Cephalometric changes of pushing splints 3 compared to rapid maxillary expansion and facemask therapy on the airway space in class III growing patients: A randomized clinical trial.

BACKGROUND: Early orthopaedic treatment with rapid maxillary expansion (RME) associated with facemask (FM) has been shown to be effective in correcting Class III malocclusions in children. Treatment with pushing splints 3 (PS3) has shown to correct skeletal discrepancies in Class III growing patients. However, the effects of orthopaedic treatment on the upper airways in children with Class III malocclusion is controversial. OBJECTIVES: The aim of this study was to evaluate the cephalometric changes in the airways of PS3 compared to the RME/FM protocol. MATERIALS AND METHODS: In this study, 48 patients with Class III malocclusion (age range 5.5-8.5 years old) were selected for this study, and 24 were treated with PS3 appliance and 24 with RME/FM therapy. Lateral cephalograms before (T0) and at the end of the treatment (T1) were analysed to compare pharyngeal spaces. Paired and unpaired t tests were used for data analysis (P < .05). RESULTS: A total of 41 patients (21 patients for the PS3 group, 11 males and 10 females, mean age 7.0 ± 1.2 years; 20 patients for the RME/FM group, 10 males and 10 females, mean age 7.2 ± 1.3 years) were included. The results showed a statistically significant (P < .05) increase in the nasopharyngeal space after both therapies. However, the effects were similar considering that there were no differences between groups for the assessed variables at T0-T1. CONCLUSIONS: Early treatment of Class III malocclusion with PS3 does not induce a statistically significant increase in the sagittal airway space compared to RME/FM. The absence of untreated group could not define the role of growth in the increase of space.

Accuracy of digital workflow for placing orthodontic miniscrews using generic and licensed open systems. A 3d imaging analysis of non-native .stl files for guided protocols.

BACKGROUND: This study aimed to assess the accuracy of digital workflow for guided insertion of miniscrews in the anterior palate using restorative implant dentistry software and licensed software for orthodontic applications. METHODS: Twenty subjects (8 males, 12 females, mean age = 16.7 ± 2.1 years) were prospectively selected to receive guided insertion of bicortical palatal miniscrews. Virtual planning was performed using restorative implant dentistry software (Blue Sky Plan*, version 4.7) (group 1 = 10 subjects) and licensed orthodontic software (Dolphin Imaging Software, version 11.0) (group 2 = 10 subjects). A specific 3D Imaging technology was applied to permit the registration of the planned and achieved position of the miniscrews based on the superimposition of maxillary models. The angular deviation (accuracy error) between the planned and the achieved positions of the miniscrews were recorded. Independent Student's test was used with statistical significance set at p value < 0.05. RESULTS: The mean accuracy error recorded in group 1 was 7.15° ± 1.09 (right side) and 6.19 ± 0.80 (left side) while the mean error in group 2 was 6.74° ± 1.23 (right side) and 5.79 ± 0.95 (left side). No significant differences were recorded between the two groups (p > 0.05); instead, miniscrews placed on the right side were almost one degree higher than the left side (p < 0.05) in both groups. CONCLUSIONS: The clinical accuracy error was similar when using generic and licensed orthodontic software for guided systems.

Treatment of mild Class II malocclusion in growing patients with clear aligners versus fixed multibracket therapy: A retrospective study.

OBJECTIVE: To compare the dental and skeletal effects of intermaxillary elastics on the correction of mild Angle's Class II division 1 malocclusion with clear aligner treatment (CA) versus fixed multibracket (FMB) in growing patients. SETTINGS AND SAMPLE POPULATION: The study sample consisted of 49 consecutively patients (mean age ± SD 12.9 ± 1.7 years), 32 females and 17 males referred from the School of Orthodontics of the University of Bratislava Comenius (Slovakia). All patients were treated with a non-extraction orthodontic treatment, 25 with FMB and 24 with CA. METHODS: The cephalometric analysis was performed at the beginning (T0) and the end of the treatment (T1). The t test for unpaired data was carried out to compare cephalometric values at T0 and changes at T1-T0 between the two groups. The level of significance was set as P < .0035. RESULTS: The two groups showed no statistically significant differences (ANPg = -0.1°; P = .762) in the correction of the sagittal intermaxillary relation. The analysis of vertical skeletal changes showed no statistically significant effects on mandibular inclination (SN/MP = 0.1°; P = .840). The two treatments had a statistically significant and clinically relevant difference in controlling the inclination of the lower incisors (L1/GoGn = 4.8°, CAG = -0.5°± 3.9°; FMB = 4.3°± 5.8°; P < .001). CONCLUSIONS: Class II elastics combined with CA and FMB produce a similar correction on sagittal discrepancies in growing patients. CA presented a better control in the proclination of the lower incisors. CA and elastics might be a good alternative in the correction of mild Class II malocclusion in cases where a proclination of lower incisors is unwanted.

Evaluation of mandibular changes after rapid maxillary expansion: a CBCT study in youngsters with unilateral posterior crossbite using a surface-to-surface matching technique.

OBJECTIVES: The purpose of this study was to evaluate mandibular asymmetry in youngsters with posterior unilateral crossbite (PUXB), through cone-beam computed tomography and reverse engineering technique, before and after rapid maxillary expansion (RME) treatment. MATERIALS AND METHODS: Forty cone-beam computed tomography (CBCT) images were obtained from all patients at two time points, namely T0 acquired before the placement of a Hyrax expander and T1 after appliance removal. The CBCT scans were segmented and volume rendered into a surface there-dimensional (3D) mesh model. Thereafter, mandibular models were digitally registered by using a "best-fit" algorithm. Surface and volumetric changes, between T0 and T1, were compared by using Student's t tests. RESULTS: A slight increase of 0.45 cm3 of the total mandibular volume was found at T1 when compared with T0 (p < 0.001). The mandibular hemi-volume on the crossbite side (CB) was slightly smaller than the non-crossbite side both at T0 and T1. However, the mean differences of hemi-volume from the CB (crossbite) and non-CB side between T0 and T1 show a decrease of 0.26 cm3 (p < 0.001). Findings for the surface-to-surface deviation analysis demonstrated a fine percentage of matching at T0 which slightly improved at T1 (p < 0.001). CONCLUSIONS: Youngsters affected by PUXB showed a very slight and not statistically significant volumetric and morphological asymmetry between CB side and non-CB side at T0. However, the change in mean differences of 0.26 cm cannot be considered clinically relevant. CLINICAL RELEVANCE: Mandibles in young PUXB patients exhibit only a very mild mandibular asymmetry. Although the statistically significant mean change found right after RME removal cannot be considered clinically relevant, a more consistent sample and a longer follow-up could be of interest in explaining the short-term findings.

Impact of Magnetic Stimulation on Periodontal Ligament Stem Cells.

The aim of this study was to evaluate the effect of a time-dependent magnetic field on the biological performance of periodontal ligament stem cells (PDLSCs). A Western blot analysis and Alamar Blue assay were performed to investigate the proliferative capacity of magnetically stimulated PDLSCs (PDLSCs MAG) through the study of the MAPK cascade (p-ERK1/2). The observation of ALP levels allowed the evaluation of the effect of the magnetic field on osteogenic differentiation. Metabolomics data, such as oxygen consumption rate (OCR), extracellular acidification rate (ECAR) and ATP production provided an overview of the PDLSCs MAG metabolic state. Moreover, the mitochondrial state was investigated through confocal laser scanning microscopy. Results showed a good viability for PDLSCs MAG. Magnetic stimulation can activate the ERK phosphorylation more than the FGF factor alone by promoting a better cell proliferation. Osteogenic differentiation was more effectively induced by magnetic stimulation. The metabolic panel indicated significant changes in the mitochondrial cellular respiration of PDLSCs MAG. The results suggested that periodontal ligament stem cells (PDLSCs) can respond to biophysical stimuli such as a time-dependent magnetic field, which is able to induce changes in cell proliferation and differentiation. Moreover, the magnetic stimulation also produced an effect on the cell metabolic profile. Therefore, the current study demonstrated that a time-dependent magnetic stimulation may improve the regenerative properties of PDLSCs.

Cephalometric effects of Pushing Splints 3 compared with rapid maxillary expansion and facemask therapy in Class III malocclusion children: a randomized controlled trial.

BACKGROUND: Pushing Splints 3 (PS3) device was recently introduced for the treatment of Class III malocclusion in children. OBJECTIVES: To assess the effect on the sagittal maxillary position (SNA, primary outcome) of PS3 therapy compared with rapid maxillary expansion and facemask therapy (RME/FM) and to compare skeletal and dento-alveolar effects in growing Class III patients. TRIAL DESIGN: This trial was a single-centre randomized controlled trial with two groups randomly allocated in a 1:1 ratio of equal size by sealed-envelope randomization, conducted at the Dentistry Unit of Bambino Gesù Children's Hospital, IRCCS (Rome, Italy). METHODS: A total of 48 patients with Class III malocclusion were included in the study and randomly allocated to the two groups: PS3 therapy and RME/FM therapy. Only the RME/FM group underwent palatal expansion, and both groups were instructed to wear the appliances 14 hours/day. Pre- (T0) and post-treatment (T1) cephalograms were taken. An independent sample t-test and regression analysis were used to analyse the data (P value <0.05). Researchers involved in statistics and tracings were blinded to the treatment allocation. RESULTS: A total of 42 patients (21 for each group) completed the study. The maxillary sagittal position improved similarly in both groups (SNA = 0.4°; P = 0.547). A statistically significant decrease of SNPg angle (-1.6°; P < 0.001) and increase of ANPg angle (1.4°; P = 0.018) were found in the RME/FM group compared with PS3 group. CoGoMe angle significantly decreased in RME/FM group compared with PS3 group (-1.7°; P = 0.042). The regression analysis showed an association between SN/MP angle at T0 and the differences between T1 and T0 of SNPg (B = 0.13; P = 0.005) and SN/MP (B = -0.19; P = 0.034). Only three patients (PS3 = 2; RME/FM = 1) had breakages of the devices. LIMITATIONS: Results are limited to short-term effects. CONCLUSION: RME/FM therapy and PS3 are both effective therapies for the early correction of Class III malocclusion. The PS3 controlled better mandibular divergency reducing the clockwise rotation in patients with higher mandibular inclination. REGISTRATION: This study was not registered in a clinical trial registry.

Pseudo Hemifacial Microsomia With Condylar-Coronoid Collapse: New Therapeutic Approach in Growing Patients.

The purpose of this study is to describe the management of 2 dimorphic patients affected by Hemimandibular Hypoplasia with Condylar-Coronoid Collapse (HH-CCC), also called Pseudo Hemifacial Microsomia, where the orthopedic treatment gave an excellent long-term follow-up. The patients were a 7-year-old female and a 6-year-old male with a HH-CCC on the left side, an asymmetrical face with chin deviation, class II dental malocclusion and canting of the occlusal plane. An X-ray evaluation and clinical observation confirmed the unilateral mandibular deficiency and the collapse of the condyle on the coronoid process on the affected side. The treatment plan consisted of the use of an asymmetrical functional appliance with a vertical screw. The appliance was gradually activated on the vertical plane on one side by a screw incorporated on an acrylic plate. It was used for 22 hours/day, including sleep time but not during meals. This treatment improved the patient' s facial appearance. HH-CCC showed a positive response to functional therapy.

Short-term effects of the Sander bite-jumping appliance on the pharyngeal airways in subjects with skeletal Class II malocclusion: A retrospective case-control study.

BACKGROUND: Skeletal Class II subjects present often a retruded mandible that might increase the probability of breathing disorders. OBJECTIVE: To evaluate the effects of functional treatment by means of the Sander bite-jumping appliance (BJA) on the upper airways of growing subjects. METHODS: Thirty-four subjects (21 males, 13 females; mean age 11.1 ± 1.2 years) with skeletal Class II malocclusion due to mandibular retrusion were treated with the Sander BJA (BJA group). The control group consisted of thirty-four untreated subjects with skeletal Class II malocclusion (25 males, 9 females; 10.4 ± 1.2 years; CTR group). The effect of the Sander BJA appliance on the airway dimensions was evaluated by comparing lateral cephalograms recorded before (T0) and after (T1) the period of observation/treatment. Within- and between-group comparisons were statistically evaluated according to the distribution of the data (P < .05). RESULTS: The oropharyngeal region (ph_pph) increased in the BJA group (1.8 ± 3.2; P = .001) but the difference respect to the CTR group was not statistically significant (0.73 ± 4.0; P = .314; P = .077). The tongue height (th) increased in the BJA group (2.8 ± 3.7; P < .001), and this increase was statistically significant respect to the CTR group (0.6 ± 4.7; P = .461; P = .038). In the BJA, the Ans_Pns_P angle showed a statistically significant decrease (-3.8 ± 7.8; P = .007) compared to the CTR group (-0.1 ± 5.4; P = .705; P = .026). CONCLUSIONS: The airway dimensions increased for both control subjects and Class II patients treated with Sander BJA due to physiological growth. The Sander BJA induced a statistically significant change in the tongue and soft palate position, but the clinically relevant of these changes is questionable.

"Pressure pain threshold over masticatory muscles and temporomandibular joint in patients with juvenile idiopathic arthritis".

BACKGROUND: Juvenile idiopathic arthritis (JIA) is an autoimmune, chronic, inflammatory joint disease, affecting children and adolescents. Patients with JIA may have pain and fatigue in muscles. There are not studies evaluating the pressure pain thresholds (PPTs) of both masticatory muscles and temporomandibular joint (TMJ) in patients with JIA. OBJECTIVE: This study aimed to investigate PPTs of masticatory muscles and TMJ in subjects with JIA. METHODS: Fifty-one JIA patients and fifty-two healthy subjects were recruited. JIA group was assessed for with a standardised clinical examination for temporomandibular disorders. In all subjects, the PPT was evaluated in the following sites: anterior temporalis (AT) and masseter (MM) muscles, TMJ and thenar (TH) eminence. Comparisons between groups were assessed with unpaired t test and ANOVA (P < .05). RESULTS: Pressure pain thresholds were significantly lower among JIA patients compared with controls (P < .001) for all analysed sites. The presence of TMJ pain at palpation was significantly associated with a lower PPT at TMJ (P = .031). CONCLUSIONS: Patients with JIA have generally lowered pain threshold to mechanical stimulus, which suggests an effect of JIA on nocicepton-modulating processes.

Cephalometric outcomes of a new orthopaedic appliance for Class III malocclusion treatment.

OBJECTIVE: To evaluate dental and skeletal effects of a new orthopaedic appliance for the treatment of Class III malocclusion in growing patients. MATERIAL AND METHODS: This retrospective cephalometric study was performed on a sample of 18 patients with a skeletal Class III malocclusion (4 males; 14 females; mean age 8.8 ± 1.5 years) treated with the Pushing Splints 3 (PS3) protocol. The control group consisted of 18 subjects (5 males; 13 females; mean age 9.1 ± 1.8 years) selected from a database of subjects with untreated Class III malocclusion. The cephalometric analysis was performed at the beginning (T0) and the end of the orthopaedic therapy (T1). Significant differences between the treated and control groups were assessed with independent samples t-test (P < 0.05). RESULTS: In the PS3 group, the post-treatment cephalometric values showed a forward displacement of the maxilla, resulting in a statistically significant increase of the SNA angle. ANPg and Wits appraisal improved significantly compared with the control group. Lingual inclination of mandibular incisors and buccal inclination of the upper incisors were significantly increased in comparison with the control group. No significant differences were recorded for backward mandibular rotation. LIMITATIONS: This study presents a short-term evaluation of the treatment and the use of a historical control group. CONCLUSIONS: The PS3 was effective for the treatment of Class III malocclusion in growing patients, with favourable maxillary advancement and control of the vertical skeletal relationships.

Effect of verbal and written information on pain perception in patients undergoing fixed orthodontic treatment: a randomized controlled trial.

BACKGROUND: Pain can discourage patients from seeking orthodontic treatment or compromise their compliance during therapy. OBJECTIVES: To determine the effects of verbal and written information on orthodontic pain after fixed appliance placement. TRIAL DESIGN: Two-arm parallel design randomized controlled trial. METHODS: Healthy adolescents with permanent dentition enrolled for orthodontic treatment were assigned to the study or control group using computer-generated random lists and allocation concealment with sealed envelopes. Participants completed baseline questionnaires to assess anxiety (State-Trait Anxiety Inventory Trait Version, Form X-2) and somatosensory amplification (Somatosensory Amplification Scale). Brackets were placed in the maxillary arch, from first molar to first molar, and an Australian archwire 0.012 inch was used for alignment. General verbal information on orthodontic treatment was given to all patients by the same clinician. Participants included in the study group received also detailed verbal instructions on orthodontic pain together with a take-home information leaflet by another clinician. Outcome included assessments of pain intensity with a Numerical Rating Scale (NRS) on the day of appliance placement (Day 1, bedtime) and twice a day for the following 6 days (Day 2 to Day 7, morning, bedtime), and analgesic consumption. Participants, statistician, and clinicians who gave general verbal information on orthodontic treatment and instructions about how to score pain intensity were blinded to group assignment. RESULTS: Sixty patients were assigned to the study (n = 30, mean age: 15.4 ± 1.3 years) or control group (n = 30, mean age: 14.7 ± 3.2 years). At baseline, no significant between-group differences were present in terms of anxiety and somatosensory amplification. Orthodontic pain scores were significantly lower in the study group compared with the control one, at bedtime on Day 1 (P < 0.05) and in the morning of Day 2 (P < 0.01). No significant between-group differences were found in following measurements. Overall, analgesic consumption was significantly lower in study compared with the control (P < 0.01). CONCLUSION: A combination of verbal and written information on orthodontic pain after placement of fixed appliances reduced patient's self-reported pain in the early stages. REGISTRATION: This study was not registered.

Two-dimensional versus three-dimensional Frӓnkel Manoeuvre: a reproducibility study.

BACKGROUND/OBJECTIVES: To assess intra- and inter-observer reproducibility of the evaluation of the Frӓnkel Manoeuvre (FM) on three-dimensional (3D) scans and to compare it to the assessment on two-dimensional (2D) pictures. MATERIALS/METHODS: This study included 44 individuals with a skeletal Class II malocclusion [9-16-years old mean age ± standard deviation: 13.5 ± 2.01 years]. All patients had a full Class II molar relationship, overjet ≥6 mm and point A, Nasion, point B angle (ANB) ≥5 degrees. During the FM, each patient was invited to bite in centric occlusion and then to posture the mandible forward to reach a Class I molar relationship. The FM was recorded both by a normal camera and a 3D scanner (3dMD system). Six examiners divided into two groups according to their orthodontic clinical experience (<5 and >10 years), and one gold standard in the evaluation of FM, commented twice (every 15 days) on both 2D photographs (T0 and T2) and 3D scans (T1 and T3). The intra-observer agreement and the inter-observer agreement compared to the gold standard were evaluated by computing the Cohen's K. RESULTS: The agreement between observations for each examiner ranged from 0.36 to 1 on 2D pictures (T0 versus T2), and from 0.22 to 0.69 on 3D scans (T1 versus T3). The overall agreement was 0.63 (95 per cent CI = 0.35-0.91) in 2D analysis and 0.5 (95 per cent CI = 0.35-0.64) in 3D analysis. CONCLUSIONS/IMPLICATIONS: The FM was less reproducible when performed on 3D records than on 2D pictures.

Midpalatal Suture Density Evaluation after Rapid and Slow Maxillary Expansion with a Low-Dose CT Protocol: A Retrospective Study.

Background and objectives: The aim of the present paper is to use low-dose computed tomography (CT) to evaluate the changes in the midpalatal suture density in patients treated with rapid maxillary expansion (RME) and slow maxillary expansion (SME). Materials and Methods: Thirty patients (mean age 10.2 ± 1.2 years) were retrospectively selected from the existing sample of a previous study. For each patient, a low-dose computed tomography examination was performed before appliance placement (T0) and at the end of retention (T1), seven months later. Using the collected images, the midpalatal suture density was evaluated in six regions of interest. Results: No significant differences were found between the timepoints in the rapid maxillary expansion group. Three out of six regions of interest showed significant decreases between the timepoints in the slow maxillary expansion group. No significant differences were found in comparisons between the two groups. Conclusions: The midpalatal suture density showed no significant differences when rapid maxillary expansion groups were compared to slow maxillary expansion groups, suggesting that a similar rate of suture reorganization occurs despite different expansion protocols.

Differences in craniofacial growth of Class II individuals from different decades: A retrospective study.

OBJECTIVES: To detect changes in mandibular growth between a historical group (HG) from the American Association of Orthodontics Foundation Craniofacial Growth Legacy Collection (AAOF Legacy) and a contemporary group (CG) of normodivergent or hypodivergent Class II untreated subjects. SETTING AND SAMPLE POPULATION: The sample included radiographs from the AAOF Legacy and from the University of Naples 'Federico II' collected during a previous RCT. MATERIALS & METHODS: The HG was composed of 26 individuals (around 1960) from the AAOF Legacy (15 from the Burlington Growth Study, nine from the Oregon Growth Study and two from the Michigan Growth Study) who were matched by sex, age and race with the 26 individuals of the CG (around 2010). Two lateral cephalograms obtained at T0 and T1 (12 months) were selected, and one examiner performed the cephalometric measurements according to Pancherz's method. The normal distribution of data was confirmed by the Shapiro-Wilk test, MANOVA analysis and t test for paired and unpaired data were performed. The level of significance was set according to Bonferroni's correction. RESULTS: At T0 and T1, the between-group comparisons revealed greater linear dimensions for Maxillary base, Maxillary incisor and Mandibular incisor in the CG than in the HG (P ≤ 0.002). No significant difference was found in the growth rate for linear skeletal measurement between the HG and the CG. CONCLUSIONS: In this study, the cephalometric analysis showed larger maxillary dimensions for the CG than the HG, while no differences were shown between the growth rate and direction of the two groups.

Effects of maxillary expansion on the upper airways: Evidence from systematic reviews and meta-analyses.

BACKGROUND: Constricted maxilla is frequently associated with reduced nasal airway dimensions. Wheatear skeletal maxillary expansion (ME) is effective on the dimension of the upper airways is still a debated issue. OBJECTIVES: This overview aimed to report the evidence provided by systematic reviews (SRs) on the effect of ME on the upper airways and to assess the methodological quality of the included SRs. METHODS: Six electronic databases have been explored up to November 2017. After title and abstract screening, SRs addressing the effects of fixed palatal expanders on the dimension and function of the nasal airways were included. The methodological quality of the included SRs was assessed using the updated version of A Measurement Tool to Assess Systematic Review (AMSTAR-2). RESULTS: Eight SRs were included. The methodological quality of most of the included SRs ranged between low and critically low. One SR was rated of high quality. A significant increase in nasal linear dimensions was reported both in the short and long term, but supported by low-/critically low-quality SRs. The significant increase in nasal cavity volume was the only outcome supported by a high-quality SR Controversial results were found with regards to nasal function. CONCLUSION: Whenever a constricted maxilla is present general dentists, paediatricians and ENTs should be familiar with the potential improvement provided by ME. However, due to the low/critically low quality of SRs supporting these results, ME cannot be indicated only for upper airways enhancement, but should be supported by an orthodontic indication.

Temporomandibular joint damage in juvenile idiopathic arthritis: Diagnostic validity of diagnostic criteria for temporomandibular disorders.

BACKGROUND: Diagnostic criteria reported in the expanded taxonomy for temporomandibular disorders include a standardised clinical examination and diagnosis (DC/TMD 3.B) of temporomandibular joint (TMJ) damage in patients with juvenile idiopathic arthritis (JIA); however, their validity is unknown. OBJECTIVES: To assess the validity of DC/TMD 3.B for the identification of TMJ damage in JIA-patients, using magnetic resonance imaging (MRI) as gold standard, and to investigate the relation between clinical findings and TMJ damage. METHODS: Fifty consecutive JIA patients (9-16 years) were recruited. DC/TMD 3.B were compared with TMJs MRI (100 TMJs) performed maximum at 1 month from the visit. The severity of TMJ damage was scored in four grades. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), logistic regression models with odds ratio of DC/TMD 3.B and clinical findings respect to MRI were calculated. RESULTS: The DC/TMD 3.B were inadequate in the identification of TMJ damage (sensitivity = 0.15, specificity = 0.92, PPV = 0.85, NPV = 0.28, P = 0.350). Chin deviation and TMJ crepitus were associated with worse TMJ damage (P = 0.006; P = 0.034). Reduced mouth opening (OR = 3.91, P = 0.039) and chin deviation (OR = 13.7, P = 0.014) were associated with the presence of TMJ damage. Combining "pain" (history of pain, TMJ pain, pain during movements) and "function" (TMJ crepitus, reduced mouth opening, chin deviation) clinical findings, the sensitivity and the specificity were 0.88 and 0.54. CONCLUSION: DC/TMD 3.B present a low sensitivity to diagnose TMJ damage. Chin deviation, reduced mouth opening and TMJ crepitus are associated with TMJ damage. We suggest combining "pain" and "function" findings for the evaluation of TMJ damage in JIA patients.

Evaluation of masticatory muscle activity in patients with unilateral posterior crossbite before and after rapid maxillary expansion.

Objectives: The relationship between unilateral posterior crossbite (UPCB) and the possible asymmetric activation of the jaw muscles in children is still under debate. This study aimed at evaluating the jaw muscle activity of children with UPCB before and after rapid maxillary expansion (RME) by means of surface electromyography and a standardized sampling protocol. Subjects and methods: Twenty-nine children with UPCB (UPCB-group, mean age 9.6 ± 1.6 years) and 40 UPCB-free controls (Control-group, 10.5 ± 1.1) were recruited. The activity of the left and right anterior temporalis (AT) and superficial masseter muscles (MM) was recorded during maximum voluntary clenching and a chewing task (T0). In the UPCB-group, data were collected, also, after the correction of the UPCB with RME (T1) and 6 months later (T2), without any further treatment. Electromyographic indices comparing the activity of paired muscle were computed via software to estimate the extent of asymmetric AT and MM activity. Paired and unpaired t-test or Wilcoxon-signed rank and Mann-Whitney U test, ANOVA or Friedman test and chi-squared test were used in the statistical analysis. Results: Both groups presented with asymmetric activity of the muscles, which did not differ between groups (T0, all P > 0.05). The treatment determined a decrease in muscular activity (T1, P = 0.040), and a more asymmetric pattern of muscle activation during chewing (T1, P = 0.040), which returned similar to baseline values at T2 (all P > 0.05). Conclusions: UPCB does not contribute to an asymmetric activation of AT and MM during functional tasks. The treatment of UPCB by RME did not determine a more symmetric activity of the assessed muscles.

Prevalence of malocclusion in children with obstructive sleep apnoea.

OBJECTIVES: To describe the prevalence of malocclusions in 2- to 10-year-old children suffering from obstructive sleep apnoea (OSA) and to evaluate the association between occlusal variables and OSA. SETTING AND SAMPLE POPULATION: A total of 2101 consecutive patients referred to an otorhinolaryngology unit were considered for the study. One hundred and fifty-six children (range 2-10 years) with suspected OSA were selected for a sleep study. The final sample consisted of 139 children suffering from OSA and a control group of 137 children. MATERIALS AND METHODS: All patients included in the study underwent a clinical orthodontic examination to record the following occlusal variables: primary canine relationship, presence of a posterior crossbite, overjet and overbite. Odds ratios and 95% confidence intervals, comparing the demographic characteristics and dental parameters in OSA vs non-OSA children, were computed. Multivariable logistic regression models were developed to compare independent variables associated with OSA to non-OSA children. RESULTS: The prevalence of malocclusions in children with OSA was 89.9% compared to 60.6% in the control group (P < 0.001). Factors independently associated with OSA compared to the control group were posterior crossbite (OR = 3.38; 95%CI:1.73-6.58), reduced overbite (OR = 2.43; 95%CI:1.15-5.15.), increased overbite (OR = 2.19; 95%CI:1.12-4.28) and increased overjet (OR = 4.25; 95%CI:1.90-9.48). CONCLUSIONS: This study showed a high prevalence of malocclusion in children with OSA compared to the control group. The posterior crossbite and deviations in overjet and overbite were significantly associated with OSA. The presence of these occlusal features shows the importance of an orthodontic evaluation in screening for paediatric OSA.

Dentoskeletal effects of oral appliance wear in obstructive sleep apnoea and snoring patients.

OBJECTIVES: To evaluate the dentoskeletal changes associated with long-term and continuous mandibular advancement device (MAD) use in sleep-related breathing disorder patients. METHODS: Cephalometric measurements and three-dimensional model analysis were performed at baseline and after 3.5 ± 1.1 years in 20 snoring and obstructive sleep apnoea patients treated with the Silensor® appliance. Intra-group differences were compared using paired t-test or Wilcoxon signed-rank test. A regression analysis was performed for variables that showed a statistically significant difference between time points to evaluate the influence of treatment time and patient's initial characteristics on their variations. The statistical significance was set at P < 0.05. RESULTS: At cephalometric assessment, the maxilla revealed a significant decrease in horizontal position (SNA: -0.4 ± 0.72 degree, P = 0.021) and a significant retroclination of the upper incisor (-1.59 ± 1.07 degree, P < 0.001), while the mandible displayed a significant downward rotation (0.88 ± 1.28 degree, P = 0.006) and a proclination of the lower incisor (2.27 ± 1.38 degree, P < 0.001). Model analysis showed a decrease in upper total space discrepancy (-0.66 ± 0.72 mm, P < 0.002), overjet (OJ; -0.34 ± 0.47 mm, P < 0.011), and overbite (-0.4 ± 0.52 mm, P < 0.004). In the regression analysis, treatment time influenced the lower incisor inclination (Beta = -0.713, P = 0.018) and OJ (Beta = -0.218, P = 0.018); patients' initial characteristics had an effect on OJ (Beta = -0.195, P = 0.011). LIMITATIONS: A larger sample size could increase the generalizability of the findings. CONCLUSION: MAD wear after a mean of 3.5 years determines statistically significant but clinically irrelevant dentoskeletal changes. Their potential occurrence should be thoroughly discussed with patients; regular follow-up visits by a specialist experienced in dental sleep medicine are also mandatory during treatment in addition to polysomnographic examinations.

Digital evaluation of nasal changes induced by rapid maxillary expansion with different anchorage and appliance design.

BACKGROUND: Scientific evidence showed that rapid maxillary expansion (RME) affects naso-maxillary complex, increasing nasal width and volume. This study aimed to evaluate nasal changes induced by rapid maxillary expansion with different anchorage and appliance design by using low dose and cone beam computed tomography. METHODS: A total of 44 patients (20 males, mean age 8y 8 m ± 1y 2 m; 24 females mean age 8y 2 m ± 1y 4 m) were included in the investigation and divided into three groups according to the appliance: Hyrax-type expander anchored to permanent teeth, modified Hyrax-type expander anchored to deciduous teeth, modified Haas-type expander anchored to deciduous teeth. Maxillary expansion was performed until overcorrection and the expander was passively kept in situ for 7 months at least. All patients had three-dimensional imaging before expansion (T0) and after the retention period (T1). Nasal floor width, nasal wall width, maxillary inter-molar width were measured by means of Mimics software. The paired sample t-test was employed to assess the significance of the differences between the time points; the analysis of variance test (ANOVA) was used to compare differences between groups. RESULTS: The statistical analysis revealed significant differences between T0 and T1 for each recorded measurement in each group; no significant differences were found by comparing groups. CONCLUSIONS: Rapid maxillary expansion produces a significant skeletal transverse expansion of nasal region in growing patients. No significant differences in nasal effects are expected when the appliance is anchored onto deciduous teeth, with or without the palatal acrylic coverage.