A Three-Dimensional Evaluation of Skeletal and Dentoalveolar Changes in Growing Class II Patients after Functional Appliance Therapy: A Retrospective Case-Control Study.

Background: The aim was to assess three-dimensionally mandibular and maxillary changes in growing Class II patients treated with removable functional appliances followed by fixed appliances. Methods: Twenty-four Class II patients (age range: 9 to 14, mean: 12.1 ± 1.1 years) treated with removable functional appliances followed by fixed appliances (functional appliance group-FAG) were retrospectively selected and compared to an age-matched control group (CG) treated with fixed appliances only. To be included in the study, pre- and post-treatment CBCT scans had to be available. The CBCTs were used to analyze, in 3D, the changes following treatment and growth. Results: Before treatment, overjet (FAG: 9 mm ± 2.8 (mean ± standard deviation); CG: 4 mm ± 1.7), ANB (FAG: 5.7° ± 2.0; CG: 3.2° ± 1.4), and effective mandibular length (FAG: 113.0 mm ± 4.1; CG: 116.6 mm ± 5.9) were statistically significantly different between the two groups. After treatment, overjet (FAG: -6.8 mm ± 2.8; CG: -1.8 mm ± 1.8) and effective mandibular length (FAG: 6.3 mm ± 2.6; CG: 3.9 mm ± 2.6) statistically significantly changed. There was a significant difference in the treatment effect between the FAG and the CG in overjet, ANB, and effective mandibular length. Conclusions: The results indicate that functional appliances are effective in correcting Class II malocclusions. The growth modification in the FAG resulted in an increase in mandibular length. Yet, the final length of the mandible in the FAG was smaller when compared to the CG.

Stability, survival, patient satisfaction, and cost-minimization of CAD/CAM versus conventional multistranded fixed retainers in orthodontic patients: a 2-year follow-up of a two-centre randomized controlled trial.

BACKGROUND: CAD/CAM (computer-aided design/computer-aided manufacturing) fixed retainers (FRs) as an alternative to multistranded FRs to maintain orthodontic treatment outcome. OBJECTIVES: The primary aim was to compare CAD/CAM versus conventional multistranded FRs in terms of stability until 2 years. Secondary outcomes were failure rates, patient satisfaction, and cost-minimization. TRIAL DESIGN: 2-arm parallel, two-centre randomized controlled trial. METHODS: Patients were randomized to CAD/CAM or conventional FRs in both arches, in a 1:1 ratio and blocks of four. Allocation concealment was secured by using sequentially numbered envelopes. Patients were blinded. FRs were bonded at the end of treatment, and patients were recalled after 12 and 24 months. First-time retainer failures were recorded and digital impressions were taken. Arch widths and lengths, as well as Little's Irregularity Index (LII), were measured. Additionally, patients answered satisfaction questionnaires. Linear mixed models were applied for measurements and patient satisfaction. Survival analyses were estimated with Kaplan-Meier curves, along with Cox-regression modelling. Cost-minimization analysis was undertaken. RESULTS: One hundred and eighty-one patients were randomized (98 in Centre 1, and 83 in Centre 2): 90 in CAD/CAM and 91 in conventional group. One hundred and fifty three patients attended T24 follow-up. There were no significant differences in LII and arch dimensions between groups for failure-free patients. Within 24 months, 34% maxillary CAD/CAM FRs and 38% maxillary conventional FRs failed, along with 42% mandibular CAD/CAM FRs and 40% mandibular conventional FRs, with no significant difference in survival between groups (hazard ratios conventional to CAD/CAM: maxillary arch: 1.20 [P = 0.46], mandibular arch: 0.98 [P = 0.94]). There were no significant differences in patient satisfaction between groups. No harms were observed. Cost-minimization analysis showed that CAD/CAM FRs were slightly cheaper than conventional FRs. CONCLUSIONS: There were no clinically significant differences in LII, arch widths, and lengths between CAD/CAM and conventional FRs after 24 months. There were no differences in failures and patient satisfaction between groups. CAD/CAM FRs were slightly cheaper than conventional FRs. TRIAL REGISTRATION: ClinicalTrials.gov NCT04389879.

Health-related quality of life, jaw function and sleep-disordered breathing among patients with dentofacial deformity.

BACKGROUND AND OBJECTIVES: Patients with dentofacial deformity (DFD) requiring orthognathic treatment have poor aesthetics, jaw function and psychological well-being, which potentially affect the quality of life. This study aimed to investigate the health-related general, oral and orthognathic quality of life, jaw function and sleep-disordered breathing at different stages of orthognathic surgical treatment. METHODS: A total of 120 consecutive patients with DFD were recruited and grouped as pre-orthodontic treatment (group 1), pre-surgery (group 2), 4 months post-surgery (group 3), 24 months post-surgery (group 4) and in addition 30 controls without DFD (group 0). Outcomes were assessed using general health Short Form Survey (SF-36), Oral Health Impact (OHIP-14), Orthognathic Quality of Life Questionnaire (OQLQ), STOP-Bang and Jaw Function Limitation Scale (JFLS) questionnaires. In addition, presence or absence of pain was recorded. Data were tested with analysis of variance, Kruskal-Wallis test, Tukey post hoc test and structural equation modelling (SEM). RESULTS: Results revealed SF-36 (p = .814) and STOP-Bang (p = .143) total scores did not differ between control and treatment groups. In contrast, OHIP-14, OQLQ and JFLS total scores differed between groups (p = .001). Higher scores were observed in groups 1 (p = .001), 2 (p = .001) and 3 (p = .041) compared to group 0, indicating poor oral health in patients with DFD. Importantly, in group 4, oral health-related quality of life was better, and OHIP-14 (p = .936) and JFLS (p = .572) scores did not differ from controls. OQLQ scores of group 4 were significantly lower than group 1 (p = .001) but higher than group 0 (p = .013). SEM results revealed a significant negative associations of pain with JFLS and OQLQ; OHIP-14 with OQLQ; OHIP-14 with SF-36; and finally STOP-Bang with SF-36. Positive associations were observed between JFLS and OHIP-14; OHIP-14 and OQLQ. CONCLUSION: Oral health-related quality of life and jaw function appears to be improved 24 months after orthognathic surgery. Pain and limitation in jaw function had a negative association with health-related quality of life.

Striving for Perfection: How Stable Is Orthodontic Treatment When Excellent Outcomes Are Achieved? A 9-Year Post-Treatment Retrospective Study.

(1) Aims: The main objective of this retrospective study was to assess the long-term stability of difficult orthodontic treatments treated to an excellent result and to correlate stability to possible prognostic factors. Secondary objectives were to observe the changes in retention protocol over time and to assess Oral Health-related Quality of Life (OHRQoL) after a long-term post-treatment follow-up. (2) Methods: Cases presented for final examination by orthodontic postgraduate students were retrospectively screened for eligibility. Eligible patients were recalled for a post-treatment recall appointment (T2), consisting of a clinical examination and intraoral scan, and were asked to complete the Oral Health Impact Profile-14 (OHIP-14-DK). Gender, age at treatment commencement (T0), treatment modality and duration, and retention protocol were extracted from the records. At T2, the duration of the retention period was recorded, and retainers in place were clinically compared to the original retention protocol. The following variables were assessed on the sets of models at T0, T1 (end of treatment), and T2: arch length and width, overjet and overbite, Dental Aesthetic Index (DAI), Peer Assessment Rating score (PAR), and Little's Irregularity Index (LII). Multiple regression models were conducted. (3) Results: Eighty-five subjects attended T2. The mean post-treatment follow-up was 9.4 years +/- 2.4. In the upper arch, at T1, 74 patients had a combination of fixed and removable retainers, while at T2, 55 had a fixed retainer only. In the lower arch, at T1, 67 patients had a fixed retainer only, with this number increasing to 76 at T2. From T0 to T1, the PAR score improved by 96.1%, with the improvement remaining at 77.5% at T2. The stability of lower inter-canine and upper inter-premolar widths was significantly correlated with the extent of changes during treatment. The presence of a lower fixed retainer at T2 and a low LII at T1 were prognostic factors for stability. The mean weighted total OHIP-14 score at T2 was very low (1.6 ± 2.4 points). (4) Conclusions: In a sample with an initial high-severity malocclusion and treated to an excellent outcome, long-term stability was very good. Good stability can be retained when a lower fixed retainer is present at T2 and when a low LII is achieved at T1.

Associations between temporomandibular disorders, pain, jaw and masticatory function in dentofacial deformity patients: A cross-sectional study.

BACKGROUND AND OBJECTIVE: Patients with dentofacial deformity often present with impaired masticatory function, orofacial pain and temporomandibular disorders (TMD). This study investigates the relationship between TMD, pain, jaw and masticatory function at different stages of orthognathic surgical (OS) treatment. METHODS: A total of 120 OS patients were prospectively recruited and grouped as pre-orthodontic (group 1), pre-surgery (group 2), 4-month post-surgery (group 3), 24-month post-surgery (group 4), in addition to 30 controls (group 0). Outcomes were assessed using: Jaw Function Limitation Scale (JFLS), McGill pain questionnaire, DC/TMD instrument, voluntary maximum bite force (MVBF), and masticatory efficiency (ME) using two-coloured chewing gum. Data were analysed using structural equation modelling. RESULTS: The prevalence of non-painful TMD did not differ between groups (p = .827). However, the prevalence of painful TMD differed between groups (p = .001). Among the painful TMDs, the highest prevalence was observed for masseter myalgia in group 2 (p = .031), and importantly group 4 did not differ from group 0 (p = .948). The MPQ score was significantly higher in group 1 (p = .001) compared to group 0, and the JFLS score was significantly higher in groups 1, 2 and 3 compared to group 0. Notably, MPQ (p = .756) and JFLS (p = .572) scores in group 4 were not different from group 0. However, MVBF (p = .996) and ME (p = .991) did not differ between groups 1 and 4. The association of self-reported pain and jaw function with the masticatory function was observed in OS patients. CONCLUSION: OS was not associated with a negative impact on TMD. Jaw function and pain levels were similar to controls at the 24-month follow-up. The masticatory function was further affected by the surgery and seems to require a longer recovery time. Moreover, it was confirmed that pain and TMD were associated with limitations in jaw function and impacts on masticatory function.

Stability, survival, and patient satisfaction with CAD/CAM versus conventional multistranded fixed retainers in orthodontic patients: a 6-month follow-up of a two-centre randomized controlled clinical trial.

OBJECTIVES: The primary aim of this two-arm parallel two-centre randomized controlled trial was to compare computer-aided design and computer-aided manufacturing (CAD/CAM) versus conventional multistranded fixed retainers (FRs) in terms of stability over 6 months. Secondary outcomes were failure rates and patient satisfaction. METHODS: Patients were randomized to CAD/CAM or conventional FRs in both arches, in 1:1 ratio and blocks of four. Allocation concealment was secured by using sequentially numbered envelopes. Patients were blinded. Retainers were bonded at the end of orthodontic treatment (T0), and patients were recalled after 1 (T1), 3 (T3), and 6 (T6) months. First-time retainer failures were recorded and digital impressions were taken. Arch widths and lengths, as well as Little's Irregularity Index (LII), were measured. Additionally, patients answered satisfaction questionnaires. Linear mixed models were applied for measurements and patient satisfaction. Survival analyses were estimated with Kaplan-Meier curves, along with Cox-regression modelling. RESULTS: One hundred and eighty-one patients were randomized (98 in Centre 1, and 83 in Centre 2): Ninety in the CAD/CAM group and 91 in the conventional group. Three subjects dropped out at baseline, as they did not attend any of the follow-up appointments.168 patients attended the T6 visit. There were no significant differences in arch dimensions between T0 and T6, whilst the LII was different only in the CAD/CAM group (mean difference: 0.2 mm; 95% confidence interval: 0.1 to 0.4; P < 0.001). Within 6 months, 39 upper retainers (19 out of 88 CAD/CAM and 20 out of 90 conventional retainers) and 52 lower retainers failed (26 out of 88 CAD/CAM and 26 out of 90 conventional retainers), with no significant difference between the survival of both types of retainers (hazard ratios conventional to CAD/CAM: upper arch: 0.99 [P =0.99], lower arch: 0.93 [P = 0.80]). There were no significant changes in patient satisfaction between the groups. No harms were observed. CONCLUSIONS: There were no clinically significant differences in LII, arch widths and lengths between CAD/CAM and conventional retainers after 6 months. There was no difference in failures and in patient satisfaction between both types of FRs. REGISTRATION: ClinicalTrials.gov NCT04389879.

Pharyngeal airway changes five years after bimaxillary surgery - A retrospective study.

The aim of this study was to retrospectively evaluate pharyngeal airway (PA) changes after bimaxillary surgery (BMS). Preoperative, immediate- and 5-year postoperative cone-beam computed tomography images of subjects who underwent BMS were assessed. The primary outcome variable was the PA volume. The secondary outcome variables were the retropalatal and oropharyngeal volumes, cross-sectional area, minimal hydraulic diameter, soft tissue, skeletal movements and sleep-disordered breathing (SDB). A total of 50 patients were included, 33 female and 17 male, with a mean age of 26.5 years. A significant increase in the PA volume was seen immediately after surgery (40%), and this increase was still present at 5-year follow-up (34%) (P < 0.001). A linear mixed model regression analysis revealed that a mandibular advancement of ≥5 mm (P = 0.025) and every 1-mm upward movement of epiglottis (P = 0.016) was associated with a volume increase of the oropharyngeal compartment. Moreover, ≥5-mm upward movement of hyoid bone (P = 0.034) and every 1-mm increase in minimal hydraulic diameter (P < 0.001) correlated with an increase of the PA volume. A total of 30 subjects reported improvement in the SDB at 5-year follow-up. This study demonstrated that BMS led to an increase in PA dimensions in non-OSA patients, and these changes were still present at 5-year follow-up. BMS seemed to induce clinical improvement in SDB.

Operating time for wire ligation with self-ligating and conventional brackets: A standardized in vitro study.

OBJECTIVE: Operating time is one of the main advantages attributed from the literature to the use of self-ligating brackets (SLB). The aim of this study is to investigate the time needed for a complete archwire change procedure with conventional brackets (CB) and SLBs in a standardized in vitro research setting, comparing operators with different expertise. MATERIALS AND METHODS: Thirty-three participants were divided into three equal groups: undergraduate students, postgraduate students, and orthodontists. Three sets of typodonts bonded with three types of brackets, including passive SLBs, active SLBs, and CBs using both steel and elastic ligatures were investigated. Operators had to insert, ligate, deligate, and remove wires in sets of typodonts representing an actual dentition before and after orthodontic treatment, mounted in phantoms. Archwire change procedure times were compared between the different bracket/ligation systems, between the before- and after-treatment typodonts, and between operators. RESULTS: There were significant differences between SLBs and CBs, the greatest difference being 11 min 16 s between passive SLBs and CBs ligated with metallic ligatures at T0, for the total archwire change procedure by the operators overall. For all the operators, there was a statistically significant difference in total archwire change procedure time between the systems. The undergraduate students were the slowest when using CBs, but they showed no significant difference compared to the other users when using SLBs. CONCLUSION: SLBs can offer a significant operating time reduction compared to CBs, and time saving is not dependent on the operator's experience and training.

Indirect vs direct bonding of mandibular fixed retainers in orthodontic patients: Comparison of retainer failures and posttreatment stability. A 5-year follow-up of a single-center randomized controlled trial.

INTRODUCTION: This 2-arm parallel trial aimed to assess the number of failures of mandibular fixed retainers bonded with direct and indirect bonding methods at a 5-year follow-up and investigate the stability of intercanine and interpremolar distances. METHODS: Consecutive patients from the clinic of the University of Geneva (Switzerland) were randomly allocated to either direct or indirect bonding of a mandibular fixed retainer at the end of orthodontic treatment. Inclusion criteria included the presence of all mandibular incisors and canines; and the absence of active caries, restorations, fractures, or periodontal disease of these teeth. The patients were randomized in blocks of 4 using an online randomization service, with allocation concealment secured by contacting the sequence generator for assignment. Two and 5 years (T5) after bonding the retainers, the patients were recalled, and impressions were taken. The primary outcome was the 5-year survival of the mandibular fixed retainer bonded with both bonding methods. The secondary outcomes were the intercanine and interpremolar distances and the assessment of unexpected posttreatment changes (ie, changes in torque and/or rotations of the mandibular incisors and canines). Blinding was applicable for outcome assessment only. Kaplan-Meier curves were generated, and a Cox proportional hazard regression model was fitted for bonding type, age, and treatment. Linear mixed models were fitted to intercanine and interpremolar distances: bonding type, time, age, and treatment were modeled as outcomes. RESULTS: Sixty-four patients were randomized in a 1:1 ratio. At T5, 6 patients without previous failure were lost to follow-up from each group. At T5, the fixed retainer was debonded in 14 patients (54%) for each group. The hazard ratio of indirect bonding to direct bonding was 1.09 (95% confidence interval, 0.26-4.60; P = 0.91); there was no statistically significant difference in survival between the groups. Regarding intercanine and interpremolar distances, none of the tested prognostic factors reached statistical significance. Unexpected posttreatment changes were observed in 6 failure-free patients, all bonded with the direct bonding method. Only 1 patient required debonding of the fixed retainer. No other serious harms were observed. CONCLUSIONS: The 5-year survival rate for both direct and indirect bonding methods was 46%, without a statistically significant difference between bonding methods. Bonded retainers were effective in maintaining intercanine and interpremolar distances. Unexpected posttreatment changes were only observed with retainers bonded with the direct bonding method. REGISTRATION: The trial was not registered. PROTOCOL: The protocol was not published before trial commencement. FUNDING: No funding or conflict of interest to be declared.

Restricted upper airway dimensions in patients with dentofacial deformity from juvenile idiopathic arthritis.

BACKGROUND: This retrospective, cross-sectional study aimed to assess the pharyngeal airway dimensions of patients with juvenile idiopathic arthritis (JIA) and moderate/severe JIA-related dentofacial deformity (mandibular retrognathia/micrognathia), and compare the results with JIA patients with a normal mandibular appearance and a group of non-JIA patients. METHODS: Seventy-eight patients were retrospectively included in a 1:1:1 manner as specified below. All patients had previously been treated at the Section of Orthodontics, Aarhus University, Denmark. All had a pretreatment cone beam computed tomography (CBCT). Group 1 (JIA+); 26 JIA patients with severe arthritis-related dentofacial deformity and mandibular retrognathia/micrognathia. Group 2 (JIA-); 26 JIA patients with normal mandibular morphology/position. Group 3 (Controls); 26 non-JIA subjects. Dentofacial morphology and upper airway dimensions, excluding the nasal cavity, were assessed in a validated three-dimensional (3D) fashion. Assessment of dentofacial deformity comprised six morphometric measures. Assessment of airway dimensions comprised nine measures. RESULTS: Five morphometric measures of dentofacial deformity were significantly deviating in the JIA+ group compared with the JIA- and control groups: Posterior mandibular height, anterior facial height, mandibular inclination, mandibular occlusal inclination, and mandibular sagittal position. Five of the airway measurements showed significant inter-group differences: JIA+ had a significantly smaller nasopharyngeal airway dimension (ad2-PNS), a smaller velopharyngeal volume, a smaller minimal cross-sectional area and a smaller minimal hydraulic diameter than JIA- and controls. No significant differences in upper airway dimensions were seen between JIA- and controls. CONCLUSION: JIA patients with severe arthritis-related dentofacial deformity and mandibular micrognathia had significantly restricted upper airway dimensions compared with JIA patients without dentofacial deformity and controls. The restrictions of upper airway dimension seen in the JIA+ group herein were previously associated with sleep-disordered breathing in the non-JIA background population. Further studies are needed to elucidate the role of dentofacial deformity and restricted airways in the development of sleep-disordered breathing in JIA.

In Vitro Comparison of Different Invisalign® and 3Shape® Attachment Shapes to Control Premolar Rotation.

Aim: To evaluate in vitro the differences of various Invisalign® attachments in their effectiveness during derotation of an upper second premolar in terms of forces and moments created and compare them to the 3Shape® box attachment as well as to no attachment at all. Materials and Methods: A Force System Identification (FSI) machine, comprising two load sensors, was used in this study. Sensor 1 was connected to the test tooth (i.e. upper second premolar) carrying a different attachment design, and the fixed sensor (Sensor 2) was connected to the base model. Once the corresponding aligner was passively seated on the teeth, 12 different setups (i.e. 11 different attachments and one setup with no attachment at all) were tested by rotating the test tooth 4.5° mesially and 4.5° distally, in increments of 0.45°. Results: The vertical rectangular attachments were able to generate the highest derotational moment on both mesial and distal rotations but also received the most side effects (intrusive force, torque, and tipping). The no-attachment setup performed least favorably in terms of derotational ability but exhibited the least side effects. In the y-axis, all attachments received a buccal root torque with a lingual force during disto-rotation and a lingual root torque with a buccal force during mesio-rotation. Conclusion: Attachments are necessary for derotating an upper second premolar. An aligner incremental change of more than 1° derotation can generate high moments. The vertical rectangular attachments perform best in derotations; however, they exhibit the most side effects. Finally, despite presenting the least side effects, derotation of a premolar with no attachment is not as efficient.

Translation and cross-cultural adaptation of the sleep-related breathing disorder scale of the Pediatric Sleep Questionnaire into Danish language.

OBJECTIVE/BACKGROUND: Sleep-disordered breathing (SDB) is common but often underestimated in children. The gold standard for assessing SDB is polysomnography, but it is expensive and time-consuming. The Paediatric Sleep Questionnaire (PSQ/SRDB) is a validated screening tool for SDB, which represents an efficient and alternative tool for screening SDB among children. However, a translated and validated Danish version of the PSQ/SRDB is not available yet. Our aim was to cross-culturally translate the PSQ/SRDB into Danish language for use in clinical and research settings. PATIENTS/METHODS: The translation was carried out through forward-backward translation techniques performed by a panel of experts, and the cross-cultural adaptation was achieved by pretesting of the pre-final version. Internal consistency of the Danish PSQ/SRDB version was measured by Cronbach's alpha coefficients, while Cohen's kappa was used to evaluate test-retest reliability. Construct validity was assessed by factor analysis of the principal components. RESULTS: The Danish PSQ/SRDB was administered to the caregivers of 348 children. An overall Cronbach's alpha of 0.72 was found, confirming the survey's consistency, with the results for the domains ranging 0.52-0.70. The Danish PSQ/SRDB showed moderate to perfect reliability for all items, except for one question (C14). Factor analysis performed on the Danish PSQ/SRDB showed that the predetermined four factors were similar with the original version of the PSQ/SRDB. CONCLUSIONS: The Danish version of the PSQ/SRDB has been successfully translated and cross-culturally adapted, suggesting that it can be used as an appropriate paediatric screening tool for SDB in Denmark.

Does quality of orthodontic treatment outcome influence post-treatment stability? A retrospective study investigating short-term stability 2 years after orthodontic treatment with fixed appliances and in the presence of fixed retainers.

OBJECTIVE: The present study aimed to evaluate stability 2 years after orthodontic treatment and to investigate the influence of various pre-treatment and post-treatment prognostic factors on stability. SETTING AND SAMPLE POPULATION: Consecutive patients treated with full fixed appliance and retained with fixed retainers were retrospectively assessed for eligibility. MATERIALS AND METHODS: Digital models were analysed at treatment start (T0), end of treatment (T1) and 2 years post-treatment (T2). The Peer Assessment Rating (PAR) index, Little's Irregularity Index (LII), arch width and length, overjet, overbite and presence of unexpected post-treatment changes were assessed. Multiple regression analyses were conducted to model the relationship of all outcomes with several prognostics simultaneously. RESULTS: The sample consisted of 287 subjects (mean treatment time: 25.1 months, standard deviation [SD] 7.5; mean post-treatment follow-up: 27.5 months, SD 6.1) with a mean weighted PAR score of 29.5 (SD 8.6) at T0, 1.8 (SD 2.9) at T1 and 3.2 (SD 3.6) at T2. At T1, 95% of the subjects had a perfect LII versus 86% at T2. An increased LII at T1 correlated with increased LII and PAR changes from T1 to T2. PAR at T1 as well as overjet at T0 was a significant prognostic factor for PAR at T2. At T2, five cases (1.7%) showed unexpected post-treatment changes related to fixed retainers. CONCLUSION: Short-term post-treatment stability with fixed retainers was very good. Prognostic factors for stability included LII and PAR at T1, suggesting that high-quality treatment outcome in the presence of fixed retainers may ensure post-treatment stability.

Malocclusion and oral health-related quality of life among young Danish adults. Is there a difference between subjects who received orthodontic treatment during adolescence and subjects without treatment need? A cross-sectional study.

OBJECTIVES: To evaluate and compare malocclusion traits and oral health-related quality of life (OHRQoL) between untreated young adults assessed to have no orthodontic treatment need during childhood, and young adults treated orthodontically during childhood. In addition, to investigate the relationship between malocclusion and OHRQoL. MATERIALS AND METHODS: One hundred undergraduate students were screened for eligibility. Subjects had intraoral scans and completed OHIP-14 questionnaires. Angle molar relationship, overjet, overbite, arch length and width, Little's Irregularity Index (LII), Peer Assessment Rating (PAR) index and Dental Aesthetic Index (DAI) scores were assessed. Unpaired t-tests were used to compare outcomes between treated and untreated subjects. Multiple regression analyses were conducted to model the relationship between OHIP-14 and several prognostics simultaneously. RESULTS: Ninety-six subjects were included (mean age ± SD = 23.7 ± 1.8 years): 41 treated and 55 untreated. The untreated subjects had significantly higher LII (p = .02), PAR (p = .01), DAI (p < .01) and overbite (p = .03). The treated subjects had significantly larger inter-canine and inter-premolar distances. No relationship was found between OHIP-14 and LII, PAR, DAI, age, gender and presence/absence of previous orthodontic treatment. However, the DAI score was significantly correlated with the OHIP-14 functional limitation domain. CONCLUSIONS: Untreated subjects had significantly higher LII, PAR and DAI scores than the treated subjects. DAI score was significantly correlated with the OHIP-14 functional limitation domain.

How efficient is customized lingual orthodontics? An assessment of treatment outcome.

OBJECTIVE: To assess the efficacy of lingual orthodontics by comparing setups and post-treatment casts. SETTING AND SAMPLE POPULATION: Thirty-two consecutive patients treated with a customized lingual orthodontic appliance were included in this retrospective study. MATERIALS AND METHODS: Initial casts, post-treatment casts and setups were scanned, and the digital models produced were analysed in terms of overjet; overbite; molar and canine relationships; intercanine, interpremolar and intermolar distances; upper and lower arch lengths; midline deviation; bucco-lingual angulation of all teeth and mesio-distal angulation of anterior teeth. Comparisons between setups and post-treatment casts were performed via paired t tests. Relationships between the planned and actual correction were studied using regression analysis. RESULTS: Statistically significant differences in bucco-lingual torque between setups and post-treatment casts were found for all upper teeth, except for central incisors. In the lower jaw, statistically significant differences in bucco-lingual torque were found between setups and post-treatment casts for the lower incisors and molars. No statistically significant differences in mesio-distal angulation of anterior teeth were found between setups and post-treatment casts. Upper and lower arch widths did not vary significantly between setups and final casts, except upper inter-second premolar and intermolar distances. CONCLUSION: Customized lingual appliances offer efficient control of mesio-distal angulation of all anterior teeth. Significant differences in torque between setups and post-treatment casts were observed for upper lateral incisors, canines, premolars and molars, as well as lower incisors and molars. However, the torque difference was clinically significant (over three degrees) for upper second premolars and molars only.

Does rapid maxillary expansion enlarge the nasal cavity and pharyngeal airway? A three-dimensional assessment based on validated analyses.

OBJECTIVES: To evaluate the three-dimensional changes following rapid maxillary expansion (RME) of the nasal cavity (NC) and pharyngeal airway (PA) in growing patients, using innovative and validated evaluation methods and to investigate whether a correlation between skeletal expansion and increase in airway volume exists. SETTINGS AND SAMPLE POPULATION: Records of patients who had cone beam computed tomography taken before and after orthodontic treatment with or without RME were retrospectively collected and divided into two groups: (a) RME, 39 patients (mean age 10.40 ± 1.74 years); and (b) control, 29 patients, matched for age (mean age 11.07 ± 1.45 years) and follow-up period. MATERIAL AND METHODS: Total and partial volumes of the NC and the PA were calculated. The PA centerline was determined to assess the minimal cross-sectional area and hydraulic diameter. Paired and unpaired t test were applied to compare the difference between time points and between groups. One-way ANOVA and post hoc Tukey's tests were used to compare subgroups with respect to changes in palatal width and lacrimal ducts distance. RESULTS: All of the NC, PA and skeletal parameters were significantly enlarged after RME. The NC volume and inter-molar distance in the RME were significantly larger compared to the control group. The initially lower mean values of minimal cross-sectional area and hydraulic diameter in the RME group when compared to the control group normalized after RME treatment. CONCLUSIONS: Based on validated analyses, the NC volume increase was evident after RME in the long term after controlling for growth.

Three-dimensional soft tissue changes in orthodontic extraction and non-extraction patients: A prospective study.

OBJECTIVES: To assess the soft tissue changes in orthodontic extraction and non-extraction patients on 3D stereophotogrammetric images. SETTING AND SAMPLE: 23 extraction (22.2 ± 9.2 years) and 23 non-extraction (20.3 ± 11.1 years) consecutive patients were enrolled at the Sections of Orthodontics at Aarhus University and at University of Naples Federico II. METHODS: All patients had a first 3D image taken after bonding of brackets on the upper incisors (T0), and a second 3D image (T1) after space closure in the extraction group or at insertion of the first SS or TMA rectangular wire in the non-extraction group. The 3D images were captured with 3dMDFace System and analysed with 3dMDVultus Software. After placing 19 landmarks, 15 measurements were obtained. Intragroup changes were analysed with paired t-test and intergroup changes with unpaired t-test (P < .05). RESULTS: Superimpositions of the 3D images at T0 and T1 visualized with colour-coded maps showed that soft tissue changes primarily happened in the perioral area in both groups. The Nasolabial angle increased significantly in the extraction group (3°± 4.1, P = .002), while it decreased in the non-extraction group (-1.5°± 5.5°, P = .002). There was a significant difference between the two groups (4.4°, P = .004). CONCLUSIONS: 3D comparison of the soft tissues in the extraction and non-extraction groups showed statistically significant, but clinically limited differences in the perioral area. The Nasolabial angle was significantly larger at T1 in the extraction group compared with the non-extraction group.

A community detection analysis of malocclusion classes from orthodontics and upper airway data.

OBJECTIVE: The interaction between skeletal class and upper airway has been extensively studied. Nevertheless, this relationship has not been clearly elucidated, with the heterogeneity of results suggesting the existence of different patterns for patients' classification, which has been elusive so far, probably due to oversimplified approaches. Hence, a network analysis was applied to test whether different patterns in patients' grouping exist. SETTINGS AND SAMPLE POPULATION: Ninety young adult patients with no obvious signs of respiratory diseases and no previous adeno-tonsillectomy procedures, with thirty patients characterized as Class I (0 < ANB < 4); 30 Class II (ANB > 4); and 30 as Class III (ANB < 0). MATERIALS AND METHODS: A community detection approach was applied on a graph obtained from a previously analysed sample: thirty-two measurements (nineteen cephalometric and thirteen upper airways data) were considered. RESULTS: An airway-orthodontic complex network has been obtained by cross-correlating patients. Before entering the correlation, data were controlled for age and gender using linear regression and standardized. By including or not the upper airway measurements as independent variables, two different community structures were obtained. Each contained five modules, though with different patients' assignments. CONCLUSION: The community detection algorithm found the existence of more than the three classical skeletal classifications. These results support the development of alternative tools to classify subjects according to their craniofacial morphology. This approach could offer a powerful tool for implementing novel strategies for clinical and research in orthodontics.

Validity and Reproducibility of the Peer Assessment Rating Index Scored on Digital Models Using a Software Compared with Traditional Manual Scoring.

The aim of this study was to assess the validity and reproducibility of digital scoring of the Peer Assessment Rating (PAR) index and its components using a software, compared with conventional manual scoring on printed model equivalents. The PAR index was scored on 15 cases at pre- and post-treatment stages by two operators using two methods: first, digitally, on direct digital models using Ortho Analyzer software; and second, manually, on printed model equivalents using a digital caliper. All measurements were repeated at a one-week interval. Paired sample t-tests were used to compare PAR scores and its components between both methods and raters. Intra-class correlation coefficients (ICC) were used to compute intra- and inter-rater reproducibility. The error of the method was calculated. The agreement between both methods was analyzed using Bland-Altman plots. There were no significant differences in the mean PAR scores between both methods and both raters. ICC for intra- and inter-rater reproducibility was excellent (≥0.95). All error-of-the-method values were smaller than the associated minimum standard deviation. Bland-Altman plots confirmed the validity of the measurements. PAR scoring on digital models showed excellent validity and reproducibility compared with manual scoring on printed model equivalents by means of a digital caliper.