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Orthodontic treatment for prominent lower front teeth (Class III malocclusion) in children

  1. Simon Watkinson1,
  2. Jayne E Harrison2,*,
  3. Susan Furness3,
  4. Helen V Worthington3

Editorial Group: Cochrane Oral Health Group

Published Online: 30 SEP 2013

Assessed as up-to-date: 7 JAN 2013

DOI: 10.1002/14651858.CD003451.pub2


How to Cite

Watkinson S, Harrison JE, Furness S, Worthington HV. Orthodontic treatment for prominent lower front teeth (Class III malocclusion) in children. Cochrane Database of Systematic Reviews 2013, Issue 9. Art. No.: CD003451. DOI: 10.1002/14651858.CD003451.pub2.

Author Information

  1. 1

    University of Liverpool, Department of Orthodontics, Liverpool, UK

  2. 2

    Liverpool University Dental Hospital, Orthodontic Department, Liverpool, Merseyside, UK

  3. 3

    School of Dentistry, The University of Manchester, Cochrane Oral Health Group, Manchester, UK

*Jayne E Harrison, Orthodontic Department, Liverpool University Dental Hospital, Pembroke Place, Liverpool, Merseyside, L3 5PS, UK. jayne.harrison@rlbuht.nhs.uk. jeharrison@hotmail.co.uk.

Publication History

  1. Publication Status: New
  2. Published Online: 30 SEP 2013

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Characteristics of included studies [ordered by study ID]
Abdelnaby 2010

Methods3-arm parallel randomised controlled trial


ParticipantsNumber recruited: 50 growing patients (26 males and 24 females)

Mean age: 9.7 years (range not given)

Inclusion criteria: Patients had skeletal Class III (ANB < 1 °) and mandibular prognathism (SNB > 80 °) and an anterior crossbite. Assessed for skeletal maturation with hand-wrist radiographs and shown to have not passed the peak of the pubertal growth spurt

Exclusion criteria: Not reported

Setting: Recruited from the Faculty of Dentistry, Mansoura University, Mansoura, Egypt


InterventionsComparison: 600 g chin cup versus 300 g chin cup versus untreated control

Group 1: Occipital pull soft chin cup (Dentaurum, Ispringen, Germany) with an acrylic occlusal bite plane of a thickness that just freed the occlusion anteriorly. Force applied was 600 g force per side. Patients were instructed to wear the appliance for 14 hours each day (n = 20)

Group 2: As above using 300 g per side (n = 20)

Group 3: No orthodontic or orthopaedic treatment (n = 10)


OutcomesAll measures taken prior to treatment and after 1 year

Outcomes relevant to the review: ANB


NotesSample size calculation was not described


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear riskThe method of randomisation was not described. Attempts were made to contact the authors for clarification but we are yet to receive a response

Allocation concealment (selection bias)Unclear riskThe method of allocation concealment was not described. Attempts were made to contact the authors for clarification but we are yet to receive a response

Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskThere was no mention of blinding of the assessor. Attempts were made to contact the authors for clarification but we are yet to receive a response

Incomplete outcome data (attrition bias)
All outcomes
Unclear riskThere was no mention of any loss of patients during the study. Attempts were made to contact the authors for clarification but we are yet to receive a response

Selective reporting (reporting bias)Low riskThe authors solely aimed to report on cephalometric measures and all were reported

Other biasHigh riskStated that patients "randomly divided into three groups" however groups 1 and 2 have double the number of patients compared to group 3

Arun 1994

Methods3-arm parallel randomised controlled trial


ParticipantsNumber recruited: 60 patients (26 males and 34 females)

Mean age: 8.23 years. Range 7.44 to 8.97 years

Inclusion criteria: ANB < 2.5 °, Jarabak ratio greater than 59%, antegonial notch depth less than 2 mm

Exclusion criteria: Not reported

Setting: Treated in the Marmara University Dental Faculty, Turkey


InterventionsComparison: Mandibular headgear versus chin cup versus untreated control

Group 1: Mandibular headgear group: Prefabricated tubeless bands were thoroughly adapted to the lower molar teeth. They were then removed from the mouth and orthobuccal tubes were spot welded in the middle of their buccal surfaces. The bands were seated back on the molar teeth and a facebow, with downward facing U bends of its inner bow, was inserted in to the tubes. The desired force was applied to the facebow. The bands were cemented and the patients instructed to use their appliance 24 hours later. The outer bow was initially positioned parallel to the inner bow. Later, its arms were bent downwards in the parallel position (n = 20)

Group 2: Chin cup group: Force directed obliquely on a line from the symphysis to the condyle. The head straps of the chin cup passed 1 cm above the earlaps in the temporal region and enwrapped the cranial vault. Topical application of the talcum powder was recommended in case the metal connections of the chin cup caused allergic reactions
In both treatment groups, the first review was 1 week after the insertion of the appliance and thereafter at 3-week intervals. Both groups were advised to use the appliances 16 hours per day during the 1 year treatment period. Forces were maintained at 480-500 g in both groups. The effects of any anterior crossbite were eliminated and the mandibular distal movement freed from occlusal interferences through application of posterior bite planes (n = 20)

Group 3: No treatment (n = 20)


OutcomesOpen and closed mouth lateral cephalograms were taken of all 60 patients at the beginning and end of the 12-month treatment and control period. The condylion point was first traced on the open-mouth lateral cephalogram then, using its mandibular projection as a guide, it was superimposed on the closed-mouth lateral cephalogram on which 18 cephalometric points were selected for analysis

Outcomes relevant to this review: ANB


NotesSample size calculation was not described


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low riskContact from author confirms that a random number generator was used for patient assignment on registration to the study

Allocation concealment (selection bias)High riskContact from author confirms there was no allocation concealment used

Blinding of outcome assessment (detection bias)
All outcomes
High riskContact from author confirms there was no blinding of any assessors during the study

Incomplete outcome data (attrition bias)
All outcomes
Low riskAll patients completed the study and were included in the analysis

Selective reporting (reporting bias)Low riskAll cephalometric measurements were recorded and analysed

Other biasLow riskAuthors clarified all other queries

Atalay 2010

Methods2-arm parallel randomised controlled trial


ParticipantsNumber recruited: 30 patients (16 males and 14 females)

Mean age: 8.04 years

Inclusion criteria: Skeletal Class III (ANB < 0 °), due to maxillary retrusion, or a combination of maxillary retrusion and mandibular protrusion. Angle Class III malocclusion with an anterior crossbite. An optimum SN/GoGn angle (between 26 ° and 38 °). Fully erupted maxillary incisors

Exclusion criteria: Congenitally missing teeth or congenital syndromes such as a cleft lip/palate. Previous orthodontic treatment

Setting: Patients recruited from Gazi University, Turkey


InterventionsComparison: Tandem traction bow appliance (TTBA) versus untreated control

Group 1: The modified TTBA: After dental casts were obtained, a wax construction bite was obtained with a 5-6 mm vertical opening at the molar region and without any sagittal activation. The modified TTBA comprised an upper splint, a lower splint, and a traction bow. The upper splint had Adams' clasps in the posterior region for retention and elastic hooks between the maxillary central and lateral incisors. The upper splint covered the palatal and occlusal surfaces, in addition to 1–2 mm of the buccal surfaces of the maxillary teeth. The lower splint covered the buccal and lingual surfaces of the mandibular teeth. Activator tubes were embedded in the posterior region of the lower splint. A conventional headgear facebow was modified and used as the traction bow. The outer bows of the facebow were cut to approximately 3 cm and shaped as a letter 'S'. 2 elastics that exerted a force of 400–500 g on 1 side were worn between the labial hooks and the traction bow. The elastic force was directed between 35 ° and 40 ° to the occlusal plane by arranging the position of the outer traction bows. The patients were instructed to wear the appliance approximately 14–16 hours a day. The average treatment time for this group was 9 months (n = 15)

Group 2: Control group: Observed without treatment for 8 months (n = 15)


OutcomesLateral cephalometric radiographs were taken before treatment and after a Class I molar relationship and a minimum overjet of 2 mm was obtained
Pre- and post-treatment lateral cephalograms were traced by hand and measured by 1 author. 21 parameters were evaluated

Outcomes relevant to this review: Overjet, ANB


NotesSample size calculation was not described


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low riskContact from author confirms the use of random sequence generator using the patient application numbers

Allocation concealment (selection bias)High riskContact from author confirms no allocation concealment was used

Blinding of outcome assessment (detection bias)
All outcomes
High riskContact from author confirms that no blinding of assessors was used

Incomplete outcome data (attrition bias)
All outcomes
Low riskAll patients completed the study and were accounted for in the analysis

Selective reporting (reporting bias)Low riskAll cephalometric measurements were recorded and analysed

Other biasLow riskAuthors clarified all other queries

Keles 2002

Methods2-arm parallel randomised controlled trial


ParticipantsNumber recruited: 20 patients (10 males and 10 females)

Mean age: 8.54 years. Range 7.3-10.9 years

Inclusion criteria: Healthy patients without any hormonal or growth discrepancy. Anterior crossbite with Class III molar relationship. True Class III patients. Class III patients with maxillary retrognathism

Exclusion criteria: Pseudo or functional Class III

Setting: Recruited from Marmara University, Istanbul, Turkey


InterventionsComparison: Nanda facemask versus conventional facemask

Group 1: Facemask with modified angle of force direction (Nanda group): Composed of 3 parts: a modified full-cover acrylic cap splint expansion appliance, a specially designed facebow, and a Petit type protraction headgear. The cap splint expansion appliance was modified by adding 2 tubes (3M Unitek, USA, item no. 325–303) on the buccal side of the acrylic in the premolar area. The tubes were soldered to the RME screw (Leone, item A620-09) and the acrylic was constructed. The purpose of these tubes was to accommodate the inner bows of the specially designed facebow. The facebow was constructed from an adjustable facebow (Ormco, item 200- 0227 Glendora, CA, USA). The inner bows of the facebow ended in the mouth with a special U-shaped bend in order to enter the buccal tubes from the distal, and thus be able to retain itself when an anterior pull was applied. In order to carry the level of force application above the occlusal plane, the outer bows of the facebow were bent in a 30 ° upward direction and ended with 2 hook bends in order to hold the elastics used for the facemask. These hooks were positioned around the root tips of the first and second premolars and 500 g of force was applied parallel to the Frankfort plane in an anterior direction. The same Petit-type facemask was used and the direction of the force was adjusted by moving the wire piece upward on the facemask for elastic engagement (n = 11)

Group 2: Conventional facemask: This consisted of a cap splint–type rapid palatal expander modified by adding 2 hooks in the canine area. The purpose of these hooks was to hold the elastics in place for protraction. The protraction headgear was a Petit type (Ormco Corporation, Glendore, Calif), and a force of 500 g was applied to each hook at a 30 ° angle to the occlusal plane (n = 9)

In both groups, treatment was started with 10 days of rapid maxillary expansion. Following the expansion, a facemask was applied to the patients of both groups and the appliance was used for 6 months after the onset of treatment. Patients were advised to wear the facemask for a minimum of 16 hours per day in the first 3 months and 12 hours in the second 3 months. In both groups a 500 g force was used. In group 1 the force was applied parallel to the Frankfort horizontal plane, in group 2 it was angled downward 30 ° to the occlusal plane


OutcomesLateral cephalometric films were taken both at the beginning and the end of treatment (6 months). 18 linear and angular cephalometric measurements were made for all patients

Outcomes relevant to this review: ANB


NotesSample size calculation was not described


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear riskThe method of randomisation was not described. Attempts were made to contact the authors for clarification but we are yet to receive a response

Allocation concealment (selection bias)Unclear riskThe method of allocation concealment was not described. Attempts were made to contact the authors for clarification but we are yet to receive a response

Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskThere was no mention of blinding of the assessor. Attempts were made to contact the authors for clarification but we are yet to receive a response

Incomplete outcome data (attrition bias)
All outcomes
Unclear riskThere was no mention of any loss of patients during the study. Attempts were made to contact the authors for clarification but we are yet to receive a response

Selective reporting (reporting bias)Low riskThe authors solely aimed to report on cephalometric measures and all were reported

Other biasLow riskNone detectable

Mandall 2010

Methods2-arm parallel randomised controlled trial


ParticipantsNumber recruited: 73 patients (34 males and 39 females)

Mean age: 8.86 years

Inclusion criteria: 7-9 years old at the time of registration. 3 or 4 incisors in crossbite in the intercuspal position. Clinical assessment of a Class III skeletal problem

Exclusion criteria: Child of non-Caucasian origin. Cleft lip and palate and/or craniofacial syndrome. A maxillo-mandibular planes angle greater than 35 ° or lower face height greater than 70 mm. Previous history of TMJ signs or symptoms. Lack of consent

Setting: Patients were recruited through UK orthodontic departments at 5 district general hospitals and 3 university teaching hospitals. Patient recruitment was optimised by writing to all general dental practitioners, who referred to each unit, explaining the type of patient we were looking to recruit. Additionally, the consultant orthodontist in each centre screened up to 5 local primary schools for suitable children in the 8–9 years old age group


InterventionsComparison: Facemask versus untreated control

Group 1: Facemask group: A bonded maxillary acrylic expansion device was placed. This consisted of a metal framework and a midline expansion screw to which 3 mm acrylic was adapted. The appliance was modified, if needed, with acrylic extending over the upper incisor edges to increase appliance retention. 1 vestibular hook was located, on each side, in the upper deciduous first molar position, for elastic traction. The appliance was cemented with glass ionomer cement, but if it later debonded, it was re-cemented with composite, following acid etching of the buccal and palatal cusps of the upper first permanent molars. For patients with posterior crossbites, the expansion screw was activated one quarter turn (0.25 mm) per day until the lingual cusps of the upper posterior teeth approximated the buccal cusps of the lower posterior teeth. If no transverse change was required, the maxillary splint was still activated once a day for 7–10 days in order to disrupt the circum-maxillary sutures. A commercially available adjustable facemask was used (TP Orthodontics), which had bilateral vertical rods connected to both chin and forehead pads. This design was adjustable vertically to customize the fit. If patients experienced chin reddening, ventilation holes were drilled through the plastic chin pad or soft padding was added. Elastics were connected bilaterally to the adjustable midline crossbow in a downwards and forwards direction. Patients were asked to wear the facemask for 14 hours per day, continuously, during the evening and night. A co-operation calendar was used in an attempt to increase treatment compliance, although this was not formally statistically evaluated. Extra-oral elastics of increasing strength were used (3/80 8 oz elastics for 1–2 weeks; then 1/20 14 oz elastics; then 5/160 14 oz elastics) until a force of 400 g per side was delivered. The direction of elastic traction was downwards and forwards 30 ° from the vestibular hooks on the bonded maxillary expander to the adjustable crossbar of the facemask. Additionally, the elastics could be crossed over to prevent catching or interference (n = 35)

Group 2: Control: Following collection of initial records the patients allocated to the control group received no clinical intervention. They were recalled 15 months after registration for collection of final records (n = 38)

Both groups were then recalled for follow-up at 3 years


OutcomesData were collected at the following time points:
DC1: baseline data at study registration
DC2: 15 months after baseline data collection

DC3: 3 years after baseline data collection

Cephalometric and occlusal measurements: The lateral cephalograms were traced by an experienced clinician who was blinded as to group allocation. To determine the rotations of the maxillary and occlusal planes superimposition of the DC1, DC2 and DC3 lateral cephalometric radiographs was undertaken by another author using Bjork's structural method which employs the anterior zygomatic process as the reference landmark. PAR scores were measured by a calibrated examiner. Overjet measurements were recorded from study models, with a steel millimetre ruler, by an experienced examiner

Psychosocial measures: The short form of the Piers–Harris children's self concept scale (60 questions) (Piers 2002) was used to evaluate self concept. This may have been influenced by receiving early Class III treatment. Psychosocial/oral health related quality of life effects of treatment were assessed using the OASIS (Mandall 2000), which sums the impact of concern about appearance of teeth, including nice comments, unpleasant comments, teasing, avoidance of smiling, covering the mouth because of the teeth and self perceived aesthetic component of the Index of Orthodontic Treatment Need.

TMJ examination: All the orthodontists involved in the study received training from a TMJ specialist before the start of the study to ensure that the TMJ examination was standardized. This TMJ specialist also advised that an examination appropriate for this age group of children should assess pain (lateral and intra-auricular), clicking, crepitus, locking, muscle tenderness (temporalis, masseter, and lateral pterygoid), and restriction of jaw movement (maximum opening and lateral movement). In addition, the presence of forward mandibular displacement on closure was recorded. TMJ signs or symptoms were recorded at DC1 to ensure no patients might be treated with protraction facemask that may exacerbate any TMJ problems through potential downwards and backwards rotation at the chin point. No patients were excluded at baseline because of pre-existing TMJ signs or symptoms

Outcomes relevant to this review: Overjet, ANB, Piers-Harris score, OASIS score, TMJ outcomes


NotesSample size calculation estimated that 23 children per group would give 90% power to detect a PAR reduction of 25% with a 0.05 2-sided significance level


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low riskThe randomisation list was generated in randomisation blocks of 10 with stratification according to gender. Stratification meant that a separate randomisation list was generated for girls and boys, since gender was considered to be a potential confounding factor. This was because girls and boys will grow at different times during the study and, thus, potentially confound Class III skeletal measurements

Allocation concealment (selection bias)Low riskThe computer generated randomisation sequence was concealed centrally and each clinician telephoned a research assistant to receive the treatment allocation after each patient was registered

Blinding of outcome assessment (detection bias)
All outcomes
Low riskThe lateral cephalograms were traced by an experienced clinician who was blinded as to group allocation

It was not possible to blind the clinician or the patient in this study. However, the study was single-blind, as the researchers measuring the radiographs and study models and the statistician were blinded to the treatment/control allocation until the data were analysed and the code broken. Ideally the clinician collecting the records at the 15-month DC2 time point would have also been blinded as to group allocation. However, this was not attempted, because with only 1 operator was involved at each centre they would have had the patient's notes in front of them at the time of data collection. Also, it was likely that the clinicians would have remembered who had received protraction facemask treatment

Incomplete outcome data (attrition bias)
All outcomes
Low risk2 patients were lost to follow-up in each group, and excluded from the analysis. This is unlikely to have introduced bias

Selective reporting (reporting bias)Low riskCephalometric and occlusal measurements, psychosocial measures and TMJ examination results were planned and reported

Other biasLow riskSome patients included in this study had a centric relation to centric occlusion displacement. This may have influenced the perception of the skeletal discrepancy from the lateral cephalogram, but we consider the resulting risk of bias to be minimal

Vaughn 2005

Methods3-arm parallel randomised controlled trial


ParticipantsNumber recruited: 46 patients (24 male and 22 female)

Mean age: 7.33 years (range not given)

Inclusion criteria: 0 or negative overjet on 2 or more incisors, Class III molar relationship with the mesiobuccal cusp of the maxillary permanent first molar distal to the buccal groove of the mandibular first permanent molar, or a mesial step terminal plane relationship of 3.0 mm or more if the deciduous molars were present (measured clinically). When the clinical or dental criteria were borderline, cephalometric criteria of ANB angle of 0 ° or less, Wits analysis of 3 mm or more, and nasion perpendicular to A-point of 2 mm or less

Exclusion criteria: Any craniofacial anomaly, psychosocial impairment or skeletal open bite

Setting: University hospital in USA


InterventionsComparison: Facemask with expansion versus facemask only versus untreated control

Group 1: Facemask with expansion group: Treated with palatal expansion with facemask therapy. A banded, soldered, jackscrew palatal expansion appliance was used for each subject. 2 teeth per side were banded: the first and second deciduous molars, the first permanent molar and the second deciduous molar, or the first permanent molar and premolar. The appliance was activated twice daily (0.5 mm/day) for a minimum of 7 days. Soldered hooks (.045 in) were extended to the mesial of the canine for attachment of the force-delivering elastics. Each facemask was fabricated on a model made from an impression of the patient's face. The facemask was fitted 7 to 10 days after the placement of the palatal appliance. Elastics, directed 15 ° to 30 ° downward from the occlusal plane, delivered a force of 300 to 500 g per side, as determined by a force gauge. The participants were instructed to wear the appliance full time at the beginning of treatment. Compliance was closely monitored with timecards. Once positive overjet and overbite and Class I molar occlusion were obtained, facemask wear was reduced to 14 hours a day. In anticipation of some relapse, over correction, approaching an end-to-end molar relationship and overjet of 4 to 5 mm, were the treatment objectives. The treatment results were maintained for 3 to 6 months with nighttime wear (n = 15)

Group 2: Facemask only group: The protocol in group 2 was identical to that for group 1 except that the palatal expander was not activated. If patients required transverse expansion, this was performed after final records (T2) were obtained (n = 14)

Group 3: Control group: Initial records (T0) were taken at enrolment and 1 year later (n = 17)


OutcomesLateral cephalometric radiographs were taken at T0, T1, and T2 for the control group, and at T1 and T2 for the 2 treatment groups. 55 standard cephalometric landmarks were digitised in a pre-determined order with a digitiser accurate to 0.001 mm. Traditional cephalometric measurements were used to describe changes between pre-treatment, post-treatment, and control lateral cephalograms. Measurements included a combination of the Steiner, McNamara, Ricketts, Riedel, and Wits analyses. Changes in 55 landmarks were also evaluated relative to an x-y coordinate system. The Johnston analysis also was used to differentiate between skeletal and dental changes and to provide a method to evaluate the combined treatment effects (skeletal and dental) along the mean functional occlusal plane

Outcomes of relevance to the review: ANB, Wits


NotesNo sample size calculations reported, and study likely to be under powered to detect a difference between groups 1 and 2


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Low riskQuote: "We used a block randomisation table to assign the subjects to 1 of 3 groups after obtaining proper informed consent"

Allocation concealment (selection bias)Unclear riskThere was no method of allocation concealment. Attempts were made to contact the authors for clarification but we are yet to receive a response

Blinding of outcome assessment (detection bias)
All outcomes
Low riskThe principal investigator (GAV) was blinded to the assignment

Incomplete outcome data (attrition bias)
All outcomes
Unclear riskNumber of drop-outs was not clear in the text. Attempts were made to contact the authors for clarification but we are yet to receive a response

Selective reporting (reporting bias)Low riskAll cephalometric measures recorded and reported as intended

Other biasLow riskNone detectable

Xu 2001

Methods2-arm parallel randomised controlled trial


ParticipantsNumber recruited: 60 patients (27 male and 33 female)

Mean age: 9.3 years. Range 8 to 11 years

Inclusion criteria: Children with skeletal anterior crossbite and abnormal facial morphology

Exclusion criteria: Tooth or functional Class III patients. This lead to the exclusion of 20 of the 60 patients leaving 40 to be randomised

Setting: University hospital in China


InterventionsComparison: Facemask versus untreated control

Group 1: A jackscrew rapid palatal expander welding with the bands of maxillary first molar and first premolar was attached to the patient's posterior teeth. The protraction hook was located in the position of maxillary canines. After the first week of expander placement, the expander was activated with 90 ° winding each time twice per day. After 2 weeks, active expansion treatment was stopped and the maxillary protraction started. The protraction treatment used a force of 400-500 g lasted 12 hours per day (n = 20)

Group 2: Observation only (n = 20) 

Duration of treatment: 11-13 months (mean 11.3 months)


OutcomesLateral cephalometric films taken at baseline and 11-13 months (right after the treatment), on which 9 linear and 6 angular measurements were made

Outcomes relevant to this review: ANB


NotesSample size calculation not described


Risk of bias

BiasAuthors' judgementSupport for judgement

Random sequence generation (selection bias)Unclear riskThe article states "the children were randomly divided into two groups" but no further details were given. Attempts were made to contact the authors for clarification but we are yet to receive a response

Allocation concealment (selection bias)Unclear riskThe method of allocation concealment was not described. Attempts were made to contact the authors for clarification but we are yet to receive a response

Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskThere was no mention of blinding of the assessor. Attempts were made to contact the authors for clarification but we are yet to receive a response

Incomplete outcome data (attrition bias)
All outcomes
Low riskAll the participants with skeletal Class III were assessed

Selective reporting (reporting bias)Low riskAll measures targeted were reported

Other biasLow riskNo other sources of bias identified

 
Characteristics of excluded studies [ordered by study ID]

StudyReason for exclusion

Altug 1989Retrospective control group therefore not a prospective RCT

Arman 2004Retrospective control group therefore not a prospective RCT

Arman 2006Retrospective control group therefore not a prospective RCT

Baik 1995Retrospective control group therefore not a prospective RCT (author contacted)

Barrett 2010Retrospective control group therefore not a prospective RCT

Biren 1993Not RCT

Cozza 2004Not RCT

El 2010Analysed condylar position during treatment, not an outcome of interest to this review

Gokalp 2010Not RCT

Goyenc 2004Not RCT

Isci 2010Not RCT

Jamilian 2011Not RCT

Kurt 2011Not RCT

Mucedero 2007Not RCT

Pavoni 2009Not RCT

Sar 2011Not RCT

Tortop 2007Retrospective control group therefore not a prospective RCT

Ucem 2004Not RCT

Ulgen 1994Not RCT (contact with author)

Wilmes 2009Patients over 16

Yagci 2010Not RCT

Yagci 2011Retrospective

 
Comparison 1. Facemask versus untreated control (combined facemask groups)

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Overjet1Mean Difference (IV, Fixed, 95% CI)Subtotals only

    1.1 1 year follow-up
169Mean Difference (IV, Fixed, 95% CI)4.10 [3.04, 5.16]

    1.2 3-year follow-up
163Mean Difference (IV, Fixed, 95% CI)2.5 [1.21, 3.79]

 2 ANB3Mean Difference (IV, Fixed, 95% CI)Subtotals only

    2.1 1 year follow-up
3155Mean Difference (IV, Fixed, 95% CI)3.93 [3.46, 4.39]

    2.2 3-year follow-up
163Mean Difference (IV, Fixed, 95% CI)1.4 [0.43, 2.37]

 3 Piers-Harris self concept1Mean Difference (IV, Fixed, 95% CI)Subtotals only

    3.1 1 year follow-up
169Mean Difference (IV, Fixed, 95% CI)1.5 [-0.96, 3.96]

    3.2 3-year follow-up
163Mean Difference (IV, Fixed, 95% CI)0.6 [-2.57, 3.77]

 4 OASIS1Mean Difference (IV, Fixed, 95% CI)Subtotals only

    4.1 1 year follow-up
169Mean Difference (IV, Fixed, 95% CI)-4.0 [-7.40, -0.60]

    4.2 3-year follow-up
163Mean Difference (IV, Fixed, 95% CI)-3.40 [-7.99, 1.19]

 5 Wits146Mean Difference (IV, Fixed, 95% CI)-3.84 [-5.31, -2.37]

 
Comparison 2. Facemask with expansion versus facemask only

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 ANB129Mean Difference (IV, Fixed, 95% CI)-0.13 [-1.40, 1.14]

 2 Wits129Mean Difference (IV, Fixed, 95% CI)-0.16 [-1.63, 1.31]

 
Comparison 3. Nanda facemask versus conventional facemask

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 ANB120Mean Difference (IV, Fixed, 95% CI)1.29 [0.16, 2.42]

 
Comparison 4. Chin cup versus untreated control

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 ANB [Degrees]150Mean Difference (IV, Fixed, 95% CI)1.96 [1.58, 2.34]

 2 Wits [mm]150Mean Difference (IV, Fixed, 95% CI)4.94 [4.45, 5.42]

 
Comparison 5. 600 g chin cup versus 300 g chin cup

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 ANB140Mean Difference (IV, Fixed, 95% CI)0.10 [-0.31, 0.51]

 2 Wits140Mean Difference (IV, Fixed, 95% CI)-0.30 [-1.12, 0.52]

 
Comparison 6. Tandem traction bow appliance versus untreated control

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Overjet130Mean Difference (IV, Fixed, 95% CI)3.30 [2.46, 4.14]

 2 ANB130Mean Difference (IV, Fixed, 95% CI)1.7 [1.09, 2.31]

 
Comparison 7. Mandibular headgear versus chin cup

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 ANBOther dataNo numeric data

 
Analysis 7.1 Comparison 7 Mandibular headgear versus chin cup, Outcome 1 ANB.
ANB

StudyMandibular meanChin cup meanControl meanMann-Whitney P value mandibular versus controlMann-Whitney P value chin cup versus control

Arun 19941.01.2-0.5<0.001<0.001

 
Summary of findings for the main comparison. Facemask compared to no treatment for prominent lower front teeth in children

Facemask compared to no treatment for prominent lower front teeth in children

Patient or population: children with prominent lower front teeth
Settings: dental hospital
Intervention: facemask
Comparison: no treatment

OutcomesIllustrative comparative risks* (95% CI)Relative effect
(95% CI)
No of participants
(studies)
Quality of the evidence
(GRADE)
Comments

Assumed riskCorresponding risk

No treatmentFacemask

Overjet - 1 year treatment
Follow-up: at end of treatment
The mean overjet - 1 year follow-up in the intervention groups was
4.1 higher
(3.04 to 5.16 higher)
69
(1 study)
⊕⊕⊕⊝
moderate1

Overjet - 1 year treatment
Follow-up: mean 2 years post-treatment
The mean overjet - 3-year follow-up in the intervention groups was
2.5 higher
(1.21 to 3.79 higher)
63
(1 study)
⊕⊕⊕⊝
moderate1

ANB - 1 year follow-up
Follow-up: mean 1 year
The mean ANB - 1 year follow-up in the intervention groups was
3.93 higher
(3.46 to 4.39 higher)
155
(3 studies)
⊕⊕⊝⊝
low2,3

ANB - 3-year follow-upThe mean ANB - 3-year follow-up in the intervention groups was
1.4 higher
(0.43 to 2.37 higher)
63
(1)
⊕⊕⊕⊝
moderate1

*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: confidence interval.

GRADE Working Group grades of evidence.
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

 1 Downgraded because only one study with this comparison reported overjet.
2 Downgraded because one study at low risk of bias, and two at unclear risk of bias.
3 Downgraded due to heterogeneity: Chi2 = 11.29, degrees of freedom (df) = 2 (P value = 0.004); I2 = 82%
 
Summary of findings 2. Chin cup compared to no treatment for prominent lower front teeth in children

Chin cup compared to no treatment for prominent lower front teeth in children

Patient or population: children with prominent lower front teeth
Settings: dental hospital
Intervention: chin cup (300 g, 600 g or 480 to 500 g)
Comparison: no treatment

OutcomesIllustrative comparative risks* (95% CI)Relative effect
(95% CI)
No of participants
(studies)
Quality of the evidence
(GRADE)
Comments

Assumed riskCorresponding risk

No treatmentChin cup

Chin cup

ANB
Follow-up: mean 1 year
No treatmentSee comment901
(2 studies)
⊕⊝⊝⊝
very low
2 studies: Unable to pool data, however, a statistically significant benefit was found for ANB. Insufficient evidence from 2 studies at high risk of bias to determine whether or not chin cup is an effective treatment

*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: confidence interval.

GRADE Working Group grades of evidence.
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

 1 Downgraded because both studies were at high risk of bias with only one study providing outcome data.
 
Summary of findings 3. Tandem traction bow appliance compared to no treatment for prominent lower front teeth in children

Tandem traction bow appliance compared to no treatment for prominent lower front teeth in children

Patient or population: children with prominent lower front teeth
Settings: dental hospital
Intervention: Tandem traction bow appliance
Comparison: control

OutcomesIllustrative comparative risks* (95% CI)Relative effect
(95% CI)
No of participants
(studies)
Quality of the evidence
(GRADE)
Comments

Assumed riskCorresponding risk

No TreatmentTandem traction bow appliance

Overjet at end of 1 year of treatmentThe mean overjet in the intervention groups was
3.3 higher
(2.46 to 4.14 higher)
301
(1 study)
⊕⊝⊝⊝
very low
Insufficient evidence from a single study at high risk of bias to determine whether or not tandem traction bow is an effective treatment

ANB at end of 1 year of treatmentThe mean ANB in the intervention groups was
1.7 higher
(1.09 to 2.31 higher)
301
(1 study)
⊕⊝⊝⊝
very low
Insufficient evidence from a single study at high risk of bias to determine whether or not tandem traction bow is an effective treatment

*The basis for the assumed risk (e.g. the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: confidence interval.

GRADE Working Group grades of evidence.
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

 1 Downgraded because only one small study at high risk of bias reported this outcome.
 
Table 1. Data for comparisons with single study

ComparisonOutcomeStudyEffect measureP value

Facemask versus controlOverjet (post-treatment)Mandall 20104.10 mm (95% CI 3.04 to 5.16)< 0.0001

Overjet (3 years follow-up)Mandall 20102.50 mm (95% CI 1.21 to 3.79)0.0001

Piers-Harris (post-treatment)Mandall 20101.50 (95% CI -0.96 to 3.96)0.23

Piers-Harris (3 years follow-up)Mandall 20100.60 (95% CI -2.57 to 3.77)0.71

OASIS (post-treatment)Mandall 2010-4.00 (95% CI -7.40 to -0.60)0.02

OASIS (3 years follow-up)Mandall 2010-3.40 (95% CI -7.99 to 1.19)0.15

Facemask with expansion versus facemask onlyANBVaughn 2005-0.13 ° (95% CI -1.40 to 1.14)0.84

 WitsVaughn 2005-0.16 mm (95% CI -1.63 to 1.31)0.83

Nanda facemask versus conventional facemaskANBKeles 20021.29 ° (95% CI 0.16 to 2.42)0.02

Chin cup versus controlANBAbdelnaby 20101.96 ° (95% CI 1.58 to 2.34)< 0.00001

WitsAbdelnaby 20104.94 mm (95% CI 4.45 to 5.42)< 0.00001

600 g chin cup versus 300 g chin cupANBAbdelnaby 20100.10 ° (95% CI -0.31 to 0.51)0.63

 WitsAbdelnaby 2010-0.30 mm (95% CI -1.12 to 0.52)0.47

Tandem traction bow appliance versus controlOverjetAtalay 20103.30 mm (95% CI 2.46 to 4.14)< 0.0001

 ANBAtalay 20101.70 ° (95% CI 1.09 to 2.31)< 0.0001

 CI = confidence interval.