Long-term effects produced by early treatment of Class III malocclusion with rapid maxillary expansion and facemask followed by fixed appliances: A multicentre retro-prospective controlled study.

OBJECTIVE: To assess the short- and long-term dentoskeletal effects of early Class III treatment with rapid maxillary expansion and facemask (RME/FM) followed by fixed appliances. MATERIALS AND METHODS: A total of 44 patients (27 females, 17 males) treated consecutively with RME/FM were included from the archives of 3 centres. Three lateral cephalograms were available: T0 (before the start of RME/FM therapy, mean age 8.1 ± 1.8 years), T1 (immediately after RME/FM, mean age 9.8 ± 1.6 years), and T2 (long-term observation, mean age 19.5 ± 1.6 years). A control group of 17 untreated Class III subjects (12 females and 5 males) also was selected. Between-group statistical comparisons were performed with ANCOVA. RESULTS: No statistically significant differences for any of the cephalometric variables were found at T0. In the short term, the treated group showed significant improvements in ANB (+2.9°), Wits appraisal (+2.7 mm), SNA (+1.8°) and SNB (-1.1°). A significant closure of CoGoMe angle (-1.3°) associated with smaller increments along Co-Gn (-2.4 mm) also was found together with a significant increase in intermaxillary divergence (+1.3°). In the long-term, significant improvements in ANB (+2.6°), Wits appraisal (+2.7 mm) and SNB (-1.7°) were recorded together with a significant closure of the CoGoMe angle (-2.9°). No significant long-term changes in vertical skeletal relationships were found. CONCLUSIONS: RME/FM therapy was effective in improving Class III dentoskeletal relationships in the short term. These changes remained stable in the long-term due mainly to favourable mandibular changes.

Efficacy of an automatic electric toothbrush with nylon bristles in dental plaque removal: a cross-over randomized controlled trial.

OBJECTIVES: The objective of this single-use, five-treatment, five-period, cross-over randomized controlled trial (RCT) was to compare the efficacy in dental plaque removal of a new Y-shaped automatic electric toothbrush (Y-brush) compared to a U-shaped automatic electric toothbrush (U-brush), a manual toothbrushing procedure (for 45 and 120 s), and no brushing (negative control). MATERIALS AND METHODS: Eligible participants were volunteer students randomized to the treatments in the five periods of the study. The primary outcome measure was the reduction in full-mouth plaque score (FMPS) after brushing while the secondary outcome variable was a visual analogic scale (VAS) on subjective clean mouth sensation. Mixed models were performed for difference in FMPS and VAS. RESULTS: After brushing procedures, manual toothbrushing (120 s) showed a statistically significant reduction in FMPS than Y-brush (difference 36.9; 95%CI 29.6 to 44.1, p < 0.0001), U-brush (difference 42.3; 95%CI 35.1 to 49.6, p < 0.0001), manual brushing (45 s) (difference 13.8; 95%CI 6.5 to 21.1, p < 0.0001), and No brushing (difference 46.6; 95%CI 39.3 to 53.9, p < 0.0001). Y-brush was significantly more effective than No brushing (difference 9.8; 95%CI 2.5 to 17.0, p = 0.0030), while there was no significant difference compared to U- brush. Similar results were obtained for the differences in the Clean Mouth VAS. CONCLUSIONS: Y-brush was significantly more effective than no brushing (negative control) in removing dental plaque. When compared to manual toothbrushing for both 45 and 120 s, however, Y-brush was less effective in dental plaque removal. CLINICAL RELEVANCE: Modified design of automatic toothbrushing devices could improve plaque reduction, especially in patients with intellectual disabilities or motor difficulties.

Comparison between digital and conventional impression techniques in children on preference, time and comfort: A crossover randomized controlled trial.

OBJECTIVE: To compare the conventional alginate impression and the digital impression taken with an intraoral scanner of both dental arches in children, using a randomized crossover design. TRIAL DESIGN: This is a monocentric, controlled, superiority, randomized, crossover, open study. METHODS: Twenty-four orthodontic patients between 6 and 11 years of age underwent intraoral scanning (TRIOS 3; 3Shape) and alginate impression of both dental arches with an interval of 1 week between the two procedures. Participants were recruited from September 2021 to March 2022 and the study was completed in April 2022. Impression time for the two procedures was compared. Patients were asked which one of the two impression procedures they preferred. A questionnaire including Visual Analogue Scale (VAS) for comfort, pain, gag reflex and difficulty in breathing, was administered to the patients. RESULTS: Eighteen out of 24 patients preferred digital impression (75%, 95% confidence interval [CI]: 55% to 88%; P = .014). Scanning time was significantly shorter than alginate impression time (difference -118 seconds; 95% CI: -138 to -99; P < .001). Comfort was significantly higher for digital impression (difference 1.7; 95% CI: 0.5 to 2.8; P = .007). There was no difference in pain (difference -0.2; 95% CI: -1.5 to 1.0; P = .686) while gag reflex and breathing difficulties were smaller for digital impression (gag reflex difference -2.5; 95% CI: -4.0 to -0.9; P = .004 and breathing difficulties difference -1.5; 95% CI: -2.5 to -0.5; P = -.004). CONCLUSIONS: Digital impression is preferred by children aged 6-11 years and it is significantly faster in acquisition time than conventional alginate impression. REGISTRATION: The study was registered on ClinicalTrials.gov with registration number NCT04220957 on January 7th, 2020 (https://clinicaltrials.gov/ct2/show/NCT04220957).

Effects produced by the facemask with and without skeletal anchorage for the orthopaedic treatment of Class III malocclusion in growing patients: a systematic review and meta-analysis of RCTs.

BACKGROUND: Skeletally anchored facemask has been proposed to maximize skeletal effects and minimize dental effects in the treatment of Class III malocclusion in growing patients. OBJECTIVE: To compare the dento-skeletal effects produced by the facemask with or without skeletal anchorage for the treatment of Class III malocclusion in growing patients. MATERIALS AND METHODS: PubMed, Cochrane Library, Scopus, Embase, Web of Science, and OpenGrey were used for the electronic search without language, publication status, and year restrictions. Only RCTs were included. Inclusion criteria were: growing patients (age under 18 years) with Class III malocclusion, with indications for treatment with the facemask. Data were extracted by two independent reviewers. GRADE statement was executed. The mean of differences (MD) and the risk ratio (RR) were used. RESULTS: Three articles with a total of 123 patients were included. One article was at low risk of bias while two were at high risk of bias. There were no significant differences between the two groups in ANB angle, Wits appraisal, SNB angle, and SN-MP angle. SNA angle was significantly increased in the skeletally anchored facemask (pooled MD = 0.80 favouring skeletal anchorage, 95% CI from 0.29 to 1.31, P = 0.002, I2 = 12 per cent, three studies, GRADE moderate). The U1-SN angle was significantly reduced in the skeletally anchored facemask (pooled MD = -5.91 favouring skeletal anchorage, 95% CI from -7.64 to -4.27, P < 0.00001, I2 = 0 per cent, two studies, GRADE moderate). There were significantly less complications in tooth-anchored facemask (pooled RR = 7.98 favouring dental anchorage, 95 per cent CI from 1.04 to 61.27, P = 0.05, I2 = 0 per cent, two studies, GRADE low). LIMITATIONS: Few RCTs (three) were included, and two studies were at high risk of bias. There were no long-term RCTs comparing skeletally anchored facemask with dental-anchored facemask. Only Asiatic patients were included in this systematic review. CONCLUSIONS: Skeletally anchored facemask was associated to a greater increase of SNA angle at the end of treatment though clinically not significant. Facemask with skeletal anchorage determined a reduced inclination of maxillary incisors compared to dental-anchored facemask with greater risks of complications. REGISTRATION: PROSPERO register (CRD42020221982).

Variations in maxillary second molar position of untreated subjects with normal occlusions: A long-term observational study.

INTRODUCTION: The purpose of the present study was to evaluate the long-term variations in maxillary second molar position in untreated subjects with normal occlusion. SETTING AND SAMPLE POPULATION: A sample of 39 subjects (18 females and 21 males) selected from the University of Michigan Growth Study (UMGS) was followed longitudinally with digital dental casts at 3 observation times: T1, when the maxillary permanent second molars were fully erupted, T2, last observation available in the longitudinal series (38 subjects), and T3, at least 20 years after T2 (12 subjects). MATERIALS AND METHODS: Digital measurements were recorded with an open-source software. Outcome variables were sagittal and transverse inclinations of the upper second molars. Two mixed-effect models were performed. RESULTS: The maxillary second molars had a distolingual inclination at T1, T2 and T3. Sagittal and transverse inclination showed progressive significant uprighting from T1 through T3 (P < .001). From T1 to T2, the adjusted difference in sagittal crown inclination was 8.0° (95% CI from 6.5° to 9.6°; P < .001). From T2 to T3, the adjusted difference was 5.5° (95% CI from 3.0° to 8.1°; P < .001). From T1 to T2, the adjusted difference in transverse crown inclination was 1.9° (95% CI from 0.4° to 3.5°; P = .011). From T2 to T3, the adjusted difference was 6.0° (95% CI from 3.4° to 8.5°; P < .001). CONCLUSIONS: Along with age, maxillary second molars showed a progressive significant uprighting with a decrease in the distal and lingual inclinations.

Post-pubertal effects of the Alt-RAMEC/FM and RME/FM protocols for the early treatment of Class III malocclusion: a retrospective controlled study.

OBJECTIVE: To assess the stability of the effects of the modified Alt-RAMEC and facial mask (FM) protocol at a post-pubertal observation. METHODS: Twenty-one Class III patients (11 males and 10 females, 6.5 ± 0.7 years) treated consecutively with the Alt-RAMEC/FM approach and presenting with lateral cephalograms taken before treatment (T1), after treatment (T2), and at post-pubertal observations (T3) were compared with 22 Class III patients (9 males and 13 females, 6.9 ± 1.2 years) treated with the rapid maxillary expansion (RME) and FM protocol and with 15 Class III untreated subjects (7 males and 8 females, 6.2 ± 2.2 years). At T3, all patients showed a post-pubertal skeletal maturation stage (CS4-CS6). Descriptive statistics and statistical comparisons between the three groups at T1 and for the T3-T1, T2-T1, and T3-T2 changes were assessed by means of the ANOVA or Kruskal-Wallis test. RESULTS: During the overall observation period, Alt-RAMEC/FM and RME/FM protocols produced statistically significant favourable effects when compared with the Control group (ANB + 2.8° and +2.2°, respectively; Wits appraisal +4.4 mm and +2.7 mm, respectively). No statistically significant differences were found between the outcomes of the Alt-RAMEC/FM and RME/FM protocols neither at the post-pubertal or short-term observations. LIMITATIONS: Retrospective study and the comparison with an historical control sample of subjects with untreated Class III malocclusion. CONCLUSIONS: The Alt-RAMEC/FM protocol cannot be recommended as the approach of choice for the therapy of Class III dentoskeletal disharmony in very young subjects compared to the conventional RME/FM protocol.

Comparison of the dento-skeletal effects produced by Leaf expander versus rapid maxillary expander in prepubertal patients: a two-center randomized controlled trial.

OBJECTIVE: This study aimed to compare the skeletal and dentoalveolar effects produced by slow maxillary expansion (SME) with the Leaf expander versus the conventional rapid maxillary expansion (RME) on digital dental casts, lateral and postero-anterior cephalometric radiographs. TRIAL DESIGN: This is a superiority, two-center, two arms parallel balanced randomization trial. METHODS: Patients in the mixed dentition were included with a transverse interarch discrepancy of at least 3 mm. An expansion screw using moderate continuous forces (Leaf group) was compared to a conventional RME screw (RME group). The primary response variable was the difference in maxillary intermolar width (U6-U6) measured at baseline (T0) and one-year follow-up (T1) on the digital dental casts. Other dento-skeletal variables were also measured on digital dental casts and cephalograms. Computer-generated block randomization was used with allocation concealed in sequentially numbered opaque sealed envelopes. The examiner was blinded on the type of expander used. Linear models were used for statistical analysis. RESULTS: Twenty-eight patients in the Leaf group and 28 patients in the RME group were randomized and included in the study. There were no dropouts. U6-U6 did not show a statistically significant difference between the two groups (-0.4 mm in favor of the RME group, 95% CI from -1.2 to 0.5, P = 0.365). As for the other secondary variables no statistically significant differences were found between the two groups except maxillary intercanine width (U3-U3, -0.9 mm in favor of the RME group, 95%CI from -1.5 to -0.3, P = 0.005) and maxillary skeletal width (Mx-Mx, -1.4 mm in favor of the RME group, 95%CI from -2.4 to -0.3, P = 0.013). CONCLUSIONS: No significant differences between the RME and Leaf groups were detected for any of the analyzed dento-skeletal variables except the T1-T0 differences in U3-U3 and Mx-Mx that were significantly greater in the RME group. REGISTRATION: The study was registered in the ISRCTN register on 08/11/2016 with the number ISRCTN18263886. FUNDING: No funding or conflict of interest to be declared.

Predicting mandibular growth based on CVM stage and gender and with chronological age as a curvilinear variable.

OBJECTIVE: The aim of this study was to develop a prediction model that combines the information derived from chronological age (analysed as a curvilinear variable), gender and the CVM method to predict mandibular growth. SETTINGS AND SAMPLE POPULATION: 50 participants (29 females, 21 males) were selected from the AAOF Craniofacial Growth Legacy Collection, the Michigan Growth Study and the Denver Child Growth study. MATERIALS AND METHODS: In this investigation, 456 lateral cephalograms were analysed by applying a mixed effect model. The outcome variable was the annualized increment in total mandibular length (Co-Gn) during the year following the lateral cephalogram on which the cervical stage and chronological age were evaluated. The predictive variables were chronological age up to the fifth order, gender, stage of cervical vertebral maturation, as well as interactions between age and gender, age and cervical stage, and gender and cervical stage. RESULTS: Cervical stage, chronological age up to the fourth order, gender, and the interaction between age and gender were significant predictors of annualized increments in mandibular length. The annualized increment in Co-Gn was significantly greater for CS 3 when compared to all other cervical stages. Further, annualized increments in Co-Gn for CS 1 and CS 2 were significantly greater when compared to CS 5. CONCLUSIONS: Cervical stage, chronological age and gender can be used jointly to predict the annualized increment in mandibular growth. Cervical stage 3 exhibited the greatest annualized increase in mandibular length.

Prognostic approach to Class III malocclusion through case-based reasoning.

OBJECTIVE: This investigation evaluates the evidence of case-based reasoning (CBR) in providing additional information on the prediction of future Class III craniofacial growth. SETTINGS AND SAMPLE POPULATION: The craniofacial characteristics of 104 untreated Class III subjects (7-17 years of age), monitored with two lateral cephalograms obtained during the growth process, were evaluated. MATERIALS AND METHODS: Data were compared with the skeletal characteristics of subjects who showed a high degree of skeletal imbalance ('prototypes') obtained from a large data set of 1263 Class III cross-sectional subjects (7-17 years of age). RESULTS: The degree of similarity of longitudinal subjects with the most unbalanced prototypes allowed the identification of subjects who would develop a subsequent unfavourable skeletal growth (accuracy: 81%). The angle between the palatal plane and the sella-nasion line (PP-SN angle) and the Wits appraisal were two additional craniofacial features involved in the early prediction of the adverse progression of the Class III skeletal imbalance. CONCLUSIONS: Case-based reasoning methodology, which uses a personalized inference method, may bring additional information to approximate the skeletal progression of Class III malocclusion.

Occlusal Plane and Skeletal Changes After Cervical Headgear Treatment With and Without Lower Utility Arch in Class II Growing Patients.

ABSTRACT: The purpose of this study was to investigate skeletal and dental changes affecting occlusal plane inclination after cervical headgear treatment with and without lower utility arch. In order to distinguish the orthodontic changes from natural growth a control group was employed.The sample of this study consisted by 20 Class II subjects (10 males, 10 females; mean age 8.54) treated by using cervical headgear, 19 class II children (19 males, 9 females; mean age 8.64) treated with cervical headgear and utility arch, and 21 Class II patients (11 males, 10 females; mean age 8.41) who had no therapy.Lateral head films were studied for all the patients before treatment (T1) and after therapy (T2) for all the treated groups and at the beginning and at the end of observational period for the control group; cephalometric analysis was carried out in order to seek for the modifications between time points and between groups.Means and standard deviation have been analyzed for all the groups. In order to compare the modification between the time points within the same group the ANOVA test was applied. The ANOVA test was used to compare the mean differences (T2-T1) of 3 groups.The study revealed that there were significant changes in occlusal plane inclination after the different treatment modalities employed instead control group. The treatment with cervical headgear and utility arch is more effective than cervical headgear alone in lowering occlusal plane posteriorly when it is compared with controls.

Dento-skeletal effects produced by rapid versus slow maxillary expansion using fixed jackscrew expanders: a systematic review and meta-analysis.

BACKGROUND: No systematic review and meta-analysis of dento-skeletal effects following rapid maxillary expansion (RME) and slow maxillary expansion (SME) using the same jackscrew expander with different activation protocols is available. OBJECTIVE: To compare dento-skeletal effects produced by RME with those induced by SME using the same fixed jackscrew expanders in growing patients. SEARCH METHODS: PubMed (MEDLINE), Cochrane Library, Scopus, Embase, and OpenGrey were searched with no language or publication date restrictions. SELECTION CRITERIA: Only randomized controlled trials (RCTs) were selected and the following inclusion criteria were used: growing patients in mixed or permanent dentition, with maxillary transverse discrepancy, dental crowding, and treated with fixed jackscrew maxillary expander (e.g. Hyrax, Haas) activated to achieve either RME or SME. DATA COLLECTION AND ANALYSIS: Data were extracted by two independent reviewers. The quality of the included RCTs was assessed according to the Cochrane risk-of-bias tool for randomized trials (RoB 2.0). For the aggregation of continuous data, the mean of the differences (MD) between treatments was used. A random effect model was applied. RESULTS: From 4855 retrieved articles, 3 studies were selected, 1 at unclear risk and 2 at high risk of bias. Maxillary intermolar distance showed no significant differences between the two modalities of expansion [pooled MD = 0.99 mm favouring RME, with 95% confidence interval (CI) = -2.09 to 4.06, P = 0.53, I2 = 90%]. As for maxillary molar inclination measured as the angle formed by the axes passing through the disto-buccal cusps and the apexes of the palatine root of the first upper molars, it was significantly smaller in the SME group (MD = -11.51°, with 95% CI = -15.23 to -7.79, P < 0.0001). Posterior maxillary expansion was significantly greater in RME than SME (pooled MD = 0.75 mm, with 95% CI = 0.27-1.23, P = 0.002, I2 = 0%). CONCLUSIONS: Both RME and SME produce an effective dento-skeletal expansion of the maxilla. RME is slightly more effective in increasing the posterior transverse skeletal width of the maxilla while SME induces smaller molar inclination. REGISTRATION: PROSPERO CDR42018105530.

Comparison between two screws for maxillary expansion: a multicenter randomized controlled trial on patient's reported outcome measures.

OBJECTIVE: The objective of this study was to compare an expansion screw of the maxilla that generates moderate and continuous forces versus a conventional screw for rapid maxillary expansion (RME) on patient-reported outcome measure during the first 12 weeks of treatment. TRIAL DESIGN: This is a superiority, multicenter, two-arm parallel balanced randomization trial. METHODS: Patients in the mixed dentition were included with a transverse discrepancy between the two arches of at least 3 mm. An expansion screw using moderate continuous forces (Leaf group, treated with an expansion screw with Ni-Ti springs) was compared to a conventional RME screw that generates intermittent heavy forces (RME group). The primary response variable was the visual analogue scale (VAS) on pain calculated in the first 12 weeks of therapy. The VAS on difficulty on speaking and oral hygiene, patient satisfaction, and complications were also evaluated. A computer-generated block randomization was used with allocation concealed in sequentially numbered opaque-sealed envelopes. Blinding was not applicable. Linear models were used for statistical analysis. RESULTS: Twenty-eight patients in the Leaf group and 28 patients in the RME group were randomized and included in the study. There were no dropouts. The mean of the VAS for pain was 0.3 ± 0.4 in the Leaf group and 0.6 ± 0.5 in the RME group. The difference was -0.3 (95 per cent CI from -0.5 to -0.0; P = 0.017) in favour of the Leaf group. The difference in pain was marked in the first week (Leaf group 2.2 ± 2.3; RME group 3.7 ± 2.6; difference -1.5; 95 per cent CI from -2.7 to -0.3; P = 0.019). CONCLUSIONS: Patients in the Leaf group experienced a lower degree of pain, especially during the first week following the application of the expander. For the other variables, no significant differences were reported between the two treatments. REGISTRATION: The study was registered in the ISRCTN register on 8 November 2016 with the number ISRCTN18263886.

A multilevel analysis of craniofacial growth in subjects with untreated Class III malocclusion.

OBJECTIVE: To analyse the craniofacial growth of a long-term semi-longitudinal sample of Caucasian subjects with untreated Class III malocclusion. SETTING AND SAMPLE POPULATION: A total of 144 Caucasian subjects (of North American and Italian origin) with untreated Class III malocclusion. MATERIALS AND METHODS: Subjects aged 2 years and 9 months up to 21 years and 7 months were selected. A multilevel model was used to calculate growth curves for ten variables for both each individual subject and for the whole sample. RESULTS: There was a statistically significant increase for total mandibular length (Co-Gn. T2-T1 = 8.4 mm), midfacial length (Co-A. T2-T1 = 3.4 mm) and lower anterior facial height (ANS-Me. T2-T1 = 3.8 mm). The multilevel analysis showed two points of acceleration of growth (about 3-5 years of age and 11-15 years of age) for seven out of ten variables. For Co-Gn and Co-A variables, males presented points of maximum growth delayed by 1 year in comparison with females, with a greater duration (1 year longer) and a greater total growth of about 5 mm. Active mandibular growth continued for a long time after the pubertal spurt: increases in mandibular length ended at about 17 years of age in females and at 21 years and 7 months in males. CONCLUSIONS: Untreated Class III malocclusion showed a specific growth curve, especially for the mandible, whose excesses added up over time. In males, the amounts of mandibular and midfacial growth during the whole observation time were greater and lasted longer than in females.

Changes in canine inclination after rapid and slow maxillary expansion compared to untreated controls.

OBJECTS: Palatally displaced canines (PDC) might represent condition causing several clinical problems, such as roots resorption and malocclusion, and can develop palatal canine impaction. Some interceptive treatments such as rapid maxillary expansion were suggested in order to foster maxillary canine eruption. Among expansion protocols, no data are available about differences between rapid and slow maxillary expansion on maxillary canine eruption. The aim of this study was therefore to evaluate α-angle changes in palatally displaced canines using rapid and slow maxillary expansion compared to untreated control patients. SETTING AND SAMPLE POPULATION: The final sample comprised 19 patients treated with rapid maxillary expansion (RME group), 17 treated with slow maxillary expansion (SME group) and 22 control patients (Control group). MATERIALS AND METHODS: α-angle was measured on panoramic films to detect canine inclination at the beginning, and at the end of maxillary expansion treatment or observation, time and changes over time were compared. RESULTS: In the comparisons among groups, RME group was the only group showing a decrease in α-angle measurements that was statistically significant also when compared to the other groups, except for the left side when compared to SME group. CONCLUSION: RME treatment significantly and positively affected canine position when compared to SME treatment and control group.

How to Prevent Mandibular Lower Border Notching After Bilateral Sagittal Split Osteotomies for Major Advancements: Analysis of 168 Osteotomies.

PURPOSE: Mandibular ramus bilateral sagittal split osteotomy (BSSO) has been the most commonly used technique in orthognathic surgery for mandibular advancement. However, a common complication of BSSO has been the occurrence of visible and palpable osseous defects at the inferior border of the mandible. The aim of the present study was to determine whether bone grafting of the osseous defect at surgery would reduce the defect at 1 year postoperatively compared with no bone grafting. MATERIALS AND METHODS: The present retrospective cohort study evaluated patients who had undergone mandibular ramus BSSO for 10 mm or more of advancement. The primary predictor variable was BSSO surgery with bone grafting of the defect (graft group [GG]) versus no bone graft (no graft group [NGG]). The size of the mandibular ramus inferior border defect was the outcome variable considered within the framework of a 1-year postoperative cone beam computed tomography (CBCT) analysis. Gender, age, and the amount of advancement were also considered in the multilevel regression analyses. RESULTS: From January 2012 to November 2016, 84 patients (168 osteotomies) had undergone BSSO surgery with 10 mm or more of mandibular advancement at the Facesurgery Center (Parma, Italy). Their mean age was 27.4 years (range, 17 to 44 years). Of the 84 patients, 40 had undergone BSSO with bilateral bone grafts (GG). The monocortical block of the iliac crest bone was used as the bone homograft. The final residual defect was measured at 1 year postoperatively on CBCT scans. The GG and NGG had presented with a mean final defect of 0.7 mm (range, 0 to 4.5 mm) and 3.0 mm (range, 0 to 5.5 mm), respectively. Complete absence of the defect was achieved in 72% of the osteotomies in the GG and 9% of the osteotomies in the NGG. CONCLUSIONS: The use of an iliac crest bone allograft block in the gap between 2 segments during mandibular advancement of 10 mm or more substantially reduced the size and incidence of inferior border defects.

Development and validation of a prediction model for long-term unsuccess of early treatment of Class III malocclusion.

AIM: To develop and validate a prediction model to forecast long-term stability of early treatment with rapid maxillary expansion (RME) and facemask (FM) in a large sample of Class III growing patients. METHODS: The Brazilian Group (BG) consisted of 73 consecutively treated Caucasian Class III patients (41 females and 32 males). Mean age at T0 (before treatment) was 7.1 ± 1.6 years, while mean age at T1 (long-term follow-up) was 21.8 ± 3.2 years. The Italian Group (IG, validation cohort) comprised 28 consecutively treated Caucasian Class III patients (14 females and 14 males, mean age at T0 9.0 ± 1.3 years and mean age at T1 18.2 ± 1.4 years). Cephalometric analysis was performed on lateral cephalograms at T0. Gender and cephalometric variables, chronologic age, and dentition phase at T0 were used as predictors for long-term unsuccessful treatment at T1. All predictors for unsuccessful treatment in the BG were subjected to bivariate logistic regression. Only those statistically significant predictors in the bivariate logistic regression entered mixed stepwise logistic regression with P = 0.05 to enter and to leave. The validity of the prediction model derived from the BG was then tested on the IG. RESULTS: The prediction model consisted of only one cephalometric variable: the angle between the Condylar Axis and the Mandibular Plane (CondAx-MP) (odds ratio: 1.52, 95% confidence interval: 1.25-1.85, P < 0.0001). Unsuccessful treatment at T1 was predicted for values of CondAx-MP at T0 greater than the cut-off value of 147.8 degrees. BG patients predicted incorrectly were 3 out of 22 for the unsuccessful cases and 1 out of 51 for the successful cases. Therefore, accuracy was 0.95, sensitivity 0.86, specificity 0.98, and positive and negative predictive values were 0.95 and 0.94. When the predictive model was applied on IG, all five unsuccessful cases were predicted correctly, while only 1 out of 23 successful patients was predicted incorrectly. CONCLUSION: CondAx-ML was identified as a reliable predictor for long-term stability of early Class III treatment with RME and FM.

Three-dimensional evaluation of the maxillary effects of two orthopaedic protocols for the treatment of Class III malocclusion: A prospective study.

OBJECTIVES: To compare the three-dimensional maxillary dentoskeletal effects of a modified alternate rapid maxillary expansion and constriction facemask protocol (Alt-RAMEC/FM) with the traditional rapid maxillary expansion facemask protocol (RME/FM) performed in deciduous or early mixed dentition Class III patients. SETTING AND SAMPLE POPULATION: Orthodontic Clinic of the Section of Dentistry of the Department of Surgery and Translational Medicine of the University of Florence. Thirty-four Class III patients were enrolled and allocated by alternating assignment to either Alt-RAMEC/FM or RME/FM therapy. MATERIALS AND METHODS: Prior to treatment, all patients were evaluated, and a cone beam computed tomography (CBCT) scan was acquired. After completion of the orthopaedic therapy (average interval 1.2 years), a follow-up CBCT scan was obtained. Anatomic landmark identification on the CBCTs and subsequent quantification of the changes were performed. The primary outcome variable was the anteroposterior displacement of the anterior nasal spine (ANS AP). The treatment groups were compared with independent samples t tests. RESULTS: The patients in the two treatment groups showed a similar degree of compliance. No statistically significant differences were recorded for any variable when comparing the Alt-RAMEC/FM and RME/FM groups. In particular, the between-group difference for ANS AP was 0.0 mm (95%CI: -0.6;0.7, P = 0.933). CONCLUSIONS: Both Alt-RAMEC/FM and RME/FM produced favourable orthopaedic changes in Class III growing patients. Neither protocol was superior to the other in terms of maxillary protraction effectiveness.

Comparison of the effects on facial soft tissues produced by rapid and slow maxillary expansion using stereophotogrammetry: a randomized clinical trial.

OBJECTIVE: To compare the effects on facial soft tissues produced by maxillary expansion generated by rapid maxillary expansion (RME) versus slow maxillary expansion (SME). MATERIALS AND METHODS: Patients in the mixed dentition were included with a transverse discrepancy between the two arches of at least 3 mm. A conventional RME screw was compared to a new expansion screw (Leaf expander) designed to produce SME. Both screws were incorporated in a fixed expander. The primary outcome was the difference of the facial tissue changes in the nasal area measured on facial 3D images captured immediately before application of the expander (T0) and after one year of retention, immediately after the expander removal (T1). Secondary outcomes were soft tissue changes of other facial regions (mouth, lips, and chin). Analysis of covariance was used for statistical analysis. RESULTS: Fourteen patients were allocated to the RME group, and 14 patients were allocated to the SME group. There were no dropouts. Nasal width change showed a difference between the two groups (1.3 mm greater in the RME group, 95% CI from 0.4 to 2.2, P = 0.005). Also, intercanthal width showed a difference between treatments (0.7 mm greater in the RME group, 95% CI from 0.0 to 1.3, P = 0.044). Nasal columella width, mouth width, nasal tip angle, upper lip angle, and lower lip angle did not show any statistically significant differences. The Y-axis (anterior-posterior) components of the nasal landmark showed a statistically significant difference between the two groups (0.5 mm of forward displacement greater in the RME group, 95% CI from 0.0 to 1.2, P = 0.040). Also, Z-axis (superior-inferior) components of the lower lip landmark was statistically significant (0.9 mm of downward displacement in favor of the RME group, 95% CI from 0.1 to 1.7, P = 0.027). All the other comparisons of the three-dimensional assessments were not statistically significant. CONCLUSIONS: RME produced significant facial soft tissue changes when compared to SME. RME induced greater increases in both nasal and intercanthal widths (1.3 mm and 0.7 mm, respectively). These findings, though statistically significant, probably are not clinically relevant. Trial registration ISRCTN, ISRCTN18263886. Registered 8 November 2016, https://www.isrctn.com/ISRCTN18263886?q=Franchi&filters=&sort=&offset=2&totalResults=2&page=1&pageSize=10.

Stability of quad-helix/crib therapy in dentoskeletal open bite: a long-term controlled study.

INTRODUCTION: The purpose of this study was to evaluate the long-term stability of quad-helix/crib treatment in subjects with dentoskeletal open bite. METHODS: Twenty-eight subjects (11 boys, 17 girls; mean age, 8.2 ± 1.3 years) were treated consecutively with quad-helix/crib appliances. The patients were reevaluated at the end of active treatment with the quad-helix/crib (mean age, 9.7 ± 1.6 years) and at least 5 years after the completion of treatment (mean age, 14.6 ± 1.9 years). A control group of 20 untreated subjects with the same dentoskeletal disharmony was used for the statistical comparison (Mann-Whitney U test). RESULTS: In the long term, the quad-helix/crib group showed a significant reduction in the ANB angle (-1.3°), a downward rotation of the palatal plane (1.8°), a greater increase in overbite (2.1 mm), and a decrease in overjet (-1.5 mm) when compared with the controls. CONCLUSIONS: In the long term, the use of the quad-helix/crib appliance led to successful outcomes in about 93% of the patients considered. Correction of dentoskeletal open bite was associated with a clinically significant downward rotation of the palatal plane.

Long-Term Assessment of Treatment Timing for Rapid Maxillary Expansion and Facemask Therapy Followed by Fixed Appliances: A Multicenter Retro-Prospective Study.

BACKGROUND: to determine the role of treatment timing in the long-term effects produced by rapid maxillary expansion and facemask therapy (RME/FM) in Class III patients. METHODS: This study compared two sample groups treated with RME/FM followed by fixed appliances: the early prepubertal group (EPG) (17 patients; mean age before treatment (T0), 5.8 ± 0.7 years; range, 4.3-6.9 years) and the late prepubertal group (LPG) (17 patients; mean age at T0, 10.1 ± 0.8 years; range, 9.0-11.1 years). Lateral cephalograms for the two groups were examined before treatment (T0) and at a long-term observation (T1) (EPG, 19.8 ± 1.0 years; LPG, 21.0 ± 2.1 years). Independent sample t-tests were performed to compare the two groups at T0 and T1. RESULTS: No statistically significant differences were found for any of the cephalometric variables at T0, except for the total mandibular length, overjet, and inclination of the maxillary incisors to the palatal plane, which were greater in the LPG. At T1, no statistically significant differences were detected for any of the cephalometric variables. CONCLUSIONS: There were no significant long-term differences when treating Class III patients with RME/FM, either during an early prepubertal phase (≤7 years of age) or during a late prepubertal phase (≥9 years of age).