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European Journal of Orthodontics - current issue - Recent Medical Updates

Impact of oral-health-related quality of life and self-esteem on patients with missing maxillary lateral incisor after orthodontic space closure: a single-blinded, randomized, controlled trial
<span class="paragraphSection"><div class="boxTitle">Summary</div><div class="boxTitle">Background</div>The maxillary lateral incisor is one of the teeth most likely to suffer agenesis, resulting in spacing between the central incisor and the canine.<div class="boxTitle">Objective</div>To compare maxillary lateral incisor agenesis with space closure treatment versus non-treatment based on measurements of the self-perceived oral-health-related quality of life (OHRQoL) and self-esteem of the participants.<div class="boxTitle">Subjects and methods</div>A total of 44 people, aged 17–49 years, with missing lateral incisors were randomly assigned to two groups (<span style="font-style:italic;">n</span> = 22 in each)—a treated group in which the space was orthodontically closed (TG) and a control group that remained untreated (CG). Randomization was performed by a researcher who was not involved in the clinical part of the study. The outcomes were assessed using the Oral Health Impact Profile and Rosenberg’s Self-Esteem Scale, which were applied before (phase 1) and after (phase 2) the orthodontic treatment in the TG, and at baseline (phase 1) and 12 months after (phase 2) in the CG. All the data were blindly evaluated, supporting the single-blinded design of the study.<div class="boxTitle">Results</div>All participants finished the randomized controlled trial, and the demographic characteristics were similar between the groups. In phase 1, the levels of self-esteem and OHRQoL at baseline were similar (<span style="font-style:italic;">P</span> = 0.079, <span style="font-style:italic;">P</span> = 0.693, respectively). In phase 2, the self-esteem scores of the CG decreased and the OHRQoL increased (<span style="font-style:italic;">P</span> = 0.005, <span style="font-style:italic;">P</span> &lt; 0.001, respectively), while self-esteem increased in the TG and the OHRQoL decreased (<span style="font-style:italic;">P</span> &lt; 0.001). The CG had lower scores than the TG for self-esteem, but the opposite was observed for OHRQoL (<span style="font-style:italic;">P</span> &lt; 0.001).<div class="boxTitle">Limitations</div>Information bias may have occurred. Since the questionnaires could not have been applied at the same time in both groups, the time difference between the two assessments may have led to random and systematic error.<div class="boxTitle">Conclusions</div>The spacing resulting from missing maxillary lateral incisors had a negative impact on the OHRQoL and self-esteem of the participants, while orthodontically closing those spaces had a positive impact on those aspects.<div class="boxTitle">Clinical trial registration</div>This study was not registered.<div class="boxTitle">Protocol</div>The protocol was not published before trial commencement.</span>


Stability of maxillary anterior teeth after 2 years of retention in adolescents: a randomized controlled trial comparing two bonded and a vacuum-formed retainer
<span class="paragraphSection"><div class="boxTitle">Summary</div><div class="boxTitle">Background</div>Retention of the maxillary anterior teeth is commonly recommended to maintain the teeth in their corrected positions. Both fixed and removable retention methods are used, but the certainty of evidence is low.<div class="boxTitle">Objective</div>To evaluate post-treatment changes in irregularity of the maxillary six anterior teeth and single tooth contact point discrepancy (CPD) of three different retention methods.<div class="boxTitle">Trial design</div>Three-arm parallel group single-centre randomized controlled trial.<div class="boxTitle">Materials and methods</div>Ninety patients, 54 girls and 36 boys, were recruited to the study. The inclusion criteria were adolescent patients treated with fixed appliances at least in the maxilla. After gaining informed consent from the patient and their custodians, the patients were randomized to one of three groups: bonded retainer 13–23, bonded retainer 12–22, and removable vacuum-formed retainer (VFR) covering the maxillary teeth including the second molars. The randomization, prepared by an independent person, used blocks of 30. The primary outcomes were changes in single CPD and Little’s irregularity index (LII) measured on digitalized three-dimensional study casts before and after 2-year retention. The study casts were anonymized before assessment and the changes were blinded for the assessor. Data were evaluated on an intention-to-treat basis. Thus, all randomized patients were incorporated into the final analysis.<div class="boxTitle">Results</div>The LII and CPDs increased slightly in all three groups without any statistically significant differences between the groups. The VFR group showed a small intercanine width increase and some more changes of canine rotations than in the other groups.<div class="boxTitle">Harms</div>No harm was observed in any subjects and none of the patients needed retreatment.<div class="boxTitle">Limitations</div>The trial was a single-centre study and short-term changes were evaluated.<div class="boxTitle">Conclusions</div>All three retention methods showed equally effective retention capacity and all the changes found in the three groups were small and considered clinically insignificant. Thus, the null hypothesis was confirmed. All three methods can be recommended.<div class="boxTitle">Trial registration</div>NCT04616755</span>


Dentists at War: 12 Who Went Beyond the Call of Duty
<span class="paragraphSection">Author: WahlNorman. Dentists at War: 12 Who Went Beyond the Call of Duty. Author House. ISBN: 978-1-7283-6007-2, pages: 1. Price: £4.99.</span>


Modelling risk factors for high/low Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ) in the Australian adults
<span class="paragraphSection"><div class="boxTitle">Summary</div><div class="boxTitle">Objective</div>Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ) is an instrument to assess the subjective perception needed for orthodontic treatment (OT). The study aimed to (1) evaluate the psychosocial impact of dental aesthetics and the potential role of OT and (2) determine associations between PIDAQ with self-rated general and oral health, oral health-related quality of life (OHRQOL), and receipt of OT among Australian adults.<div class="boxTitle">Methods</div>Data were obtained from the 2013 Australian National Dental Telephone Interview Survey (NDTIS). The PIDAQ was utilized as main outcome, comprising items from four conceptual domains: self-confidence, social impact, psychological impact, and aesthetic concern. Participants reported their socio-demographic, behavioural, self-rated general and oral health as well as the poor OHRQOL using the Oral Impact on Daily Performance (OIDP) instrument and OT. The mean of PIDAQ and four subscales score and their 95% confidence intervals (CI) were estimated. Generalized liner regression was used to estimate association between PIDAQ and covariates by calculating the mean ratio (MR) and their 95% CI.<div class="boxTitle">Results</div>There were 2936 Australian adults who completed the PIDAQ items. The mean PIDAQ score was 28.8 (95% CI: 28.0–29.6). Higher PIDAQ scores were identified among those who reported non-Australian birth, lower incomes, infrequent dental visits, less than 21 teeth and brushing teeth less than twice a day, fair/poor self-rated general and oral health, and poor OHRQOL. In multivariable modelling, the mean PIDAQ score was 1.91 (95% CI: 1.82–2.00) times higher among those with OIDP score &gt;3 and 1.06 (95% CI:1.01–1.10) times higher in those who had OT, comparing with their counterparts. Also, higher PIDAQ scores were identified among females, last visiting a dentist more than 2 years ago, fair or poor self-rated oral and general health.<div class="boxTitle">Conclusions</div>Higher PIDAQ scores that have a greater impact on OHRQOL were associated with poorer self-rated general and oral health. This may be explained by unfavourable dental attendance and oral health habits. The positive correlation with OIDP scores verifies the validity of the PIDAQ. Those who had received OT had lower PIDAQ and OIDP scores.</span>


Is wearing orthodontic appliances associated with eating difficulties and sugar intake among British adolescents? A cross-sectional study
<span class="paragraphSection"><div class="boxTitle">Summary</div><div class="boxTitle">Aim</div>To determine whether wearing orthodontic appliances was associated with eating difficulty and lower sugars intake among British adolescents.<div class="boxTitle">Methods</div>This study analysed data from 4116 12- and 15-year-olds who participated in the 2013 Children’s Dental Health Survey in the UK. Information on eating difficulties in the past 3 months and usual intake of six sugary items was collected through self-administered questionnaires. The presence and type of orthodontic appliances (fixed or removable) were assessed during clinical examinations. Logistic regression was used to evaluate the association between wearing orthodontic appliances and eating difficulty whereas linear regression was used to evaluate the association between wearing orthodontic appliances and sugars intake. Regression models were adjusted for socio-demographic, behavioural, and clinical characteristics of adolescents.<div class="boxTitle">Results</div>12.9 per cent of the 4116 adolescents wore orthodontic appliances (10.1 per cent fixed and 2.8 per cent removable), 21.0 per cent reported eating difficulties and the mean daily intake of sugars was 5.3 times/day (SD: 3.7, range: 0–20). Adolescents with fixed appliances had 4.02 (95% CI: 3.03, 5.33) greater odds of reporting eating difficulty than those with no appliances, but no differences were found between adolescents wearing removable and no appliances. No association was found between wearing orthodontic appliances and daily sugars intake either [coefficients of 0.20 (95% CI: –0.27, 0.66) and –0.30 (95% CI: –0.96 to 0.36) for adolescents wearing fixed and removable appliances, respectively].<div class="boxTitle">Conclusion</div>Wearing fixed orthodontic appliances were associated with greater odds of reporting eating difficulty, but not with lower sugars intake among British adolescents.</span>


The relationship between malocclusion and oral health-related quality of life among adolescents: a systematic literature review and meta-analysis
<span class="paragraphSection"><div class="boxTitle">Summary</div><div class="boxTitle">Background</div>Malocclusion is a deviation from an anatomical norm that occurs in various populations. Evidence shows that it has physical and psychological implications as well as an influence on the patient’s oral health-related quality of life (OHRQoL). Self-perception of oral health plays an important role in the understanding of malocclusion’s influence on the quality of life. Malocclusion has been reported to impair a patient’s function, appearance, interpersonal relationships and psychological well-being.<div class="boxTitle">Objectives</div>The aim of this study was to investigate whether adolescents aged between 11 and 18 years with malocclusion are at increased risk for having a high level of OHRQoL compared with those without malocclusion.<div class="boxTitle">Search methods</div>The Ovid Medline, Embase and Scopus databases were used to identify studies measuring the association between malocclusion and HRQoL.<div class="boxTitle">Selection criteria</div>Only cross-sectional studies were included, and the following inclusion criteria were used: subjects were systemically healthy; data were available for untreated malocclusion and OHRQoL; malocclusion was measured by Dental Aesthetic Index and Index of Orthodontic Treatment Needs; OHRQoL was assessed by Child Perception Questionnaire, Child Oral Health Impact Profile and Child Oral Health Impact Profile; and the paper was published in English.<div class="boxTitle">Data collection and analysis</div>Data were extracted by two independent reviewers. The Appraisal tool for Cross-Sectional Studies (AXIS) was used to establish the risk of bias, and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) evidence quality assessment tool was used to assess the impact of malocclusion on adolescents across studies.<div class="boxTitle">Results</div>The initial search yielded 530 papers. Eleven cross-sectional studies were included in the meta-analyses, and all data describing the relationship between malocclusion and OHRQoL were gathered via a structured questionnaire. Our results showed that malocclusion is linked to decreased OHRQoL in children and adolescents aged between 11 and 18 years in continuously analysed studies. However, in dichotomously analysed studies, it was shown that young people without malocclusion are linked to decreased OHRQoL.<div class="boxTitle">Conclusions</div>Adolescents with severe levels of malocclusion might have among the worst levels of OHRQoL. The effects of malocclusion on OHRQoL were influenced by the age of the adolescents as well as by their culture and environment.<div class="boxTitle">Registration</div>PROSPERO (CRD42020178657).</span>


Influence of BMI percentile on craniofacial morphology and development in children and adolescents
<span class="paragraphSection"><div class="boxTitle">Summary</div><div class="boxTitle">Background</div>The prevalence of childhood and adolescent obesity is increasing worldwide. Reports suggest that elevated body mass index (BMI) is associated with larger craniofacial dimensions and advanced dental and skeletal development. Such an association is important for timing orthodontic treatment relative to pubertal growth and dental eruption.<div class="boxTitle">Materials and Methods</div>To evaluate associations between BMI, craniofacial morphology, dental age, and cervical vertebrae maturation staging (CVMS), 400 participants were consecutively selected (8–15 years, <span style="font-style:italic;">n</span> = 200 overweight and obese BMI &gt;85%, 200 normal weight) from the University of North Carolina database. Records were analysed for cephalometric measures, Demirjian index values, and CVMS. Bivariate statistics and linear regression analysis evaluated whether CVMS, dental age, and cephalometric dimensions varied with BMI.<div class="boxTitle">Results</div>Overweight/obese children and adolescents had a proportionally larger bimaxillary prognathic skeletal pattern compared to those of normal weight. These cephalometric measurements [articulare–gnathion (Ar–Gn), condylion–anterior nasal spine (Co–ANS), sella–gonion (S–Go), nasion–menton (N–Me), anterior nasal spine–menton (ANS–Me), sella-nasion-A point (SNA), sella-nasion-B point (SNB), and sella-nasion-pogonion (SNPg)] were significantly different [statistically (<span style="font-style:italic;">P</span> &lt; 0.05) and clinically (&gt;2 mm or &gt;2 degrees)] between the two study groups, with a linear relationship between BMI percentile and craniofacial dimension. The overweight/obese BMI group had a mean dental age 1.4 years advanced relative to the normal weight group (<span style="font-style:italic;">P</span> &lt; 0.05), with an advancement of nearly one CVM stage between the ages of 12 and 14 (<span style="font-style:italic;">P</span> &lt; 0.05).<div class="boxTitle">Limitations</div>The study is retrospective.<div class="boxTitle">Conclusions</div>Obese/overweight children and adolescents have proportionally larger antero-posterior and vertical dimensions and are more likely to experience advanced dental and skeletal maturation. Obese/overweight subjects may enter their growth spurt at a younger age and have earlier eruption of teeth, affecting treatment timing. BMI percentile should be a consideration for orthodontic treatment in growing patients.</span>


Perception of pain in Class II malocclusion children treated with cervical headgear: a randomized controlled trial
<span class="paragraphSection"><div class="boxTitle">Summary</div><div class="boxTitle">Objectives</div>The aims of this study were: 1. to evaluate the experience of pain perceived by children during separator placement and headgear wear; 2. to find possible associations between the perceived intensity of pain and the levels of Substance P (SP) and interleukin-1 beta (IL-1β) in the gingival crevicular fluid (GCF) during these procedures; 3. to identify other factors, such as previous pain experience, which could be associated to the patients’ perceived discomfort or pain during treatment.<div class="boxTitle">Trial design</div>Nine-month parallel-group randomized controlled trial.<div class="boxTitle">Methods</div>Forty Class II malocclusion children (8–12 years) were included, half of which received a cervical headgear while the other half did not receive any treatment during the study period. Baseline pain data were recorded including previous experience to general and dental pain, Corah’s Dental Anxiety Scale, and baseline pain using a visual analogue scale (VAS). Elastic separators were placed in children for 1 week, followed by molar band and cervical headgear placement. Children were seen at various time points throughout the 9-month period where at each appointment, a VAS assessment of pain as well as GCF sampling was carried out to quantify the levels of SP and IL-1β. Multiple regression analysis was performed to ascertain the influence of factors including sex, age, time, headgear wear, and baseline pain data on pain severity.<div class="boxTitle">Results</div>Pain severity and SP and IL-1β levels in the GCF follow a similar pattern, with peaks being observed 1 day after orthodontic elastic separator placement. Pain was more severe after the placement of orthodontic separators than following cervical headgear wear. With regard to pain predictors, pain is more severe in older children, those with a worse previous general pain experience, and those with higher levels of IL-1β, particularly after elastic separator placement.<div class="boxTitle">Conclusions</div>Orthodontic pain and discomfort following orthodontic separator placement and cervical headgear wear depends on factors including age, previous pain experience, and the level of IL-1β in the GCF.</span>


Computer-aided indirect bonding versus traditional direct bonding of orthodontic brackets: bonding time, immediate bonding failures, and cost-minimization. A randomized controlled trial
<span class="paragraphSection"><div class="boxTitle">Summary</div><div class="boxTitle">Introduction</div>The primary aim of this randomized controlled trial was to compare the time for bracket bonding using either direct or computer-aided indirect bonding; a secondary aim was to assess immediate bracket debondings and cost minimization.<div class="boxTitle">Methods</div>Consecutive patients were randomly allocated to two groups (blocks of four, online-generated sequence) using a split-mouth design with a direct and a computer-aided indirect bonding method: group 1 (upper right and lower left quadrants: indirect bonding; upper left and lower right quadrants: direct bonding) or group 2 (opposite situation). The primary outcome was difference in time spent for bonding brackets. The secondary outcome was immediate bracket debondings (at the bonding appointment). Time for indirect bonding was recorded in two steps: digital bracket placement and clinical bonding procedure. Outcome assessment was blinded. Friedman’s ANOVA test was used to assess differences in bonding time. Chi-square test was used to compare immediate debondings. A cost-minimization analysis was undertaken.<div class="boxTitle">Results</div>Thirty-seven patients were randomized to group 1 or 2. Ten patients were excluded: 15 patients were analyzed in group 1 and 12 in group 2. Clinical chair time for bonding half a mouth was significantly shorter for computer-aided indirect bonding (12 minutes 52 seconds) than for direct bonding (16 minutes 47 seconds) (<span style="font-style:italic;">P</span> &lt; 0.001). When adding the time for digital bracket placement, the total bonding time (28 minutes 14 seconds) was longer for indirect bonding than for direct bonding (<span style="font-style:italic;">P</span> &lt; 0.001). There was no single immediate debonding with the direct bonding method, while 14 brackets were lost with the indirect bonding method (5.1 per cent) (<span style="font-style:italic;">P</span> = 0.0001). Cost-minimization analysis showed that computer-aided indirect bonding was more expensive than direct bonding.<div class="boxTitle">Conclusions</div>The clinical chair time was significantly shorter for computer-aided indirect bonding than for direct bonding. However, the total bonding time for computer-aided indirect, including digital bracket placement, was longer than for direct bonding. There were significantly more immediate debondings with computer-aided indirect bonding than with direct bonding. Under these conditions, computer-aided indirect bonding was more expensive than direct bonding.<div class="boxTitle">Registration</div>This trial was retrospectively registered on ClinicalTrials.gov (University of Aarhus Protocol Record 10101).<div class="boxTitle">Protocol</div>The protocol was not published before trial commencement.</span>


Vacuum-formed retainers and bonded retainers for dental stabilization—a randomized controlled trial. Part II: patients’ perceptions 6 and 18 months after orthodontic treatment
<span class="paragraphSection"><div class="boxTitle">Summary</div><div class="boxTitle">Objective</div>To compare removable vacuum-formed Essix C retainers with bonded cuspid-to-cuspid retainers (CTCs) regarding patients’ perceptions after debonding and 6 and 18 months of retention.<div class="boxTitle">Trial design</div>A single-centre two-arm parallel-group randomized controlled trial.<div class="boxTitle">Methods</div>This trial included 104 adolescent patients, computer-generated randomized, with sequentially numbered, opaque and sealed envelopes, into two groups and stratified by gender. They were treated with fixed appliances with and without tooth extractions in both jaws and were ready for debond. Patients in the intervention arm received a vacuum-formed retainer (VFR) in the mandible (<span style="font-style:italic;">n</span> = 52), and patients in the active comparator arm received a CTC (<span style="font-style:italic;">n</span> = 52). Both groups had a VFR in the maxilla. Treatment outcome satisfaction, quality of care and attention, side-effects during the retention phase, and retainer acceptance and compliance were assessed with questionnaires at baseline (T1, 2 weeks after debond) and after 6 (T2) and 18 months (T3) of retention. Operator was blinded to group assignment during measurements.<div class="boxTitle">Results</div>Ninety-five patients completed the questionnaires at all three time points. Patients were overall satisfied with treatment outcome, quality of care and attention, and how their retainers worked at all three time points, with no differences between groups. At T1 and T3, the VFR group reported significantly more pain and discomfort (T1: <span style="font-style:italic;">P</span> = 0.005, T3: <span style="font-style:italic;">P</span> &lt; 0.0001) and soreness (T1: <span style="font-style:italic;">P</span> = 0.001, T3: <span style="font-style:italic;">P</span> = 0.011) in the mandible compared to the CTC group. The CTC group found it easier to get used to their retainers. After 18 months, 70.5 per cent in the VFR group and 73.9 per cent in the CTC group reported the recommended wear-time of the VFRs. Decreased wear-time was correlated to perceived pain and discomfort (<span style="font-style:italic;">r</span><sub><span style="font-style:italic;">s</span></sub> = −0.421, <span style="font-style:italic;">P</span> &lt; 0.0001).<div class="boxTitle">Limitations</div>The results were limited by our retainer design and recommended wear regimen.<div class="boxTitle">Conclusions</div>Both groups reported high treatment outcome satisfaction and low levels of side-effects during the retention phase. Nevertheless, the VFR group reported more pain and discomfort at T1 and at T3. Self-reported compliance was the same in both groups. The VFR group was more concerned about relapse.<div class="boxTitle">Trial registration</div>NCT03070444 (https://clinicaltrials.gov).</span>


Patient satisfaction after orthognathic surgery: a 3 year follow-up of 60 high-angle Class II individuals
<span class="paragraphSection"><div class="boxTitle">Summary</div><div class="boxTitle">Background and objectives</div>High-angle Class II malocclusion is considered challenging to treat to a stable result and, although studies report treatment outcome in terms of morphology, patient satisfaction has not been addressed. The objectives of the present study were to examine patients’ motives for treatment and satisfaction with the results.<div class="boxTitle">Material and methods</div>A structured questionnaire was distributed 3 years post-operatively to 93 consecutively treated patients with an initial diagnosis of mandibular-plane angle (ML/NSL) ≥34.0 degrees and ANB angle ≥4.0 degrees. Three surgical subsamples were defined: one-piece Le Fort I, bilateral sagittal split osteotomy, or a combination of the two (Bimax). Lateral cephalometric radiographs were used to assess morphological characteristics and post-treatment changes.<div class="boxTitle">Results</div>Questionnaire participation was 69.8 per cent. The most frequently reported motives for seeking treatment were to improve oral function (85.0 per cent) and dental appearance (71.7 per cent). Thirty per cent were very satisfied, 53.3 per cent were satisfied, and 16.7 per cent were dissatisfied with the overall treatment result. Dissatisfaction was associated with a persisting post-treatment anterior open bite (AOB), horizontal relapse at B point, and with sensory impairment.<div class="boxTitle">Conclusions and implications</div>A higher rate of dissatisfaction was found than what has usually been reported for othognathic surgical patients, and this was associated with a persisting AOB. In addition, mandibular relapse and impaired sensory function were related to dissatisfaction and are associated with mandibular surgery. Prospective high-angle Class II patients should be comprehensively informed about the unpredictability of treatment outcomes in terms of occlusion and facial appearance.</span>


Satellite cell capacity for functional adaptation of masseter muscle in Class II and Class III patients after orthognathic surgery—a pilot study
<span class="paragraphSection"><div class="boxTitle">Summary</div><div class="boxTitle">Aim</div>The aim of the prospective pilot study was to analyze the biomarkers <span style="font-style:italic;">CD34, Pax7, Myf5</span>, and <span style="font-style:italic;">MyoD</span> for stimulation of satellite cells (SCs), which are responsible for functional adaptation.<div class="boxTitle">Subjects and Methods</div>Forty-five Caucasian patients were consecutively recruited from the Maxillo-Facial-Surgery at TU Dresden. Eleven orthognathic Class III patients, 24 Class II patients, and 10 controls with Class I were involved in the study. Tissue samples from masseter muscle were taken from the patients pre-surgically (T1) and 7 months later (T2). Samples from controls were taken during the extraction of third molars in the mandible. Polymerase chain reaction (PCR) for relative quantification of gene expression was calculated with the delta delta cycle threshold (ΔΔC<sub>T</sub>) method.<div class="boxTitle">Results</div>The results show significant differences for the marker of SC stimulation between the controls, the patient groups, males, and females. The gene expression of <span style="font-style:italic;">CD34</span> was post-surgically upregulated for Class III (0.35–0.77, standard deviation [SD] = 0.39, <span style="font-style:italic;">P</span> &lt; 0.05) in comparison with controls. For <span style="font-style:italic;">Pax7</span>, there was a significant difference shown between the retrognathic and the prognathic group because of downregulation in Class II patients (1.64–0.76, SD = 0.55, <span style="font-style:italic;">P</span> &lt; 0.05). In Class III patients, there was a significant upregulation for <span style="font-style:italic;">Myf5</span> (0.56–1.05, SD = 0.52, <span style="font-style:italic;">P</span> &lt; 0.05) after surgery too.<div class="boxTitle">Conclusions</div>The significant decline of <span style="font-style:italic;">Pax7</span> in Class II patients indicates a deficiency of stimulated SC post-surgically. The expression of <span style="font-style:italic;">CD34</span> and <span style="font-style:italic;">Myf5</span> in Class II stayed unchanged. In contrast, there was an upregulation for all Class III patients, mainly in females, shown post-surgically. This may be one reason for weak functional adaptation and relapse in Class II patients.</span>


The impact of obesity on orthodontic treatment outcome in adolescents: a prospective clinical cohort study
<span class="paragraphSection"><div class="boxTitle">Summary</div><div class="boxTitle">Introduction</div>This prospective clinical cohort study investigated the potential influence of obesity on orthodontic treatment outcome.<div class="boxTitle">Methods</div>A prospective cohort of adolescent patients undergoing routine fixed appliance treatment were recruited into normal-weight or obese groups based upon body mass index (BMI) centile and followed up until the completion of treatment. Primary outcome was treatment duration, and secondary outcomes included treatment outcome (occlusal change measured using peer assessment rating [PAR]), appointment characteristics, and compliance measures.<div class="boxTitle">Results</div>A total of 45 patients mean age 14.8 (1.6) years were included in the final analysis. The normal-weight group included 23 patients with mean BMI 19.4 (2.4) kg/m<sup>2</sup> and the obese group 22 patients with mean BMI 30.5 (3.8) kg/m<sup>2</sup>. There were no significant differences in baseline demographics between groups, except for BMI and pre-treatment PAR. The normal-weight group had a mean pre-treatment PAR of 25.6 (8.3) and the obese 33.3 (11.8) giving the obese group a more severe pre-treatment malocclusion (<span style="font-style:italic;">P</span> = 0.02). There were no significant differences in treatment duration between groups (<span style="font-style:italic;">P</span> = 0.36), but obese patients needed less time per each additional baseline PAR point compared to normal weight (<span style="font-style:italic;">P</span> = 0.02). Obese patients also needed less appointments compared to normal-weight patients (<span style="font-style:italic;">P</span> = 0.02). There were no significant differences between groups for appointment characteristics or compliance. Finally, obese patients were more likely to experience a great PAR reduction than normal-weight patients (relative risk = 2.6; 95% confidence interval = 1.2–4.2; <span style="font-style:italic;">P</span> = 0.02).<div class="boxTitle">Conclusions</div>There were no significant differences in treatment duration between obese and normal-weight patients. Obesity does not appear to be a risk factor for negative orthodontic treatment outcome with fixed appliances.</span>


The relation of severe malocclusion to patients’ mental and behavioral disorders, growth, and speech problems
<span class="paragraphSection"><div class="boxTitle">Summary</div><div class="boxTitle">Background</div>Severe malocclusions appear in up to 20 per cent of the population. Many neuropsychiatric diseases are likely to have a neurodevelopmental, partially genetic background with their origins as early as fetal life. However, the possible relationship between neurodevelopmental disorders and severe malocclusions is unclear. The aim of this study was in a population-based setting (270 000 inhabitants) to investigate whether patients with severe malocclusions have more mental and behavioural disorders and growth or speech problems than controls without severe malocclusion.<div class="boxTitle">Material and Methods</div>The study group consisted of patients from the Espoo Health Care Center, Finland, born in year 2000, who were retrospectively screened for their medical and dental records, including their possible mental and behavioural disorders (i.e. attention deficit hyperactivity disorder, Asperger’s syndrome, autism, mood disorder, or broadly defined behavioural abnormalities, learning problems, mental disorders, sleep disturbances, anxiety symptoms, depressive symptoms, and eating-related symptoms) and their need of orthodontic treatment according to the Treatment Priority Index (TPI). The study group consisted of a severe malocclusion group (<span style="font-style:italic;">n</span> =1008; TPI 8–10) and a control group (<span style="font-style:italic;">n</span> = 1068) with no severe malocclusion (TPI 0–7).<div class="boxTitle">Results</div>Patients with severe mandibular retrognatia (<span style="font-style:italic;">P</span> &lt; 0.000), lip incompetence (<span style="font-style:italic;">P</span> = 0.006), or neurodevelopmental disorders (mental and behavioural; <span style="font-style:italic;">P</span> = 0.002) were found to have significantly more speech problems than the controls. The patients with severe malocclusions were leaner, that is, body mass index (kg/m<sup>2</sup>) &lt;17, underweight; 17–25, normal weight; &gt;25, overweight) than controls (<span style="font-style:italic;">P</span> = 0.003), and underweight patients had a significant association with retrognathic maxilla (<span style="font-style:italic;">P</span> &lt; 0.000) compared to normal or overweight patients. No significant relationship between neurodevelopmental disorders and severe malocclusions, that is, retrognatia of maxilla, hypodontia, and severe dental crowding was observed.<div class="boxTitle">Conclusion</div>Our results indicate that patients with severe mandibular retrognatia, lip incompetence, or neurodevelopmental disorders were found to have significantly more speech problems than controls. During orthodontic treatment of patients with severe malocclusion, special attention should be paid to patients with severe mandibular retrognatia, lip incompetence, and speech problems to detect signs of possible neurodevelopmental disorders and record if potential follow-up measures are in place.</span>


Relapse 1 week after bracket removal: a 3D superimpositional analysis
<span class="paragraphSection"><div class="boxTitle">Summary</div><div class="boxTitle">Objectives</div>To measure tooth movement 1 week post-treatment and assess potential correlation with changes invoked during treatment.<div class="boxTitle">Subjects and methods</div>Thirty-eight patients were recruited (19 males, 19 females). Polyvinyl siloxane impressions were taken after bracket debonding (T1) and 1 week later (T2) and digitally scanned. During this period no retention was used. The digital casts were superimposed on structures of the hard palate. Translation and rotation of the first molars, canines, and central incisors were recorded. Additionally, movement of these teeth was assessed from the beginning (T0) until the end of treatment (T1). The correlation between the post-treatment relapse (T1–T2) and tooth movement during treatment (T0–T1) was investigated <span style="font-style:italic;">via</span> the Spearman correlation coefficient.<div class="boxTitle">Results</div>Relapse was detected and reflected changes in tooth position during treatment. For the first molars (right, left) the correlation between treatment and post-treatment tooth movement was evident in the transverse direction (<span style="font-style:italic;">r</span> = −0.38, <span style="font-style:italic;">P</span> = 0.020; <span style="font-style:italic;">r</span> = −0.32, <span style="font-style:italic;">P</span> = 0.052), tipping (<span style="font-style:italic;">r</span> = −0.40, <span style="font-style:italic;">P</span> = 0.015; <span style="font-style:italic;">r</span> = −0.34, <span style="font-style:italic;">P</span> = 0.034) and the antero-posterior direction (<span style="font-style:italic;">r</span> = −0.31, <span style="font-style:italic;">P</span> = 0.061; <span style="font-style:italic;">r</span> = −0.36, <span style="font-style:italic;">P</span> = 0.027); for the canines (right and left), as rotation around their long axis (<span style="font-style:italic;">r</span> = −0.55, <span style="font-style:italic;">P</span> = 0.003; <span style="font-style:italic;">r</span> = −0.58, <span style="font-style:italic;">P</span> = 0.002); for central incisors (right and left) in the antero-posterior direction (<span style="font-style:italic;">r</span> = −0.55, <span style="font-style:italic;">P</span> = 0.000; <span style="font-style:italic;">r</span> = −0.48, <span style="font-style:italic;">P</span> = 0.03), transverse direction (<span style="font-style:italic;">r</span> = −0.43, <span style="font-style:italic;">P</span> = 0.07; <span style="font-style:italic;">r</span> = −0.32, <span style="font-style:italic;">P</span> = 0.047), and rotation around their long axis (<span style="font-style:italic;">r</span> = −0.53, <span style="font-style:italic;">P</span> = 0.001; <span style="font-style:italic;">r</span> = −0.28, <span style="font-style:italic;">P</span> = 0.089).<div class="boxTitle">Conclusions</div>Post-treatment changes in tooth position were mostly related to tooth movement during treatment. The reported correlations may help clinicians predict short-term relapse, evaluate long-term retention need, and design individualized retention schemes.</span>


Failure rates among metal brackets cured with two high-intensity LED light-curing lamps: an in vivo study
<span class="paragraphSection"><div class="boxTitle">Summary</div><div class="boxTitle">Objective</div>The objective of this split-mouth clinical trial was to compare bonding failure rates of metal brackets bonded with two different light-emitting diode (LED) light-curing lamps with different high-intensity power outputs.<div class="boxTitle">Materials and methods</div>Forty patients were included for a total of 800 brackets that were randomly bonded (left and right sides in a 1:1 ratio) in maxillary and mandibular arches using two different LED devices. An LED of 3200 mW/cm<sup>2</sup> and an LED of 5000 mW/cm<sup>2</sup> were used in this split-mouth clinical trial. Bonding failures during the initial 6 months of orthodontic treatment were recorded as maxillary versus mandibular, anterior teeth versus posterior teeth, and left side versus right side.<div class="boxTitle">Results</div>Five dropouts were recorded for discontinuing orthodontic treatment and 700 brackets were analysed in total. The bonding failure rates for 3200 and 5000 mW/cm<sup>2</sup> LEDs were 6.0 and 7.4 per cent, respectively (<span style="font-style:italic;">P</span> = 0.450), which were not statistically significantly different. There were no significant differences in bracket survival rates between the LEDs used (<span style="font-style:italic;">P</span> = 0.866). The posterior teeth presented a higher index of bond failures (odds ratio, 3.14; 95% confidence interval, 1.68–5.87; <span style="font-style:italic;">P</span> &lt; 0.001).<div class="boxTitle">Limitations</div>Direct comparison was only done between two high-intensity LED lights rather than against conventionally used halogen lights.<div class="boxTitle">Conclusion</div>Similar bonding failures were recorded using both LED devices (3200 and 5000 mW/cm<sup>2</sup>). Significantly more bonding failures occurred in premolar teeth than in anterior teeth.</span>


Comparison of post-treatment changes with and without retention in adolescents treated for maxillary impacted canines—a randomized controlled trial
<span class="paragraphSection"><div class="boxTitle">Summary</div><div class="boxTitle">Objective</div>To evaluate whether retention is needed after orthodontic treatment of impacted maxillary canines.<div class="boxTitle">Trial design</div>Two-arm parallel group single-centre randomized controlled trial.<div class="boxTitle">Materials and methods</div>Sixty-three patients, 39 girls and 24 boys, were recruited to the study. The inclusion criteria were patients with at least one impacted or unerupted maxillary canine, and moderate irregularity of the maxillary six anterior teeth according to Little’s index (LI). After gaining informed consent from the patient and their custodians, the patients were randomized to one of two groups, i.e. to a non-retention group or a retention group. The randomization process was prepared and carried out by an independent person not involved in the trial and the randomization used blocks of 20 (10 + 10). Primary outcomes were changes in single contact point discrepancy, and LI measured on digitalized three-dimensional study casts 1-year post-treatment. The study casts were anonymized before assessment and the changes were blinded for the assessor. Data were evaluated on an intention-to-treat basis. Thus, all randomized patients were incorporated into the final analysis. In the non-retention group a 10-week interim period was used to detect patients who eventually have a relapse immediately after treatment. If so, the patient got the arch-wire reinserted. Most patients in the retention group received a vacuum-formed retainer and pretreatment spacing cases got a bonded retainer.<div class="boxTitle">Results</div>Mean irregularity change was 0.4 mm in the retention and 1.3 mm in the non-retention group (<span style="font-style:italic;">P</span> &lt; 0.001). Maximum change was 2.5 mm in the retention and 3.2 mm in the non-retention group (<span style="font-style:italic;">P</span> &lt; 0.001). Most changes in the non-retention group occurred during the 10-week interim period. In the non-retention group, one patient developed contact point discrepancy of &gt;2 mm during the interim period and was realigned.<div class="boxTitle">Harms</div>One patient met the stopping guideline criteria. This patient had the arch wire reinserted for 2 months. After realignment, the patient received a retention appliance.<div class="boxTitle">Limitations</div>The trial was a single-centre study and short-term changes were evaluated.<div class="boxTitle">Conclusions</div>Changes between the retention and the non-retention group were statistically but not clinically significant. Since satisfactory clinical results 1-year post-treatment were found in the non-retention group, retention does not appear to be needed. The 10-week interim period was useful in detecting patients who might have a relapse immediately after treatment.<div class="boxTitle">Trial registration</div>The trial was not registered.</span>