Mandibular molar protraction: A comparison between fixed functional appliances and temporary anchorage devices.

INTRODUCTION: This study aimed to compare the efficiency of temporary anchorage devices (TADs) and fixed functional appliances (FFAs) for mandibular molar protraction. METHODS: Orthodontic records of 1050 consecutively treated patients with molar protraction were screened. Thirty-six records (22 females and 14 males; mean age, 17.4 years) were divided into two groups: TAD (21 subjects with 25 edentulous spaces) and FFA (15 subjects with 24 edentulous spaces). The primary outcome measure was the efficiency of protraction [magnitude and time required for protraction (rate) and anchor loss (AL)]. The secondary outcomes involved measuring the type of tooth movement (TOTM), external apical root resorption (EARR), alveolar bone height change (ABHC), alveolar bone width change (ABWC) and appliance failure. RESULTS: The rate of tooth movement was significantly higher for FFAs (0.83 ± 0.35 mm/month) versus TADs (0.49 ± 0.2 mm/month) (P = .005). Total treatment duration was less for FFAs (34.78 ± 8.1 months) versus TADs (47.72 ± 13.94 months) (P = .002). TOTM was similar for both (P = .909). EARR was 1.42 ± 1.38 mm for TAD and 1.25 ± 0.88 mm for FFA (P = .81). ABHC increased in the FFA group (1.01 ± 3.62 mm) and decreased for the TAD group (0.68 ± 1.66 mm). ABWC increased for both TAD (1.81 ± 1.73 mm) and FFA (1.75 ± 1.35 mm). The failure rate was 50% for FFAs and 33% for TADs. CONCLUSIONS: Both systems provided translation of lower molars with comparable anchorage control. However, FFAs were more efficient than TADs for lower molar protraction.

Machine Learning for the Diagnosis of Orthodontic Extractions: A Computational Analysis Using Ensemble Learning.

Extraction of teeth is an important treatment decision in orthodontic practice. An expert system that is able to arrive at suitable treatment decisions can be valuable to clinicians for verifying treatment plans, minimizing human error, training orthodontists, and improving reliability. In this work, we train a number of machine learning models for this prediction task using data for 287 patients, evaluated independently by five different orthodontists. We demonstrate why ensemble methods are particularly suited for this task. We evaluate the performance of the machine learning models and interpret the training behavior. We show that the results for our model are close to the level of agreement between different orthodontists.

Which orthodontic appliance is best for oral hygiene? A randomized clinical trial.

INTRODUCTION: Clear aligners and to a lesser extent self-ligated brackets are considered to facilitate better oral hygiene than traditional fixed orthodontic appliances. This 3-arm parallel-group prospective randomized clinical trial compared the long-term and short-term effects of clear aligners, self-ligated brackets, and conventional (elastomeric-ligated) brackets on patients' oral hygiene during active orthodontic treatment. METHODS: Seventy-one participants (41 boys, 30 girls; mean age, 15.6 years) undergoing orthodontic treatment were randomly allocated through a computer-generated randomization schedule to one of the groups based on the choice of intervention: Clear Aligners (CLA) (Align Technology, San Jose, Calif) (n = 27), preadjusted edgewise fixed appliance with self-ligated brackets (SLB) (Carriere, Carlsbad, Calif (n = 22), or preadjusted edgewise fixed appliance with elastomeric ligated brackets (ELB) (Ortho Organizers Inc., Carlsbad, CA) (n = 22). For each participant, the primary outcome, plaque index (PI), and secondary outcomes, gingival Index (GI) and periodontal bleeding index (PBI), were measured at baseline (T0), after 9 months of treatment (T1), and after 18 months of treatment (T2). Blinding of the clinicians and the patients to the intervention was impossible. It was only done for outcome assessment and for the statistician. Ten participants did not receive the allocated intervention for various reasons. RESULTS: The means and standard deviations of PI at T0 (CLA, 0.50 ± 0.51; SLB, 0.65 ± 0.49; ELB, 0.70 ± 0.73), T1 (CLA, 0.83 ± 0.48; SLB, 1.38 ± 0.72; ELB, 1.32 ± 0.67), and T2 (CLA, 0.92 ± 0.58; SLB, 1.07 ± 0.59; ELB, 1.32 ± 0.67) were similar. The odds ratio (OR) for plaque index (0 or ≥1) comparing SLB or CLA to ELB was not significant. OR for SLB vs ELB = 1.54 at T0 (95% CI, 0.39-6.27), 0.88 at T1 (95% CI, 0.03-24.69), and 0.83 at T2 (95% CI, 0.02-27.70); OR for CLA vs ELB = 1.07 at T0 (95% CI, 0.30-3.88), 0.24 at T1 (95% CI, 0.01-1.98), and 0.17 at T2 (95% CI, 0.01-1.71). However, the odds ratios comparing CLA with ELB for GI (OR = 0.14; P = 0.015) and PBI (OR = 0.10; P = 0.012) were statistically significant at T1. CONCLUSIONS: In this prospective randomized clinical trial, we found no evidence of differences in oral hygiene levels among clear aligners, self-ligated brackets, and conventional elastomeric ligated brackets after 18 months of active orthodontic treatment. REGISTRATION: The trial is registered at ClinicalTrials.gov (NCT02745626). PROTOCOL: The protocol was not published before trial commencement.

En-masse protraction of mandibular posterior teeth into missing mandibular lateral incisor spaces using a fixed functional appliance.

Protraction of mandibular posterior teeth requiring absolute anchorage has always been a challenge, especially when the space is located in the anterior region, since more teeth must be protracted. Traditionally, skeletal anchorage devices have been used for anchorage reinforcement during protraction. However, drawbacks such as requirement of a surgical step, inability to tolerate heavy forces, and patient willingness to undergo such surgical procedures can be limiting factors. Additionally, the mechanics involved can sometimes create undesirable side effects, thereby limiting their application in such situations. This report describes the use of a fixed functional appliance as an anchorage-reinforcement device for en-masse protraction of mandibular posterior teeth into a missing lateral incisor space.

Anchorage reinforcement with a fixed functional appliance during protraction of the mandibular second molars into the first molar extraction sites.

Protraction of posterior teeth into edentulous spaces is a challenge. This report describes the treatment of a 19-year-old woman with missing mandibular first molars owing to caries. A fixed functional appliance was used for anchorage reinforcement during mandibular second molar protraction. Eight millimeters of bilateral protraction was done with bodily mesial movement of the molars and no lingual tipping of the incisors.

Long-term surgical versus functional Class II correction: a comparison of identical twins.

The purpose of this twin case comparison was to assess the short- and long-term effects of nonsurgical treatment vs orthognathic surgical treatment for Class II correction. Two identical twins (age 13 years 3 months) were treated for Class II correction where one patient was treated nonsurgically using a fixed functional appliance, while the other was treated using orthognathic mandibular advancement surgery. The patients were recalled and evaluated 5 years in retention. Comparing changes in the short and long term, surgical treatment led to superior skeletal results compared to the nonsurgical twin. However, the soft tissue profile was remarkably similar for both patients suggesting that soft tissue profile changes may not necessarily follow similar changes in the bony skeletal structures.

Mechanism of Class II correction in prepubertal and postpubertal patients with Twin Force Bite Corrector.

OBJECTIVE: To compare the dentoskeletal effects and treatment efficiency of the Twin Force Bite Corrector (TFBC) appliance in Class II correction of patients treated before or after the pubertal growth spurt. MATERIALS AND METHODS: Forty-one normodivergent Class II patients treated with the TFBC appliance were divided into two groups based on their cervical vertebral maturation stage (CVMS). Group 1 (G1) consisted of 23 patients (mean age 12.44 ± 1.59 years) where treatment was initiated before the pubertal growth spurt (CVMS I and II), while group 2 (G2) consisted of 18 patients (mean age 13.76 ± 1.44 years) where treatment was started after the pubertal growth spurt (CVMS III to V). Dentoskeletal measurements were made on lateral cephalograms taken before (T1) and after orthodontic treatment (T2). RESULTS: During treatment, G1 had significantly greater skeletal correction than G2, with more dentoalveolar effects being observed in G2 than G1. However, on comparing both groups at the end of treatment (T2) when growth is complete, no differences in the parameters measured were observed. Overall, treatment time was significantly longer for G1 (3.67 ± 1.45 years) compared to G2 (2.75 ± 1.07 years). CONCLUSIONS: There is no difference in overall dentoskeletal effects obtained at the end of treatment by the TFBC appliance in normodivergent prepubertal vs postpubertal patients. However, treatment efficiency based on treatment timing is significantly greater for the postpubertal group.

Cephalometric comparison of vertical changes between Begg and preadjusted edgewise appliances.

The purpose of this retrospective study was to quantify and compare the vertical dimensional changes in bialveolar dental protrusion patients undergoing extraction of all four first premolars between the preadjusted edgewise appliance (PEA) and the Begg appliance. The cephalometric records of 55 patients (14 males and 41 females) with Class I bimaxillary protrusion were selected and divided into two groups based on the appliance used, i.e Begg or PEA mechanotherapy. To minimize the effects of growth, the subjects were at least in stage VI of skeletal maturation. The mean age was 18.25 ± 3.2 years for the Begg group and 18.03 ± 3.5 years for the PEA group. Skeletal and dental changes were analysed in both groups on lateral cephalograms taken pre- (T1) and post- (T2) treatment. A Student's t-test was used to analyse the treatment changes. Within group results showed a significant increase in face height and extrusion and mesial movement of the upper and lower molars for both groups. However, no significant differences were observed when the groups were compared. A significant correlation was found between the change in lower molar to mandibular plane angle and lower anterior face height for both groups. No significant difference was found when the Begg mechanotherapy was compared to the PEA technique on vertical dimensional changes. It can be speculated that mesial movement of the molars tended to keep pace with their extrusion and negated any bite opening effect with both mechanotherapies.