Abstract Introduction The present study analysed the tooth movement patterns and stress distribution in patients presenting with anterior alveolar bone loss, associated with the use of force vectors applied from a mini-screw to distalise the mandibular dentition. Methods Mandibular anterior teeth characterised by alveolar bone loss (zero, one third, one half of the root length) were constructed from a cone-beam computed tomography image, and a mini-screw was inserted into the mandibular buccal shelf. A distalising force of 2 N was applied from the mini-screw to three different lengths of an anterior retraction hook: 2, 7, and 12 mm. The tooth displacement and von Mises stress distribution in the periodontal ligament (PDL) were calculated via a finite element analysis. Results In all the models, significant movement was found around the anterior segment, and the stress was primarily concentrated at the cervical margin and apical area of the lateral incisor and canine teeth. With absorption of the anterior alveolar bone, extrusive lingual inclination of the anterior teeth, intrusive distal tipping of the posterior teeth and stress concentration in the PDL increased. Long retraction hooks led to lingual root and intrusive crown movement of the incisors and reduced uncontrolled distal tipping movement of the posterior teeth but also increased the range and magnitude of stress in the PDL of the anterior teeth. Conclusion During the distalisation of the mandibular dentition associated with anterior alveolar bone horizontal resorption, different retraction hook heights may be selected to control the movement of the teeth. Special consideration should be given to stress in the PDL of the mandibular incisors.

Abstract Objectives To investigate the debonding protocols used by orthodontists in New Zealand. Materials and methods A pilot-tested electronic questionnaire was distributed to all full members of the New Zealand Association of Orthodontists (NZAO). The survey consisted of 12 questions which collected demographic information and details of the debonding protocols practiced by the orthodontists. Results The response rate to the survey was 56.6% (n=60 respondents). Most NZ orthodontists (80.0%, n=48) preferred the use of debonding pliers to remove orthodontic brackets. A total of 23 different methods were identified for the subsequent removal of residual adhesive of which a low-speed tungsten carbide bur was the most popular tool (83.3%, n=50). The majority of the NZ orthodontists (96.7%, n=58) performed polishing after the removal of residual adhesive. About 80% (n=47) of the NZ orthodontists reported iatrogenic damage to the enamel following debonding. Almost all NZ orthodontists (98.3%, n=59) were satisfied with their debonding protocol. Conclusion Orthodontists in New Zealand use different debonding protocols, of which the most common was the use of debonding pliers combined with a low-speed tungsten carbide bur without irrigation, followed by additional polishing using pumice and a rubber cup. The commonly-used debonding protocol may not necessarily be the most appropriate approach based on current best evidence. Orthodontists should maintain a critical stance and consistently re-assess the literature to evaluate the appropriateness of their debonding protocol.

Abstract Lingual orthodontic treatment offers an aesthetic alternative but presents unique challenges in bracket positioning. The present article introduces a modified design and fabrication process for rigid vacuum-formed indirect bonding trays for lingual bracket application. The technique is presented through a clinical case report of an adult patient who presented with bimaxillary dentoalveolar protrusion and managed using lingual appliances, premolar extractions, and mini-screws. The modified rigid vacuum-formed trays enabled the accurate simultaneous bonding of multiple teeth as well as individual teeth. The technique offers several advantages over existing indirect bonding methods, including time-saving, simplicity, easy removal of excessive adhesive, and potential cost-effectiveness. The superimposition of post-bonding scans and the digital orthodontic setup showed high agreement between the planned and actual bracket positions. Additionally, the close alignment between the planned orthodontic setup and the achieved treatment outcome highlights the reliability of the technique for predictable lingual orthodontic treatment. Further clinical studies with larger sample sizes are needed to confirm the effectiveness of this technique.

Abstract Objective To evaluate the accuracy of the Invisalign appliance in correcting an anterior deep bite in adults and to compare different mechanisms of bite opening. Materials and methods This retrospective study included 25 patients (mean age 32.28 years) who presented with a moderate overbite (Group 1, with an overbite ranging from 3.5 mm to 5 mm) or a severe overbite (Group 2, with an overbite ≥ 5 mm), treated by the same operator using the Invisalign appliance. Digital models generated for the ClinCheck process were analysed at the initial (T0), planned (ST1), and clinically achieved (ET1) stages using Geomagic Control X software (3D Systems, Rock Hill, SC, USA) to measure overbite correction. The accuracy and mechanisms of deep bite correction (proclination and intrusion of the incisors, posterior tooth extrusion) were assessed. Statistical analysis was performed using R 4.1.2 (R Foundation for Statistical Computing, Vienna, Austria). Results Significant differences were found between the ST1 and ET1 stages of overbite correction in both groups (P < 0.01). Group 1 showed the highest mean accuracy (51.35%) with a mean difference of 1.15 mm between ST1 and ET1. Group 2 had the lowest mean accuracy (41.56%) with a mean difference of 2.11 mm. No significant differences in mean accuracy were found between the groups or between the mechanisms of overbite correction (P > 0.05). Conclusion The Invisalign appliance shows significant inaccuracy between the ClinCheck simulation and the clinical outcome in correcting moderate and severe deep bites in adults. There was similar predictability between the different bite opening mechanisms.

Abstract Background Clear aligner treatments have gained popularity due to their aesthetic advantages over traditional metal brackets. Attachments play a crucial role in enhancing the efficacy of treatment by addressing challenges posed by the flexibility of aligner materials. This comprehensive review aims to clarify the significance of attachments used during clear aligner therapy and explore the nuances of their design, placement, and material selection. Methods A systematic search of literature databases including Web of Science, PubMed, Scopus, Google Scholar, and Cochrane was conducted. Twelve sets of keywords related to clear aligner therapy and attachments were applied for the search. Results A total of 24 studies that met the inclusion criteria and focused on the biomechanics of attachments, attachment shape, attachment placement and materials used in attachment production were included in the analysis. Conclusions Within the limits of the review, the use of attachments in clear aligner therapy can enhance the efficacy of treatment by facilitating complex tooth movements. The selection of materials, as well as the design and positioning strategies of attachments, should be customised for each patient to optimise treatment success. By the use of clinical studies, future research should focus on the long-term performance of attachments to confirm their effectiveness in achieving planned tooth movements, particularly regarding design, positioning, and the materials used.

Abstract Introduction The purpose of this study was to compare the mechanical changes of clear aligners manufactured using either the direct method (Graphy Tc-85) or the indirect method (CA Pro or Invisalign) following an exposure to different liquids. Material and Method The clear aligners were produced using a single patient’s digital maxillary model. CA Pro aligners were produced indirectly using the Ministar S device, while Graphy Tc-85 resin aligners were produced directly using a three-dimensional printer (Ackuretta, Taipei, Taiwan). Invisalign appliances were produced by Align Technology, Inc. The appliances were randomly divided into seven groups: a control group and six experimental groups. The control group appliances were not immersed in any liquid. The appliances in the experimental groups were immersed in six different liquids (orange juice, soy sauce, cola, red wine, tea, and coffee) for 24 hr at 37°C. Following immersion, the upper right first molar section of each appliance was separated using an abrasive disc and embedded in a 2 mm thick acrylic layer. A cyclic loading test was conducted using a specialised mechanism (a combination of a dynamometer and a deformation depth measuring instrument) and each sample was subjected to varying cyclical forces until a deformation depth of 1 mm was reached. The force magnitude required to achieve the 1 mm material deformation at the 1st, 5th, 10th, and 50th cycles of loading was recorded for each sample. Results As a result of repeated loads, the indenting force values decreased in the three sample groups, regardless of the liquid in which the appliances had been stored. However, soy sauce and orange juice had a greater detrimental effect on the mechanical properties of the aligners compared to the other liquids. On comparing the force values required for the material to reach a 1 mm depth during the 1st and 50th loadings, the decreases were recorded as 0.4% for Graphy Tc-85, 26.3% for CA Pro, and 42.1% for Invisalign. Conclusions Of the tested aligners, Graphy Tc-85 was the most resistant to repetitive loads, while Invisalign was the least resistant. It is inherently difficult to predict how different liquids will affect aligners made of different materials.

Abstract Objectives To investigate orthodontic bond failure rates and the associated effectiveness of pumice prophylaxis as a preparatory step before applying self-etching primers (SEP). Methods Twenty participants with an average age of 23.9 years ± 5.13, were included in the trial. A total of 320 teeth were randomly assigned, using block randomisation in a 1:1 ratio (block of four), to either pumiced (n=160) or non-pumiced (n=160) quadrants. After preparation using SEP, the teeth were bonded with stainless steel brackets and monitored for bracket failure until a one-month period in a 0.019˝ × 0.025˝ stainless steel arch wire. Results The Fisher’s Exact Test and Chi-Square tests showed an overall bracket failure rate of 4.4%, with 1.8% in the pumiced and 2.5% in the non-pumiced group. The majority of bracket failures occurred on the 0.014˝ nickel titanium arch wire (71.4%) and an associated ARI score of one (57.1%). No significant difference was found in bracket failure rates between both groups related to the location, arch, ARI score or arch wire type (P>0.05). Conclusions Omitting pumice prophylaxis before applying SEP in orthodontic bonding does not lead to a higher bond failure rate, and factors like location, arch, ARI score, and arch wire type did not influence bracket failure in either group.

Abstract Introduction The purpose of this cross-sectional study was to survey the perception and attitude of Australian orthodontists toward accelerated orthodontic treatments. Methods An online questionnaire was distributed to 427 members of the Australian Society of Orthodontists. The questions related to: clinic demographics, familiarity with appliances/procedures to accelerate orthodontic treatment, the use of appliances/procedures to accelerate orthodontic treatment, and satisfaction with the outcomes when employing these appliances/procedures. Results The response rate was 42.38%. Of the respondents, 26.6% used customised fixed appliances which provided satisfactory outcomes. A small proportion of the respondents routinely used adjunctive procedures to accelerate treatment: 3.5% (n=6) corticotomies, 1.2% (n=2) piezocision, and 1.2% (n=2) intraoral vibrating devices. Conclusion Although a significant number of Australian orthodontists use customised fixed appliances to improve the efficiency of orthodontic treatment, the use of adjunctive procedures to accelerate tooth movement remains very low. Further research is needed to understand the possible limitations and restrictions surrounding this area of practice.

Abstract Objective This study aimed to describe orthodontic treatment patterns of children in Australia. Methods Using data from the 2012-2014 National Child Oral Health Study (NCOHS), a cross-sectional survey representative of children in Australia aged 5 to 14 years involving parental-completed questionnaires, standardised oral examinations and malocclusion severity assessment, the present study examined: sociodemographic characteristics, types and providers of orthodontic treatment, extraction rates, treatment need levels and orthodontic service access. Results Adolescents (31.7%), children from higher-income households (22.0%), and those with handicapping malocclusions (46.6%) accessed services more than their counterparts. Of those who had ever accessed services, pre-adolescents mostly had a consultation only (46.5%) and were predominantly treated using removable appliances (25.1%). Adolescents mostly had fixed appliances (38.0%). Extractions were involved in 31.0% of fixed appliance treatments. Private orthodontists provided the majority of treatment services (80.6%). There were greater numbers of higher-severity malocclusions affecting males, indigenous children, and children from lower-income households compared with their counterparts. In those with higher-severity malocclusions, males, children with high-school-only-educated parents, and children from lower-income households accessed services less than their counterparts. Conclusions The present study provides baseline information for Australian orthodontic services. Disparities in malocclusion severity and service access were noted. Increased malocclusion severity did not necessarily increase the likelihood of accessing services.

Abstract Background If detected at the appropriate age, a Class II malocclusion can be improved or camouflaged by utilising functional appliances to manipulate a child’s skeletal growth spurt to advantage. Aim The aim of this study was to evaluate the use of functional appliances by orthodontists currently practising in Australia. Methods This was a cross-sectional study design that utilised a nation-wide online survey consisting of 22 questions related to: clinic/clinician demographics, appliance preference and treatment timing, the provision of first phase functional appliance treatment and treatment protocols for removable functional appliance therapy. The survey was distributed via the Australian Society of Orthodontists to its 428 members. Statistical analysis was conducted through Qualtrics XM® data analysis software, version 04/30/2023 (Qualtrics XM®, Provo, UT, USA. https://www.qualtrics.com) with a significance level set at P < 0.05. Results A total of 166 responses were received representing a response rate of 38.8%. Ninety-nine per cent of survey respondents (n = 139) reported prescribing functional appliances to correct a Class II malocclusion with the Twin Block appliance as the most-commonly prescribed. It was found that a two phase, removable functional appliance followed by fixed appliances was the preferred choice for Class II treatment when utilising a functional appliance. The most common age to commence functional appliance therapy was between 10 and 12 years, incorporating 9 to 12 months of full-time wear, followed by a 4- to 6-month retention period. There appears to be a clear relationship between an orthodontist’s preferred choice of Class II treatment when employing functional appliances and their orthodontic training institution. Conclusion It is common practice for orthodontists in Australia, to utilise functional appliances in the management of a Class II malocclusion. However, the prescribing patterns for functional appliance therapy are not uniform. Variations appear evidenced-based depending on the practice location and the institution from which the orthodontist graduated.