C. Debernardi

Efficacy of clear aligners in controlling orthodontic tooth movement: A systematic review

OBJECTIVE To assess the scientific evidence related to the efficacy of clear aligner treatment (CAT) in controlling orthodontic tooth movement. MATERIALS AND METHODS PubMed, PMC, NLM, Embase, Cochrane Central Register of Controlled Clinical Trials, Web of Knowledge, Scopus, Google Scholar, and LILACs were searched from January 2000 to June 2014 to identify all peer-reviewed articles potentially relevant to the review. Methodological shortcomings were highlighted and the quality of the studies was ranked using the Cochrane Tool for Risk of Bias Assessment. RESULTS Eleven relevant articles were selected (two Randomized Clinical Trials (RCT), five prospective non-randomized, four retrospective non-randomized), and the risk of bias was moderate for six studies and unclear for the others. The amount of mean intrusion reported was 0.72 mm. Extrusion was the most difficult movement to control (30% of accuracy), followed by rotation. Upper molar distalization revealed the highest predictability (88%) when a bodily movement of at least 1.5 mm was prescribed. A decrease of the Littles Index (mandibular arch: 5 mm; maxillary arch: 4 mm) was observed in aligning arches. CONCLUSIONS CAT aligns and levels the arches; it is effective in controlling anterior intrusion but not anterior extrusion; it is effective in controlling posterior buccolingual inclination but not anterior buccolingual inclination; it is effective in controlling upper molar bodily movements of about 1.5 mm; and it is not effective in controlling rotation of rounded teeth in particular. However, the results of this review should be interpreted with caution because of the number, quality, and heterogeneity of the studies.

Chewing pattern and muscular activation in open bite patients

Different studies have indicated, in open bite patients, that masticatory muscles tend to generate a small maximum bite force and to show a reduced cross-sectional area with a lower EMG activity. The aim of this study was to evaluate the kinematics parameters of the chewing cycles and the activation of masseters and anterior temporalis muscles of patients with anterior dental open bite malocclusion. There have been no previous reports evaluating both kinematic values and EMG activity of patients with anterior open bite during chewing. Fifty-two young patients (23 boys and 29 girls; mean age±SD 11.5±1.2 and 10.2±1.6years, respectively) with anterior open bite malocclusion and 21 subjects with normal occlusion were selected for the study. Kinematics parameters and surface electromyography (EMG) were simultaneously recorded during chewing a hard bolus with a kinesiograph K7-I Myotronics-Usa. The results showed a statistically significant difference between the open bite patients and the control group for a narrower chewing pattern, a shorter total and closing duration of the chewing pattern, a lower peak of both the anterior temporalis and the masseter of the bolus side. In this study, it has been observed that open bite patients, lacking the inputs from the anterior guidance, that are considered important information for establishing the motor scheme of the chewing pattern, show narrower chewing pattern, shorter lasting chewing cycles and lower muscular activation with respect to the control group.

Diagnostic accuracy and measurement sensitivity of digital models for orthodontic purposes: A systematic review

INTRODUCTION Our objective was to assess the accuracy, validity, and reliability of measurements obtained from virtual dental study models compared with those obtained from plaster models. METHODS PubMed, PubMed Central, National Library of Medicine Medline, Embase, Cochrane Central Register of Controlled Clinical trials, Web of Knowledge, Scopus, Google Scholar, and LILACs were searched from January 2000 to November 2014. A grading system described by the Swedish Council on Technology Assessment in Health Care and the Cochrane tool for risk of bias assessment were used to rate the methodologic quality of the articles. RESULTS Thirty-five relevant articles were selected. The methodologic quality was high. No significant differences were observed for most of the studies in all the measured parameters, with the exception of the American Board of Orthodontics Objective Grading System. CONCLUSIONS Digital models are as reliable as traditional plaster models, with high accuracy, reliability, and reproducibility. Landmark identification, rather than the measuring device or the software, appears to be the greatest limitation. Furthermore, with their advantages in terms of cost, time, and space required, digital models could be considered the new gold standard in current practice.

Reproducibility of surface EMG in the human masseter and anterior temporalis muscle areas

Abstract The aim of this study was to test the hypothesis that surface electromyography (sEMG) recordings, made at mandibular rest position from the masseter and temporalis anterior areas, are intraand inter-session reproducible. A template was designed and built to permit the correct electrode placement from one session to the next session. A sample of 18 subjects was examined. Two groups, homogeneous for age, sex, and craniofacial morphology were selected. The first group included asymptomatic subjects with no signs or symptoms of temporomandibular joint dysfunction (TMD) and the second group included patients suffering from muscle-related TMD. Data were obtained from different sEMG recordings made at mandibular rest position in the same session and in different sessions, repositioning the electrodes using a template designed for that purpose. The electromyograph used in this study is part of the EMG K6-l Win Diagnostic System. Results showed that reproducibility of sEMG signals from the masseter and anterior temporalis areas at mandibular rest position is possible.

Periodontal health during clear aligners treatment: a systematic review

BACKGROUND Clear aligner treatment (CAT) has been cited as a safe and comfortable orthodontic procedure for adult patients. However, the available evidence is scarce. OBJECTIVE To perform a systematic review of the existing literature in order to assess periodontal health during CAT. SEARCH METHODS AND SELECTION CRITERIA Pubmed, Pubmed Central, National Library of Medicines Medline, Embase, Cochrane Central Register of Controlled Clinical trials, Web of Knowledge, Scopus, Google Scholar, and LILACS were searched from January 1945 to September 2014 to identify all peer-reviewed papers potentially relevant to the review. DATA COLLECTION AND ANALYSIS After duplicate selection and extraction procedures, the risk of bias was assessed according to the Centre for Reviews and Dissemination criteria, and a 3-point grading system, as described by the Swedish Council on Technology Assessment in Health Care (SBU), was used to rate the methodological quality of the selected papers. A PICOS table was used for data extraction. RESULTS Five relevant articles were selected from the 1247 identified articles. The level of evidence was moderate for all the studies. A significant improvement of the periodontal health indexes was revealed, in particular when CAT was compared to fixed appliances. No periodontal CAT adverse effects were observed in the selected studies. CONCLUSIONS Periodontal health indexes were significantly improved during CAT. The results of this review should be interpreted with some caution because of the number, quality, and heterogeneity of the included studies.

Alexithymia, anger and psychological distress in patients with myofascial pain: a case-control study

Aims: The aim of this study was to investigate psychological distress, anger and alexithymia in a group of patients affected by myofascial pain (MP) in the facial region. Methods: 45 MP patients [mean (SD) age: 38.9 (11.6)] and 45 female healthy controls [mean (SD) age: 37.8 (13.7)] were assessed medically and psychologically. The medically evaluation consisted of muscle palpation of the pericranial and cervical muscles. The psychological evaluation included the assessment of depression (Beck Depression Inventory—short form), anxiety [State-Trait Anxiety Inventory Form Y (STAI-Y)], emotional distress [Distress Thermometer (DT)], anger [State-Trait Anger Expression Inventory—2 (STAXI-2)], and alexithymia [Toronto Alexithymia Scale (TAS)]. Results: the MP patients showed significantly higher scores in the depression, anxiety and emotional distress inventories. With regard to anger, only the Anger Expression-In scale showed a significant difference between the groups, with higher scores for the MP patients. In addition, the MP patients showed significantly higher alexithymic scores, in particular in the Difficulty in identifying feelings (F1) subscale of the TAS-20. Alexithymia was positively correlated with the Anger Expression-In scale. Both anger and alexithymia showed significant positive correlations with anxiety scores, but only anger was positively correlated with depression. Conclusion: A higher prevalence of depressive and anxiety symptoms associated with a higher prevalence of alexithymia and expression-in modality to cope with anger was found in the MP patients. Because the presence of such psychological aspects could contribute to generate or exacerbate the suffering of these patients, our results highlight the need to include accurate investigation of psychological aspects in MP patients in normal clinical practice in order to allow clinicians to carry out more efficacious management and treatment strategies.

Effects of therapy on masseter activity and chewing kinematics in patients with unilateral posterior crossbite

OBJECTIVE To describe the effects of therapy on masseter activity and chewing kinematic in patients with unilateral posterior crossbite (UPC). DESIGN Fifty children (age: mean ± SD: 9.1 ± 2.3 years) with UPC (34 on the right side, 16 on the left side) and twenty children (age: 9.5 ± 2.6 years) with normal occlusion were selected for the study. The mandibular motion and the muscular activity during chewing soft and hard boli were simultaneously recorded, before and after correction with function generating bite, after a mean treatment time of 7.3 ± 2.4 months plus the retention time of 5-6 months. The percentage of reverse cycles and the percent difference between ipsilateral and contralateral peaks of the masseter electromyography envelopes were computed. RESULTS Before therapy, the percentage of reverse cycles during chewing on the crossbite side was greater in patients than in controls (P<0.001) and significantly reduced after therapy (P<0.001) towards the reference normal value (soft bolus; pre: 57 ± 30%, post:12 ± 17%; hard bolus; pre: 65 ± 34%, post: 12 ± 13%; reference value: soft bolus 4 ± 2%, hard bolus 5 ± 3%). Before therapy the percent difference between electromyography envelope peaks in patients was lower than in controls (P<0.01) and significantly increased after therapy (P<0.05) becoming similar to the reference normal value. CONCLUSIONS The correction induced a normal-like coordination of masseter muscles activity together with a significant reduction of the reverse chewing patterns. The previous altered muscular activation corresponded to the altered kinematics of reverse chewing cycles that might be considered a useful indicator of the severity of the masticatory function involvement.

The Orthodontic Treatment of TMD Patients: EMG Effects of a Functional Appliance

Abstract The aim of this work was to test the effects of the Function Generator Bite (FGB) on the masticatory muscles of temporomandibular joint dysfunction (TMD) subjects. Two groups were selected for the study. A group of 20 TMD patients (group F) requiring orthodontic treatment and treated with FGB and a group of 10 healthy subjects (group H) were considered. Both groups were evaluated before the therapy began (T0) and then after 18 months of therapy (T1). An electromyographic analysis of the masseter and temporalis anterior muscles and a clinical evaluation according to the Research Diagnostic Criteria for TMD (RDC/TMD) were performed. A statistical difference between the two groups was observed at T0 with respect to the activity index. TMD subjects showed a lower value of the index. Further studies are necessary to fully understand the utility of this EMG index as a diagnostic indicator.

Efficacy of rofecoxib and nimesulide in controlling post-extraction pain in oral surgery: a randomised comparative study

SUMMARY Rofecoxib 50 mg day−1 for 6 days provided better postoperative analgesia than nimesulide 200 mg day−1 in a randomised trial in patients (n = 130) undergoing surgical extraction of third molars. The superiority of rofecoxib over nimesulide was especially marked during the first 2–3 postoperative days and in patients with fully impacted molars. The drugs had similar effects on clinical signs of local postoperative inflammation. The effectiveness of rofecoxib in this study, plus considerations of the toxicity profile of nimesulide, support the conclusion that rofecoxib is preferable to nimesulide for relief of post-operative pain in patients undergoing surgical extraction of molars.

Clinical and Instrumental Evaluation of the Temporomandibular Joint Before and After Surgical Correction of Asymptomatic Skeletal Class III Patients

Abstract The purpose of this prospective study was to evaluate the temporomandibular joint (TMJ) morphology, the disk position, and the TMJ symptoms before and after surgical-orthodontic correction of skeletal class III malocclusion. Eleven adult patients were recruited to participate in this longitudinal study. Each patient received presurgical and postsurgical orthodontic treatment with fixed appliances. Six patients were corrected exclusively through mandibular setback, whereas 5 received combined mandibular setback and maxillary advancement. All patients were investigated before and 2 years after treatment through (1) clinical examination, (2) magnetic resonance imaging, and (3) Computerized axiography (CA). The incidence of clinical signs and symptoms was reduced 2 years after surgical-orthodontic treatment, the condyle-disk relationship and TMJ appearance at magnetic resonance imaging were unchanged, and CA showed a significant improvement of TMJ border movements. Mandibular setback surgery does not appear to alter the condyle-disk relationship, whereas correction of class III malocclusion seems to improve clinical and CA signs of TMJ function. Further controls and more long-term evaluation of these patients are necessary to assess the maintenance of these improvements in time.