The effectiveness of bone anchored maxillary protraction (BAMP) in the management of class III skeletal malocclusion in children aged 11-14 years compared with an untreated control group: A multicentre two-arm parallel randomised controlled trial.

OBJECTIVE: To evaluate the effectiveness of bone anchored maxillary protraction (BAMP) in the management of class III skeletal malocclusion in children aged 11-14 years compared with an untreated control group in terms of perceived need for orthognathic surgery, skeletal and dental change, and psychological impact. DESIGN: A multicentre two-armed parallel randomised controlled trial. SETTING: Six UK hospital orthodontic units. METHODS: A total of 57 patients were randomly allocated into either the BAMP group (BAMPG) (n = 28) or a no treatment control group (CG) (n = 29). OUTCOMES: Data collection occurred at registration (DC1),18 months (DC2) and 3 years (DC3), where skeletal and dental changes were measured from lateral cephalograms and study models. Oral Aesthetic Subjective Impact Score (OASIS) and Oral Quality of Life (OHQOL) questionnaires were used to assess the psychological impact of treatment. RESULTS: The mean age was 12.9 ± 0.7 years and 12.6 ± 0.9 years in the BAMPG and CG, respectively. At DC2, the BAMPG achieved a class III ANB improvement of +0.6° compared with -0.7° in the CG (P = 0.004). The overjet improvement was +1.4 mm for the BAMPG and -0.2 mm for the CG (P = 0.002). There was no evidence of any other group differences for the other skeletal or dental cephalometric outcomes (P > 0.05) or the questionnaire data (OASIS P = 0.10, OHQOL P = 0.75). At DC2, the 18-month follow-up, 22% of the BAMPG achieved a positive overjet. At the 3-year follow-up (DC3), fewer patients in the BAMPG were perceived to need orthognathic surgery (48%) compared with 75% of patients in the CG (P = 0.04), with an odds ratio of 0.31 (95% confidence interval = 0.10-0.95). CONCLUSION: The BAMP technique did not show any social or psychological benefits; however, the skeletal class III improvement in ANB and the overjet change were sufficient to reduce the perceived need for orthognathic surgery by 27% compared with the CG.

Mini-implant assisted posterior intrusion: A quantification of anterior bite closure in nongrowing subjects.

INTRODUCTION: This study aimed to identify the vertical radiographic changes in nongrowing patients after treatment of anterior open bites (AOBs) using mini-implant assisted intrusion and to provide a predictive model to quantify the achievable intrusion. METHODS: This retrospective radiographic study evaluated the dentoskeletal changes in adults using orthodontic mini-implants in 53 treated patients with AOB. Radiographs before and after posterior intrusion were utilized to evaluate the associated changes. Conventional cephalometric analyses provided data for assessment. A paired t test was used to identify significant changes. A regression model (best subsets selection algorithm) was generated to quantify the relationship between mini-implant-assisted intrusion and the resultant change in overbite. A matched, untreated control sample was used for comparison. RESULTS: One hundred percent of AOBs were corrected using mini-implant-assisted intrusion of the maxillary molars. The overbite increased by an average of 3.6 mm. The average amount of maxillary first molar intrusion was 2.67 mm. The mandibular first molar moved an average of 1.93 mm closer to the palatal plane because of an average clockwise mandibular rotation of 0.78°. The occlusal plane steepened by an average of 3.95°. If all other inputs are held constant, 1 mm of intrusion of the maxillary first molar results in a 0.86 mm increase in overbite. CONCLUSIONS: Mini-implant-assisted intrusion successfully treated AOB in adults with significant dentoalveolar but no significant skeletal changes. An average of 2.67 mm of intrusion of the maxillary first molars is achievable with this method showing that 1 mm of intrusion of the maxillary first molar increased overbite by 0.86 mm. Longer periods of intrusion resulted in greater amounts of bite closure.

The digital Twin Block appliance: Concept, design and fabrication.

The Twin Block appliance (TBA) has evolved over the decades to remain a very effective treatment for growing Class II patients. This article introduces how two new versions of the TBA may be produced through an entirely digital workflow, from intra-oral scanning to thermoplastic appliance fabrication, using a novel computer-aided design process.

In-house three-dimensional printing within the digital orthodontic workflow.

Intraoral scanning techniques, and the associated software, have revolutionized model acquisition, analysis, and virtual planning in orthodontics. Three-dimensional printing is the final aspect of this digital workflow, converting these virtual models and simulations of the tooth and occlusal movements into physical reality. This article provides an insight into how in-house three-dimensional printing is now a feasible and transformative reality for many orthodontic settings and how this empowers orthodontists to optimize their patient care.

Introducing 3D printing in your orthodontic practice.

Many orthodontists are aware of the potential applications of three-dimensional (3D) printing in orthodontics but are hesitant in introducing this technology into their clinical practice and workflow. Therefore, this article explains the hardware and software requirements, plus the workflow.

The accuracy of maxillary positioning using digital model planning and 3D printed wafers in bimaxillary orthognathic surgery.

OBJECTIVE: Orthognathic wafers may be made using digital model movements and CAD-CAM technology. This paper analysed the accuracy of maxillary movements using this new process. DESIGN: Retrospective study of pre and post-operative cephalograms. PARTICIPANTS: Thirty consecutive orthognathic patients undergoing bimaxillary osteotomies in a UK hospital. METHODS: Jaw movements were planned using cephalometric and Orthoanalyzer™ software. The resultant intermediate and final wafer occlusal relationships were used for wafer fabrication by 3D printing of the inter-occlusal space. Pre- and post-operative lateral cephalograms were compared in terms of maxillary antero-posterior and vertical movements. Statistical analyses including the paired t-test, two-sample t-test and Fisher's exact test. RESULTS: Wide individual variation was observed between the planned and actual movements. Thirteen cases (43%) had a 2 mm discrepancy in at least one variable. Statistically significant differences between the planned and actual maxillary vertical movements were observed for the molar (U6y: p < 0.0001) and anterior maxillary (Ay: p < 0.01) differences. Analysis of a subgroup with primarily impaction movements demonstrated a statistically significant bias towards excessive maxillary advancement (U1x: p < 0.01) and incisor impaction (U1y: p < 0.01) in this group. CONCLUSIONS: This new digital surgical wafer technique achieves a similar level of accuracy to the conventional facebow and model surgery process.

A 3D printed surgical analogue to reduce donor tooth trauma during autotransplantation.

Surgical trauma and prolonged extra-alveolar exposure of the donor tooth's root sheath are both complicating factors during tooth autotransplantation surgery. This case report describes a 12-year-old female patient who underwent surgical transplantation of a maxillary second premolar to a central incisor site. A three-dimensional printed analogue of the donor tooth was fabricated from a cone beam (CBCT) scan of the tooth in order to minimise the extra-oral (exposure) time and frequency of trial insertions of the donor tooth into the recipient socket. The laboratory and clinical aspects of this novel technique are described.

Early class III protraction facemask treatment reduces the need for orthognathic surgery: a multi-centre, two-arm parallel randomized, controlled trial.

OBJECTIVE: To evaluate whether patients who had received early class III protraction facemask treatment were less likely to need orthognathic surgery compared with untreated controls. This paper is a 6-year follow-up of a previous clinical trial. DESIGN: Multi-centre 2-arm parallel randomized controlled trial. SETTING: Eight United Kingdom hospital orthodontic departments. PARTICIPANTS: Seventy three 7- to 9-year-old children. METHOD: Patients were randomly allocated, stratified for gender, into an early class III protraction facemask group (PFG) (n = 35) and a control/no treatment group (CG) (n = 38). The primary outcome, need for orthognathic surgery was assessed by panel consensus. Secondary outcomes were changed in skeletal pattern, overjet, Peer Assessment Rating (PAR), self-esteem and the oral aesthetic impact of malocclusion. The data were compared between baseline (DC1) and 6-year follow-up (DC4). A per-protocol analysis was carried out with n = 32 in the CG and n = 33 in the PFG. RESULTS: Thirty six percent of the PFG needed orthognathic surgery, compared with 66% of the CG (P = 0.027). The odds of needing surgery was 3.5 times more likely when protraction facemask treatment was not used (odds ratio = 3.34 95% CI 1.21-9.24). The PFG exhibited a clockwise rotation and the CG an anti-clockwise rotation in the maxilla (regression coefficient 8.24 (SE 0.75); 95% CI 6.73-9.75; P < 0.001) and the mandible (regression coefficient 6.72 (SE 0.73); 95% CI 5.27-8.18; P < 0.001). Sixty eight per cent of the PFG maintained a positive overjet at 6-year follow-up. There were no statistically significant differences between the PFG and CG for skeletal/occlusal improvement, self-esteem or oral aesthetic impact. CONCLUSIONS: Early class III protraction facemask treatment reduces the need for orthognathic surgery. However, this effect cannot be explained by the maintenance of skeletal cephalometric change.

Controlled canine retraction using orthodontic mini-implants coupled with bondable powerarms.

Many patients present with a substantial amount of anterior dental crowding, necessitating canine retraction prior to incisor alignment. Conventional biomechanics typically requires anchorage reinforcement and risks distal tipping of the canine crown and a delay before incisor alignment. However, it is now possible to produce controlled canine retraction without anchorage loss, even with narrow, flexible archwires in situ. This enables simultaneous alignment of displaced incisors. This technique involves a combination of orthodontic mini-implants (OMIs) and a powerarm bonded directly on either the labial or palatal surface of the target tooth, as described in this paper.

Dentoskeletal changes following mini-implant molar intrusion in anterior open bite patients.

OBJECTIVE: To evaluate skeletal and dental changes after intrusion of the maxillary molars in subjects with anterior open bite. MATERIALS AND METHODS: This retrospective cephalometric study evaluated skeletal and dental changes resulting from the use of maxillary orthodontic mini-implants in 31 consecutively treated patients. Radiographs were taken at the start and end of maxillary molar intrusion to evaluate the associated changes. Statistical analysis was performed using a one-sample t-test. RESULTS: The mean treatment observation time was 1.31 years (SD  =  2.03). The maxillary first molars (P  =  0.0026) and second molars (P  =  0.039) were intruded. However, the mandibular first molars (P  =  0.0004) and second molars (P  =  0.003) erupted in adolescent patients. Both the maxillary and mandibular first molars inclined distally (P  =  0.025 and P  =  0.044, respectively). The mandibular plane angle decreased (P  =  0.036), lower facial height decreased (P  =  0.002), and the occlusal plane angle increased (P  =  0.009). The overbite increased (P < .0001). The ANB angle decreased (P < .0001). Mandibular dental and skeletal changes were more apparent in adolescents, while adults tended toward maxillary changes. CONCLUSIONS: Vertical traction from orthodontic mini-implants reduces the maxillary posterior dentoalveolar height, thereby assisting orthodontic closure of anterior open bite. However, simultaneous eruption or extrusion of the mandibular molars should be controlled. Adolescent patients tend to demonstrate more favorable effects of mandibular autorotation than do adults.

Molar intrusion in the management of anterior openbite and 'high angle' Class II malocclusions.

Orthodontic correction of anterior openbite has conventionally involved extraction therapy or an adjunctive maxillary impaction osteotomy. However, bone anchored molar intrusion treatments have been reported in recent years as a less invasive alternative for such patients. This paper describes the concepts and treatment processes involved with mini-implant molar intrusion to correct anterior openbite and reduce patients' excessive vertical facial proportions.

Mini-implant applications in orthognathic surgical treatment.

Orthognathic surgical treatment conventionally relies on the use of full arch fixed orthodontic appliances. However, the introduction of orthodontic mini-implants has altered surgical options in terms of providing an alternative to fixation (intermaxillary fixation, IMF) screws and even to maxillary osteotomy. This paper describes the integration of mini-implants within orthognathic treatments in terms of 'surgery first' treatments and by introducing the concept of the conversion of bimaxillary cases into mandible-only surgery treatments.

Correction of the occlusal and functional sequelae of mandibular condyle fractures using orthodontic mini-implant molar intrusion.

We report on the non-surgical management of an adult female whose bilateral mandibular condylar fractures had resulted in a clockwise (posterior) mandibular rotation, limitation of mandibular movements and increased occlusal loading on the molar teeth. She refused maxillary surgery and was treated with a minimally-invasive approach, involving orthodontic fixed appliances and mini-implant intrusion of the maxillary molar teeth. This provided both occlusal and functional improvements, including a significant increase in the inter-incisal distance, which were stable after one year of retention.