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Background: Bilateral posterior crossbite (BPXB) is a severe malocclusion associated with maxillary hypoplasia. BPXB may involve the same or a different number of teeth between the sides. Objectives: To evaluate the masticatory function in BPXB and the association between the masticatory alterations and the occlusal features of BPXB. Methods: This observational study included 170 participants: 130 patients with BPXB (65 occlusally symmetric BPXB, i.e. same number and type of posterior teeth in crossbite between the sides, F = 33, M = 32, median age 9.6 (8.2–13) [years.months]; 65 patients occlusally asymmetric BPXB, F = 30, M = 35, median age 9.9 (8.3–13.6)) and 40 controls (F = 25, M = 15, median age 10.2 (9.4–11.6)). The masticatory function was evaluated by the detection of the Reverse Chewing Cycles (RCCs) recorded with a kinesiograph using standardised soft and hard boluses. Results: The frequency of RCCs was significantly increased in all BPXB patients compared to controls (p <.000). In symmetric BPXB patients, there were no significant differences in the frequency of RCCs during chewing on the left or the right side. In asymmetric BPXB patients, the frequency of RCCs was significantly increased during chewing on the side with relatively more teeth in crossbite (p <.000). Conclusions: The masticatory function was significantly altered in all BPXB patients and it was differently affected by symmetric or asymmetric occlusal features of the malocclusion. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the effects of treatment of bilateral posterior crossbite (BPXB) on mandibular kinematics by the percentage of reverse chewing cycles (RCCs) during soft and hard bolus chewing before and after the correction of the malocclusion with function‐generating bite (FGB). Materials and Methods: This prospective study included 71 subjects: 19 patients with occlusally symmetric BPXB (M = 9; F = 10; mean age 9.3 ± 2.2[yr.mo]), 32 patients with occlusally asymmetric BPXB (19 with more teeth in crossbite on the right side (right prevalent side), M = 7; F = 12; mean age 8.2 ± 1.6 [yr.mo] and 13 on the left side, M = 7; F = 6; mean age 9.6 ± 1.9 [yr.mo]) and 20 controls without malocclusion (M = 8; F = 12; mean age 10.2 ± 1.7 [yr.mo]). Masticatory patterns were recorded before (T0) and after (T1) the correction of the malocclusion with FGB, with the K7‐I® kinesiograph using standardized soft and hard boluses. Results: BPXB was corrected in all included patients. At T0, the percentage of RCCs in BPXB was significantly increased compared to controls (P <.0001); symmetric BPXB showed no difference in RCCs between the sides, whereas asymmetric BPXB showed significantly more RCCs on the side with more teeth in crossbite (prevalent side). After treatment with FGB (T1), the percentage of RCCs was significantly reduced in both symmetric BPXB patients (soft bolus, P =.003; hard bolus, P <.001) and asymmetric BPXB patients (prevalent side: soft and hard bolus, P <.00001; non‐prevalent side: soft bolus, P =.01 and hard bolus, P =.0002). Conclusion: Functional correction of BPXB with FGB significantly improved mandibular kinematics during chewing. [ABSTRACT FROM AUTHOR]

Objective: To evaluate mastication in a group of patients with adolescent idiopathic scoliosis (AIS) with a control group, by means of the prevalence of reverse chewing cycles (RCCs). Material and Methods: This study included a group of patients (N = 32; F = 24; M = 8; mean age ± SD = 14 ± 3 years) with a confirmed diagnosis of AIS and a group of control subjects (N = 32; F = 24; M = 8; mean age ± SD = 13 ± 6 years) without spinal disorders. Mastication was recorded with both a hard and a soft bolus, following a standardized protocol, and the prevalence of RCCs was compared between the groups. Results: The prevalence of RCCs was significantly higher in the AIS group, with both a soft and a hard bolus, compared to the control group (P <.001). Conclusion: The results of this study indicate that the presence of AIS influences mastication, one of the main functions of the stomatognathic system. A multidisciplinary approach to these patients may be relevant in providing the best possible treatment outcomes. [ABSTRACT FROM AUTHOR]

Objective: To compare morphologic findings in MRI and skeletal divergence of a group of patients with temporomandibular joint disorders (TMD) subdivided into condylar symmetric and asymmetric.Methods: Fifty-nine adults (26.7 years old) with TMD were retrospectively recruited. Condylar height symmetry was evaluated by orthopantomography (Habets's method) and used to divide patients into Symmetric and Asymmetric groups; skeletal divergence was assessed on lateral cephalograms. MRI was used to evaluate the condylar long axis' angle, the glenoid fossa morphology, and the degree of disc displacement.Results: Asymmetric subjects showed a hyperdivergent skeletal pattern (p = 0.036), asymmetric condylar long axis (p = 0.018), and deeper (p = 0.025) and asymmetric (p = 0.001) glenoid fossa compared to symmetric subjects.Conclusion: Patients with TMD and condylar asymmetry diagnosed with orthopantomography are more likely to show hyperdivergent skull in cephalometry, condylar asymmetry of both height and major axis, and a steeper glenoid fossa in MRI. [ABSTRACT FROM AUTHOR]

Objectives: This study aims to evaluate the effectiveness of upper Michigan occlusal splint (OS) compared to mandibular OS in terms of pain, range of motion (ROM), and muscle activity as assessed by surface electromyography (sEMG) in patients affected by muscle-related temporomandibular disorders (TMD). Patients and methods: In this randomized-controlled trial, a total of 40 adult patients (13 males, 27 females; mean age: 47.2±12.8 years; range, 22 to 56 years) with a diagnosis of myofascial pain, lasting from at least three months on at least one masseter muscle. The patients were randomly allocated into two groups: Group 1 (n=20) using upper Michigan OS and Group 2 (n=20) using mandibular OS. At baseline (T0), at one (T1), three (T2), and six months (T3), the following outcomes were assessed: myofascial pain by Visual Analog Scale (VAS) and ROM of mandible movements, activity of the main masticatory muscles through sEMG. Results: There were no significant intra-group differences in the outcome measures assessed in both groups. However, Group 2 had a significantly higher right lateral mandibular ROM at T2 (7.1±3.1 vs. 9.8±2.3, respectively; p<0.05) and a significantly higher left lateral mandibular ROM at T3 (7.6±3.5 vs. 10.5±2.1, respectively; p<0.05). We found no significant difference in none of the sEMG parameters. Conclusion: Our study results suggest that OS, independently from being built on the upper or lower arch, seems to not have significant effects in reducing pain over a six-month period in TMD patients [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to compare sensitivity differences and interpretative agreement for magnetic resonance imaging (MRI) and computed axiography (CA) tracings in a patient population group with temporomandibular disorder (TMD). Materials and Methods: A convenience sample of 173 patients (53 men, 120 women; mean age: 33.2 ± 2.6 years) diagnosed with TMD was selected for this study. Each patient underwent an evaluation as per the European Academy of Craniomandibular Disorders clinical form as well as MRI and CA. Results: Use of the MRI results as the gold standard for the planned comparison led to the following observations: a CA sensitivity of 68% for joints without morphologic changes (so-called normal temporomandibular joints [TMJs]), sensitivity of 27% for those with disc displacement, and sensitivity of 8% for those with osteoarthritis. The kappa index, or agreement between the two examination methods, was weak for normal TMJs (0.16), acceptable for anterior disc displacement with reduction (0.28), little for anterior disc displacement without reduction (0.10), and very little for morphologic alterations (0.01). Conclusion: The sensitivity and agreement of the two examination methods was generally low. It was even worse when pathologic changes in the TMJ were more severe. MRI and CA are different examinations that could both be considered for severe TMD diagnosis. [ABSTRACT FROM AUTHOR]