Fan Yuming 5th Year, Group 11 THE INFLUENCE OF EXTRACTION AND NON-EXTRACTION TREATMENT ON CLASS II PATIENTS’ SOFT TISSUE PROFILE. A LITERATURE REVIEW

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Fan Yuming

5th Year, Group 11

THE INFLUENCE OF EXTRACTION AND NON-EXTRACTION

TREATMENT ON CLASS II PATIENTS’ SOFT TISSUE PROFILE.

A LITERATURE REVIEW

Master’s thesis

Supervisor Prof. Dalia Smailienė

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LITHUANIAN UNIVERSITY OF HEALTH SCIENCES MEDICAL ACADEMY

FACULTY OF ODONTOLOGY CLINIC OF ORTHODONTICS

THE INFLUENCE OF EXTRACTION AND NON-EXTRACTION TREATMENT ON CLASS II PATIENTS’ SOFT TISSUE PROFILE. A LITERATURE REVIEW

Master’s Thesis

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EVALUATION TABLE OF THE MASTER’S THESIS

OF THE TYPE OF SYSTEMIC REVIEW OF SCIENTIFIC LITERATURE Evaluation: ... Reviewer: ...

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No. MT parts MT evaluation aspects

Compliance with MT requirements and evaluation Yes Partially No 1 Summary (0.5 point)

Is summary informative and in compliance with the thesis

content and requirements? 0.3 0.1 0

2 Are keywords in compliance with the thesis essence? 0.2 0.1 0 3 Introduc-

tion, aim and tasks

(1 point)

Are the novelty, relevance and significance of the work

justified in the introduction of the thesis? 0.4 0.2 0 4 Are the problem, hypothesis, aim and tasks formed clearly

and properly? 0.4 0.2 0

5 Are the aim and tasks interrelated? 0.2 0.1 0

6 Selection criteria of the studies, search methods and strategy (3.4 points)

Is the protocol of systemic review present? 0.6 0.3 0 7 Were the eligibility criteria of articles for the selected

protocol determined (e.g., year, language, publication condition, etc.)

0.4 0.2 0

8 Are all the information sources (databases with dates of coverage, contact with study authors to identify additional studies) described and is the last search day indicated?

0.2 0.1 0

9 Is the electronic search strategy described in such a way that it could be repeated (year of search, the last search day; keywords and their combinations; number of found and selected articles according to the combinations of keywords)?

0.4 0.1 0

10 Is the selection process of studies (screening, eligibility, included in systemic review or, if applicable, included in the meta-analysis) described?

0.4 0.2 0

11 Is the data extraction method from the articles (types of investigations, participants, interventions, analysed factors, indexes) described?

0.4 0.2 0

12 Are all the variables (for which data were sought and any

assumptions and simplifications made) listed and defined? 0.4 0.2 0 13 Are the methods, which were used to evaluate the risk of

bias of individual studies and how this information is to be used in data synthesis, described?

0.2 0.1 0

14 Were the principal summary measures (risk ratio,

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15 Systemiza- tion and analysis of data (2.2 points)

Is the number of studies screened: included upon assessment for eligibility and excluded upon giving the reasons in each stage of exclusion presented?

0.6 0.3 0

16 Are the characteristics of studies presented in the included articles, according to which the data were extracted (e.g., study size, follow-up period, type of respondents) presented?

0.6 0.3 0

17 Are the evaluations of beneficial or harmful outcomes for each study presented? (a) simple summary data for each intervention group; b) effect estimates and confidence intervals)

0.4 0.2 0

18 Are the extracted and systemized data from studies

presented in the tables according to individual tasks? 0.6 0.3 0 19

Discussion (1.4 points)

Are the main findings summarized and is their relevance indicated?

0.4 0.2 0

20 Are the limitations of the performed systemic review discussed?

0.4 0.2 0

21 Does author present the interpretation of the results? 0.4 0.2 0 22

Conclusions (0.5 points)

Do the conclusions reflect the topic, aim and tasks of the Master’s thesis?

0.2 0.1 0

23 Are the conclusions based on the analysed material? 0.2 0.1 0

24 Are the conclusions clear and laconic? 0.1 0.1 0

25

References (1 point)

Is the references list formed according to the requirements? 0.4 0.2 0 26 Are the links of the references to the text correct?

Are the literature sources cited correctly and precisely? 0.2 0.1 0 27 Is the scientific level of references suitable for Master’s

thesis?

0.2 0.1 0

28 Do the cited sources not older than 10 years old form at least 70% of sources, and the not older than 5 years – at least 40%?

0.2 0.1 0

Additional sections, which may increase the collected number of points 29

Annexes Do the presented annexes help to understand the analysed topic?

+0.2 +0.1 0 30 Practical

recommen- dations

Are the practical recommendations suggested and are

they related to the received results? +0.4 +0.2 0

31 Were additional methods of data analysis and their

results used and described (sensitivity analyses, meta-regression)?

+1 +0.5 0

32 Was meta-analysis applied? Are the selected

statistical methods indicated? Are the results of each meta-analysis presented?

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General requirements, non-compliance with which reduce the number of points 33

General requirements

Is the thesis volume sufficient (excluding annexes)?

15-20 pages (-2 points)

<15 pages (-5 points) 34 Is the thesis volume increased artificially?

-2 points -1 point 35 Does the thesis structure satisfy the requirements

of Master’s thesis? -1 point -2 points

36 Is the thesis written in correct language,

scientifically, logically and laconically? -0.5 point -1 points 37 Are there any grammatical, style or computer

literacy-related mistakes? -2 points -1 points 38 Is text consistent, integral, and are the volumes of

its structural parts balanced? -0.2 point -0.5 points 39

Amount of plagiarism in the thesis. >20% (not evaluated) 40 Is the content (names of sections and sub-

sections and enumeration of pages) in compliance with the thesis structure and aims?

-0.2 point -0.5 points 41 Are the names of the thesis parts in compliance

with the text? Are the titles of sections and sub-sections distinguished logically and correctly?

-0.2 point -0.5 points 42 Are there explanations of the key terms and

abbreviations (if needed)? -0.2 point -0.5 points 43 Is the quality of the thesis typography (quality of

printing, visual aids, binding) good? -0.2 point -0.5 points

*In total (maximum 10 points):

*Remark: the amount of collected points may exceed 10 points

Review’s comments: _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________________________________________

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SUMMARY

Title:

The influence of extraction and non-extraction treatment on Class II patients’ soft tissue profile. A literature review.

Objective:

To compare the effect of non-extraction (NE) orthodontic treatment and treatment with teeth extraction (E) on Class II patients’ soft tissue profile changes in terms of tissue thickness, lips length, soft tissue profile convexity, nasal measurements, facial height, lower lip and chin relationship.

Material and methods:

An electronic search in MEDLINE (PubMed), Science Direct and Cochrane Central Register of Controlled Trials (CENTRAL) databases was carried out for relevant articles published in the recent ten years. Ten studies met the inclusion criteria and were included in the final analysis, of which eight were retrospective studies, one was a randomised clinical trial, and one was a prospective clinical trial. Cochrane ROBINS-I tool, Rob 2.0 tool was used for the risk of bias assessment of the included studies.

Results:

Both NE and E treatments of Class II malocclusion demonstrated having a significant influence in affecting patients’ lip thickness, length, position, facial convexity, nose position, thickness, facial height and chin thickness. None of the investigated treatment modalities demonstrated having a significant influence on the patient’s facial profile. The E treatment influenced the soft tissue on nasal length but did not affect the upper lip protrusive length.

Conclusions:

Ten selected studies found that teeth extraction and non-extraction in the orthodontic treatment of Class II patients affect the soft tissue profile. However, no significant changes between the two treatment modalities were detected. These effects showed no relation to patients’ age and gender.

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9 INTRODUCTION

Class II malocclusions are frequently observed in the orthodontic practice and are characterised by an incorrect relationship between the maxillary and mandibular arches because of the skeletal or dental problems or a combination of both [1].

Skeletal pattern, growth pattern, face profile, molar relationship, dentition, the crowding of the lower anterior teeth are the impact factors in making the treatment protocol decision [2,3]. A primary social concern of orthodontic treatment is facial aesthetics. Kiekens et al. showed that parents believe, after receiving orthodontic treatment, their children become more attractive in the career, have higher social acceptance and more success [4]. Many children, teenagers, adults and parents believe that pleasant facial beauty is a significant factor in psychological well-being [5].

The observed facial profile mainly depends on the facial pattern, facial convexity angle and lower facial angle [6]. The aesthetic aspects on the face are frontal, temporal, supraorbital, orbital, infraorbital, nasal, zygomatic, buccal, labial, mental, parotid-masseteric, and auricular region [7].

Having a better facial esthetic profile is the main purpose of orthodontic treatment. Modern tooth extraction guidelines point out that the choice of tooth extraction should be determined according to the degree of difference in the length of the patient’s dental arch [1]. The soft tissue affection was neglected in terms of extraction decision. However, the extraction decision should be based on the patients’ specific soft tissue paradigm [8].

It is important to access the available evidence for the effects of non-extraction treatment and treatment with tooth extraction on the facial profile changes of patients diagnosed with orthodontic Class II malocclusion in order to provide evidence in making decision of maintaining the tooth or not in the further clinical treatment.

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10 The tasks of the following review are:

1. To compare the effect of non-extraction and extraction orthodontic treatment on soft tissue thickness.

2. To anlyse the effect of non-extraction and extraction orthodontic treatment on lips length. 3. To examine the effect of non-extraction and extraction orthodontic treatment on soft tissue profile

convexity.

4. To check the effect of non-extraction and extraction orthodontic treatment on nasal measurements. 5. To investigate the effect of non-extraction and extraction orthodontic treatment on facial height. 6. To compare the effect of non-extraction and extraction orthodontic treatment on lower lip and

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11 1. SEARCH METHODS AND STRATEGY

1.1. Protocol

The review was conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement for reporting systematic reviews [9].

1.2. Focus Question

The following focus question was developed according to the population, intervention, comparison, outcome, and study design (PICOS) (Table 1): What are the influences of extraction and non-extraction treatment on Class II patients’ soft tissue profile.

Table 1. Population, Intervention, Comparison, Outcome, and Study design. (PICOS) Population Patients with Class II malocclusion

Intervention Class II patients under treatment with tooth extraction Comparison Class II patients under treatment without tooth extraction

Outcome Soft tissue measurements based on the marked cephalometric analysis points regarding soft tissue profile before and after treatment. (UL-Ulp; LL-Ulp; Pog-Pog’; Stms-Sn; Stmi-ILS; Stms-Stmi; SS-Ls; SnPg’G’; N’ Sn Pog-Pog’; n’.Prn.Pog-Pog’; H.NB; E line-Ls; E line-Li; H line-Li; S line-Ls; S line-Li; Pg’Sn line-Ls; Pg’Sn line-Li; VRL-prn/ VRL-sn/ VRL-ss/ VRL-ls/ VRL-li/ VRL-si/ VRL-pog’; Cm.Sn.Ls; Z angle; Sn-Prn; Prn-Pg’Ls; ANS’-ME’; N’-ME’; N’-Gn’; Li.B’.Pog’ )

Study design Retrospective, prospective studies, Randomised clinical trials

1.3. Information sources

The electronic databases MEDLINE (PubMed), Science Direct, and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched for relevant articles that had been published in the recent ten years (2010.Jan.01- 2021, Feb. 28). The search was limited to human studies and those in the English language.

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12 1.4. Article Searching

The following mesh terms and free-text words were used for all three databases search (Table 2): Table 2. Summary of keyword combination.

PubMed Searching

Search Query Result

#1 "Tooth Extraction"[Mesh] OR "extract*"[tw] OR "tooth remov*"[tw] AND (clinicaltrial[Filter])

19,784 #2 "Malocclusion, Angle Class II"[Mesh] OR "class 2*"[tw] AND

(clinicaltrial[Filter])

617

#3 #1 AND #2 56

#4 #1 AND #2 Filters: Clinical Trial, from 2010 - 2020 30 ScienceDirect Search

Search Keywords Result

#1 Class II, Soft tissue, extraction, non-extraction 665 #2 Class II, Soft tissue, extraction, non-extraction (2010-2020, Research

articles)

86

Cochrane library

Search Keywords Result

#1 extraction 22393

#2 non-extraction 103

#3 soft tissue 8710

#4 Class II 142708

#5 #1 and #2 and #3 and #4 5

#6 2010-2020, Clinical trials 2

1.5. Selection of studies

During the first literature selection stage, the titles and abstracts of all identified studies were screened for eligibility.

1.6. Inclusion criteria

The following inclusion criteria were applied:

(1) Study type: randomised clinical trials, prospective clinical trials, and retrospective studies; (2) Class II patients with no age limit;

(3) Studies included both extraction and non-extraction treatment;

(4) The changes of soft tissue profile, measured on cephalograms or clinical photos.

1.7. Exclusion criteria

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13 (1) Clinical records with the hard tissue changes (e.g., alveolar bone changed);

(2) Case reports, literature reviews; (3) Studies on animals;

(4) Studies on patients with genetic syndromes and severe facial malformations.

1.8. Data extraction

Data extraction templates were used to retrieve general information on the Author, Date of publication, Country, Study design, Main objective, Study sample: Groups (Number), Gender (M/F), Age, Inclusion criteria, and Exclusion criteria (Annex 1).

Intervention, methods, the timing of examination, outcome of interest, results, and the author’s conclusion were presented in Annex 4. Results included changes in soft tissue thickness, changes in lips length, changes of soft tissues convexity, changes of soft tissue planes, changes of nasal measurements, changes of facial height in test and control groups extracted for data analysis (Annex 2).

1.9. Risk of bias assessment

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14 The article searching flow chart according to the requirement of PRISMA [9] is shown in Figure 1.

Figure 1. PRISMA flow diagram

Records identified through PubMed (Medline), Science Direct (Embase) and

Cochrane library database searching, 2010-2020 (n=118) S creen in g E lig ib ilit y Id en tif ic a tio

n _{Additional records identified}

through other sources (n = 0)

Records after duplicates removed (n =105) Records screened (n = 105) Records excluded (n = 74) Full-text articles assessed for eligibility

(n = 31)

Full-text articles excluded, with reasons

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15 2. SYSTEMIZATION AND ANALYSIS OF DATA

2.1. Study selection

A total of 118 articles were initially identified in the electronic databases, of which 13 were duplicates. One huandred and five papers were screened based on their titles and abstracts, of which 74 articles were excluded because they were not related to the subject or did not fulfil the eligibility criteria. The final 31 articles were assessed for eligibility through full-text evaluation, after which 21 articles were excluded. In the end, 10 articles that met the inclusion criteria were included in the qualitative synthesis (Figure 1).

2.2. Study exclusion

The reasons for excluding studies after full-text assessment were as follows: only focus with the extraction groups [12–18], the clinical records were not clear showed with the base of the measurement on the cephalometric analysis for soft tissue parameters [2,19–27], the study results published twice [28]. Three articles containing Class I and Class II malocclusion patient records where Class II data was not possible to separate were finally excluded [29–31].

2.3. Study design

The included ten studies are described in Annex 1. Eight studies were retrospective [32–39], one was a randomised clinical trial [40], and the remaining one was a prospective clinical trial [41].

2.4. Risk of bias of individual studies

The included non-randomised clinical trials are presented in Annex 3. Six selected studies were judged as having moderate risk of bias [33–36,38,41], three selected studies having high risk of bias [32,37,39].

One randomised clinical trial study [40] was evaluated as having low risk of bias. The risk of bias assessment is presented inAnnex 4.

2.5. Study Population

The present analysis involved Class II malocclusion patients enrolled in a regular orthodontic practice. A total of 751 patients were included. The mean age of the included patients ranged from 10.5 [37] to 32.8 years [34]. Nine studies selected teenagers as the study samples [32–35,37–41]. Only one study chose adults for the study sample [36].

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16 much higher female proportion in their whole group [35]. The remaining seven selected studies had almost an equal number of female and male patients samples [32–34,36,37,39,40].

Four studies’ patient samples were based on Asian population [35,39–41], four studies’ patient samples from South American population [32–34,36], one study’s patient samples were in a North American [41], and one study’ patient samples were European population [37]. Patient-related data is summarised in Annex 1.

Regarding the malocclusion classification, most studies chose Class II-1 patients as the study samples. Only one study chose the Class II patients as their study samples [33]. The selected studies grouped division based on the molar cusp relationship. For the severity description, the molar relationship was the primary method to classify the studies. Ten selected studies used the skeletal relationship as ANB and overjet degree for anterior teeth relationship to distinguish the Class II-1 patients.

2.6. Intervention

Based on the study’s design, treatments with tooth extraction or without tooth extraction were used in the Class II patients’ samples and correlated with the proper orthodontic treatment methods. Among the selected studies, based on the treatment protocol, with tooth extraction or treatment without tooth extraction, seven selected studies had two groups [33,34,37–41], three selected studies [32,35,36] had three groups in their research.

The extraction treatment groups.

The test groups included Class II patients with extraction treatment. According to tooth extraction protocol classification, two of the studies both had four premolars extractions (4E) and two premolars extractions group (2E) [32,36], four studies contained only two premolars extractions group [33– 35,41], two studies included only four premolars extractions groups [38,39], one studies contained upper first permanent molar extractions (UME) [37]. One studies did not describe the type of premolar extraction [40].

The Non-extraction treatment groups.

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17 Treatment methods correlated with the extraction treatment groups and non-extraction treatment groups.

Fixed appliance methods were used in all studies of the tooth extraction group. After tooth extraction, elastic chain, extra-oral headgear, and mini-implants where used to create the anchorage. According to the treatment period, the treatments with the extractions lasted longer than those without extractions. Treatment protocols used in the test and control groups are described in Annex 1.

2.7. Methods and timing of examination

All of the studies used the cephalometric radiographs to record the soft tissue profile, and one of them additionally used photos to record the data changes [36]. Regarding the timing of examination, eight of them used the T0 (before treatment) and T1 (after treatment) as the timing point [33–35,37– 41], while one study used the T1 and T2 (post-treatment, follow-up) [32], one study used the T0 and T2 [36].

2.8. Outcome of interest

The final chosen ten articles have their critical study criterion for their primary purposes. Each reference’s data extraction focuses on the soft tissue profile cephalometric parameters measurement, distributed mainly in seven areas [32–41]. These seven areas are list as follows:

1. Changes in soft tissue thickness investigated by measuring these parameters:

Upper lip thickness/ Max. 1 to labrale superiusb/ A-A’/ UL-Ulp/ ANS-Sn [32,35,38]; Lower lip thickness/ Md. 1 to labrale inferius/ B-B’/ LL-Ulp [32,35,38];

Chin thickness/ Pog-Pog’/ pog-pog’ [32,35,40];

2. Changes in lip length investigated by measuring these parameters: Upper lip length/ Stms-Sn [35,38];

Lower lip length: Stmi-ILS [35,38]; Inter labial gap: Stms-Stmi [35,38,40]; Upper lip protrusive length: SS-Ls [40].

3. Changes in soft tissue profile convexity investigated by measuring these parameters: Facial angle: G-Sn-Pg / SnPg’G’ (FA) [41];

Facial convexity:

n’.Sn.Pog’/ N’ Sn Pog’/ N’NsPog’/ na-sn-pog°/ N-Sn-Pog [32,35,37,38,40]; Nasal protrusive: n’.Prn.Pog’/ na-prn-pog [32,35]

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18 4. Changes in soft tissue plane investigated by measuring these parameters:

E line-Ls/ Sulcus superius -E line/ E-ls/ UL-E plane/ UL-Pog’Prn [32,34–38,41]; E line-Li/ Sulcus inferius -E line/ E-li/ LL-E Plane/ LL-Pog’Prn [32,34–38,41]; H line-Li [36];

S line-Ls/ UL-Pog’Cm/ UL- S line/ Ls-Pg’Cm(Ls-S) [32,34,36]; S line-Li/ LL-Pog’Cm/ LL-S line/ Li-Pg’Cm(Ls-S) [32,34,36]; Pg’Sn line-Ls/ UL-Pog’Sn/ UL-SnPg’/ Ls-(Sn-Pog’) [32–34,36,40]; Pg’Sn line-Li/ LL-Pog’Sn/ LL-SnPg’ [32–34,36];

VRL-prn/ VRL-sn/ VRL-ss/ VRL-ls/ VRL-li/ VRL-si/ VRL-pog’ [35];

5. Changes in nasal measurements investigated by measuring these parameters: Nasalabial angle/ Cm.Sn.Ls/ ColSnLs (NLA) [32,34–38,40,41];

Z angle [36,38];

Nasal length Sn-Prn (NL) [32];

Tip of nose-H line: Prn-Pg’Ls (H-nose)/ H-pr [32,34,36]; Nose thickness: Prn-Nperp [32].

6. Changes in facial height by measuring these parameters : Lower facial height [39];

ANS’-ME’/N’-ME’ [39]; N’-Gn’ [40]

7. Changes in lower lip and chin relationship investigated by measuring these parameters: Mentolabial angle / Li.B’.Pog’ [32,35,38];

The cephalometric measuring points are shown in Annex 5.

2.9. Results of individual studies

The results of the included studies were summarised in Annex 2.

In the following texts, “NE” means treatment without tooth extraction, and “E” means treatment with tooth extraction.

1. Soft tissue thickness

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19 Atik et al. and Verma et al. [35,38] mentioned orthodontic treatment, both NE and E, affecting the upper lip thickness. Both studies showed that NE and E groups increased the upper lip’s thickness. However, no significance was detected when compare between NE and E groups.

Atik et al. and Verma et al. [35,38] indicated that all the NE groups decreased the lower lip thickness. In the E group, two studies had the opposite result: Atik et al. [15] showed a reduced effect, and Verma et al. [38] showed an increased output. Compared to the NE and E group in the two studies, Verma et al. [38] showed a significant difference between NE and E groups, wherever Atik et al. [35] did not have.

Three selected studies pointed out almost no NE group changes for the chin thickness [32,35,40]. Two studies showed the chin would be thicker [32,35], and one study showed the chin would be thinner after treatment in the E group [40]. Compared to the NE and E groups, one study showed a significant difference between them [35].

In addition, Mendes L.M.et al. mentioned some upper and lower lip thickness parameters. The result showed that both the NE and E groups had slight changes, and there was no significant difference in NE and E groups [32].

In summary, the NE or E treatments did not affect the upper lip thickness, but might slightly affect the lower lip thickness and chin thickness.

2. Lip length

Four of the included studies analysed the changes in lip length. The results showed that:

Atik et al. and Verma et al. pointed out the upper lip length changes after the orthodontic treatment contained the NE and E. In the NE group of the two studies, almost had no changes during the treatment. Atik indicates nearly no difference in the E group, but Verma et al. pointed out the increased parameter. Comparing NE and E groups, only study by Verma et al.showed a significant difference [35,38].

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20 Hemmatpour et al.was concerned about the upper lip protrusion, and the study result showed the NE (SUS2) group had slightly increased upper lip protrusion. However, the opposite change in the E group. There was a significant difference comparing NE and E groups [40].

Based on these studies reported changes in the lip length parameter, it could be found that there were no changes in upper lip length in the NE group and slightly increased the lower lip length, inter-labial gap, and upper lip protrusion. The E groups showed extraction would increase the upper lip length or might not change, increasing the lower lip length and might cause the increase or decrease of the inter-labial gap, reducing the upper lip protrusive length. Comparing the NE and E groups, there was no significant effect on lower lip length, which might significantly affect the upper lip length, inter-labial gap, and upper lip protrusion length.

3. Soft tissue profile convexity

Seven of the included studies analysed the changes in the soft tissue profile convexity parameter. The results showed that:

Upadhyay et al. indicated that both the NE and E groups showed reduced facial angles. Compare NE and E groups difference effect, and there had no significant difference [41].

Five studies [32,35,37,38,40] indicated that the facial convexity changes during the NE or E orthodontic treatment. In all NE groups in these five studies, only Mendes et al.’ study pointed out a reduced facial convexity after treatment [32]. In contrast, four other studies showed increased facial convexity in NE groups [35,37,38,40]. Three studies showed the reduction of facial convexity in the E groups [32,35,40], and the other two studies found the higher facial convexity angle [37,38]. Comparing NE and E groups, only Hemmatpour et al. [40] mentioned a significant difference between the groups, and the other four studies did not find any significant effects on facial convexity [32,35,37,38].

Mendes et al. [32] and Atik et al.’s [35] studies evaluated the Nasal protrusive angle. The NE groups in their research showed the confounding result. Mendes et al. found nose would be more prominent after the treatment [32], while Atik et al. found it would be retracted [35]. However, in both studies E group showed an increased nose protrusion after the treatment. Moreover, there was no significant difference in NE and E groups [32,35].

Mendes et al. [32] and Janson et al.’s [34] studies indicated the angle between H and NB line variation in result of the NE or E orthodontic treatment. Both studies showed a decrease of the H/NB angle in NE and E groups, and there was no significant difference between them.

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21 4. Soft tissue plane

Seven studies showed the NE and E groups had no effect or reduced distance from the upper lip to the esthetic line [32,34–38,41]. Treatments with E or without E did not showed a significant difference in the distance from the upper lip to the esthetic line.

Seven studies measured the lower lip’s distance to esthetic line changes during the treatment [32,34– 38,41]. Six studies showed that NE or E treatments did no change or reduced the distance from the lower lip to the esthetic line [32,34–38]. In contrast, Upadhyay et al. [41] indicated NE treatment would increase the distance. Compared with NE and E groups, only Upedhyay et al.[41] demonstrated that NE and E groups significantly differed in the lower lip position’s effect.

Three studies measured the changes in the distance of the S line-Ls and the S line-Li in their research [32,34,36]. The study results showed these two parameters reduced after the treatments with E and the NE treatments, which means that the lips will be protrusive after treatment. Three studies showed no significant difference in the changes of the two parameters involving S-line-Ls and S-line-Li in the NE and E groups.

Five studies [32–34,36,40] measured Pg’Sn line-Ls distance, and results showed treatment with E and NE would decrease distance, which means the upper lip would become protrusive after treatment. Hemmatpour et al. [40] indicated the treatments with E and the NE treatments had a significant effect. The remaining four studies [32–34,36] did not show a substantial difference between NE and E groups.

Four studies [32–34,36] measured Pg’Sn line-Li distance, and results showed treatment with E and NE would decrease the space, which means the lower lip would become protrusive after treatment. All four studies showed the treatments with E and the NE treatments did not show a significant difference.

Only Atik et al. [35] used the distance of VRL-prn/ VRL-sn/ VRL-ss/ VRL-ls/ VRL-li/ VRL-si /VRL- pog’ to indicate the soft tissue affected the treatments with E and the NE treatments. The outcome indicated both NE and E groups increased distance. Comparing the different treatment protocol results, treatment with NE and using the pendulum appliance and headgear were significantly differed from treatment with E.

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22 5. Nasal measurements

Three [32,36,40] studies showed the NE and E groups had decreased the Nasalabial angle. Five studies [34,35,37,38,41] showed opposite results. Three studies [38,40,41] showed there was a significant difference between the NE and E groups.

Janson et al. [34] and Verma et al. [38] showed that both NE and 4E groups increased Z angle. Only Verma et al. [38] showed a significant difference between E and NE groups.

Mendes et al.[32] indicated nasal length increased in NE group and E group a significant difference. Three selected studies [32,34,36] showed that after E and NE treatments the nose would be retrusive. The NE and E groups in these three studies did not have a significant difference.

Mendes et al. [32] indicated NE treatment and treatment with E would increase the nose’s thickness. Two of the different treatment protocols did not have a significant difference.

Therefore, NE treatment and treatments with E might affect the nose position. Most of them showed the nose would become protrusive and downward after treatment and increase the thickness after treatment. Two treatment types showed significant differences in the Nasolabial Angle and Z angle in the study, but in general, no considerable difference existed.

6. Facial height

Hemmatpour et al. [40] and Ye et al. [39] indicated the facial height changed after the treatment. Compare the result showed NE treatment would both increase the lower anterior face and face height. Similarly, treatment with E would increase the lower anterior face height but decreased the total face height. There was a significant difference between the NE and E groups on the lower anterior face height and entire face height [39,40].

7. Relationship of lower lip and chin

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23 2.10. Author’s conclusion

Seven studies showed no effects in the soft tissue profile during Class II malocclusion treatment without tooth extraction [32–34,36–39]. Three studies showed that Class II non-extraction treatment affects soft tissue profile on the increased lip thickness on lower mouth area [40], and changing lip position [35,41].

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24 3. DISCUSSION

Regarding the comparison of the ten selected studies, it was found that Class II malocclusion treatment would influence the soft tissue profile. The ten chosen studies contained twenty-eight different measured parameters to indicate changes of the soft tissue under treatment. Comparing NE and E, these two various interventions for the treatment protocol, outcomes of measured parameter indicated the same effect and some had a different effect.

3.1. The influence of non-extraction treatment on soft tissue profile changes

In ten selected studies, the parameter regarding the soft tissue measurement in treatment without tooth extraction changed in some aspects:

First: Increased upper lip thickness, lower lip length, upper lip protrusive length, distance of E-line to the upper lip, distance of S line to the upper lip, distance of S line to lower lip, distance of Pg’Sn’line to the upper lip, distance of VRL line to Prn/Sn/ Ss/ls/li/si/pog’, Z angle, nasal length, nasal thickness, H line to the nose, lower anterior face height, proportion of anterior face to total face height, total face height and the mentolabial angle.

Second: Decreased facial angle, H.NB angle

Third: Some aspects both had increased and decreased results, such as lower lip thickness, chin thickness, upper lip length, interlabial gap, facial convexity, nasal protrusion angle, distance of E line to lower lip, and naso-labial angle.

According to the results of changes in these parameters, it was found that NE treatment of Class II malocclusion patients would affect the lip thickness, lip length, lip position, nose position, nose thickness, facial convexity, facial height, chin thickness.

3.2. The influence of extraction treatment on soft tissue profile changes

From ten selected studies, the parameter regarding the soft tissue measurement change in some aspects:

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25 Those aspects have decreased parameters resulting from the facial angle, the H.NB angle, and the total facial height.

Those aspects have non-changed parameter results: the upper lip protrusive length.

Both aspects have increased and decreased parameter results: the lower lip thickness, the chin thickness, the Inter-labial gap, the facial convexity, the nasal protrusion angle and the nasal labial angle.

As the result of these parameter, explore the E treatment Class II malocclusion patients would influence the soft tissue on the lip thickness, the chin thickness, the lip length, the lip position, the facial convexity, the nasal position, nasal thickness, nasal length, the facial height. Nevertheless, the upper lip protrusive length did not influence.

3.3. The differences between non-extraction and extraction treatment on soft tissue profile changes

Comparing the E treatment and NE treatment, there was no significant difference in the following soft tissue aspect: the upper lip thickness, lower lip length, facial angle, nasal protrusion angle, H.NB angle, the distance of E line to the upper lip, the distance of S line to the upper and lower lip, the distance of Pg’Sn line to lower lip, the distance of VRL to pog’, the nasal length, the nasal thickness, the distance of line to the nose, the proportion of anterior lower facial height to the total facial height, and the mentolabial angle.

On the other hand, the soft tissue aspects in the upper lip protrusive length, the distance of VRL line to Prn/ Sn/ ss/ ls/ li/ si, the lower anterior facial height and the total facial height had the significant difference when comparing with the NE treatment and the E treatment.

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26 3.4. The reasons for non-extraction and extraction differences on soft tissue profile changes Potential factors may contribute to the different soft tissue profile changes.

1, The selection of soft tissue parameters depends on the author’s purpose.

Of ten selected studies, five studies used ten more soft parameters for their studies [32,34–36,38]. Regarding their study purpose, all of them were focused on the tooth extraction or non-extraction Class II patient treatment influence on soft tissue and facial profile esthetic.

In the remaining five studies [33,37,39–41], the number of soft tissue parameters used ranges from two to nine. In contrast, these five studies used more than fourteen dental, skeletal parameters for their study. Consider these five studies found that these studies mainly focus the dental skeletal and soft tissue changes compared in the tooth extraction or without tooth extraction treatment, which had to compare more skeletal parameters to indicate their differences.

2, Patients sample age could influence the outcomes.

Only Janson et al. [36] the selected patient samples were adults. This research showed that after treatment, patients’ noses and lips became retrusive. Specifically, there was no significant difference in soft tissue profile changes between treatment with E and NE. Other studies mainly selected teenager patients as the study samples. This result was the same as Ghorbanyjavadpour and Rakhshan conclusion, and age was not associated with soft tissue profile attractiveness [42]. Besides, Maetevorakul S et al. pointed out the age could predicate the various soft tissue profile changes following treatment of Class II Division 1 malocclusion patient morphology [20]. Based on the result indicated, it found that the adult patients had the same soft tissue effect as the teenage patients, in both NE and E.

3, Patient samples gender could influence the outcomes.

Verma et al. [38] and Upadhyay et al. [41] studies only included only female patient for their research. It detected that both had some significant soft tissue effects among the two treatment groups. Compared to the remaining eight selected studies, which included mixed-gender groups, had a similar outcome. In Ghorbanyjavadpour and Rakhshan conclusion, gender did not associate with profile attractiveness [42]. However, Ajwa N et al. mentioned that there were significant changes in Saudis’ facial structures between males and females [43].

4, Type of tooth extraction could influenced the outcomes.

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27 four premolars and first molars. Conversely, findings were different as Omar Z et al. and Iared W et al., where. both studies indicated that first premolar or second premolar teeth extraction had similar

esthetic outcomes [44,45]. Regarding Omar Z et al., and Iared W et al., the ten selected studies’

outcomes need to consider more factors to ensure the findings.

3.5. Limitations

Based on the selection studies, ten studies included four continents, Asia, South America, North America, and Europe. Africa and Oceania were not included in the studies. Four out of ten studies are all come from Brazil, South America [32–34,36]. This was a significant high-risk factor for balancing the study distribution.

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28 4. CONCLUSIONS

Ten selected studies found that NE and E in the orthodontic treatment of Class II patients would affect the soft tissue profile and the following conclusion were made:

1. Soft tissue thickness

NE or E treatments did not affect the upper lip thickness, but might slightly affect the lower lip thickness and chin thickness.

2. Lip length

Comparing the NE and E groups, there was no significant effect on lower lip length, which might significantly affect the upper lip length, inter-labial gap, and upper lip protrusion length.

3. Facial convexity

Overall, Class II malocclusion treatment would change the soft tissue’s convexity. However, there was no significant difference found between the two treatment options.

4. Nasal measurement

Therefore, E and NE treatments might affect nose would become protrusive and downward after treatment and increase the thickness after treatment. Two treatment types showed significant differences in the nasolabial angle and Z angle in the study, but it was not considerable.

5. Facial height

NE and E treatment would both increase the lower anterior face height, but only E would decreased the total face height. There was a significant difference between the NE and E groups on the lower anterior face height and entire face height.

6. Lip and chin relationship

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29 5. PRACTICAL RECOMMENDATIONS

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30 6. ACKNOWLEDGEMENT

I would like to express my deep and sincere gratitude to my supervisor, Prof. Dalia Smailienė, for her support, advice and guidance throughout the accomplishment of my thesis.

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33 24. Gkantidis N, Halazonetis DJ, Alexandropoulos E, Haralabakis NB. Treatment strategies for

patients with hyperdivergent Class II Division 1 malocclusion: Is vertical dimension affected? American Journal of Orthodontics and Dentofacial Orthopedics 2011;140:346–55. https://doi.org/10.1016/j.ajodo.2011.05.015.

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Class II Division 1 patients following extraction and non-extraction treatment. Dental Research Journal 2013;10:9.

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34 34. Janson G, Castello Branco N, Aliaga-Del Castillo A, Henriques JFC, de Morais JF. Soft tissue treatment changes with fixed functional appliances and with maxillary premolar extraction in Class II division 1 malocclusion patients. European Journal of Orthodontics 2018;40:214–22. https://doi.org/10.1093/ejo/cjx053.

35. Atik E, Akarsu-Guven B, Kocadereli I. Soft tissue effects of three different Class II/1-camouflage treatment strategies. Journal of Orofacial Orthopedics 2017;78:153–65. https://doi.org/10.1007/s00056-016-0066-9.

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37. Booij JW, Goeke J, Bronkhorst EM, Katsaros C, Ruf S. Class II treatment by extraction of maxillary first molars or Herbst appliance: dentoskeletal and soft tissue effects in comparison. Journal of Orofacial Orthopedics 2013;74:52–63. https://doi.org/10.1007/s00056-012-0112-1. 38. Verma S, Sharma V, Tandon P, Singh G, Sachan K. Comparison of esthetic outcome after

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appliance on class II/1 patients at their postpubertal-peak growth period compared with the extraction method: A randomized clinical trial. Journal of Orofacial Orthopedics 2017;78:41–51. https://doi.org/10.1007/s00056-016-0060-2.

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35 44. Omar Z, Short L, Banting DW, Saltaji H. Profile changes following extraction orthodontic

treatment: A comparison of first versus second premolar extraction. International Orthodontics 2018;16:91–104. https://doi.org/10.1016/j.ortho.2018.01.017.

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36 8. ANNEXES

Annex 1. Summary of the Characteristics of Reference Studies.

No. Author, Year, Study design

Country Main objective Study sample: Groups (Number) Gender (%M), Age Inclusion criteria Exclusion criteria

1 Mendes, L.M.et al. 2019 [32]

RS

Brazil Class II-1 E or NE influence of profile attractiveness Total: 68 (38/30) (55%M) G1: NE (N=20) 9/11 14.43±3.48 (T1) G2: U2E (N=27) 14/13 15.30±1.78 (T1) G3: 4E (N=21) 15/6 15.01±1.40 (T1)

1. Class II-1 malocclusion; 2. NE or with 2/ 4 premolar E; 3. Orthodontic records in good conditions;

4. Long-term cephalograms; 5. Taken>8 years after treatment; 6. No anterior tooth loss in the long-term period. Not described 2 Pupulim, D. C.et al. 2019.4 [33] RS

Brazil Compare the CEF changes in Class II-1 patients treated with Jones Jig appliance or with U2E. Total: 44 (22/22) (50%M) G1: NE (N=21) 11/10 12.88±1.23 (T0) G2: U2E (N=23) 11/ 12 13.59±1.91 (T0)

1. Patients who initially presented with bilateral Class II

malocclusion and who were treated with the Jones Jig appliance or with maxillary first premolars extractions and fixed edgewise appliances;

2. Class II malocclusion with minimum anteroposterior severity of 1/4 Class II;

molar relationship as evaluated on the study models;

3. Presence of all permanent teeth up to the first molars;

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37 4. Mild to moderate crowding in

the maxillary arch; 5. No previous orthodontic treatment; and with complete orthodontic records.

3 Janson et al. 2018 [34] RS

Brazil Soft tissue changes of Class II-1 patients treated with fixed functional appliance and those treated with U2E Total: 48 (23/25) (47%M) G1: NE (N=23) 13/10 12.17 (T0) G2: U2E (N=25) 10/15 13.05 (T0)

1.Bilateral Class II molar relationship;

2.No agenesis/supernumerary /lost teeth;

3. Maxillary arches without crowding, mandibular arches with slight or no crowding at pre-treatment, and a Class I canine relationship at the post-treatment.

Not described

4 Hemmatpour, S. et al.

2017.1 [40] RCT

Iran Evaluate the

therapeutic effects of the Sabbagh Universal Spring 2 (SUS 2) fixed functional appliance compared to the premolar extraction method in correcting Class II-1 malocclusion in patients who had passed their peak of postpubertal growth (stages 4–6 of Cervical Vertebral Maturation Index). Total: 40 (15/25) (37.5%M) G1: NE (N=20) 7/13 15.75± 1.02 (T0) G2: U2E (N=20) 8/12 15.40 ± 0.99 (T0)

1. Systemic health, 12–18 years old, having permanent dentition only, being at stages 4–6 of cervical vertebra maturation index (CVMIS4–6);

2. Having a molar full-cusp class II relationship, ANB angles ≥4°, upper incisor to NA-line angles above 18°;

3. Having full-cusp molar Class II and being clinically proper candidates for upper premolar extraction or fixed functional therapy;

4. Patients treated with SUS 2 needed to have canine and molar Class I relationships at the end of the treatment, whereas patients treated with the extraction

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38 protocol needed to have molar

class II and canine class I relationships after the treatment. 5 Atik, E et al.

2017.3 [35] RS

Turkey Compare soft tissue effects of Class II treatments with the Forsus device, the pendulum appliance, and the U2E

Total: 54 (15/39) (27.7%M) G1: NE (N =20) 6/14 15.91 (13.30–18.00) (T0) G2: NE (N=19) 4/15 16.08 (13.10–20.90) (T0) G3: U2E (N=15) 5/10 19.04 (14.40–22.50) (T0) 1. Class II ANB ≥ 4°; 2. SNA > 80° and/or SNB < 78°; 3. Overjet ≥ 4 mm;

4. At least an end-to-end canine and molar relationships; 5. T0: 13-22 years; 6. No previous history of orthodontic treatment;

7. No congenitally missing teeth other than the third molars.

Not described

6 Janson, G. et al. 2016.6 [36] RS

Brazil To compare NE, U2E, 4E protocols regarding long-term adult facial

aesthetics, age appearance, and soft-tissue measures. Total: 63 (35/280) (55.5%M) G1: NE (N=20) 9/11 30.77 (T0) G2: 2E (N=25) 13/12 30.99 (T0) G3: 4E (N=18) 13/5 32.8 (T0)

1. Class II-1 malocclusion; 2. Adult min. 21 years of age; 3. Availability of orthodontic records;

4. No anterior tooth loss in the long-term period;

5. Frontal and lateral extra-oral photographs, taken at min. 8 years after treatment.

Not described

7 Booij, J. W. et al. 2013.1 [37] RS

Germany Compare dental skeletal and soft tissue treatment Class II effects of U first permanent molar

Total: 154 (81 /73)(52.5%M) G1: UME (N=79) 41/38 10.5-14.7 (T0) G2: NE+Herbstappliance (N=75)

1. Caucasian origin; complete records;

2. Overjet ≥ 4 mm;

3. Treatment includes UE first permanent molars or Herbst appliance;

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39 E and Herbst

appliance.

40/35

10.7-15.5 (T0)

4. Age at start of treatment between 10 and 15 years; 5. No aplasia or additional extractions;

6. No craniofacial anomalies; 7. Teeth 18 and 28 present (extraction group only) 8 Verma, S. et al.

2013 [38] RS

India Compare the post-treatment soft-tissue profiles of

successfully managed Class II-1 treated with either all U4E or treatment with a NE therapy. Total: 100 (0/100) (0%M) G1: U4E (N=50) 0/50 14.1 (T0) G2: NE (N=50) 0/50 13.5 (T0) 1. Female patients;

2. Treated with fixed edgewise mechanics;

3. Availability of high-quality pre-treatment and post-treatment cephalometric radiographs. 1. Craniofacial congenital anomalies; 2. Significant facial asymmetries; 3. Class II-2;

4. Class II patients with an initial ANB angle more than 5°; 5. Single arch extraction. 9 Ye, C. et al. 2012.9 [39] RS

China Compare the effectiveness of 2-phase (Twin Block followed by the fixed appliance) non-extraction therapy with) and 1-phase therapy with the extraction of 4 first premolars) treatment of Class II-1 malocclusion. Total: 146 (66/80) (45.2%M) G1:NE (N=70) 33/37 13.4 (T0) G2: U4E(N=76) 33/43 13.2 (T0) 1. Skeletal Class II - 1 malocclusion;

2. Overjet greater than 5mm, severely retrusive;

3. Vertical growth pattern or average growth pattern;

4. All patients started therapy at peak velocity in craniofacial growth;

5. Proclination or normal angle of the lower incisors;

6. No significant pre-treatment differences. Not described 10 Upadhyay, M. et al. 2012.3 [41]

America Compare the treatment effects of maxillary anterior

Total: 32 (0/32) (0%M) G1: NE (N=18)

0/18

1. Cervical vertebrae maturation stage IV or higher;

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40

PCT teeth retraction with

mini-implant anchorage in young adults with Class II-1 undergoing U2E with FA.

16.51±3.51 (T0) G2: U2E (N=14)

0/14

17.38 ± 2.85 (T0)

2. Class II molar relation with no subdivision malocclusion; 3. Overjet ≥6 mm;

4. Permanent dentition with all the teeth present, except third molars; 5. Minimal crowding of the dental arches (≤3 mm).

RS: Retrospective study; RCT: Randomised clinical trial; PCT: Prospective clinical trial; NE: Non-extraction treatment;

2E: Treatment with 2 premolar extractions; 4E: Treatment with 4 premolar extractions; U: Upper; L: Lower;

UME: Upper Molar Extraction FA: Fixed appliances;

G: Group

T0: Before treatment T1: After treatment

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41 Annex 2. Summary of the Results of the studies.

No. Author Intervention Methods and timing of

examination

Outcome of interest Results Author’s conclusion

1 Mendes L.M.et al. [32] G1: FA + headgear + functional appliance G2:U2E + FA + headgear G3: 4E + FA + headgear CEF T1 T2

1. Change in Nasal measures:

Cm.Sn.Ls; Prn-Sn; Prn-Pog’Ls; Prn-Nperp 2. Change in soft tissue plane:

UL-Pog’Cm; LL-Pog’Cm; UL-Pog’Prn; LL-Pog’Prn; UL-Pog’Sn; LL-Pog’Sn 3. Change in lower lip and chin relationship:

Li.B'.Pog';

3. Change in Soft tissues thickness: ANS-Sn; A-A’; UL-Ulp; LL-Llp; B-B’; Pog-Pog’ 4. Change in soft tissue convexity:

n’.Sn.Pog’; n’.Prn.Pog’; Pog’Ls.NB

At the long-term post-treatment stage, the NE group had a significantly greater nasal length than the 2E group.

No significant differences in other soft tissue profile variables between the groups.

The post-treatment profile attractiveness was significantly higher in the 2E than in the 4E group and NE group

The long-term profile

attractiveness in the 2E group was significantly greater compared with the NE and 4E groups. 2 Pupulim, D. C.et al. [33] G1: Jones Jig appliance+ FA G2:U2E + FA CEF T0 T1

1. Change in soft tissue plane: UL-SnPg’

LL-SnPg’

No significant soft tissue profile changes in both groups.

Two treatment protocols produced similar changes in the soft tissue profile. 3 Janson et al [34] G1: FA + Class II elastics G2: U2E + FA+ extraoral appliance (anchorage) + Class II elastics CEF T0 T1

1. Changs in soft tissue plane:

UL–E plane; UL–S line; UL–SnPg’; H–Pr; LL–E; LL–S line; LL–SnPg′;

2. Changes in Nasal measurement: Z angle; Nasolabial angle

3. Change in soft tissue profile convexity: H.NB

No significant differences in any soft tissue profile variable between the groups.

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42 4 Hemmat pour, S. et al. [40] G1: SUS2 + FA G2: UE + FA CEF T0 T1

1.Change in lip length SS-Ls

2. Change in soft tissue thickness: Pog-Pog’

3. Change in Nasal measurement Nasolabial

4. Change in the soft tissue plane Ls-(Sn-Pog’)

5.Change in lip length: Stms–Stmi

5. Change in facial height N’-Gn’, N’NsPog’

Both E and NE increased the lip length, and the NE increased more.

The NE group has increased the Chin thickness, lip gap, facial height, and Facial convexity, and the E group is all decreased. The NE group showed a

decrease in the Nasolabial Angle, but in the E group increased.

Both the E and UE have

decreased the lip protrusion, and the E decreases more.

SUS2 thickens the soft tissue over the lower face skeleton except for the chin area.

Extraction did not change the soft tissue thickness

5 Atik, E et al. [35] G1: FA G2: Pendulum appliance + headgear G3: U2E + FA+ miniscrew CEF T0 T1

1. Change in soft tissue plane:

VRL-prn; VRL-sn; VRL-ss; VRL-ls; E-ls; VRL-li; VRL-si; VRL-pog’; E-li; 2. Change in soft tissue thickness:

Upper lip thickness; Soft tissue chin

thickness (pog-pog’); Lower lip thickness; 3. Change in lip length

Upper lip length; Interlabial gap; Lower lip length;

4. Change in Nasal measurement:

na-prn-pog°; na-sn-pog°; nasolabial angle°; 5. Change in lower lip and chin relationship

Mentolabial angle°

Compare Nose exchange, the NE group, has more changes than the E group.

Compare to the lip. The NE group has more protrusive upper and lower lip positions than the E group.

Pendulum and extraction treatment groups showed significant differences concerning the upper and lower lip position changes, significantly more significant in the pendulum group.

6 Janson, G. et al. [36] G1: Headgear + FA G2: U2E + FA G3: 4E + FA CEF Photo T0, T2

1. Change in Nasal measurement:

Prn-Pg’Ls (H-nose); ColSnLs (NLA); 2. Change in soft tissue plane:

Li-Pg’Sn(Li-H); Ls-Pg’Prn(Ls-E); Li-Pg’Prn(Li-E);Ls-Pg’Cm(Ls-S); Li-Pg’Cm (Li-S);Ls-Pg’Sn(Ls-Pg’Sn);

The upper and lower lip length, lower anterior facial height significant longer in the 4E group.

Other soft-tissue measures did not show significant changes.

Treatment of full Class II-1with and without extractions did not influence facial attractiveness, age appearance, and overall soft-tissue

(43)

43 Li-Pg’Sn(Li-Pg’Sn); 7 Booij, J. W. et al. [37] G1: UME+FA G2: Herbst appliance + FA CEF T0 T1

1.Change in soft tissue profile convexity: N-Sn-Pog

2. Change in soft tissue plane: Li-E Line; Ls-E Line

3.Change in Nasal measurement: Nasolabial Angle

NE group have a significantly more decrease in soft tissue facial profile convexity (1.05°) than the E group (1.83°). The nasolabial angle increased significantly more in the E group (p= 0.025).

More dental and maxillary effects can expect in conjunction with upper first molar extraction treatment. The skeletal and mandibular effects will prevail with Herbst therapy 8 Verma, S. et al. [38] G1: U4E + FA G2: NE + FA CEF T0 T1

1. Change in Nasal measurement: Nasolabial angle; ‘Z’ angle;

2. Change in lower lip and chin relationship: Mentolabial Angle;

3. Change in soft tissue convexity N’-Sn-Pog’

4. Change in soft tissue plane:

Sulcus superius- E line; Sulcus inferius- E line

5. Change in soft tissue thickness: Max. 1 to labralesuperius;

Md. Mandibular 1 to labraleinferius 6. Change in lip length:

Sn-Stms; Stmi-ILS; Stms-Stmi

The E group has more upper lip retraction than the NE group. The E group has more nose protrusive changes than the NE group.

The E group has more increase lower lip thickness than the NE group.

The E group has more upper lip length increase than the NE group.

The E group has increased more Interlabial gasp than the NE group.

Other soft tissue measurements did not show significant changes.

The extraction or

non-extraction decision, if based on good diagnostic criteria, seems to have no systematic

detrimental effects on the facial profile. 9 Ye, C. et al. [39] G1: Twinblock + FA G2: U4E + FA CEF T0 T1

1. Change in facial height: Lower facial height ANS’-ME’/N’-ME’

The lower face height

significantly increased in both groups, but the increased amount was more in the NE group (P=0.007).

There is no significant change in the ratio of the lower anterior

The proclination of the mandibular incisors in the 2-phase group might restrain the mandibular bone from growing enough and cause the

Fan Yuming 5th Year, Group 11 THE INFLUENCE OF EXTRACTION AND NON-EXTRACTION TREATMENT ON CLASS II PATIENTS’ SOFT TISSUE PROFILE. A LITERATURE REVIEW

Fan Yuming

THE INFLUENCE OF EXTRACTION AND NON-EXTRACTION

TREATMENT ON CLASS II PATIENTS’ SOFT TISSUE PROFILE.

A LITERATURE REVIEW

TABLE OF CONTENTS

SUMMARY