Australasian Orthodontic Journal Volume 38 No. 2 2022 183 ☉ Open Access. Published by Sciendo. BY 4.0 cc © 2022 Author(s). This work is licensed under the Creative Commons Attribution 4.0 License (https://creativecommons.org/licenses/by/4.0/) Determination of treatment options for Class III malocclusions in adult patients based on cephalometric values: a systematic review Saritha Sivarajan,* Nor Nadia Zakaria,* Noor Asyikin Azmily,* Mang Chek Wey,* Mohamed Abd El-Ghafour † and Mona M. Salah Fayed † Department of Paediatric Dentistry and Orthodontics, Faculty of Dentistry, Universiti Malaya, Lembah Pantai, Kuala Lumpur 50603, Malaysia* Department of Orthodontics, Faculty of Dentistry, Cairo University, 11 El Saraya St., Manial, Cairo, Egypt † Objective: The present systematic review aimed to determine cephalometric values that may be used as a guide in deciding between orthodontic camouflage and orthognathic surgery to treat a Class III malocclusion in adults. In addition, a secondary aim was to identify treatment complications and aesthetic perceptions by laypersons/orthodontists. Methods: Without a language restriction, an electronic search of six databases and a hand search of three orthodontic journals were performed until September 2021. All studies comparing orthodontic camouflage and orthognathic surgery in Class III malocclusion patients, were included. Data extraction was carried out independently by two authors with disagreement resolved by a third author. The risk of bias related to individual studies was appraised using a modified version of the STROBE checklist. The results were summarised qualitatively, and no meta-analysis was undertaken due to the high heterogeneity between the studies. Results: With the quality of evidence ranging from moderate to high, six retrospective studies were included. A cephalometric analysis comprising the Holdaway angle, overjet, the Wits appraisal, lower incisor inclination, the maxillary-mandibular ratio, overbite, gonial angle and an additional combination were used as a guide. No treatment complications were reported. One study examined the perception of facial profile attractiveness in borderline surgical Class III malocclusions and found no difference in outcome and significant improvements in both camouflage and surgical groups. Conclusion: The existing evidence is insufficient to identify a cephalometric parameter threshold in deciding between orthodontic camouflage and orthognathic surgery. PROSPERO database protocol no. CRD42020165164. (Aust Orthod J 2022; 38: 183 - 193. DOI: 10.2478/aoj-2022-0021) Received for publication: February, 2022 Accepted: June, 2022 Saritha Sivarajan: [email protected]; Nor Nadia Zakaria: [email protected]; Noor Asyikin Azmily: [email protected]; Mang Chek Wey: [email protected]; Mohamed Abd El-Ghafour: [email protected]; Mona M. Salah Fayed: [email protected] Introduction A Class III malocclusion presents with a variety of skeletal and dental features, which may include a large or protrusive mandible, a retrusive maxilla, a protrusive mandibular dentition, a retrusive maxillary dentition, and any combination of these characteristics. 1 e aetiology of a Class III malocclusion can either be classified as genetic/hereditary or environmental. In contrast to a Class II malocclusion, the heredi- tary influences on the development of a Class III malocclusion are more profound 2 but the most important aetiological factor is the skeletal relation- ship. Based on cephalometric studies, a Class III malocclusion may have an increase in mandibular length, coupled with an anterior positioning of the glenoid fossa so that the condylar head is positioned
Determination of treatment options for Class III malocclusions in adult patients based on cephalometric values: a systematic review
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Australasian Orthodontic Journal Volume 38 No. 2 2022 183 Open Access. Published by Sciendo. BY 4.0cc © 2022 Author(s). This work is licensed under the Creative Commons Attribution 4.0 License (https://creativecommons.org/licenses/by/4.0/)
Determination of treatment options for Class III malocclusions in adult patients based on cephalometric values: a systematic review
Saritha Sivarajan,* Nor Nadia Zakaria,* Noor Asyikin Azmily,* Mang Chek Wey,* Mohamed Abd El-Ghafour† and Mona M. Salah Fayed†
Department of Paediatric Dentistry and Orthodontics, Faculty of Dentistry, Universiti Malaya, Lembah Pantai, Kuala Lumpur 50603, Malaysia* Department of Orthodontics, Faculty of Dentistry, Cairo University, 11 El Saraya St., Manial, Cairo, Egypt†
Objective: The present systematic review aimed to determine cephalometric values that may be used as a guide in deciding between orthodontic camouflage and orthognathic surgery to treat a Class III malocclusion in adults. In addition, a secondary aim was to identify treatment complications and aesthetic perceptions by laypersons/orthodontists. Methods: Without a language restriction, an electronic search of six databases and a hand search of three orthodontic journals were performed until September 2021. All studies comparing orthodontic camouflage and orthognathic surgery in Class III malocclusion patients, were included. Data extraction was carried out independently by two authors with disagreement resolved by a third author. The risk of bias related to individual studies was appraised using a modified version of the STROBE checklist. The results were summarised qualitatively, and no meta-analysis was undertaken due to the high heterogeneity between the studies. Results: With the quality of evidence ranging from moderate to high, six retrospective studies were included. A cephalometric analysis comprising the Holdaway angle, overjet, the Wits appraisal, lower incisor inclination, the maxillary-mandibular ratio, overbite, gonial angle and an additional combination were used as a guide. No treatment complications were reported. One study examined the perception of facial profile attractiveness in borderline surgical Class III malocclusions and found no difference in outcome and significant improvements in both camouflage and surgical groups. Conclusion: The existing evidence is insufficient to identify a cephalometric parameter threshold in deciding between orthodontic camouflage and orthognathic surgery. PROSPERO database protocol no. CRD42020165164. (Aust Orthod J 2022; 38: 183 - 193. DOI: 10.2478/aoj-2022-0021)
Received for publication: February, 2022 Accepted: June, 2022
Saritha Sivarajan: [email protected]; Nor Nadia Zakaria: [email protected]; Noor Asyikin Azmily: [email protected]; Mang Chek Wey: [email protected]; Mohamed Abd El-Ghafour: [email protected]; Mona M. Salah Fayed: [email protected]
Introduction A Class III malocclusion presents with a variety of skeletal and dental features, which may include a large or protrusive mandible, a retrusive maxilla, a protrusive mandibular dentition, a retrusive maxillary dentition, and any combination of these characteristics.1 The aetiology of a Class III malocclusion can either be classified as genetic/hereditary or environmental.
In contrast to a Class II malocclusion, the heredi- tary influences on the development of a Class III malocclusion are more profound2 but the most important aetiological factor is the skeletal relation- ship. Based on cephalometric studies, a Class III malocclusion may have an increase in mandibular length, coupled with an anterior positioning of the glenoid fossa so that the condylar head is positioned
184 Australasian Orthodontic Journal Volume 38 No. 2 2022
SIVARAJAN, ZAKARIA, AZMILY, WEY, EL-GHAFOUR AND SALAH FAYED
more anteriorly to promote mandibular prognathism. A reduction in maxillary length and a retruded position of the maxilla also lead to a Class III skeletal pattern. However, of the described features, an increase in mandibular length and an anterior positioning of the glenoid fossa are more influential in the creation of a Class III malocclusion.3
The treatment options for a Class III malocclusion are growth modification, orthodontic camouflage, or a combination of orthodontics and orthognathic surgery. All of these modalities can achieve satis- factory improvements depending on the planning and execution of treatment.4 Recent studies have investigated the prognostic approach as a treatment decision tool in young Class III patients.5–7 In adults, a treatment decision between orthodontic camouflage and orthognathic surgery for Class III malocclusion management has been a major challenge as the decision is complicated by many factors that need careful consideration.
Patients seek orthognathic surgery for a variety of reasons, the most common of which are an im- provement in facial and dental aesthetics, along with an improvement in oral function.8 However, surgical intervention has associated risks related to intra-operative complications such as an inadequate osteotomy, haemorrhage due to vascular injuries, nerve exposure and damage, dental injuries, and soft tissue changes. Surgery also has several post-operative complications such as paraesthesia, infection, relapse, temporomandibular disorders, and malunion or non- union of bone sites. Therefore, the correct treatment decision between camouflage or orthognathic surgery is crucial.9
Orthognathic surgery is usually performed at an older age once facial growth has been completed or is about to cease. This is to ensure that the surgical planning is more accurate, favourable and stable results are achieved without post-surgical growth interference. The consideration of maturation is still controversial because chronological and dental age do not necessarily correlate with skeletal growth. The earliest age to commence orthognathic surgery is 14.9 years for females and 16.3 years for males.10 The latest age for orthognathic surgery in both genders is between 50 and 64 years.10 In the management of a Class III skeletal discrepancy, clinicians tend to delay surgical treatment as there is potential for continuing mandibular maturation until the age of 20 years or
beyond. A recent time series analysis indicated the median age of orthognathic surgery is at 22 years.11
Proffit and Ackermann presented the concept of three envelopes of tooth movement for orthodontic treatment alone, orthodontic treatment associated with growth, and that associated with surgical treatment.12 However, the criteria still remain insufficient to determine a definitive treatment option. Several studies have shown that a baseline lateral cephalometric analysis is pivotal to develope a precise diagnosis and surgical plan.4,13–15 An early study, that was based on 40 pre- treatment lateral cephalometric films of a Caucasian population, found a value of −4° for the ANB angle, 83° for the inclination of the lower incisors to the mandibular plane and 3.5° for the Holdaway angle designates a threshold of corrective possibility for a Class III malocclusion using orthodontic appliances.13 However, taking the overlap of box-and-whisker plots as critical values for the treatment decision is not an accepted scientific statistical method.14 More recent studies employed stepwise discriminative analysis to determine treatment modalities in borderline Class III malocclusion cases.4,14,15 A study based on a Southern Chinese population found that a Holdaway (H) angle greater than 12° could be successfully treated by orthodontics alone4 and Eslami et al. recommended an H angle greater than 10.3° and a Wits appraisal greater than −5. 8 mm as a guide for cases that could be successfully camouflaged.15
However, to date, there has been no systematic review which has examined the cephalometric threshold values for Class III malocclusion treatment options. Therefore, the present review aimed to determine whether there are critical cephalometric measurements that can be used as a guide to decide whether orthodontic camouflage or orthognathic surgery is appropriate in the management of a Class III malocclusion.
Objectives The objectives of the systematic review and meta- analysis were to evaluate available evidence related to the cephalometric values which act as a guide for the determination of optimal treatment by either orthodontic camouflage or orthognathic surgery in adult Class III malocclusion patients. In addition, a secondary aim was to report the complications of each treatment option (gingival recession, root resorption,
Australasian Orthodontic Journal Volume 38 No. 2 2022 185
CEPHALOMETRIC PARAMETERS IN TREATING BORDERLINE CLASS III MALOCCLUSION
dehiscence, tooth mobility, tooth sensitivity and black triangles) and aesthetic perceptions by laypersons/ orthodontists.
Materials and methods
Protocol and registration The current systematic review was conducted in ac- cordance with the Cochrane Handbook for System- atic Reviews of Interventions and reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The review protocol was submitted in March 2020 and registered with the OSF/Center for Open Science. The review was also submitted in January 2020 and was successful- ly registered with the National Institute of Health Research Database (https:// www.crd.york.ac.uk/ prospero/; trial registration number: PROSPERO CRD42020165164 in July 2020.
Eligibility criteria The PICO for the study was:
• Population: Adult patients aged 18 years and older presenting with a Class III malocclusion
• Intervention: Orthognathic surgery • Comparison: Orthodontic camouflage • Outcome:
1. Primary outcomes: To determine the cephalo- metric threshold values to serve as guides for the best treatment option, whether orthodontic cam- ouflage or orthognathic surgery in adult Class III malocclusion patients.
2. Secondary outcome: To report the complications associated with orthodontic camouflage and or- thognathic surgery (gingival recession, root resorp- tion, dehiscence, tooth mobility, tooth sensitivity and black triangles) and aesthetic perceptions by laypersons/orthodontists.
Study design Included were randomised controlled trials (RCTs), quasi-randomised, prospective studies, retrospective cohort, and cross-sectional studies in the present search. Non-human studies (animal or laboratory studies) and studies on patients with craniofacial malformations were excluded. No language restrictions were applied and all articles were included. Google translator was
used to translate the title and abstract of non-English articles.
Information sources and literature search A comprehensive electronic database search was conducted until the 18th September 2021 with no language nor publication date restrictions. Science Direct, PubMed, Ovid MEDLINE, Web of Science, Scopus and Open Grey were databases searched using Medical Subject Headings and free-text words for PubMed which were optimised for each database (Table I). A hand search of three orthodontic journals, namely the Angle Orthodontist, the European Journal of Orthodontics and the American Journal of Orthodontics and Dentofacial Orthopedics was conducted between Jan 2005 until September 2021. In addition, the reference lists of all the included studies were screened. If necessary, corresponding authors were contacted to obtaining clarifications or for additional data extraction.
Study selection The literature search, study inclusion, methodology quality assessment and data extraction were performed independently and in duplicate by two authors (N.N.Z. and N.A.A.). Any conflicts were resolved by contacting the third, fourth and fifth authors (S.S., W.M.C. and M.M.S.F.). The articles were first screened by title and abstract. Relevant articles were then screened by full text and compared against the inclusion/exclusion criteria for a final selection.
Data items and collection Data extraction was carried out by two review authors independently (N.N.Z. and N.A.A.) using a standardised data extraction form. The data extraction was cross-checked by the third author (S.S.). Data extraction applied the following items: demographic characteristics of the studies, cephalometric cut-off value between orthodontic camouflage and ortho- gnathic surgery in Class III malocclusions and post- treatment complications.
Risk of bias in individual trials The risk of bias was analysed by using the RoB Coch- rane tool for RCTs and prospective non-randomised
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ng in
es in
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ey w
or ds
CEPHALOMETRIC PARAMETERS IN TREATING BORDERLINE CLASS III MALOCCLUSION
studies. For retrospective cohort and cross-sectional studies, the risk of bias was examined with the aid of a modified version of the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist comprising seven items related to: (1) study design, (2) study setting, (3) participants criteria, (4) sample size, (5) variable description, (6) outcome measurements, and (7) statistical analysis. The quality of the studies was categorised as weak (3 or less), moderate (4 or 5) and high quality (6 or more) by two pairs of independent reviewers in duplicate (N.N.Z. & N.A.A.) and (S.S. & W.M.C.). Any disagreements were resolved by discussion and consultation with the fifth author to reach a consensus (M.M.S.F.).
Summary measures and approach to data synthesis The studies were eligible for quantitative synthesis if two or more reported the same outcome, and used the same measurement unit and tools. The data were combined using MedCalc Software Ltd (Belgium-version 19.4.1) for quantitative analysis. Otherwise, the results were summarised qualitatively. Statistical heterogeneity was inspected using the I-squared index, assigning values of 25%, 50% and 75% corresponding to low, moderate and high heterogeneity. According to the I2 test, the random- effect model was applied to studies with more than 50% heterogeneity.16
Additional analyses No subgroup analysis was undertaken.
Results
Study selection The comprehensive search yielded a total of 13033 articles of which 3414 were duplicates. The remaining 9619 articles were screened by title and abstract. A total of 9598 articles were excluded by title and 9 articles were excluded by abstract. A final sample of 12 articles were then screened by full text after which 6 studies met the inclusion criteria. The results from the database search are presented in Table I. Figure 1 illustrates the study selection and identification process. Six articles4,13,17–22 were excluded as two studies4,13 recruited participants below 18 years of age, one study17
was a review article, and three studies16–20 did not define the cephalometric values differentiating orthognathic surgery and camouflage.
Study characteristics The characteristics of the selected studies are presented in Table II. No RCTs or quasi-randomised nor prospective clinical trials were identified. All of the six currently included studies14,15,21–24 were retrospective in nature. The total sample sizes of the studies ranged from 47 to 175. The mean age of the patients was greater than 18 years of age in four studies,15,22–24 two studies14,21 did not specify the mean age, but included adult patients in the studies. No data were reported on the gender of the patients in two studies,21,22 three studies14,15,24 had more female than male patients and one study23 recruited equal numbers of male and female patients.
Risk of bias within individual studies Two studies15,24 were judged to be of high quality and four studies14,21–23 were of moderate quality (Table III). All of the moderate quality studies did not completely report on the research parameters and sample size calculations.
Results of individual studies
Primary outcomes Based on the five retrospective studies,14,15,21–23 the parameters that were used to determine the Class III cephalometric values identifying camouflage and orthognathic surgery treatment options were the Holdaway angle, overjet, Wits appraisal, lower incisor inclination, the maxillary-mandibular ratio, overbite, gonial angle and a combination of parameters. Two of the included papers calculated the threshold value using a formula that included more than one of the previously identified parameters (Table IV). The cephalometric value of the Holdaway angle between orthodontic camouflage versus orthognathic surgery in Class III malocclusion cases was reported by two studies15,21 (Table IV). Both used discrimina- tive analysis to determine the cephalometric values. However, there were high levels of methodological heterogeneity that removed the value of a meta-analysis for this parameter.
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Records identified from*: Databases (n = 13033)
Science Direct (n = 3842) PUBMED (n = 1333) Ovid (n = 648) Web of Science (n = 371) Scopus (n = 6839) OpenGrey (n = 0)
Registers (n = 0)
Records removed before screening :
Duplicate records removed (n = 3414) Records marked as ineligible by automation tools (n = 0) Records removed for other reasons (n = 0)
Records screened (n = 9619)
Records excluded** (n = 9607)
Reports not retrieved (n = 0)
Reports assessed for eligibility (n = 12)
Reports excluded: 1. Review article (n = 1) 2. Studies didn’t report on
cut-off values for camouflage or surgery (n = 3)
3. Studies with recruitment age below 18 years (n = 2)
Studies included in review (n = 6) Reports of included studies (n = 6)
Identification of studies via databases and registers
Id en
ti fi
ca ti
o n
S cr
ee n
in g
In cl
u d
Figure 1. Preferred Reporting Items for Systematic Reviews and Meta-Analyses flow diagram of the included studies.
The application of overjet, overbite, maxillary-man- dibular ratio, lower incisal angle and gonial angle as the cephalometric values was recommended in a single study23 (Table IV). The use of the Wits appraisal in isolation as a determining cephalometric factor was advocated by Tseng et al.23 and Eslami et al.15 However, the former used receiver operating characteristic (ROC) analysis whereas the latter study used a discriminative analysis to derive the Wits appraisal values. Due to methodological heterogeneity, no meta-analysis was undertaken for this outcome. Two studies14,22 advocated a combination of criteria as the cephalometric values (Table IV), and again, the data from the studies could not be pooled for meta- analysis.
Secondary outcomes No study reported the possible adverse effects associated with orthodontic camouflage or orthognathic surgery which have been identified as gingival recession, root resorption, dehiscence, tooth mobility, tooth sensitivity and the development of black triangles.
One study reported the aesthetic perceptions of laypersons/orthodontists regarding camouflage and orthognathic surgery.24 At pre-treatment, the ortho- gnathic surgery group had a statistically poorer profile attractiveness as graded by the orthodontists in comparison to the camouflage group. Following treatment, the camouflage and orthognathic surgery groups reported significant improvement in profile
Australasian Orthodontic Journal Volume 38 No. 2 2022 189
CEPHALOMETRIC PARAMETERS IN TREATING BORDERLINE CLASS III MALOCCLUSION
Table II. Characteristics of the included studies.
Study Study design Study setting Participants Mean age Gender
Stellzig-Eisenhauer, Lux and Schuster 200214
Retrospective study
Departments of Orthodontics of the Universities of Frankfurt, Heidelberg, and Würzburg, Germany.
Total sample: 175 CG: 87 SG: 88
Overall: NA CG: NA SG: NA *Sample of adult patient
Overall: M: 82; F: 93
Eslami et al. 201815
Total sample: 65 CG: 36 SG: 29
Overall: NA CG: 23.5 ± 4.8, SG: 24.8 ± 3.1
Overall: M: 27; F: 38 CS: M: 15; F: 21 SG: M: 12; F: 17
Benyahia et al. 201121
Retrospective study
Orthodontics unit at the CHIS dental consultation and treatment center in Rabat, Morocco, and the Clairval CHP maxillofacial and esthetic clinic in Marseille, France
Total sample: 47 CG: 22 SG: 25
Overall: NA CG: NA SG: NA *Sample of adult patient
Overall: NA CG: NA SG: NA
Kochel et al. 201122
Retrospective study
Department of Orthodontics of the University of Wuerzburg in Germany and from 7 cooperative private practices
Total sample: 69 CG: 28 SG: 41
Overall: NA CG: Mean 27.6, Median 23.6 SG: Mean 26.3, Median 24.2
Overall: NA CG: NA SG: NA
Tseng et al. 201123
Overall: 23 years range, 18–34
Overall: M: 40; F: 40
Watanabe et al. 202024
Brazil Total sample: 60 CG: 30 SG: 30
Overall: NA CG: 18.5 ± 4.4 SG: 20.1 ± 2.4
Overall: M: 29; F: 31 CS: M: 13; F: 17 SG: M: 16; F: 14
Note: CG: Camouflage group, SG: Surgical group, M: Male, F: Female, NA: Not available.
Table III. Risk of bias of included studies.
Author and year Study design
Setting Participants
criteria Sample
size Variable
description Outcome
measurement Statistical
√ X √ X √ √ √ 5 Moderate
Benyahia et al. 201121 X X √ X √ √ √ 4 Moderate
Kochel et al. 201122 X X √ X √ √ √ 4 Moderate
Tseng et al. 201123 √ X √ X √ √ √ 5 Moderate
Watanabe et al. 202024
√ √ √ √ √ √ √ 6 High
Note: The quality of the studies will be categorized as weak (3 and less), moderate (4 or 5) and high quality (6 or more) by two independent reviewers.
190 Australasian Orthodontic Journal Volume 38 No. 2 2022
SIVARAJAN, ZAKARIA, AZMILY, WEY, EL-GHAFOUR AND SALAH FAYED
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. C ep
ha lo
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CEPHALOMETRIC PARAMETERS IN TREATING BORDERLINE CLASS III MALOCCLUSION
attractiveness. At a post-treatment assessment, both groups reported similar attractiveness based on profile silhouettes generated from the lateral cephalograms.24
Discussion
Summary of evidence At the time of registration with OSF/Center for Open Science, there was no…
Determination of treatment options for Class III malocclusions in adult patients based on cephalometric values: a systematic review
Saritha Sivarajan,* Nor Nadia Zakaria,* Noor Asyikin Azmily,* Mang Chek Wey,* Mohamed Abd El-Ghafour† and Mona M. Salah Fayed†
Department of Paediatric Dentistry and Orthodontics, Faculty of Dentistry, Universiti Malaya, Lembah Pantai, Kuala Lumpur 50603, Malaysia* Department of Orthodontics, Faculty of Dentistry, Cairo University, 11 El Saraya St., Manial, Cairo, Egypt†
Objective: The present systematic review aimed to determine cephalometric values that may be used as a guide in deciding between orthodontic camouflage and orthognathic surgery to treat a Class III malocclusion in adults. In addition, a secondary aim was to identify treatment complications and aesthetic perceptions by laypersons/orthodontists. Methods: Without a language restriction, an electronic search of six databases and a hand search of three orthodontic journals were performed until September 2021. All studies comparing orthodontic camouflage and orthognathic surgery in Class III malocclusion patients, were included. Data extraction was carried out independently by two authors with disagreement resolved by a third author. The risk of bias related to individual studies was appraised using a modified version of the STROBE checklist. The results were summarised qualitatively, and no meta-analysis was undertaken due to the high heterogeneity between the studies. Results: With the quality of evidence ranging from moderate to high, six retrospective studies were included. A cephalometric analysis comprising the Holdaway angle, overjet, the Wits appraisal, lower incisor inclination, the maxillary-mandibular ratio, overbite, gonial angle and an additional combination were used as a guide. No treatment complications were reported. One study examined the perception of facial profile attractiveness in borderline surgical Class III malocclusions and found no difference in outcome and significant improvements in both camouflage and surgical groups. Conclusion: The existing evidence is insufficient to identify a cephalometric parameter threshold in deciding between orthodontic camouflage and orthognathic surgery. PROSPERO database protocol no. CRD42020165164. (Aust Orthod J 2022; 38: 183 - 193. DOI: 10.2478/aoj-2022-0021)
Received for publication: February, 2022 Accepted: June, 2022
Saritha Sivarajan: [email protected]; Nor Nadia Zakaria: [email protected]; Noor Asyikin Azmily: [email protected]; Mang Chek Wey: [email protected]; Mohamed Abd El-Ghafour: [email protected]; Mona M. Salah Fayed: [email protected]
Introduction A Class III malocclusion presents with a variety of skeletal and dental features, which may include a large or protrusive mandible, a retrusive maxilla, a protrusive mandibular dentition, a retrusive maxillary dentition, and any combination of these characteristics.1 The aetiology of a Class III malocclusion can either be classified as genetic/hereditary or environmental.
In contrast to a Class II malocclusion, the heredi- tary influences on the development of a Class III malocclusion are more profound2 but the most important aetiological factor is the skeletal relation- ship. Based on cephalometric studies, a Class III malocclusion may have an increase in mandibular length, coupled with an anterior positioning of the glenoid fossa so that the condylar head is positioned
184 Australasian Orthodontic Journal Volume 38 No. 2 2022
SIVARAJAN, ZAKARIA, AZMILY, WEY, EL-GHAFOUR AND SALAH FAYED
more anteriorly to promote mandibular prognathism. A reduction in maxillary length and a retruded position of the maxilla also lead to a Class III skeletal pattern. However, of the described features, an increase in mandibular length and an anterior positioning of the glenoid fossa are more influential in the creation of a Class III malocclusion.3
The treatment options for a Class III malocclusion are growth modification, orthodontic camouflage, or a combination of orthodontics and orthognathic surgery. All of these modalities can achieve satis- factory improvements depending on the planning and execution of treatment.4 Recent studies have investigated the prognostic approach as a treatment decision tool in young Class III patients.5–7 In adults, a treatment decision between orthodontic camouflage and orthognathic surgery for Class III malocclusion management has been a major challenge as the decision is complicated by many factors that need careful consideration.
Patients seek orthognathic surgery for a variety of reasons, the most common of which are an im- provement in facial and dental aesthetics, along with an improvement in oral function.8 However, surgical intervention has associated risks related to intra-operative complications such as an inadequate osteotomy, haemorrhage due to vascular injuries, nerve exposure and damage, dental injuries, and soft tissue changes. Surgery also has several post-operative complications such as paraesthesia, infection, relapse, temporomandibular disorders, and malunion or non- union of bone sites. Therefore, the correct treatment decision between camouflage or orthognathic surgery is crucial.9
Orthognathic surgery is usually performed at an older age once facial growth has been completed or is about to cease. This is to ensure that the surgical planning is more accurate, favourable and stable results are achieved without post-surgical growth interference. The consideration of maturation is still controversial because chronological and dental age do not necessarily correlate with skeletal growth. The earliest age to commence orthognathic surgery is 14.9 years for females and 16.3 years for males.10 The latest age for orthognathic surgery in both genders is between 50 and 64 years.10 In the management of a Class III skeletal discrepancy, clinicians tend to delay surgical treatment as there is potential for continuing mandibular maturation until the age of 20 years or
beyond. A recent time series analysis indicated the median age of orthognathic surgery is at 22 years.11
Proffit and Ackermann presented the concept of three envelopes of tooth movement for orthodontic treatment alone, orthodontic treatment associated with growth, and that associated with surgical treatment.12 However, the criteria still remain insufficient to determine a definitive treatment option. Several studies have shown that a baseline lateral cephalometric analysis is pivotal to develope a precise diagnosis and surgical plan.4,13–15 An early study, that was based on 40 pre- treatment lateral cephalometric films of a Caucasian population, found a value of −4° for the ANB angle, 83° for the inclination of the lower incisors to the mandibular plane and 3.5° for the Holdaway angle designates a threshold of corrective possibility for a Class III malocclusion using orthodontic appliances.13 However, taking the overlap of box-and-whisker plots as critical values for the treatment decision is not an accepted scientific statistical method.14 More recent studies employed stepwise discriminative analysis to determine treatment modalities in borderline Class III malocclusion cases.4,14,15 A study based on a Southern Chinese population found that a Holdaway (H) angle greater than 12° could be successfully treated by orthodontics alone4 and Eslami et al. recommended an H angle greater than 10.3° and a Wits appraisal greater than −5. 8 mm as a guide for cases that could be successfully camouflaged.15
However, to date, there has been no systematic review which has examined the cephalometric threshold values for Class III malocclusion treatment options. Therefore, the present review aimed to determine whether there are critical cephalometric measurements that can be used as a guide to decide whether orthodontic camouflage or orthognathic surgery is appropriate in the management of a Class III malocclusion.
Objectives The objectives of the systematic review and meta- analysis were to evaluate available evidence related to the cephalometric values which act as a guide for the determination of optimal treatment by either orthodontic camouflage or orthognathic surgery in adult Class III malocclusion patients. In addition, a secondary aim was to report the complications of each treatment option (gingival recession, root resorption,
Australasian Orthodontic Journal Volume 38 No. 2 2022 185
CEPHALOMETRIC PARAMETERS IN TREATING BORDERLINE CLASS III MALOCCLUSION
dehiscence, tooth mobility, tooth sensitivity and black triangles) and aesthetic perceptions by laypersons/ orthodontists.
Materials and methods
Protocol and registration The current systematic review was conducted in ac- cordance with the Cochrane Handbook for System- atic Reviews of Interventions and reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The review protocol was submitted in March 2020 and registered with the OSF/Center for Open Science. The review was also submitted in January 2020 and was successful- ly registered with the National Institute of Health Research Database (https:// www.crd.york.ac.uk/ prospero/; trial registration number: PROSPERO CRD42020165164 in July 2020.
Eligibility criteria The PICO for the study was:
• Population: Adult patients aged 18 years and older presenting with a Class III malocclusion
• Intervention: Orthognathic surgery • Comparison: Orthodontic camouflage • Outcome:
1. Primary outcomes: To determine the cephalo- metric threshold values to serve as guides for the best treatment option, whether orthodontic cam- ouflage or orthognathic surgery in adult Class III malocclusion patients.
2. Secondary outcome: To report the complications associated with orthodontic camouflage and or- thognathic surgery (gingival recession, root resorp- tion, dehiscence, tooth mobility, tooth sensitivity and black triangles) and aesthetic perceptions by laypersons/orthodontists.
Study design Included were randomised controlled trials (RCTs), quasi-randomised, prospective studies, retrospective cohort, and cross-sectional studies in the present search. Non-human studies (animal or laboratory studies) and studies on patients with craniofacial malformations were excluded. No language restrictions were applied and all articles were included. Google translator was
used to translate the title and abstract of non-English articles.
Information sources and literature search A comprehensive electronic database search was conducted until the 18th September 2021 with no language nor publication date restrictions. Science Direct, PubMed, Ovid MEDLINE, Web of Science, Scopus and Open Grey were databases searched using Medical Subject Headings and free-text words for PubMed which were optimised for each database (Table I). A hand search of three orthodontic journals, namely the Angle Orthodontist, the European Journal of Orthodontics and the American Journal of Orthodontics and Dentofacial Orthopedics was conducted between Jan 2005 until September 2021. In addition, the reference lists of all the included studies were screened. If necessary, corresponding authors were contacted to obtaining clarifications or for additional data extraction.
Study selection The literature search, study inclusion, methodology quality assessment and data extraction were performed independently and in duplicate by two authors (N.N.Z. and N.A.A.). Any conflicts were resolved by contacting the third, fourth and fifth authors (S.S., W.M.C. and M.M.S.F.). The articles were first screened by title and abstract. Relevant articles were then screened by full text and compared against the inclusion/exclusion criteria for a final selection.
Data items and collection Data extraction was carried out by two review authors independently (N.N.Z. and N.A.A.) using a standardised data extraction form. The data extraction was cross-checked by the third author (S.S.). Data extraction applied the following items: demographic characteristics of the studies, cephalometric cut-off value between orthodontic camouflage and ortho- gnathic surgery in Class III malocclusions and post- treatment complications.
Risk of bias in individual trials The risk of bias was analysed by using the RoB Coch- rane tool for RCTs and prospective non-randomised
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studies. For retrospective cohort and cross-sectional studies, the risk of bias was examined with the aid of a modified version of the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist comprising seven items related to: (1) study design, (2) study setting, (3) participants criteria, (4) sample size, (5) variable description, (6) outcome measurements, and (7) statistical analysis. The quality of the studies was categorised as weak (3 or less), moderate (4 or 5) and high quality (6 or more) by two pairs of independent reviewers in duplicate (N.N.Z. & N.A.A.) and (S.S. & W.M.C.). Any disagreements were resolved by discussion and consultation with the fifth author to reach a consensus (M.M.S.F.).
Summary measures and approach to data synthesis The studies were eligible for quantitative synthesis if two or more reported the same outcome, and used the same measurement unit and tools. The data were combined using MedCalc Software Ltd (Belgium-version 19.4.1) for quantitative analysis. Otherwise, the results were summarised qualitatively. Statistical heterogeneity was inspected using the I-squared index, assigning values of 25%, 50% and 75% corresponding to low, moderate and high heterogeneity. According to the I2 test, the random- effect model was applied to studies with more than 50% heterogeneity.16
Additional analyses No subgroup analysis was undertaken.
Results
Study selection The comprehensive search yielded a total of 13033 articles of which 3414 were duplicates. The remaining 9619 articles were screened by title and abstract. A total of 9598 articles were excluded by title and 9 articles were excluded by abstract. A final sample of 12 articles were then screened by full text after which 6 studies met the inclusion criteria. The results from the database search are presented in Table I. Figure 1 illustrates the study selection and identification process. Six articles4,13,17–22 were excluded as two studies4,13 recruited participants below 18 years of age, one study17
was a review article, and three studies16–20 did not define the cephalometric values differentiating orthognathic surgery and camouflage.
Study characteristics The characteristics of the selected studies are presented in Table II. No RCTs or quasi-randomised nor prospective clinical trials were identified. All of the six currently included studies14,15,21–24 were retrospective in nature. The total sample sizes of the studies ranged from 47 to 175. The mean age of the patients was greater than 18 years of age in four studies,15,22–24 two studies14,21 did not specify the mean age, but included adult patients in the studies. No data were reported on the gender of the patients in two studies,21,22 three studies14,15,24 had more female than male patients and one study23 recruited equal numbers of male and female patients.
Risk of bias within individual studies Two studies15,24 were judged to be of high quality and four studies14,21–23 were of moderate quality (Table III). All of the moderate quality studies did not completely report on the research parameters and sample size calculations.
Results of individual studies
Primary outcomes Based on the five retrospective studies,14,15,21–23 the parameters that were used to determine the Class III cephalometric values identifying camouflage and orthognathic surgery treatment options were the Holdaway angle, overjet, Wits appraisal, lower incisor inclination, the maxillary-mandibular ratio, overbite, gonial angle and a combination of parameters. Two of the included papers calculated the threshold value using a formula that included more than one of the previously identified parameters (Table IV). The cephalometric value of the Holdaway angle between orthodontic camouflage versus orthognathic surgery in Class III malocclusion cases was reported by two studies15,21 (Table IV). Both used discrimina- tive analysis to determine the cephalometric values. However, there were high levels of methodological heterogeneity that removed the value of a meta-analysis for this parameter.
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Records identified from*: Databases (n = 13033)
Science Direct (n = 3842) PUBMED (n = 1333) Ovid (n = 648) Web of Science (n = 371) Scopus (n = 6839) OpenGrey (n = 0)
Registers (n = 0)
Records removed before screening :
Duplicate records removed (n = 3414) Records marked as ineligible by automation tools (n = 0) Records removed for other reasons (n = 0)
Records screened (n = 9619)
Records excluded** (n = 9607)
Reports not retrieved (n = 0)
Reports assessed for eligibility (n = 12)
Reports excluded: 1. Review article (n = 1) 2. Studies didn’t report on
cut-off values for camouflage or surgery (n = 3)
3. Studies with recruitment age below 18 years (n = 2)
Studies included in review (n = 6) Reports of included studies (n = 6)
Identification of studies via databases and registers
Id en
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Figure 1. Preferred Reporting Items for Systematic Reviews and Meta-Analyses flow diagram of the included studies.
The application of overjet, overbite, maxillary-man- dibular ratio, lower incisal angle and gonial angle as the cephalometric values was recommended in a single study23 (Table IV). The use of the Wits appraisal in isolation as a determining cephalometric factor was advocated by Tseng et al.23 and Eslami et al.15 However, the former used receiver operating characteristic (ROC) analysis whereas the latter study used a discriminative analysis to derive the Wits appraisal values. Due to methodological heterogeneity, no meta-analysis was undertaken for this outcome. Two studies14,22 advocated a combination of criteria as the cephalometric values (Table IV), and again, the data from the studies could not be pooled for meta- analysis.
Secondary outcomes No study reported the possible adverse effects associated with orthodontic camouflage or orthognathic surgery which have been identified as gingival recession, root resorption, dehiscence, tooth mobility, tooth sensitivity and the development of black triangles.
One study reported the aesthetic perceptions of laypersons/orthodontists regarding camouflage and orthognathic surgery.24 At pre-treatment, the ortho- gnathic surgery group had a statistically poorer profile attractiveness as graded by the orthodontists in comparison to the camouflage group. Following treatment, the camouflage and orthognathic surgery groups reported significant improvement in profile
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Table II. Characteristics of the included studies.
Study Study design Study setting Participants Mean age Gender
Stellzig-Eisenhauer, Lux and Schuster 200214
Retrospective study
Departments of Orthodontics of the Universities of Frankfurt, Heidelberg, and Würzburg, Germany.
Total sample: 175 CG: 87 SG: 88
Overall: NA CG: NA SG: NA *Sample of adult patient
Overall: M: 82; F: 93
Eslami et al. 201815
Total sample: 65 CG: 36 SG: 29
Overall: NA CG: 23.5 ± 4.8, SG: 24.8 ± 3.1
Overall: M: 27; F: 38 CS: M: 15; F: 21 SG: M: 12; F: 17
Benyahia et al. 201121
Retrospective study
Orthodontics unit at the CHIS dental consultation and treatment center in Rabat, Morocco, and the Clairval CHP maxillofacial and esthetic clinic in Marseille, France
Total sample: 47 CG: 22 SG: 25
Overall: NA CG: NA SG: NA *Sample of adult patient
Overall: NA CG: NA SG: NA
Kochel et al. 201122
Retrospective study
Department of Orthodontics of the University of Wuerzburg in Germany and from 7 cooperative private practices
Total sample: 69 CG: 28 SG: 41
Overall: NA CG: Mean 27.6, Median 23.6 SG: Mean 26.3, Median 24.2
Overall: NA CG: NA SG: NA
Tseng et al. 201123
Overall: 23 years range, 18–34
Overall: M: 40; F: 40
Watanabe et al. 202024
Brazil Total sample: 60 CG: 30 SG: 30
Overall: NA CG: 18.5 ± 4.4 SG: 20.1 ± 2.4
Overall: M: 29; F: 31 CS: M: 13; F: 17 SG: M: 16; F: 14
Note: CG: Camouflage group, SG: Surgical group, M: Male, F: Female, NA: Not available.
Table III. Risk of bias of included studies.
Author and year Study design
Setting Participants
criteria Sample
size Variable
description Outcome
measurement Statistical
√ X √ X √ √ √ 5 Moderate
Benyahia et al. 201121 X X √ X √ √ √ 4 Moderate
Kochel et al. 201122 X X √ X √ √ √ 4 Moderate
Tseng et al. 201123 √ X √ X √ √ √ 5 Moderate
Watanabe et al. 202024
√ √ √ √ √ √ √ 6 High
Note: The quality of the studies will be categorized as weak (3 and less), moderate (4 or 5) and high quality (6 or more) by two independent reviewers.
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attractiveness. At a post-treatment assessment, both groups reported similar attractiveness based on profile silhouettes generated from the lateral cephalograms.24
Discussion
Summary of evidence At the time of registration with OSF/Center for Open Science, there was no…
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