Effects of eruption guidance appliance in the early treatment of Class III malocclusion.

OBJECTIVES: To evaluate the dentoskeletal effects and effectiveness of the eruption guidance appliance in Class III patients in the mixed dentition. MATERIALS AND METHODS: The experimental group comprised 22 patients with Class III malocclusion and anterior cross-bite (12 males, 10 females, mean age 7.63 ± 0.96 years) treated with the eruption guidance appliance over a mean period of 1.72 ± 0.48 years. The control group comprised 22 untreated subjects (12 males, 10 females, mean age 7.21 ± 0.60 years) with Class III malocclusion. Lateral cephalometric radiographs were obtained at pretreatment (T1) and posttreatment (T2). Intergroup comparisons were performed with Mann-Whitney and t-tests (P < .05). RESULTS: In the experimental and control groups, the anteroposterior relationship between the maxilla and mandible (ANB angle) remained stable during the treatment period (T1 to T2). The mandibular plane angle decreased in the experimental group and increased in the control group. In the experimental group, the lower anterior face height increase and maxillary molar vertical development were significantly smaller compared to controls. Positive overjet was achieved in 54% of the experimental group. CONCLUSIONS: The eruption guidance appliance produced no change in the skeletal anteroposterior relationship. The anterior cross-bite/edge-to-edge relationship was corrected in only about half of the treated subjects.

Third Molar Comparison in Class I and II Extraction and Non-extraction Orthodontic Treatment: A Retrospective Longitudinal Study.

Objective: This study compared third molar angulation and eruption status in Class I and II malocclusions after orthodontic treatment with and without first premolar extractions. Methods: The sample comprised 93 patients divided into four groups: Group 1, Class I malocclusion treated with first premolar extractions; Group 2, Class I malocclusion treated without extractions; Group 3, Class II malocclusion treated with first premolar extractions; and Group 4, Class II malocclusion treated without extractions. Panoramic radiographs were used to evaluate the third molar mesiodistal angulations at T1 (pretreatment), T2 (posttreatment), and T3 (long-term posttreatment). Third molar eruption status was assessed in dental casts. Intergroup angulations and eruption status comparisons were performed using one-way analysis of variance (ANOVA), followed by Tukey's test and Kruskal-Wallis test, respectively. Results: Significantly greater mesial angulation and percentage of erupted right maxillary third molars were observed in the Class I extraction group. Significantly greater eruption status of the right mandibular third molars was observed in the Class I and Class II malocclusion extraction groups. Conclusion: Class I and II malocclusion extraction treatment exhibited more favorable angulations and a greater number of erupted third molars than non-extraction treatment. The non-extraction groups exhibited a greater percentage of unerupted third molars.

Association of mandibular canine impaction and anatomical factors: A multicentre retrospective panoramic study in Latin America.

INTRODUCTION: Mandibular canine impaction is infrequent in dental eruption anomalies and treatment is very challenging. The aim of this multicenter retrospective panoramic study in Latin America was to evaluate panoramic radiographic imaging characteristics of mandibular canine impaction (impaction area, mandibular base contact, transmigration, impaction height and sex) and their associations. MATERIAL AND METHODS: This cross-sectional study evaluated 212 digital panoramic radiographs from three radiological centres in Tingo Maria (Peru), Bogota and Tunja (Colombia). The study included children of both sexes with impacted mandibular canines. Mandibular alpha angle, contact with mandibular basal bone (MBB), impacted sector according to 10 sectors with an adaptation of the Ericson and Kurol method, presence of transmigration and the impacted height were measured and the relationship among these measures was analyzed. Fisher's exact test, Chi-square and binary logistic regression were used. (P<0.05). RESULTS: The mandibular canine impaction showed contact with the MBB (32.08%), dental transmigration (36.79%), mainly located at an apical (40.09%) and sub-apical (36.79%) level. Transmigration mainly occurred in sectors 6 (33.30%) and 10 (25.60%) (P<0.001). It was found that for each year of increase in age, the possibility of contact with the MBB decreased (ß=0.89, P=0.010), and as the alpha angle increased by one degree the probability of contact with the MBB decreased (ß=0.97, P=0.001) and the probability of transmigration increased (ß=1.05, P<0.001). CONCLUSIONS: One third of the impacted canines were in contact with the MBB, while another third presented dental transmigration and were mainly located apically and subapically of the incisor roots. These imaging features should be taken into account when planning orthodontic treatment.

Oral health-related quality of life, adaptation/discomfort during open bite treatment with spurs: complementary analysis from a randomized clinical trial.

This single-center trial aimed to longitudinally compare the oral health-related quality of life (OHRQOL), adaptation and discomfort during anterior open bite (AOB) treatment with lingual spurs and build-ups (SBU) versus spurs only (S) approaches. Children (7-11 years) with AOB were randomly allocated into two treatment groups (SBU or S). The Child Perception Questionnaire (CPQ8-10) was applied 1 and 12 months after installation of the appliances. Questionnaires evaluating functional adaptation and discomfort during the first month of treatment were also applied. A visual analog scale (VAS) was used in these questionnaires. Generalized mixed models were used for analyzing OHRQOL and discomfort data. Generalized linear models were used to assess adaptation outcomes (α = 0.05). The SBU group included 24 patients (7 males and 17 females; mean age 8.2 years) and the S group included 25 patients (11 males and 14 females; mean age 8.3 years). Regardless of the treatment type, overall OHRQOL scores at 12 months were 0.69 times those recorded at 1 month after the appliances installation (i.e., ~ 31% reduction; exp (ß) = 0.69; 95% CI: 0.55, 0.88). A significant interaction between treatment and time was detected for the 'functional limitations' domain. For this domain, a significant improvement from the first to the twelfth month was observed in the S group (P < 0.001). Patients in both treatment groups showed similar and easy adaptation to the appliances. Independent of the type of treatment, tongue-related discomfort decreased over time. One week and one month after the appliance's delivery, the discomfort scores were 0.19 (i.e., ~ 81% reduction; exp (ß) = 0.19; 95% CI: 0.13, 0.28; P < 0.001) and 0.02 (i.e., ~ 98% reduction; exp (ß) = 0.02; 95% CI: 0.01, 0.07; P < 0.001) times, respectively, those issued immediately after the installation of the appliances. Regardless of treatment type; overall OHRQOL improved from the first to the twelfth month of AOB treatment. The functional limitations score decreased in the S group. Children showed easy adaptation, and their discomfort decreased 1 week after the installation of the appliances.Trial registration: Clinicaltrials.gov; NCT03702881, date of registration: October 11, 2018.

Alveolar morphometry in young adults with and without agenesis of the upper lateral incisor: A retrospective study.

INTRODUCTION: We aimed to compare alveolar morphometry in young adults with agenesis of the upper lateral incisor versus the side without agenesis and versus matched controls. MATERIAL AND METHODS: In this observational retrospective study, cone beam computed tomography scans were obtained of 36 upper hemiarches from young adults aged 15 to 30 years. The hemiarches were distributed into three groups: group 1: 12 upper hemiarches presenting agenesis of the upper lateral incisor; group 2: 12 upper hemiarches from the opposite side without agenesis of the upper lateral incisor (control group 1); and group 3: 12 upper hemiarches without agenesis of the upper lateral incisor matched for age and sex with respect to the affected group (control group 2). A trained and calibrated investigator performed all the alveolar measurements at two different times, including sagittal, coronal and axial slices of each hemiarch. Paired Student's t-tests, Chi-square and repeated measures ANOVA with Bonferroni correction were used, (P<0.05). RESULTS: Apical mesial evaluation of group 1 (4.22±1.19mm) was significantly lower (P<0.001) than that of groups 2 (6.72±1.17mm) and 3 (7.58±1.67mm). Apical distal evaluation also showed differences (P<0.001) among the three groups, with the dimension being smaller in group 1 with agenesis (4.53±1.14mm), followed by group 2 without agenesis (6.23±1.55mm) and the healthy control group 3 (7.73±1.71mm). CONCLUSIONS: Lateral incisor agenesis significantly reduces the alveolar dimensions of the affected area. In cases of unilateral agenesis, the unaffected side also shows sequelae, with decreased dimensions compared to cases without agenesis. This condition should be taken into account when making therapeutic decisions regarding rehabilitation with implants or canine replacement.

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.

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.

Interpretable artificial intelligence for classification of alveolar bone defect in patients with cleft lip and palate.

Cleft lip and/or palate (CLP) is the most common congenital craniofacial anomaly and requires bone grafting of the alveolar cleft. This study aimed to develop a novel classification algorithm to assess the severity of alveolar bone defects in patients with CLP using three-dimensional (3D) surface models and to demonstrate through an interpretable artificial intelligence (AI)-based algorithm the decisions provided by the classifier. Cone-beam computed tomography scans of 194 patients with CLP were used to train and test the performance of an automatic classification of the severity of alveolar bone defect. The shape, height, and width of the alveolar bone defect were assessed in automatically segmented maxillary 3D surface models to determine the ground truth classification index of its severity. The novel classifier algorithm renders the 3D surface models from different viewpoints and captures 2D image snapshots fed into a 2D Convolutional Neural Network. An interpretable AI algorithm was developed that uses features from each view and aggregated via Attention Layers to explain the classification. The precision, recall and F-1 score were 0.823, 0.816, and 0.817, respectively, with agreement ranging from 97.4 to 100% on the severity index within 1 group difference. The new classifier and interpretable AI algorithm presented satisfactory accuracy to classify the severity of alveolar bone defect morphology using 3D surface models of patients with CLP and graphically displaying the features that were considered during the deep learning model's classification decision.

Conservative Treatment of Bilateral Impacted Mandibular Canines Traction.

The objectives of the treatment of impacted canines differ according to the characteristics of dental malocclusion. Traction of the tooth is a conservative and viable alternative, which allows for maintaining stability and occlusal function. The following case report describes the treatment of an 11.6-year-old female patient, who presented bilateral impaction of mandibular canines in contact with the midline, mixed dentition in the inter-transitional period, class I angle malocclusion, with light crowding teeth. The treatment comprised three phases. The first phase, verticalization of the mandibular canines in mixed dentition, was performed to pull the impacted bilateral mandibular canines towards the dental arch to achieve their verticalization, maintaining the molar relationship, and the position of the upper and lower incisors. In the second phase, osteogenic rest was planned to relieve post-traction stress while awaiting the replacement of the mixed dentition. Finally, the third phase in permanent dentition was to align and level canines within the arch after extraction of the deciduous canines. For the viability of the permanent mandibular canines in the dental arch, orthosurgical traction was implemented, with a traction system with closed nickel-titanium coil springs with a transitory rigid dental-mucous-supported anchorage device, which allowed control and protection of the adjacent teeth and movements with helical forces of a controlled three-dimensional range. The results of the treatment were adequate, achieving consolidated molar and canine relationships, overjet, overbite, and optimal facial balance.

Concordance of the facial biotype between Bjork-Jarabak cephalometrics and photographic analysis of the facial opening angle.

Background: Analysis of the facial biotype can provide useful information for orthodontic diagnosis and can determine the type of growth of a patient to guide orthodontic treatment. The objective of this study was to determine the concordance of the facial biotype according to Bjork-Jarabak cephalometric analysis and photographic analysis of the angle of facial opening in Peruvian individuals. Material and Methods: This retrospective study included 244 cephalometric radiographs and frontal photographs of the same patients obtained from a database. The facial biotype (mesofacial, brachyfacial, or dolichofacial) was determined with the Björk-Jarabak polygon (cephalometric) and the angle of facial opening (photographic). Two trained investigators performed all the measurements. The concordance of the facial diagnosis was determined using correlations of the interclass coefficient and the kappa test. p<0.05. Results: In cases with a mesofacial biotype, both analyses coincided in 60 individuals (68.2%), while in those diagnosed with a dolichofacial biotype, the analyses only coincided in 17 individuals (10.4%). There was no concordance between the two methods regarding the brachyfacial biotype since according to the angle of facial opening none of the individuals presented a brachyfacial biotype (kappa weighted test= 0.020, p=0.586). Conclusions: Cephalometric and photographic analyses should be complementary and one should not substitute the other. Attention should be focused on dolichofacial and brachyfacial biotypes, which showed less concordance between evaluations. So, more studies are needed to follow this line of research. Key words:Facial biotype, cephalometry, photography, facial type, radiography.

Three-dimensional decision support system for treatment of canine impaction.

INTRODUCTION: This study aimed to develop a 3-dimensional (3D) characterization of the severity of maxillary impacted canines and to test the clinical performance of this characterization as a treatment decision support tool. METHODS: Cone-beam computed tomography images obtained from 83 patients with 120 impacted maxillary canines were included. Quantitative information on the canine 3D position and qualitative assessment of root damage of adjacent teeth were evaluated. A severity index was constructed on the basis of the quantitative findings. Clinical applicability was tested by comparing clinical diagnosis and treatment planning for conventional records vs the 3D characterization via a 2-part survey. RESULTS: The average quantitative assessments of impacted maxillary canine position were 6.4 ± 3.6 mm from the midsagittal plane, 11.6 ± 3.1 mm in height relative to the occlusal plane, 31.5° ± 18° of roll, and 48.8° ± 14.3° of pitch. The severity index ranged from 0-13 with a mean score of 4.5 ± 2.2. Overlap with adjacent teeth was the greatest contributor (33%) to the index. Bicortically impacted canines caused the most severe root damage. Cone-beam computed tomography was preferred for assessing root damage and overall severity, whereas conventional imaging was sufficient for height and angulation assessment. The 3D report was very important or important for evaluating root damage, canine position, overall severity, and overlap. The 3D report changed most of the decisions relating to biomechanics, patient education, and treatment time estimate. The decision of exposure and traction vs extraction was changed 22% of the time after the presentation of the 3D report. CONCLUSIONS: The overlap with adjacent teeth frequently contributes the most to the severity index. The 3D report provided relevant clinical information regarding the canine position, damage to adjacent teeth, and the severity index, with a profound impact on the decisions of the clinicians regarding biomechanics, patient education, and treatment time estimate.

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.

Postoperative chronic pain in arthroplasty papillon-lefèvre syndrome: 17-year dental follow-up: case report / Síndrome de papillon-lefèvre: seguimiento dental de 17 años: reporte de caso

Introduction: The present report describes the case of a 12-year-old patient with 17-year follow-up who was previously diagnosed with Papillon-Lefèvre Syndrome (PLS), which is a rare autosomal recessive irregularity in the cathepsin C gene (CTSC) characterized by palmoplantar hyperkeratosis and premature loss of primary and permanent teeth. Case Report: A specific mutation in the c.203 T > G gene inducing loss of function leading to PLS was detected, as was a mutation in the HLA-DRB1*11 allele, which is associated with this syndrome. There is no consanguinity of the parents, and the siblings are entirely healthy. Early identification of the main characteristics of this syndrome is imperative. Accurate diagnosis by genetic analysis allows differential diagnoses and timely comprehensive dental treatment. Conclusions: Additionally, it allows consultation with a dermatologist to maintain or improve the quality of life of patients with this condition due to progressive worsening and severity of the main physical manifestations. Keywords: Papillon-Lefevre Disease; Keratoderma, Palmo-plantar; Cathepsin C; Periodontitis; Skin Diseases, Genetic; Case reports

Introducción: El presente reporte describe el caso de un paciente de 12 años de edad con 17 años de seguimiento a quien previamente se le diagnosticó Síndrome de Papillon-Lefèvre (PLS), el cual es una rara irregularidad autosómica recesiva en el gen de la catepsina C (CTSC) caracterizada por hiperqueratosis palmoplantar y pérdida prematura de dientes primarios y permanentes. Reporte de Caso: Se detectó una mutación específica en el gen c.203 T > G que induce pérdida de función que conduce a PLS, así como una mutación en el alelo HLA-DRB1*11, que se asocia a este síndrome. No presenta consanguinidad de los padres, padres y hermanos totalmente sanos. La identificación temprana de las principales características de este síndrome es imperativa. El diagnóstico certero por análisis genético permite diagnósticos diferenciales y tratamientos odontológicos integrales oportunos. Conclusiones: Adicionalmente, permite la consulta con un dermatólogo para mantener o mejorar la calidad de vida de los pacientes con esta condición debido al progresivo empeoramiento y severidad de las principales manifestaciones físicas.

Psychological and financial impact of the COVID-19 pandemic during the first stages of the pandemic: Brazilian orthodontists´ perspective.

INTRODUCTION: Brazil faced a catastrophic situation in the coronavirus pandemic. Due to the high risk of contamination and spread of COVID-19, dentist have been attending only urgency and emergency services in Brazil at the beginning of the pandemic. OBJECTIVE: This research aimed to evaluate the psychological and financial impacts caused by the coronavirus pandemic in Brazilian orthodontists. METHODS: This population-based cross-sectional study collected demographic data and mental health measurements from 404 orthodontists. Depression, anxiety, insomnia, and distress were evaluated through Brazilian versions of the 9-item Patient Health Questionnaire (9-PHQ), the 7-item Generalized Anxiety Disorder scale and Mini-Tracking (GAD), the 7-item Insomnia Severity Index (ISI), and the 22-item Impact of Event Scale-Revised (IES-R), respectively. The demographic data of the sample was described using descriptive statistics. The data was analyzed according to sex, professional status, and economic income. Comparisons were performed using Chi-square tests, Mann-Whitney U tests, and Kruskal-Wallis followed by post-hoc tests. RESULTS: Females, graduate students, and lower incomes subgroups showed higher levels of depression, anxiety, insomnia, and distress. Most orthodontists showed moderate to extreme financial and professional concerns during the pandemic. CONCLUSION: The coronavirus pandemic negatively affected the psychological health and increased the financial concerns of the Brazilian orthodontists, mainly female, graduate students, and with income below 10k participants.

Association of breastfeeding duration with the development of non-nutritive habits, and transversal and vertical occlusal alterations in preschool children: A cross-sectional study.

BACKGROUND: Breastfeeding has multiple nutritional, immunological and psychological benefits, as well as a positive influence on the development of the stomatognathic system. OBJECTIVES: The present study attempted to determine the relationship between the duration of breastfeeding and the development of non-nutritive habits, and transversal and vertical occlusal alterations in preschool children. MATERIAL AND METHODS: This cross-sectional study involved 155 preschoolers aged 2-5 years from 3 public schools in Lima, Peru. The sample was divided into 2 groups with regard to the duration of breastfeeding: group A (n = 50) included infants that had been breastfed for up to 6 months; and group B (n = 105) included infants that had been breastfed for 6-12 months. Two trained and calibrated dentists evaluated each group, and clinically determined the presence or absence of transversal or vertical occlusal alterations. Likewise, the children's parents or caregivers were consulted to determine the development of non-nutritive habits. RESULTS: A significant association was found between breastfeeding duration and the development of the oral breathing habit; groups A and B showed a prevalence of 30.0% and 16.2%, respectively (p = 0.048). Likewise, breastfeeding duration affected the appearance of oral breathing (OR (odds ratio) = 0.84; 95% CI (confidence interval): 0.74-0.96; p = 0.011). Furthermore, the use of a bottle for more than 24 months significantly influenced the appearance of oral habits (OR = 3.55; 95% CI: 1.20-10.55; p = 0.022) and open bite (OR = 12.12; 95% CI: 1.16-126.31; p = 0.037). CONCLUSIONS: Breastfeeding duration of 6-12 months was shown to be a protective factor in preventing the appearance of oral breathing. Posterior crossbite (PCB), open bite and deep bite seemed not to be influenced by breastfeeding duration. However, the use of a bottle for more than 24 months significantly influenced the appearance of anterior open bite.

Pain and discomfort perception during miniscrew-anchored maxillary protraction: secondary data analysis of a randomized clinical trial.

OBJECTIVES: To compare the perception of pain and discomfort of patients and guardians during treatment between miniscrew-anchored maxillary protraction (MAMP) therapy using Hybrid (HH) and Conventional Hyrax (CH) expanders. MATERIALS AND METHODS: Group HH was composed of 18 subjects (8 female, 10 male; initial age: 10.80 years) with Class III malocclusion treated with a hybrid expander in the maxilla and two miniscrews in the anterior region of the mandible. Class III elastics were used from maxillary first molar to mandibular miniscrews. Group CH was composed of 14 subjects (6 female, 8 male; initial age: 11.44 years) treated with a similar protocol except for conventional Hyrax expander. Pain and discomfort of patients and guardians were assessed using a visual analog scale immediately after placement (T1), after 24 hours (T2), and 1 month after appliance installation (T3). Mean differences (MD) were obtained. Intergroup and intragroup timepoint comparisons were performed using independent t-tests, analysis of variance for repeated measures and Friedman test (P < 5%). RESULTS: Both groups demonstrated similar levels of pain and discomfort with a significant decrease after 1 month of appliance placement (MD: 4.21; P = .608). Compared to patient perceptions, guardians reported a higher level of pain and discomfort at all timepoints (MD, T1: 13.91, P < .001; T2: 23.15, P < .001; T3: 9.35, P = .008). CONCLUSIONS: MAMP therapy with HH and CH produced similar levels of pain and discomfort after appliance installation until 1 month after treatment. Pain and discomfort may not influence the choice between HH and CH expanders.

Twin-block and mandibular anterior repositioning appliances effects in Class II malocclusion correction.

INTRODUCTION: The objective of this study was to compare the cephalometric changes in Class II Division 1 malocclusion patients treated with the Twin-block (TB) and the mandibular anterior repositioning appliance (MARA). METHODS: This retrospective study was performed with 132 lateral cephalograms of patients with Class II malocclusion divided into 3 groups: a TB group comprised 21 patients with mean initial and final ages of 10.59 and 11.97 years, respectively, treated for a mean period of 1.38 years; a MARA group comprised 21 patients with mean initial and final ages of 11.98 and 13.20 years, respectively, treated for a mean period of 1.22 years; and a control group included 24 subjects with untreated Class II malocclusion with mean initial and final ages of 10.55 and 12.01 years, respectively, observed for a mean period of 1.46 years. Cephalometric intergroup comparisons regarding the treatment changes (T2 - T1) were performed with the analysis of covariance, followed by Tukey tests. RESULTS: Both appliances demonstrated significant restriction of the maxilla and improvement of the maxillomandibular relationship. The MARA produced a significantly greater amount of labial tipping and protrusion of the mandibular incisors than the other groups. The TB showed significant extrusion of the mandibular incisors and molars compared with MARA and control, respectively. Both treated groups reduced the overjet and overbite. The MARA presented a significantly greater reduction in the molar relationship than the other groups. CONCLUSIONS: The appliances showed a headgear effect on the maxilla and effectively changed Class II cephalometric parameters through a combination of skeletal and dentoalveolar effects. TB showed a greater increase in LAFH. MARA promoted greater labial tipping and protrusion of the mandibular incisors.