Infliximab partially alleviates the bite force reduction in a mouse model of temporomandibular joint pain.

Temporomandibular joint (TMJ) disorder is clinically important because of its prevalence, chronicity, and therapy-refractoriness of the pain. In this study, we investigated the effect of infliximab in a mouse model of TMJ pain using a specially-engineered transducer for evaluating the changes in bite force (BF). The mice were randomly divided into three groups (7 mice per group): the control group, the complete Freund's adjuvant (CFA) group, and the infliximab group. BF was measured at day 0 (baseline BF). After measuring the baseline BF, CFA or incomplete Freund's adjuvant was injected into both TMJs and then the changes in BF were measured at days 1, 3, 5, 7, 9, and 13 after the TMJ injection. For measuring the BF, we used a custom-built BF transducer. Control, CFA, and infliximab groups showed similar baseline BF at day 0. From day 1, a significant reduction in BF was observed in the CFA group, and this reduction in BF was statistically significant compared to that in the control group (P < 0.05). This reduction in BF was maintained until day 7, and BF started to recover gradually from day 9. In the infliximab group also, the reduction in BF was observed on day 1, and this reduction was maintained until day 7. However, the degree of reduction in BF was less remarkable compared to that in the CFA group. The reduction in BF caused by injection of CFA into the TMJ could be partially alleviated by the injection of anti-tumor necrosis factor alpha, infliximab.

Influence of congenital facial nerve palsy on craniofacial growth in craniofacial microsomia.

Facial muscles are of major importance in human craniofacial growth and development. The purpose of our study was to investigate whether congenital facial nerve palsy influences craniofacial growth in craniofacial microsomia. Fifty-one patients with unilateral craniofacial microsomia and no history of craniofacial skeletal surgery whose radiographs were taken after craniofacial growth was complete were included in this study. These patients were divided into groups in which the facial nerve was involved or uninvolved. The authors evaluated a total of seven measurement items to analyze the midface and mandibular asymmetry. Twenty patients had facial nerve involvement, and 31 had no involvement. None of the measurement items revealed any significant differences between the facial nerve-involved group and the uninvolved group within the same modified Pruzansky grade. There was no correlation between the type of facial nerve involvement and the measurement items. In relationships among the measurement items within each group, maxillary asymmetry was indirectly correlated with mandibular asymmetry or midline deviation through the occlusal plane angle in the uninvolved groups. However, in the facial nerve-involved group, the relationships disappeared. When the correlations in the facial nerve-involved group were compared with those of the uninvolved group, the relationships in the uninvolved group appeared more significant than in the facial nerve-involved group. The loss of relationships between the upper and lower jaw in the facial nerve-involved group might have been caused by subtle changes, which occur in midfacial bones and in the mandible due to facial nerve palsy. The main limitation of our study is that aside from facial nerve palsy, craniofacial microsomia has many factors that can influence craniofacial growth, such as hypoplasia of the mandibular condyle and soft tissue deficiencies.

Alleviation of capsular formations on silicone implants in rats using biomembrane-mimicking coatings.

Despite their popular use in breast augmentation and reconstruction surgeries, the limited biocompatibility of silicone implants can induce severe side effects, including capsular contracture - an excessive foreign body reaction that forms a tight and hard fibrous capsule around the implant. This study examines the effects of using biomembrane-mimicking surface coatings to prevent capsular formations on silicone implants. The covalently attached biomembrane-mimicking polymer, poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC), prevented nonspecific protein adsorption and fibroblast adhesion on the silicone surface. More importantly, in vivo capsule formations around PMPC-grafted silicone implants in rats were significantly thinner and exhibited lower collagen densities and more regular collagen alignments than bare silicone implants. The observed decrease in α-smooth muscle actin also supported the alleviation of capsular formations by the biomembrane-mimicking coating. Decreases in inflammation-related cells, myeloperoxidase and transforming growth factor-ß resulted in reduced inflammation in the capsular tissue. The biomembrane-mimicking coatings used on these silicone implants demonstrate great potential for preventing capsular contracture and developing biocompatible materials for various biomedical applications.