Short term dentoskeletal effects of mandibular advancement clear aligners in Class II growing patients. A prospective controlled study according to STROBE Guidelines.

AIM: To evaluate the dentoskeletal effects of the Invisalign® Mandibular Advancement (MA) (Align Technology, San José, CA, USA) feature in skeletal Class II growing patients with mandibular retrusion, at pre-pubertal and pubertal stages. MATERIALS AND METHODS: Study design: Forty skeletal Class II patients were prospectively recruited and treated with Invisalign® MA. They were divided into two subgroups according to the CVM stage of growth (CVM2 and CVM3) at the beginning of treatment (T0). For each patient, lateral radiographs were collected at the beginning (T0) and at the end of the mandibular advancement treatment (T1) and their measurements were compared with those obtained by an untreated control group of 32 subjects, matched for growth stage and malocclusion. RESULTS: Patients in CVM2 showed significant reduction of ANB angle, A:Po, Wits index, 11^Spp angle and significant increase of 11^41 and B Downs point. In CVM3 significant reduction of the Wits index and of 41^GoGn angle, and significant increase of the linear Co-Gn measurement, were revealed. STATISTICS: The STROBE guidelines were followed. Linear regression analysis was performed to estimate the differences of ? (T1 - T0) means between group (control was used as reference) stratifying by CVM levels. CONCLUSION: The use of Invisalign® MA is effective in treating Class II growing patient with retrognathic mandible in the short term period. While treatment at prepubertal stage of growth results in dentoalveolar rather than skeletal effects, treatment during the pubertal spurt produces skeletal effects with an annual rate of change of 5.8 mm.

Interceptive treatment effects of EF preformed appliance in pre-pubertal and pubertal skeletal Class II growing patients: A retrospective controlled study.

AIM: Interceptive treatment has been devised to improve the outcomes on growth stage and mandibular repositioning in Class II patients. The aim of this study is to test the effectiveness of Functional education (EF) (OrthoPlus, Igny, France) preformed appliance in skeletal Class II growing patients at CVM2 and CMV3 stages. MATERIALS AND METHODS: Study design: retrospective controlled study. Eighty skeletal Class II growing subjects were recruited for the study. Lateral X-rays and cephalograms were required at the beginning (T0) and at the end (T1) of the EF treatment to evaluate dento-skeletal changes. The same sub-division and sample size were adopted for respective untreated control groups. RESULTS: At prepubertal stage, the EF device showed a significant reduction of upper incisors proclination. When comparing dentoskeletal variables in the pubertal groups, significant differences were shown. In the treated group the SN^B angle increased, with the B Downs landmark moving forward. Wits index improved by 2.16 mm in the study group with an increase of all mandibular linear measurements. Fewer but significant dental changes were shown for 11^41 angle, with a mean increase of 8.90°. STATISTICS: For multiple comparisons, the Tukey test at 95% family-wise confidence level was used. The level of significance was set at p < 0.05. Statistical analyses were conducted using the R statistical package (version 3.0.3, R Core Team, Foundation for Statistical Computing, Vienna, Austria). CONCLUSIONS: EF appliance seems to be effective in the treatment of Class II growing patients. Significant improvements in upper incisors proclination and mandibular elongation are shown.

Paediatric Orthodontics Part 3: Masticatory function during development.

The importance of masticatory function during development, the aim of early therapies. Hypoplasia of the upper maxilla is a widespread condition which orthodontists often need to face during early treatment. Mechanical maxillary expansion (both rapid and slow) produce undiagnosed effects on the palatal suture and unwanted side- effects on the periodontium and alveolar process, as well as anchorage-teeth displacement, root resorption, bone fenestration. It is clear that early therapies need a non-mechanical and non-traumatic approach in the respect of the physiology and biology of one of the most important systems for the future health of the developing patient.

Effects of clear aligners on sleep bruxism: randomized controlled trial.

The possible effects on sleep bruxism (SB) of clear aligners in orthodontics are unknown. This study was conducted to analyze the effects of clear aligners on SB. Sixty subjects needing orthodontic treatment and affected by SB (33 m, 27 f, 20±;5 years) were enrolled in the study and randomly assigned to one of the following three groups: 20 were given clear aligners (CAT) (12 m, 8 f, 19±5 years), 20 occlusal splint (MOS) (9 m, 11 f, 22±5 years) and 20 a placebo splint (PMS) (12 m, 8 f, 24±3 years). All groups were followed for 6 consecutive months and monitored for SB with a portable electromyographic-electrocardiographic (EMG-ECG) device (Bruxoff®, OT Bioelettronica, Torino, Italy). MOS subjects reduced masseter contractions after 6 months of treatment (t3) (MD=-29.11, std. error 11.74, p=0.017) but increased phasic contractions related to SB after 3 months of treatment (t2) (MD=4.73, std. error 2.36, p=0.048) and tonic contractions related to SB during all the six months of treatment (t1, t2, t3) when compared to PMS. CAT subjects increased phasic contractions related to SB during the first (t1) (MD=3.94, std. error 2.27, p=0.04) and the third month (t2) of treatment (MD=4.62, std. error 2.36, p=0.046) when compared to PMS. No significant differences were found for SB index at any time for all the three groups. Although MOS and CAT affected EMG signals during sleep time differently, they did not influence the overall SB index.

Cervical vertebrae maturation: a blinded trial study.

This blinded trial was conducted to analyze possible correlations between the cervical vertebrae maturation method (CVM) and the mineralization of mandibular teeth as described by Demirjian et al. (TMS). Panoramic and cephalometric radiographs of 500 orthodontic patients were analyzed by two blinded operators. TMS was utilized to analyze mineralization of second molar, second and first premolar and canine on the left side of the mandible; CVM stage was also evaluated. A blinded statistician performed statistical correlations and multiple regression analysis. Significant relations between CVM and TMS stages were identified for each tooth. Significant age differences resulted for CVM, second molar and second premolar (p<0.05). Significant correlations for second molar were observed between TMS D and CVM I-II, TMS G and CVM III, TMS H and CVM V-VI (p less than 0.01). Second molar stage G for both sexes indicates the ongoing of growth spurt. Stage G for boys and stage H for girls correlate significantly with the late part of PGS.

Mandibular distraction osteogenesis: a systematic review of stability and the effects on hard and soft tissues.

Mandibular distraction osteogenesis (MDO) has been widely adopted in modern maxillofacial surgery due to its less invasive approach and the consistent aesthetic and functional improvements obtained. The aim of the present systematic review was to analyze the available evidence on the skeletal and soft tissue effects of MDO. The medical literature was searched to identify all peer-reviewed papers meeting the selection criteria for the final review process. A three-point grading system was used to rate the methodological quality of the selected papers. The PICO approach was used to extract data from the selected papers. The search strategy yielded eight relevant publications. The quality of the collected evidence was low to moderate. Vertical and sagittal skeletal dimensions increased significantly, by a mean of 5-10mm (P<0.05). Regarding the sagittal positioning of the lips and surrounding structures, a 90% correspondence between skeletal and soft tissue cephalometric points was observed. Significant skeletal relapse was reported, however it did not worsen the results of treatment significantly.

Agreement between clinical and portable EMG/ECG diagnosis of sleep bruxism.

The aim of this study was to compare clinical sleep bruxism (SB) diagnosis with an instrumental diagnosis obtained with a device providing electromyography/electrocardiography (EMG/ECG) recordings. Forty-five (N = 45) subjects (19 males and 26 females, mean age 28 ± 11 years) were selected among patients referring to the Gnathology Unit of the Dental School of the University of Torino. An expert clinician assessed the presence of SB based on the presence of one or more signs/symptoms (i.e., transient jaw muscle pain in the morning, muscle fatigue at awakening, presence of tooth wear, masseter hypertrophy). Furthermore, all participants underwent an instrumental recording at home with a portable device (Bruxoff; OT Bioelettronica, Torino, Italy) allowing a simultaneous recording of EMG signals from both the masseter muscles as well as heart frequency. Statistical procedures were performed with the software Statistical Package for the Social Science v. 20.0 (SPSS 20.0; IBM, Milan, Italy). Based on the EMG/ECG analysis, 26 subjects (11 males, 15 females, mean age 28 ± 10 years) were diagnosed as sleep bruxers, whilst 19 subjects (7 males, 12 females, mean age 30 ± 10 years) were diagnosed as non-bruxers. The correlation between the clinical and EMG/ECG SB diagnoses was low (ϕ value = 0.250), with a 62.2% agreement (28/45 subjects) between the two approaches (kappa = 0.248). Assuming instrumental EMG/ECG diagnosis as the standard of reference for definite SB diagnosis in this investigation, the false-positive and false-negative rates were unacceptable for all clinical signs/symptoms. In conclusion, findings from clinical assessment are not related with SB diagnosis performed with a portable EMG/ECG recorder.

Could different TMJ disc positions observed in MRI cause different sounds? Analysis on a group of subjects with ADD with reduction: a pilot study.

AIMS: Magnetic resonance imaging (MRI) is the method of choice for examining soft-tissue pathology of the temporomandibular joint (TMJ). MRI shows a high spatial resolution with accuracy for the identification of internal derangement. Tasaki developed a classification system for disc displacement in the TMJ, identifying eight different types of disc displacements in addition to the superior disc position. This study aims to test the ability of electrosonography (ESG) in discriminating different kinds of disc displacement according to the disc position criteria proposed, comparing the ESG results with those obtained by MRI. METHODOLOGY: Twenty-seven patients were selected from an initial group of 50 patients with articular disc displacement, selected by means of clinical examinations, according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) and who had both MRI and ESG studies performed. For each patient and for each peak in ESG, both in the opening and closing movements, three different parts of the sound were analyzed. The frequency (Hz) and the mean amplitude (µV) of the sounds were calculated in the three analyzed windows. Afterwards, gathering the data for the Tasaki's classes and dividing opening and closing sounds, the number of peaks was calculated, as well as average and standard deviations for both the Hz and µV. RESULTS: The peak frequency shows significant differences between different disc positions during the first and second third of the opening phase and during the first third of the closing phase. The peak amplitude shows significant differences between different disc positions during all of the opening and closing phases. CONCLUSIONS: Although limited by sample size, the present study shows the presence of different sounds with different Hzs and µVs associated with different disc positions that were recorded with ESG.

Detection of sleep bruxism: comparison between an electromyographic and electrocardiographic portable holter and polysomnography.

Recent polysomnographic (PSG) studies showed that the sleep bruxism (SB) event is preceded by a sudden shift in autonomic cardiac activity. Therefore, heart rate could be the simplest-to-record parameter for use in addition to portable home EMG monitoring to improve the accuracy in automatic detection of SB events. The aim of the study was to compare the detection of SB episodes by combined surface electromyography and heart rate (HR) recorded by a compact portable device (Bruxoff(®) ), with the scoring of SB episodes by a PSG recording. Twenty-five subjects (14 'probable' bruxers and 11 non-bruxers) were selected for the study. Each subject underwent the Bruxoff and the PSG recordings during the same night. Rhythmic masseter muscle activities (RMMAs) were scored according to published criteria. Correlation coefficients and the Bland-Altman plots were calculated to measure the correlation and agreement between the two methods. Results showed a high correlation (Pearson's r = 0·95, P < 0·0001) and a high agreement (bias = 0·05) between Bruxoff and the PSG. Furthermore, the receiver operating characteristic curve analysis showed a high sensitivity and specificity of the portable device (92·3% and 91·6%, respectively) when the cut-off was set at 4 SB episodes per hour according to published criteria. The Bruxoff device showed a good diagnostic accuracy to differentiate RMMA from other oromotor activities. These findings are important in the light of the need for simple and reliable portable devices for the diagnosis of SB both in the clinical and research settings.

Diagnostic concordance between MRI and electrovibratography of the temporomandibular joint of subjects with disc displacement disorders.

OBJECTIVES: The aim of this study is to evaluate the diagnostic concordance of MRI and electrovibratography (EVG) of the temporomandibular joint (TMJ) in the diagnosis of articular disc displacement with reduction (ADDwR) and articular disc displacement without reduction (ADDw/oR). METHODS: 50 patients (12 males, 38 females; mean age 37.46 ± 15.64 years) with a hypothesis of disc displacement were selected. For each patient an MRI of the TMJ was performed. MRIs were evaluated sorting the 100 TMJs by kind of pathology (no pathology, ADDwR, ADDw/oR, and joint hypermobility). Afterwards, the patients had an EVG exam. The EVG exams were performed with vibration transducers over each TMJ, enabling simultaneous, bilateral recording of vibrations emanating from joint sounds during the opening and closing movements. The presence of a sound peak was compared with the MRI diagnosis of ADDwR, while a multipeak aspect was compared with ADDw/oR diagnosis using Cohen's kappa test. RESULTS: The presence of a peak-shaped track has high specificity for ADDwR (90.27%). The Cohen's kappa calculated for the ADDwR was 0.5615 (good-moderate). The presence of a multipeak-shaped track has low specificity (65.22%) and sensitivity (70.42%). The Cohen's kappa calculated for the ADDw/oR was 0.2992 (poor). CONCLUSIONS: The present study recommends the use of EVG to support the clinical diagnosis of a disc displacement with reduction when MRI is not available or when subjects cannot be investigated by MRI.

Myoelectric manifestations of jaw elevator muscle fatigue and recovery in healthy and TMD subjects.

The effects of muscle pain and fatigue on the control of jaw elevator muscles are not well known. Furthermore, the myoelectric manifestations of fatigue and recovery from fatigue in the masticatory muscles are not reported in literature. The main aims of this study were (i) to evaluate the possible use of surface electromyography (sEMG) as an objective measure of fatigue of the jaw elevator muscles, (ii) to compare the myoelectric manifestations of fatigue in the temporalis anterior and masseter muscles bilaterally, (iii) to assess recovery of the investigated muscles after an endurance test and (iv) to compare fatigue and recovery of the jaw elevator muscles in healthy subjects and patients with muscle-related temporomandibular disorders (TMD). The study was performed on twenty healthy volunteers and eighteen patients with muscle-related TMD. An intra-oral compressive-force sensor was used to measure the voluntary contraction forces close to the intercuspal position and to provide visual feedback of submaximal forces to the subject. Surface EMG signals were recorded with linear electrode arrays during isometric contractions at 20%, 40%, 60% and 80% of the maximum voluntary contraction force, during an endurance test and during the recovery phase. The results showed that (i) the slope of the mean power spectral frequency (MNF) and the initial average rectified value (ARV) could be used to monitor fatigue of the jaw elevators, (ii) the temporalis anterior and masseter muscle show the same myoelectric manifestations of fatigue and recovery and (iii) the initial values of MNF and ARV were lower in patients with muscle-related TMD. The assessment of myoelectric manifestations of fatigue in the masticatory muscles may assist in the clinical assessment of TMDs.

A comparative analysis of personality profile and muscle tenderness between chronic migraine and chronic tension-type headache.

This study was aimed at comparing the personality profile, the psychiatric comorbidity (depression and anxiety) and the tenderness of the pericranial and cervical muscles in women with chronic migraine (CM) and chronic tension-type headache (CTTH). Forty-one CM and 34 CTTH women were enrolled. A clinical evaluation (according to SCID-I) and a psychometric assessment (MMPI-2, STAI-1 and STAI-2) were performed. After palpation, a Pericranial muscle Tenderness Score (PTS) and a Cervical Muscle Tenderness Score (CTS) were calculated. No significant difference was detected in MMPI-2, STAI-1, STAI-2, PTS and CTS scores between the two groups. Anxiety and depression were present in 80% of CM and in 63% of CTTH women. We did not find any significant difference either in the personality profile or in the muscle tenderness between CM and CTTH patients. This similarity points to a role of these factors, in association with psychiatric comorbidity, in the chronicisation of headache.

Effects of a functional appliance on masticatory muscles of young adults suffering from muscle-related temporomandibular disorders.

The aim of this study was to investigate the effects of an original orthodontic functional appliance [function generating bite for deep bite correction (FGB-D)] on masticatory muscle activity in subjects suffering from muscle-related temporomandibular disorders (TMD). Electromyographic (EMG) analysis was performed on 33 young adults (nine men, 24 women) to evaluate the contractile symmetry of the right and left masseter and anterior temporalis muscles. The subjects were divided into three groups: a muscle-related TMD group requiring orthodontic treatment for deep bite correction (three men, eight women) and treated with FGB-D; a muscle-related TMD group not requiring orthodontic treatment (three men, eight women) and treated with a Michigan occlusal splint; and a TMD-free group (three men, eight women) as a control group. Records were made by surface EMG of maximum voluntary teeth clenching, with and without the functional appliance or occlusal splint in place, before and after 12 months of therapy. A torque index was derived from the surface EMG recordings to estimate lateral displacement of the mandible. The results show that the FGB-D corrects the torque index and thus the lateral displacement of the mandible.

Effects of different jaw relations on postural stability in human subjects.

Authors investigated the effects of different jaws relations on body posture in a sample of 95 subjects. All subjects underwent a posturometric and stabilometric analysis using a computerized footboard. Tests were performed in three mandibular positions: centric occlusion, rest position and myocentric position, respectively determined by teeth engagement, joints position, and muscles contraction. All subjects showed variations of body posture in the different mandibular positions. Statistical analysis (analysis of variance for repeated measures) confirmed that postural variations in different jaws relations were significant: in particular, the SKN multiple comparison test showed that myocentric position improved postural balance on frontal plane with respect to the other jaw positions considered.

Personality traits, depression and migraine in women: a longitudinal study.

Our purpose was to examine the association between personality traits, depression and migraine in the long term. In 56 women with migraine a psychological assessment was carried out to assess the presence of major depression, and the Minnesota Multiphasic Personality Inventory (MMPI) and the State and Trait Anxiety Inventory (STAI) were administered at baseline (T0) and after 6-7 years (T2). Frequency, severity and duration of migraine were recorded at T0, after treatment (T1) and at T2, and their relation to the prevalence of depression and to the MMPI and STAI data was examined (ANOVA, Student's t-test, chi2 analysis, and multiple regression analysis). Pain parameters improved in all patients in T0-T1, but at T2 were higher in patients with depression at T0. The patients whose migraine improved at T2 had, at T0 and T2, significantly lower MMPI and STAI scores. Multiple regression analysis showed a correlation of the MMPI depression score and STAI 1,2 scores at T0 with headache frequency at T2. We conclude that the co-occurrence of migraine, personality changes and depression in women does not appear to influence the results of treatment at short-term, but it seems to be influential on headache history in the long term.

Evaluation of the utility of cephalometric parameters in constructing complete denture. Part I: placement of posterior teeth.

Various types of parameters, including cephalometric ones, have been used in the construction of complete denture. This study aimed to evaluate the utility of cephalometric parameters for this purpose. The position of the posterior teeth in a group of 42 edentulous patients, successfully rehabilitated with complete denture according to clinical parameters, was evaluated by cephalometrics. The following were determined: vertical dimension of occlusion (VDO); orientation of the occlusal plane; and subdivision of the denture space. The cephalometric parameters do not correspond to the clinical positioning of the posterior teeth in successful rehabilitation with complete denture.

Observations on the correlation between posture and jaw position: a pilot study.

The aim of this pilot study was twofold. The first was to show a method for having an objective and dynamic analysis of body posture, evaluating weight distribution and its connections with different mandibular positions. The second was to verify if a neuromuscularly stimulated occlusal position, called myocentric occlusal position, is associated with a positive or negative postural charge. For the second aim a group of 20 subjects (including both males and females), was chosen. Posture of each subject was analyzed in three different conditions: centric occlusion, rest position and myocentric position. To evaluate the dynamic of posture a platform capable of measuring the weight on the feet supporting points and the related variations during time of observation and the swinging of body barycenter was used. The data showed that there is an improvement in the position of the barycenter from the centric occlusion to the myocentric position. Such an improvement can't be observed from the intercuspal position to the rest position. The results of this pilot study are discussed.

TMJ clicking: a comparison of clinical examination, sonography, and axiography.

A sample of 30 subjects, 15 with and 15 without subjective temporomandibular joint (TMJ) complaints (noises, sounds), underwent a clinical examination, a sonography and an axiography, to detect TMJ clicking. The clinical examination found 22 noisy joints in a total of 60 TMJs considered. Axiography found 19 noisy joints and sonography 32. While 90% of the examined joints showed agreement between axiography and clinical examination (with a little higher sensitivity demonstrated by clinical examination with respect to axiography), 20% of the joints were positive for clicking in sonography only. Sonography showed a high sensitivity in detection of joint noises which suggests its utility as a screening test for early detection of craniomandibular disorders.