- Journal Details
- First Published
- 01 May 1967
- Publication timeframe
- 1 time per year
- Open Access
Page range: 1 - 2
- Open Access
Page range: 3 - 13
Introduction: Incisal torque in orthodontics has always been important due to its relationship with smile aesthetics and the stability of a final treatment outcome. The aim of this study was to quantify the accuracy of torque expression predicted by ClinCheck® planning associated with Invisalign® treatment, compared to clinical outcomes.
Methodology: Forty adult patients consecutively treated using the Invisalign appliance were selected. Torque and the interincisal angle (IIA) were measured at T0 (pretreatment), T1 (predicted post-treatment), and R (end of initial aligner sequence) stages on STL files using metrology software (Geomagic Control X).
Results: The difference between the predicted and achieved torque (torque differential) was statistically significant (
Conclusions: Torque was under-expressed when the teeth were moving labially, and fully- or over-expressed when moved lingually, indicating Invisalign’s inefficiency in torqueing incisors in the labial direction.
- Open Access
Prevention of incipient carious lesions with various interventions during fixed and removable orthodontic treatment. A systematic review and meta-analysis
Page range: 14 - 30
Objective: To systematically review and quantify the effectiveness of interventions in reducing caries development during orthodontic treatment and evaluate the quality of evidence for the development of clinical guidelines.
Materials and methods: A comprehensive literature search of the Cochrane, EMBASE and MEDLINE databases was conducted to identify eligible randomised controlled trials (RCTs). The risk of bias was assessed using the Cochrane risk of bias (RoB 2) tool. In order to facilitate the development of clinical guidelines, the quality of the evidence was assessed using Grading of Recommendations, Assessment, Development and Evaluation (GRADE).
Results: A total of 18 RCTs were included in the qualitative synthesis, of which 10 had a high risk of bias, and eight had minor concerns. Three RCTs that investigated the efficacy of fluoride interventions during fixed orthodontic treatment were included in the quantitative synthesis. The pooled effect size resulted in a risk reduction of 0.23 (95% CI: -0.35, -0.11,
Conclusions: Although fluoride is the most effective evidence-based preventive intervention during orthodontic treatment, large RCTs are required to provide high quality evidence. Further studies are needed to evaluate the caries preventive effects of oral hygiene programs, chlorhexidine, CPP-ACP and other interventions.
- Open Access
Page range: 31 - 36
Objective: To evaluate the duration of combined orthodontic and orthognathic surgical cases treated either in the public or private health system in Western Australia.
Methods: The clinical records of 100 patients from the Orthodontics Department from the University of Western Australia Dental School and 100 patients from a private orthodontic practice in Perth, Australia who received combined surgical-orthodontic treatment were retrospectively assessed. Three statistical models were applied to explore the associations between treatment time (total, pre-surgery and post-surgery), clinical setting and extractions.
Results: Total treatment time was shorter in the private setting: 18.8 months for non-extraction and 22.0 months for extraction cases, and longer in the public university setting: 24.5 months for non-extraction and 27.7 months for extraction cases. Pre-surgical treatment time was shorter in the private setting: 13.1 months for non-extraction and 17.1 months for extraction cases, and longer in the public university setting: 17.1 months for non-extraction and 21.1 months for extraction cases. Post-surgical treatment time was shorter in the private setting: 5.5 months and longer in the public university setting: 7.1 months.
Conclusion: In a Western Australian health system, the treatment duration of combined orthodontic and orthognathic surgery cases is longer in the public university setting than in private practice.
- Open Access
Dental developmental stage affects the treatment outcome of maxillary protraction in skeletal Class III children: A systematic review and meta-analysis
Page range: 37 - 49
Background: The aim of this study was to investigate the effect of the stage of dental development on the treatment outcome of maxillary protraction in skeletal Class III children.
Materials and methods: The Medline, Web of Science, Embase, Cochrane Library, CMB and CNKI database were searched to identify all of the relevant articles published prior to 30 August 2019. The grey literature was also searched. Human controlled clinical trials in which patients with a skeletal Class III malocclusion were treated by maxillary protraction (facemask with or without rapid maxillary expansion) were considered. The quality of the included studies was assessed using ROBINS-I. Meta-analysis was performed using RevMan 5.3.
Results: A total of 19 trials were included in the systematic review and 16 trials were included in the meta-analysis, of which three studies were assessed as low risk of bias (high quality), eight were assessed as having a moderate risk of bias, and five were assessed as a high risk of bias. The treatment effect of maxillary protraction in skeletal Class III children was greater in the primary dentition than that in the early mixed dentition with respect to an increase in SNA, ANB and SN/GoGn. The treatment effect was greater in the early mixed dentition than in the late mixed dentition, with an evident decrease in SNB. The treatment effect was greater in the early mixed dentition than that which occurred in the early permanent dentition, with an increase in SNA and ANB. The treatment effect was not significantly different, either between the primary dentition and late mixed dentition, or between the late mixed dentition and early permanent dentition. No study compared the treatment effect between the primary dentition and early permanent dentition.
Conclusion: The dental developmental stage affects the treatment effect of maxillary protraction in skeletal Class III children. The treatment effect at an early dentition stage may be more effective than that at a late dentition stage in improving a skeletal Class III relationship. Although the variations in effectiveness between the various dental stage groups were generally statistically significant, most variations were small, with unclear clinical significance.
- Open Access
Mandibular effects of temporary anchorage devices in Class II patients treated with Forsus Fatigue Resistant Devices: A systematic review
Page range: 50 - 61
Objective: To determine whether temporary anchorage devices (TADs) could enhance the mandibular effects of Forsus Fatigue Resistant Devices (FFRD) in growing patients presenting with a Class II malocclusion.
Materials and methods: Without language restriction, electronic and manual searches were conducted through databases and relevant journals until the 20th February, 2020. Studies comparing the therapeutic effects in Class II patients treated with TA-anchored FFRD and patients receiving conventional FFRD were considered eligible. Two reviewers independently conducted the study inclusion, data extraction and risk of bias assessment following Cochrane guidelines. The outcomes were qualitatively synthesised and the level of evidence was evaluated using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) tool.
Results: Six studies meeting the selection criteria were identified. All except one reported that a greater reduction in the proclination of the mandibular incisors was achieved in TAD-anchored groups compared with the conventionally-treated groups. Controversial results were found in the skeletal and soft tissue descriptions of positional change. The evidence quality varied from very low to moderate.
Conclusion: Moderate-quality evidence suggests that TADs are beneficial in reducing the proclination of the mandibular incisors caused by FFRD in Class II patients. Controversies related to the effects on mandibular growth and soft tissue positional change remain. There is a trend that miniplates may enhance the mandibular skeletal effects of FFRD better than miniscrews but further investigation is indicated.
- Open Access
Page range: 62 - 68
Purpose: The objective of this study was to compare the shear bond strength (SBS) of ceramic orthodontic brackets bonded to highly translucent zirconia surfaces following the use of two different primers.
Materials and methods:<Three types of highly translucent zirconia crowns, Cercon xt ML, e.max ZirCAD, and STML-ML Katana Zirconia, were milled, sandblasted, and primed using two zirconia primers, Monobond Etch and Prime and Z-Prime Plus. A ceramic bracket (Radiance) was bonded onto the facial surface of each crown. Shear bond strength was evaluated using a universal testing machine.
Results: There was no significant overall difference across the six experimental groups regarding shear bond strength. The use of the two tested zirconia primers resulted in comparable and clinically acceptable shear bond strengths.
Conclusions: Both tested zirconia primers were associated with adequate bond strength when bonding a ceramic orthodontic bracket to the three highly translucent zirconia substrates.
- Open Access
The effectiveness of Hawley and vacuum-formed retainer usage protocols on the stability of fixed orthodontic treatment results
Page range: 69 - 78
Objectives: To compare the effectiveness of Hawley and vacuum-formed retainer (VFR) usage protocols on post-treatment stability.
Methods: The inclusion criteria included patients who initially presented with mild or moderate pretreatment crowding and a Class I or Class II malocclusion. The retention protocols were defined as Group 1: Hawley retainers, 12 months full-time wear; Group 2: Hawley retainers, six months full-time, six months night-only wear; Group 3: VFR, 12 months full-time wear; Group 4: VFR, six months full-time, six months night-only wear. Study models were taken prior to treatment (T0), after debonding (T1), six months after debonding (T2), and 12 months after debonding (T3). Little’s irregularity index, intercanine and intermolar widths, arch length, overjet and overbite were measured. Repeated measure ANOVA with one-fixed factor, one-way ANOVA, Kruskal Wallis or Welch’s heteroscedastic F-test, were applied.
Results: Fifty-eight patients were analysed at T2, and 52 patients at T3. There was no significant difference between the effectiveness of a Hawley appliance or VFRs on arch stability after six months. The intercanine width changes from the sixth to 12th month of retention showed a significant difference (
Conclusions: Different wearing regimens of a Hawley appliance or VFR retainers did not reveal any difference determined by Little’s irregularity index. Full-time usage of VFRs provided better intercanine width retention than night-only Hawley retainer wear in the maxillary arch.
- Open Access
Prevalence and pattern of permanent tooth agenesis among multiracial orthodontic patients in Malaysia
Page range: 79 - 84
Objective: To determine the prevalence and pattern of hypodontia among multiracial orthodontic patients in Malaysia.
Materials and methods: Digital panoramic radiographs of 813 patients were obtained from the records of the orthodontic clinic over five years (2014–2018). The presence of hypodontia was recorded and crosschecked with clinical notes. The association of gender and ethnicity was analysed using the Chi-squared test (
Results: The prevalence of hypodontia was 7.9%, with both mandibular and maxillary lateral incisors being most commonly and equally affected teeth at 17.9%. Three patients had up to five missing teeth. No severe hypodontia was recorded. The prevalence was highest among the Chinese (8.3%), followed by Malay (7.9%) and the Indian (6.3%) population. Gender and ethnicity were found not to be associated with hypodontia. The most common missing tooth for Malays was the mandibular central incisor, for the Chinese was the mandibular lateral incisor and for the Indian population was the mandibular second premolar.
Conclusion: The prevalence of hypodontia was 7.9%. The prevalence of hypodontia was 8.3% for the Chinese, 7.9% for Malay and 6.3% for the Indian population. The most common missing teeth were the mandibular and maxillary lateral incisors.
- Open Access
Page range: 85 - 92
Objective: The objective of the present study was to evaluate condylar, ramal and condylar+ramal mandibular vertical asymmetry in a group of patients with different vertical skeletal patterns.
Methods: Mandibular condylar and ramal measurements of 104 patients were performed on panoramic radiographic images and asymmetry indices were obtained according to the Habets’ formula. The study groups consisted of 35 hypodivergent, 34 normodivergent and 35 hyperdivergent patients. Data were statistically analysed by means of two-way ANOVA, Kruskal–Wallis and Pearson chi square tests.
Results: Ramal height was significantly higher in the hypodivergent group (
Conclusion: Condylar asymmetry values were found to be higher than a 3% threshold value in all groups, but no significant differences were observed between the groups. The effect of the vertical skeletal pattern on vertical mandibular asymmetry was found to be insignificant.
- Open Access
Evaluation of the trabecular structure of the mandibular condyles by fractal analysis in patients with different dentofacial skeletal patterns
Page range: 93 - 99
Objective: An orthodontic malocclusion may affect the temporomandibular joint structures in susceptible individuals. This study aims to investigate the bone density of the mandibular condyles in patients presenting with different dentofacial skeletal patterns.
Methods: Panoramic radiographs of 200 randomly selected patients with a skeletal and dental Class I, Class II division 1, Class II division 2 and Class III malocclusion were evaluated. Bone density of the right and left mandibular condyles was measured using fractal analysis.
Results: No significant difference was detected between the right and left condyles in the various malocclusion groups. However, post-hoc tests showed that Class I patients had significantly higher FD values than Class III and Class II division 1 patients in both right and left condyles following intergroup comparisons. The only significant difference between the genders was detected in the left condyle of Class II division 1 patients, as male patients were found to have significantly higher FD values than females.
Conclusions: The results of the present study showed that Class II division 1 and Class III patients displayed significantly lower fractal dimension (FD) values in their mandibular condyles when compared to Class I patients. This might be associated with the possible presence of a temporomandibular disorder in Class II division I patients which resulted in changes to condylar structure, and with less bone complexity in the temporomandibular joint of older Class III patients likely due to continued condylar growth.
- Open Access
The application of 3D metrology software in the quantitative and qualitative assessment of aligner treatment outcomes
Page range: 100 - 108
3D metrology software (Geomagic® Control X™) can be used in orthodontic treatment to significantly improve the analysis of achieved tooth movements compared with those predicted by treatment planning software, such as ClinCheck® software (Align Technology®). The applications of this technology enable clinicians to present more accurate and detailed case presentations and analyse their treatment outcomes. Additionally, information presented may further aid clinicians in interpreting and understanding metrology-derived information, in the form of digital heat maps, when incorporated into case presentations and scientific articles.
- Open Access
Accuracy of predicted versus achieved aligner treatment outcome of a complex case using digital heatmaps
Page range: 109 - 120
A female patient, aged 15 years and 4 months at the commencement of treatment, presented with a mild Class III malocclusion, an anterior open bite and crowded, lingually collapsed arches. Non-surgical treatment was undertaken utilising the extraction of a lower incisor and clear aligners to control the vertical dimension, extrude the incisors and resolve the crowding. The case was completed in 21 months. Favourable occlusal and facial/aesthetic outcomes were obtained. A unique feature of this case report was that digital files of the prescribed and achieved outcomes were available for superimposition, and so it was possible to demonstrate the level to which the clinical outcome matched the virtual prescribed plan designated in the ClinCheck® software.
- Open Access
Orthodontic treatment of a case with a congenitally missing maxillary canine and a malformed contralateral canine
Page range: 121 - 127
Excluding third molars, the prevalence of tooth agenesis of permanent teeth ranges from 1.6% to 9.6%. The congenital absence of maxillary permanent canines is a rare condition with a reported prevalence of less than 0.5%. Case reports describing congenitally missing permanent canines are uncommon, and those that involve treatment are even more rare.
This case report describes the orthodontic treatment of a 12-year-old male patient who presented with a congenitally missing upper left permanent canine compounded by a malformed upper right permanent canine. Additionally, the patient had a retained upper left deciduous canine, a Class I molar relationship, an anterior open bite, and proclined and protruded incisors.
Treatment involved upper left first premolar substitution for the congenitally missing canine following the extraction of the upper left retained deciduous canine, the upper right first premolar, and both lower first premolars. The upper right malformed permanent canine was retained. The total treatment time was 32 months and the result remained stable 19 months later.
- Open Access
Page range: 128 - 138
Purpose and methods: The distalisation of molars using clear aligners has been found to be achievable; however, the distalisation of an entire arch is still an orthodontic challenge and reported as only clinically possible using fixed appliances. To date, there has been no study on the distalisation of both dental arches using a clear aligner system. In the present report, a case is described in which the entire maxillary and mandibular arches were successfully distalised using clear aligners and miniscrews for the treatment of a bimaxillary protrusion malocclusion in a 22-year-old female patient. Pre- and post-treatment records as well as 1.5-year follow-up records are presented.
Results: The distalisation of both dental arches was achieved using a V-pattern staging process by moving the second molars, then the first molars, followed by the premolars and the anterior teeth, as well as by elastics applied between precision cutouts in the aligners and the miniscrews. The dental arches were efficiently distalised by approximately 3 millimeters in the first molar areas after 13 months of treatment. A review 1.5 years post-treatment showed that the outcome was stable without significant relapse observed in the facial profile and occlusion.
Conclusion: The distalisation of both dental arches is achievable using clear aligner systems by applying elastics between miniscrews and precision aligner cutouts in the treatment of a bimaxillary protrusion malocclusion.
- Open Access
Page range: 140 - 146