Treatment stability with bonded versus vacuum-formed retainers after 12 months: A randomized clinical trial.

OBJECTIVE: To compare the clinical effectiveness of V-bend bonded retainers (BR) versus vacuum-formed retainers (VFR) regarding their capacity to maintain treatment stability and survival rates after 12 months. MATERIALS AND METHODS: Patients finishing orthodontic treatment were randomly allocated into two groups. The BR group received maxillary and mandibular BRs in the lingual surfaces of the anterior teeth. The VFR group received VFRs right after fixed appliances removal. The patients were evaluated at four time-points: at fixed appliances removal (T0), after 3 (T1), 6 (T2) and 12 months (T3). In each time-point digital models were obtained and analysed with the OrthoAnalyzer™ software. Treatment stability based on occlusal outcomes and retainers' survival rates were evaluated. Intergroup comparisons were performed using Mann-Whitney U-tests. The Kaplan-Meier survival plot and the log-rank test were employed to assess the retainers' survival. RESULTS: Both BR and VFR groups included 25 patients. The groups were comparable regarding their baseline characteristics. Up to 6 months, both retainers were equally effective; however, after 12 months, BRs were more effective in maintaining the incisors' alignment in the maxilla and the mandible compared to the VFRs. No differences were noticed in the intercanine and intermolar widths, overjet and overbite. There were no differences regarding the retainers' survivability in both arches. CONCLUSIONS: BRs were more effective in maintaining the alignment of the incisors in the maxilla and mandible compared to VFRs after 12 months. Both retainers presented the same survival rates after the same period.

Robin Sequence Facial Profile After Conservative Treatment: A Long-Term Follow-Up.

INTRODUCTION: Robin sequence (RS) is a congenital clinical condition characterized by micrognathia, glossoptosis, and respiratory distress. Conservative methods could be responsible for releasing feeding and respiratory impairment but little information about mandibular growth is known in long-term follow-up. OBJECTIVE: Assessing the longitudinal behavior of the facial profile of individuals with isolated RS who underwent conservative micrognathia treatment using photographs during the whole craniofacial growth. METHODS: Photographs of the right facial profile of 100 patients were used (50 individuals with isolated RS and 50 individuals without craniofacial anomaly). The individuals with RS were evaluated at 3 different times (T1: infant, T2: mixed dentition, T3: permanent dentition) by measuring the facial convexity angle (FCA; G.Sn.Pog´). A comparison between T3 and control group (C), individuals without craniofacial anomalies and in permanent dentition, was also performed, checking the FCA, nasolabial angle (Ls.Sn.Cm), mentolabial fold (Li.Si.Pog´), facial inferior third (Sn.Gn´.C) angles and the ratio between middle anterior facial height and lower anterior facial height. RESULTS: The T3 group showed an increased angle of facial convexity and increased facial inferior third angle and middle anterior facial height/lower anterior facial height ratio compared with the control group. In the longitudinal evaluation of individuals with isolated RS, significant differences were identified between T1 and T2 groups and T1 and T3 groups showing that the increased facial convexity was higher in the infants and that did not change significantly between the phases of mixed and permanent dentition. CONCLUSIONS: RS showed increased facial convexity in all phases evaluated, but their convexity decreased with growth. When compared with individuals without craniofacial anomalies, the individuals continue to exhibit retrognathism in the permanent dentition. The lack of a mandible projection has led to a considerable number of orthognathic surgeries for the correction of discrepancies.

Treatment of Class II malocclusion with 2-maxillary premolar extractions: Monthly vs biweekly appointments, which is more efficient?

INTRODUCTION: This study compared whether there is a difference in treatment time (TT) and efficiency when appointments are held once a month or at 2-week intervals in patients with Class II malocclusion treated with 2-premolar extractions METHODS: The patients of this retrospective sample were treated with the same orthodontic mechanics and divided into 2 groups according to frequencies of orthodontic appointments. Group 1 consisted of 18 patients (10 males, 8 females), with an initial mean age of 14.38 ± 1.38 years and appointments once a month. Group 2 consisted of 19 patients (9 males, 10 females), with an initial mean age of 14.12 ± 1.38 years and biweekly appointments. Edgewise fixed appliances with a slot size of 0.022 × 0.028 mm were used, and the anterior teeth were retracted en-masse with a rectangular wire and elastic chains. The Peer Assessment Rating and Objective Grading System indexes were measured in the dental models at the beginning and the end of treatment. Efficiency was assessed by dividing the percentage of improvement of each occlusal index concerning the multiplication of TT and the number of appointments. RESULTS: Both groups presented similar Peer Assessment Rating and Objective Grading System indexes at the end of treatment. Groups 1 and 2 presented different TTs (28.06 and 22.05 months, respectively); however, there were no differences regarding the efficiency of both protocols. CONCLUSIONS: Patients with Class II malocclusion treated with 2-maxillary premolars had significantly shorter treatment times when seen on biweekly appointments than those with monthly appointments; however, there was no difference in efficiency between protocols.

Comparison of nasal cavity changes between the expander with differential opening and the fan-type expander: a secondary data analysis from an RCT.

INTRODUCTION: The aim of this study was to compare the nasal cavity skeletal changes between the expander with differential opening (EDO) and the fan-type expander (FE). METHODS: This study was a secondary analysis of a previous randomized clinical trial. Forty-eight patients with posterior crossbite were randomly allocated into two study groups. Twenty-four patients (11 male, 13 female) with a mean initial age of 7.6 ± 0.9 years were treated with rapid maxillary expansion (RME) using the EDO. Twenty-four patients (10 male, 14 female) with a mean initial age of 7.8 ± 0.9 years were treated with the FE. Cone-beam computed tomography (CBCT) was performed before treatment and 1 to 6 months after the active phase of RME. Using frontal CBCT slices passing at the level of maxillary permanent first molars and maxillary deciduous canines, the width of the nasal cavity was measured in the lower, middle and upper thirds. Nasal cavity height was also evaluated in both slices. Intergroup comparisons of interphase changes were performed using t or Mann-Whitney tests (P < 0.05). RESULTS: The two groups were similar regarding baseline data. EDO showed a greater transverse increase in the lower third of the nasal cavity in both canine (P = 0.007) and molar regions (P < 0.001). No intergroup difference was observed for changes in middle and upper widths and height of the nasal cavity. CONCLUSIONS: Both expanders are effective in promoting an increase of the nasal cavity skeletal dimensions. The expander with differential opening produced a greater transverse increase in the lower third of the nasal cavity compared to the fan-type expander, both at the anterior and posterior regions of the maxilla. CLINICAL RELEVANCE: EDO might be more beneficial to pediatric patients with oral breathing and obstructive sleep apnea compared to FE.

Growth Outcomes Audit for Unilateral Cleft Lip and Palate (UCLP) After 2-stage Palate Repair.

PURPOSE: To assess the impact of 1 and 2-stage palatoplasty protocol on the dental arch relationships in unilateral cleft lip and palate (UCLP) in a single center. METHODS: Our study consisted of 349 individuals divided into 2 groups according to the palatoplasty protocol. Two-stage group comprised 169 subjects with UCLP (mean age: 6.9 y, 110 male and 59 female) who underwent lip, nasal ala, and anterior palate repair with vomer flap from 3 to 6 months (first surgery stage). Soft palate repair occurred from 12 to 18 months (second surgery stage). The one-stage group comprised 180 subjects with UCLP (mean age: 7.2 y, 108 male and 72 female) who underwent 1-stage palatoplasty. Dental models were evaluated by 3 experienced orthodontists applying Goslon Yardstick and the 5-year-old index (FYOI). The influence of the palatoplasty technique and surgeon factor on the interarch relationship was evaluated. The weighted Kappa was used to assess intraexaminer and interexaminer agreements for comparisons of dental arch relationships. Intergroup comparisons were conducted using the χ 2 test ( P <0.05). RESULTS: The intraexaminer reliability was very good (0.81 to 0.98) and interexaminer reliability varied from satisfactory to very good (0.56 to 0.83). The mean occlusal index of the 2-stage and 1-stage groups was 2.77 and 3.03, respectively. The variability of the mean index between surgeons varied from 2.38 to 3.2 in the 2-stage group and 2.91 to 3.2 in the 1-stage group. There were significant differences in the frequency of Goslon 5 index ( P =0.002) between groups, with the 2-stage group presenting less cases (1.18%) than the group 1-stage (11.11%). CONCLUSION: The interarch relationship was similar for both palate repair protocols. Two-stage palatoplasty showed a decreased prevalence of Goslon index 5.

The First Hybrid International Educational Comprehensive Cleft Care Workshop.

OBJECTIVE: Describe the first hybrid global simulation-based comprehensive cleft care workshop, evaluate impact on participants, and compare experiences based on in-person versus virtual attendance. DESIGN: Cross-sectional survey-based evaluation. SETTING: International comprehensive cleft care workshop. PARTICIPANTS: Total of 489 participants. INTERVENTIONS: Three-day simulation-based hybrid comprehensive cleft care workshop. MAIN OUTCOME MEASURES: Participant demographic data, perceived barriers and interventions needed for global comprehensive cleft care delivery, participant workshop satisfaction, and perceived short-term impact on practice stratified by in-person versus virtual attendance. RESULTS: The workshop included 489 participants from 5 continents. The response rate was 39.9%. Participants perceived financial factors (30.3%) the most significant barrier and improvement in training (39.8%) as the most important intervention to overcome barriers facing cleft care delivery in low to middle-income countries. All participants reported a high level of satisfaction with the workshop and a strong positive perceived short-term impact on their practice. Importantly, while this was true for both in-person and virtual attendees, in-person attendees reported a significantly higher satisfaction with the workshop (28.63 ± 3.08 vs 27.63 ± 3.93; P = .04) and perceived impact on their clinical practice (22.37 ± 3.42 vs 21.02 ± 3.45 P = .01). CONCLUSION: Hybrid simulation-based educational comprehensive cleft care workshops are overall well received by participants and have a positive perceived impact on their clinical practices. In-person attendance is associated with significantly higher satisfaction and perceived impact on practice. Considering that financial and health constraints may limit live meeting attendance, future efforts will focus on making in-person and virtual attendance more comparable.

Longitudinal behavior of orthodontic extraction spaces: A retrospective dental cast analysis.

INTRODUCTION: This retrospective study aimed to qualitatively and quantitatively evaluate orthodontic extraction space behavior and size at the end of treatment and the short- and long-term stages in Class I, II, and III malocclusions. METHODS: The sample comprised records of 1283 orthodontic patients treated with extractions (cross-sectional group). From these patients, 1- and 5-year posttreatment records of 214 patients were additionally evaluated (longitudinal group). Orthodontic extraction sites of immediate (end of treatment), short-term (1-year posttreatment), and long-term (5-year posttreatment) stage dental casts were measured with a digital caliper. Extraction spaces were classified according to their qualitative behavior in the open, closed, reopened, and recently closed spaces. Space qualitative longitudinal behavior was compared among the malocclusion types with chi-square tests. Kolmogorov-Smirnov normality tests were performed to check the variable's distribution. All variables showed normal distribution, except the malocclusion group ages. Therefore, parametric tests were used for all comparisons between the malocclusion groups, except for age comparisons in each stage, which were compared with the Kruskal-Wallis tests. Thus, space size and its reduction were compared among the 3 stages, in general, and between the maxillary and mandibular arches, with analysis of variance followed by Tukey tests and t tests, respectively. RESULTS: Classes I, II, and III malocclusion patients presented similar ages at each stage. At the end of treatment, 71.4% and 65.1% of the quadrants were closed in the cross-sectional and longitudinal groups, respectively, and 43.6% and 38.2% of patients presented all quadrants closed at this same stage in both groups. The reopening and late closure tendencies were 2.9 and 2.3 times greater in the short term than in the long term. Reopening tendency in the short-term was greater in Class II than in Class I malocclusion. Of the quadrants closed at the end of treatment, 87% were stable in the long term. From the quadrants with residual spaces at the end of treatment, 28.4% persisted openly in the long term. Residual space size reduced significantly in the short and long term, primarily in the mandibular arch. CONCLUSIONS: The percentage of patients with residual spaces at the end of treatment was 56.4%. Space reopening and late closure occur mainly in the first year after treatment. There was long-term stability in 87% of the quadrants closed at the end of treatment. There was a significant reduction in orthodontic extraction space size in the short and long term, especially in the mandibular arch.

Immediate dentoskeletal and periodontal effects of miniscrew-assisted rapid palatal expansion: Comparison between young vs middle-aged adults.

INTRODUCTION: This study aimed to compare the dentoskeletal and periodontal changes after miniscrew-assisted rapid palatal expansion (MARPE) in patients aged 18-29 and 30-45 years. METHODS: The sample comprised 28 subjects with transverse maxillary discrepancy successfully treated with MARPE. The young adult (YA) group comprised 14 subjects (mean age, 22.8 years; 3 male, 11 female). The middle adult (MA) group comprised 14 subjects (mean age, 36.8 years; 6 male, 8 female). All patients were treated with a 4-miniscrew MARPE expander. The activation protocol was one quarter turn twice a day until the midline diastema opening, followed by one quarter turn a day until overcorrection. Cone-beam computed tomography (CBCT) scans taken before and immediately after the expansion was analyzed using OnDemand3D Dental software. Using CBCT coronal images, transversal dentoskeletal and periodontal variables were measured in the preexpansion and postexpansion. Intergroup comparisons of expansion changes were performed using t and Mann-Whitney tests (P <0.05). RESULTS: Groups were compatible at preexpansion for most CBCT measurements. A success rate of midpalatal suture opening of 100% and 81% was observed for YA and MA groups, respectively. No intergroup differences were found for the maxillary and dental arch widths increases. The buccal tip of anchorage teeth was observed similarly in both groups. The buccal bone thickness of posterior teeth decreased, and the palatal bone thickness increased after expansion with no difference between groups. CONCLUSIONS: After MARPE, the MA group showed similar dentoskeletal and periodontal changes compared to the YA group.

Root resorption in Class II malocclusion treatment with and without maxillary premolar extractions.

INTRODUCTION: Class II malocclusion treatment efficiency with maxillary premolar extractions has been reported. However, no study evaluated the root resorption associated with this protocol. Therefore, this study aimed to compare the degree of root resorption of the maxillary incisors in Class II malocclusion treatment with and without maxillary premolar extractions. METHODS: The sample consisted of 56 patients with complete Class II malocclusion, divided into 2 groups. Group 1 comprised 28 patients (10 female, 18 male) treated with maxillary first premolar extractions, and group 2 was composed of 28 patients (16 female, 12 male) treated without extractions. The groups were matched regarding initial age, treatment time, crowding, initial malocclusion severity, finishing quality, initial overjet, and overbite. Periapical radiographs of the maxillary incisors were used to assess the degree of root resorption using a scoring system. In addition, treatment changes involving maxillary incisors were evaluated in lateral headfilms. Intergroup comparisons were performed with t, Mann-Whitney U, and chi-square tests (P <0.05). RESULTS: Overjet, overbite, inclination, vertical positional changes, and vertical and horizontal apical displacements of maxillary incisors were similar between groups. There was no statistically significant difference between groups regarding root resorption of maxillary incisors. Root resorption degree ranged from mild to moderate in both groups. CONCLUSIONS: Treating complete Class II malocclusion with 2 maxillary premolar extractions resulted in a similar root resorption as treating without maxillary premolar extractions. An individualized evaluation of root resorption predisposing factors should be performed for each patient.

Impact of bone-anchored maxillary protraction on the quality of life of subjects with complete unilateral cleft lip and palate.

INTRODUCTION: This study aimed to evaluate the influence of bone-anchored maxillary protraction (BAMP) on the oral health-related quality of life (OHRQOL) in subjects with complete unilateral cleft lip and palate (UCLP) and moderate-to-severe maxillary deficiency. METHODS: A longitudinal observational study was conducted with a sample of 20 patients (13 males, 7 females) aged 10-14 years (mean age, 11.8 years) with Goslon 3, 4, and 5. To assess the patient's perception of their OHRQOL, the Quality of Life Questionnaire for Orthosurgical Patients was administered in 2 stages: after the installation of the protraction plates (T1) and 18 months after the protraction therapy started (T2). The questionnaire was composed of 4 domains, distributed over 22 questions: social aspects, facial esthetics, oral function, and awareness of facial deformity. RESULTS: The treatment protocol improved the OHRQOL in 75% of the patients who presented UCLP. The domain social aspects of the deformity were the only one that showed a significant difference from T1 to T2 and indicated an improvement in self-esteem. The girls had worse OHRQOL than boys at T1, which was statistically significant only for the domains of social aspects of deformity and awareness of deformity. After BAMP therapy, the effect size indicated a larger change in OHRQOL in girls than in boys. CONCLUSIONS: BAMP therapy positively impacted the OHRQOL and self-esteem of patients with UCLP during adolescence.

Mandibular second premolar distoangulation: a longitudinal follow-up from the mixed to the permanent dentition.

OBJECTIVE: The aim of this study was to assess the frequency of mandibular second premolar (MnP2) distoangulation among orthodontic patients and the angular changes after a longitudinal follow-up. METHODS: The sample was collected from the orthodontic records of 865 patients. The distoangulation group was composed of 42 patients (mean age 9.29 ±â€…1.24 years, 16 male, 26 female) with distoangulation of MnP2. The control group was composed of 32 patients (mean age 9.38 ±â€…1.10 years, 15 male, and 17 female) without distoangulation of MnP2. Panoramic radiographs taken in the mixed (T1) and the early permanent dentition (T2) were analyzed in both groups. Longitudinal angular changes (distal angle θ and premolar-molar angle γ), degree of root formation, second premolar depth, and prevalence of associated dental anomalies were analyzed. Intergroup comparison was performed with Mann-Whitney, t-tests, and chi-square tests (P < 0.05). RESULTS: The prevalence of MnP2 distoangulation in the mixed dentition was 4.85%. The distoangulation group showed a smaller initial distal angle (59.34o ±â€…8.41) when compared to control group (79.88o ±â€…7.60). The spontaneous eruption of the MnP2 with distoangulation was observed in 76.57% of the sample. MnP2 distoangulation was significantly associated with agenesis of its antimere, small maxillary lateral incisors, and deciduous molar infraocclusion. LIMITATIONS: Severe cases of MnP2 distoangulation were absent in this study. CONCLUSIONS: The frequency of MnP2 distoangulation among orthodontic patients was 4.85%. Mild to moderate distoangulated Mnp2 spontaneously uprighted from the mixed to the permanent dentition. Small lateral incisors, second premolar agenesis, and infraocclusion of deciduous molar were frequently found in cases with MnP2 distoangulation.

Dentoskeletal and soft-tissue changes of class II malocclusion treatment with modified first class appliances: a prospective clinical trial.

BACKGROUND/OBJECTIVES: Intraoral distalizers are effective and conservative alternatives for Class II malocclusion treatment. However, the literature is still controversial regarding the effects of using skeletal anchorage in intraoral distalizers with different designs. The aim of this study is to compare dentoskeletal and soft-tissue changes of Class II malocclusion patients treated with three types of First Class (FC) distalizers. MATERIALS/METHODS: The sample of this prospective clinical trial included 30 consecutive patients divided into three groups: G1-FC conventionally anchored; G2-FC skeletally anchored Type 1; G3-FC skeletally anchored Type 2. Each group consisted of 10 patients. Lateral cephalograms were analyzed in two stages: at pre-treatment (T0) and after distalization (T1). The radiographs were digitized and analyzed using the software Dolphin Imaging 11.5. Comparisons of treatment changes between groups (T1-T0) were performed using one-way analysis of variance (ANOVA), followed by the Tukey test. RESULTS: Patients treated with the conventionally anchored FC showed significantly greater incisors protrusion and labial inclination, second premolars mesial inclination and mesialization than the FCs skeletally anchored. No differences were observed regarding the amount of molar distalization and molar angulation between groups. LIMITATIONS: It can be considered that the limitation of this study lies in its non-randomized design. CONCLUSIONS/IMPLICATIONS: First Class distalizers with conventional and skeletal anchorage are effective alternatives for Class II molar distalization. Distalization associated with indirect skeletal anchorage reduce the undesirable effects observed in the incisors and premolars during distalization when compared to distalization conventionally anchored.

Vertical and sagittal changes produced by an expander with differential opening and fan-type expander: A post-hoc analysis of a randomised controlled trial.

OBJECTIVE: To compare the sagittal and vertical cephalometric effects in participants treated with an expander with differential opening (EDO) versus the fan-type expander (FE). DESIGN: Two-arm parallel randomised clinical trial (RCT). METHODS: This study comprised cone-beam computed tomography-derived cephalometric images from 48 participants from a RCT. The sample was randomly allocated into two groups. The study was single-blinded. In total, 24 participants were treated with rapid maxillary expansion (RME) using EDO and 24 participants underwent RME using FE. The primary outcomes were the dentoskeletal vertical changes produced by RME. The secondary outcomes were the dentoskeletal sagittal changes. A cephalometric analysis was performed before treatment and 1 or 6 months after the active phase of RME using Dolphin Imaging Software. Intergroup comparisons of interphase changes were performed using the t-test and Mann-Whitney U test (P < 0.05). RESULTS: The final sample comprised 24 patients (11 men, 13 women; mean age = 7.6 ± 0.9 years) in the EDO group and 24 patients (10 men, 14 women; mean age = 7.8 ± 0.9 years) in the FE group. Both expanders produced a similar clockwise rotation of the mandible (FMA; mean difference [MD] = 0.09°, 95% confidence interval [CI] = -1.01 to 0.84). In the FE group, a greater increase of the SNA angle was observed after expansion compared to the EDO group (MD = 1.04°, 95% CI = -1.90 to -1.58). A greater palatal torque of maxillary incisors was observed in the FE group (MD = 1.32°, 95% CI = 0.05-2.56). Of the participants, 54% reported a little discomfort during the active phase of treatment and 46% of the participants did not report any discomfort. CONCLUSION: Both expanders produced similar vertical cephalometric changes. FEs caused slightly more maxillary anterior displacement after expansion with a compensatory palatal torque of the maxillary incisors compared to the EDOs. However, the amount of sagittal difference was not clinically relevant. TRIAL REGISTRATION: The trial was registered at ClinicalTrials.gov, under the identifier NCT03705871.

Challenges of a two-phase orthodontic treatment of a mandibular lateral incisor-canine transposition and a maxillary palatally displaced canine: A case report.

INTRODUCTION: The management of eruption disturbances in orthodontics may be challenging and requires a careful diagnosis and treatment planning. This case report discusses the challenges of a two-phase orthodontic treatment of a patient presenting with a dental eruption pattern anomaly. PATIENT CONCERNS: A 10-year-old boy was presented with no complaints for a routine orthodontic evaluation during mixed dentition. PRIMARY DIAGNOSES: The patient was diagnosed with a skeletal Class I malocclusion with unilateral posterior crossbite, incomplete mandibular lateral incisor-canine transposition and a unilateral maxillary ectopic canine. INTERVENTIONS: Phase 1 started with rapid maxillary expansion to correct maxillary constriction and the ectopic eruption of the right maxillary canine. In the mandibular arch, phase 1 included the extraction of the left primary lateral incisor and canine, alignment of the left permanent lateral incisor and orthodontic traction of the left permanent canine. The duration of phase 1 was 14 months. Phase 2 involved a comprehensive course of orthodontic treatment and started when the patient was aged 13 years. This phase lasted 18 months. RESULTS: An adequate dental occlusion was obtained, and the treatment results were stable after an 18-month follow-up. CONCLUSION: In this case, the early diagnosis of the dental anomalies was valuable as it allowed an early intervention to be undertaken, which resulted in overall treatment simplification and potentially minimised the adverse effects. This case report reinforces the importance of a careful follow-up during mixed dentition.

Early orthognathic surgery with postsurgical bone-anchored retention in unilateral cleft lip and palate: A case report.

We present a case report of early Le Fort I osteotomy with maxillary advancement retained postoperatively by Class III elastics anchored on miniplates in a growing patient with complete unilateral cleft lip and palate (UCLP). A 14-year-old boy who underwent orthognathic surgery at the pubertal growth spurt was presented. During surgery, Bollard miniplates were installed in the posterior region of the maxilla and in the anterior region of the mandible. Class III elastics anchored on miniplates were used at night (8-10 h) starting 60 days after surgery. The force of the elastics progressively increased from 100 g to 250 g. The elastics were replaced daily. The positive overjet remained stable over 15 months of postoperative follow-up. Maxillary advancement was adequately retained using Bollard miniplates and the facial profile remained stable until the end of facial growth.

Finite element analysis of two skeletally anchored maxillary molar distalisation methods.

OBJECTIVE: To compare two methods of maxillary molar distalisation with skeletal anchorage using finite element analysis (FEA). METHODS: Two digitised models were created: the miniscrew-anchored distaliser, which consisted of a distalisation method anchored in a buccal miniscrew between the first molar and second premolar (Model 1), and the miniscrew-anchored palatal appliance, which consisted of a distalisation method anchored in a miniscrew on the anterior region of the palate (Model 2). FEA was used to simulate both methods, assessing teeth displacements and stress concentration. RESULTS: The miniscrew-anchored distaliser showed greater buccal than distal displacement of the first molar, while the opposite was observed in the miniscrew-anchored palatal appliance. The second molar responded similarly in the transverse and anteroposterior perspectives with both appliances. Greater displacements were observed at crown level than in apical regions. Greater stress concentration was observed at the buccal and cervical regions of the crown in the miniscrew-anchored distaliser and the palatal and cervical regions in the palatal appliance. The stress progressively spread in the buccal side of the alveolar bone for the miniscrew-anchored distaliser and in the palatal root and alveolar bone for the palatal appliance. CONCLUSION: FEA assumes that both appliances would promote maxillary molar distalisation. A skeletally anchored palatal distalisation force seems to provide a greater molar bodily movement with less undesirable effects. Greater stress is expected at the crown and cervical regions during distalisation, and the stress concentration in the roots and alveolar bone depends directly on the region the force was applied.

Changes in third molar position after Class II subdivision malocclusion treatment with asymmetric extractions.

INTRODUCTION: This study aimed to assess the changes in third molars angulation and their available space after Class II subdivision malocclusion treatment with asymmetric premolar extractions. METHODS: The sample consisted of 37 patients (17 male, 20 female and mean age 13.18 ± 1.99 years) in group 1 (Type 1 Class II subdivision) and 25 (10 male, 15 female, mean age 13.56 ± 2.46 years) in group 2 (Type 2 Class II subdivision). In group 1, extractions were performed in the two maxillary quadrants and in the Class I mandibular quadrant. In group 2, extraction was performed in the Class II maxillary quadrant. Panoramic radiographs were used to evaluate third molar angulations and their available space pre- and post-treatment. Radiographic measurements were performed with Dolphin® Imaging 11.9. Paired t tests were used for intragroup comparison between stages and sides. RESULTS: In Type 1, there were similar improvements in third molar angulations and increases in the space available on the extraction quadrants in the maxillary arch. In the mandibular arch, there was significantly greater improvement in angulation and greater space availability in the extraction quadrant after treatment. In Type 2, there was significantly greater improvement in angulation and available space for the maxillary third molar on the extraction quadrant. In the mandibular arch, there was a similar improvement in the available space for the third molars. CONCLUSIONS: After treatment, both groups presented better angulation and significantly greater space for third molar eruptions on the extraction quadrants, when compared to the homologous non-extraction quadrants.

Comparison and reproducibility of three methods for maxillary digital dental model registration in open bite patients.

OBJECTIVE: To compare and assess the reproducibility of 3 methods for registration of maxillary digital dental models in patients with anterior open bite. Settings and sample population Digital dental models of 16 children with an anterior open bite in the mixed dentition were obtained before (T1) and after 12 months of treatment with bonded spurs (T2). METHODS: Landmarks were placed on all T2 models and 3 registration methods (R1, R2 and R3) were independently performed by 2 observers. R1 was based on 10 landmarks placed on posterior teeth. R2 was based on 5 landmarks on the palate (2 anterior, 2 posterior and 1 central). R3 used regions of interest around the 5 palatal landmarks used in R2. The differences between the registration methods were calculated by comparing the mean differences and standard deviations between the corresponding x, y and z coordinates of 6 corresponding landmarks in the T2 registered models. Repeated measures analysis of variance followed by post-hoc Bonferroni tests were used for comparisons (P < .05). The agreement between methods and the intra and interobserver reproducibility were assessed with Bland-Altman tests and intraclass correlation coefficients (ICC). RESULTS: Comparisons of R2 with R3 methods showed greater agreement, mean differences ≤0.50 mm for all landmarks, than comparisons of R1 with R2, and R1 with R3, mean differences >0.50 mm for most of the y and z coordinates (P < .05). The R1 and R3 methods presented excellent intra and interobserver reproducibility and R2 method had moderate interobserver reproducibility. CONCLUSIONS: Longitudinal assessments of open bite treatment using digital dental models could consider the posterior teeth and/or the palate as references. The R1 and R3 methods showed adequate reproducibility and yield different quantitative results. The choice will depend on the posterior teeth changes and dental models' characteristics.

Influence of rapid maxillary expansion in the stability of anterior open bite treatment.

OBJECTIVES: This study aimed to compare the stability of anterior open bite (AOB) in patients treated with and without rapid maxillary expansion (RME) before fixed palatal crib (PC) therapy in the mixed dentition. MATERIAL AND METHODS: Expansion/palatal crib group (EPC) was comprised of 25 patients (10 male, 15 female, mean initial age of 7.8 years) with AOB treated with RME before PC therapy. Palatal crib group (PC) included 25 patients with AOB (10 male, 15 female, mean initial age of 8.0 years) treated only with PC therapy. Lateral cephalograms were analyzed at pre-treatment (T0), after PC therapy (T1), and 3 years after PC removal (T2) in both groups. AOB relapse was considered when a negative overbite was observed at T2. Intergroup comparisons of interphase changes were performed using t and Mann-Whitney tests (p < 0.05). RESULTS: Treatment and post-treatment alterations showed similar changes in both groups for all cephalometric variables. Overall changes from T0 to T2 were similar between the groups except for the maxillary incisors that tipped lingually in PC group (1.PP = - 3.37°) and labially in EPC group (1.PP = 1.76°). The frequency of AOB relapse was 8% and 4% in the EPC and PC groups, respectively. Treatment time in the EPC group (9.7 months) was shorter (p = 0.024) when compared to the PC group (11.0 months). CONCLUSIONS: In the mixed dentition, stability of AOB treated with RME before fixed PC therapy was similar to PC therapy alone. However, treatment time with fixed PC was slightly shorter in the group treated with RME. CLINICAL RELEVANCE: This study aims to understand if RME performed previously to fixed palatal crib contributes to the index of stability of AOB treatment in the mixed dentition.

Upper airway changes in Class III patients using miniscrew-anchored maxillary protraction with hybrid and hyrax expanders: a randomized controlled trial.

OBJECTIVES: The aim of this study was to compare the upper airway space changes after miniscrew-anchored maxillary protraction with hybrid (HH) and conventional hyrax (CH) expanders. MATERIAL AND METHODS: The sample comprised Class III malocclusion growing patients that were randomized into two groups of miniscrew-anchored maxillary protraction. The group HH was treated with a hybrid hyrax appliance in the maxilla and two miniscrews distally to the canines in the mandible. Class III elastics were used from the maxillary first molar to the mandibular miniscrews until anterior crossbite correction. The group CH was treated with a similar protocol except for the conventional hyrax expander in the maxilla. Cone-beam computed tomography was obtained before (T1) and after 12 months of therapy (T2). The shape and size of upper airway were assessed. Intergroup comparisons were performed using Mann-Whitney U test (p < 0.05). RESULTS: The group HH was composed of 20 patients (8 female, 12 male) with a mean age of 10.76 years. The group CH was composed of 15 patients (6 female, 9 male) with a mean age of 11.52 years. Anteroposterior and transverse increases of the upper airway were found for both groups. The oropharynx and the most constricted area increased similarly in both groups. CONCLUSIONS: No differences in upper airway changes were observed using protraction anchored on hybrid or conventional hyrax expanders. CLINICAL RELEVANCE: Maxillary protraction anchored on hybrid or conventional hyrax expanders may benefit patients with breathing disorders due to the increase of the upper airway volume and most constricted area. Registration: ClinicalTrials.gov (NCT03712007).