases are upper and lower lip protrusion in relation to the E-plane and Sn-Pg' line, lower lip protrusion in relation to the true vertical line (TVL), upper lip thickness, nasolabial angle and interlabial gap.

Short-term effects of systematic premolar extraction on lip profile, vertical dimension and cephalometric parameters in borderline patients for extraction therapy--a retrospective cohort study

OBJECTIVES

The belief of many orthodontists that premolar extraction therapy leads to a loss of vertical dimension and an aggravated facial profile often predetermines a non-extraction approach. We investigated the short-term effects of systematic premolar extraction in borderline cases for extraction therapy on dentofacial parameters, especially vertical dimension and facial profile.

MATERIALS AND METHODS

Of 50 juvenile borderline cases for extraction treatment with a distinct sagittal overjet of 6-9 mm and dental crowding of >6 mm, 25 had all first premolars extracted, whereas the 25 control patients received non-extraction orthodontic treatment with corresponding fixed and removable appliances. Patient selection by multivariate cluster analysis ensured homogeneity at baseline regarding dentoskeletal parameters. Parameter changes were determined with radiographic cephalograms and compared between the extraction and non-extraction group.

RESULTS

The systematic extraction of premolars in borderline patients with a distinct sagittal overjet and crowding did not significantly influence sagittal or vertical skeletal dimension, while leading to a slightly more concave lip profile due to incisor retraction compared to the non-extraction control group.

CONCLUSIONS

The influence of premolar extractions on facial profile is often overestimated, since only slight changes in lip profile are to be expected. In integrated treatment planning, the extraction decision should not be primarily based on concerns about the aggravation of facial profile and loss of vertical dimension.

CLINICIAL RELEVANCE

The decision, whether to extract healthy premolars in borderline patients for extraction therapy, is difficult to make. Our study clarifies the repercussions on cephalometric dentofacial parameters, facilitating future orthodontic extraction decisions.

Comparison of esthetic outcome after extraction or non-extraction orthodontic treatment in class II division 1 malocclusion patients

INTRODUCTION

The extraction of premolars as a practical form of orthodontic therapy has been accepted for many years, but there remains a controversy regarding the effect of premolar extraction to improve esthetics as well as dentoskeletal relationship. The esthetic impact of the soft-tissue profile might play a major role in deciding on premolar extraction or non-extraction treatment, particularly in borderline patients. This cephalometric study was undertaken to compare the post-treatment soft-tissue profiles of successfully managed Class II, Division 1 malocclusions treated with either all first premolar extractions or treatment with a non-extraction therapy.

MATERIALS AND METHODS

The sample consisted of 100 post-pubertal female patients of Class II Division I malocclusion. Group 1, treated with four first premolar extractions, consisted of 50 female patients with a mean age of 14 years 1 month. Group 2, treated without extractions, consisted of 50 patients with a mean age of 13 years 5 months. Pre-treatment and post-treatment lateral cephalometric radiographs were evaluated. The pre-treatment to post-treatment stage comparison and the intergroup comparison of the treatment changes were conducted between extraction and non-extraction groups of Class II malocclusion samples with t-tests.

RESULTS

The soft-tissue facial profiles of the extraction and non-extraction samples were the same following active treatment except for a more retruded lower lip and a more pronounced lower labial sulcus in those patients subjected to extraction.

CONCLUSIONS

The extraction or non-extraction decision, if based on sound diagnostic criteria, seems to have no systematic detrimental effects on the facial profile.

The effect of premolar extractions on incisor position and soft tissue profile in patients with Class II, Division 1 malocclusion

OBJECTIVE

The objective of this study was to establish whether and how premolar extraction affects the soft tissue profile and incisor inclination in patients with Angle Class II, Division 1 malocclusion. Our primary intention was to identify differences between patients who had four premolars extracted and those who had only two upper premolars removed during camouflage treatment. Our control group consisted of patients with an Angle Class II, Division 1 treated without extractions.

MATERIALS AND METHODS

These patients' lateral cephalograms were cephalometrically analyzed before and after treatment. Computer-assisted analysis of the data using Onyx Ceph was followed by a single-factor variance analysis (one-way ANOVA).

RESULTS

Our results demonstrate that patients who have undergone camouflage treatment exhibit significantly more retruded upper central incisors than those with extractions in both jaws, and that their upper incisors are highly significantly more retruded and their mandibles significantly more retrognathic than those of patients who have not undergone extraction therapy.

CONCLUSION

We did not observe that the patients' profiles did become worse after extraction therapy.