Risk Factors Associated With Inferior Alveolar Nerve Injury After Extraction of Impacted Lower Mandibular Third Molars: A Prospective Cohort Study.

BACKGROUND: Inferior alveolar nerve (IAN) injury is one of the complications of impacted lower mandibular third molar (LM3) extraction. Given the unknown prognosis of IAN injuries and limited treatment options, it is critical to understand the risk factors of IAN injury before LM3 extraction. PURPOSE: The purpose of the study was to identify risk factors associated with IAN injury after LM3 extraction. STUDY DESIGN, SETTING, SAMPLE: This was a prospective cohort study including patients who underwent LM3 extraction from May to December 2021 at the authors' institution. Patients with systemic diseases, previous maxillofacial surgeries, or sensory abnormalities were excluded. PREDICTOR VARIABLE: The predictor variable is composed of several risk factors. The variables were grouped into four categories: demographic, radiographic, procedure-related, and surgeon experience. MAIN OUTCOME VARIABLE(S): The outcome variable was postoperative neurosensory disturbance coded as present or absent and was measured at 1-month (transient) and 1-year (permanent). COVARIATES: Not applicable. ANALYSES: The measurement data were represented by mean and standard deviation. The association of each variable with the presence of an IAN injury was tested by the χ2 test. Statistical significance was accepted at P < .05. RESULTS: The study sample consisted of 705 patients (37.0% male) with an average age of 28.51 ± 6.51 years. A total of 17/705 (2.4%) and 4/705 (0.57%) patients developed transient and permanent IAN injuries. The results demonstrated that the following factors were associated with higher rates of transient injury: use of chisels during surgeries (6.4%; 95% confidence interval (CI): 2.7 to 12.3; P = .02; relative risk (RR) = 11.4), LM3s located below the IAN canal (8.7%; 95% CI: 4.3 to 15.7; P < .01; RR = 7.3), compressed contact between LM3s and the IAN canal (36.4%; 95% CI: 12.3 to 78.2; P < .001; RR = 25.4), and not using corticosteroids after surgeries (3.8%; 95% CI: 1.9 to 6.5; P = .03; RR = 3.1). The only factor associated with permanent injury was compressed contact between LM3s and the IAN canal (18.2%; 95% CI: 2.2 to 62.3; P < .001; RR = 48.2). CONCLUSION AND RELEVANCE: Close proximity between LM3s and IAN canal and the use of chisels increase the risk of transient IAN injury. Corticosteroid treatment may promote nerve recovery. Compressed contact between LM3s and IAN canal is the only risk factor for permanent injury.

Modified alveolar ridge preservation to promote the osteogenesis of the distal surface of second molar after mandibular impacted third molar extraction: a preliminary study.

OBJECTIVES: The objective of the retrospective study was to explore whether the use of a modified alveolar ridge preservation technique impacts osteogenesis on the distal surface of the second molar after mandibular third molar (M3) extraction. MATERIALS AND METHODS: A total of 54 patients were enrolled in this study and divided into three different groups, including modified alveolar ridge preservation (MARP) group, traditional tooth extraction (TRA) group, and classical guided bone regeneration (GBR) group. In this study, MARP was designed with the highlights of the preservation of the alveolar bone superior and lingual to M3. These patients chose different surgical methods according to their own wishes for past infection or in order to prevent pericoronitis, and the operation time and surgical cost of each group were recorded. The periodontal conditions of the ipsilateral mandibular second molar (M2) and the height of its distal alveolar bone were measured during the postoperative follow-up. RESULTS: The probing depth, clinical attachment level, and osseous defect depth on the distal surface of the ipsilateral M2 in the MARP group were better than those of the TRA group at any time of the follow-up (P < 0.05 for all), but there was no statistical difference in the measurements when compared to the GBR group at 6 months after operation (P > 0.05 for all). CONCLUSIONS: Thus, MARP therapy not only improves the regeneration of periodontal osseous defects distal to the M2 after M3 extraction but also reduces the operation time and surgical cost. CLINICAL RELEVANCE: This paper introduces a modified surgical method that can not only economically and effectively remove the impacted mandibular third molar but also obtain stable osteogenesis.

Short-rib polydactyly and Jeune syndromes are caused by mutations in WDR60.

Short-rib polydactyly syndromes (SRPS I-V) are a group of lethal congenital disorders characterized by shortening of the ribs and long bones, polydactyly, and a range of extraskeletal phenotypes. A number of other disorders in this grouping, including Jeune and Ellis-van Creveld syndromes, have an overlapping but generally milder phenotype. Collectively, these short-rib dysplasias (with or without polydactyly) share a common underlying defect in primary cilium function and form a subset of the ciliopathy disease spectrum. By using whole-exome capture and massive parallel sequencing of DNA from an affected Australian individual with SRPS type III, we detected two novel heterozygous mutations in WDR60, a relatively uncharacterized gene. These mutations segregated appropriately in the unaffected parents and another affected family member, confirming compound heterozygosity, and both were predicted to have a damaging effect on the protein. Analysis of an additional 54 skeletal ciliopathy exomes identified compound heterozygous mutations in WDR60 in a Spanish individual with Jeune syndrome of relatively mild presentation. Of note, these two families share one novel WDR60 missense mutation, although haplotype analysis suggested no shared ancestry. We further show that WDR60 localizes at the base of the primary cilium in wild-type human chondrocytes, and analysis of fibroblasts from affected individuals revealed a defect in ciliogenesis and aberrant accumulation of the GLI2 transcription factor at the centrosome or basal body in the absence of an obvious axoneme. These findings show that WDR60 mutations can cause skeletal ciliopathies and suggest a role for WDR60 in ciliogenesis.

Access to the infratemporal fossa: A modified transzygomatic approach with preservation of masseter attachment and a long-term follow-up period.

This study aimed to introduce and evaluate the feasibility of a modified transzygomatic approach with preservation of masseter attachment for the management of infratemporal fossa tumors. This retrospective study included 20 patients treated at Shanghai Ninth People's Hospital, Shanghai Jiao Tong University, between June 2007 and August 2017. Pre- and postoperative radiological findings (magnetic resonance imaging and computed tomography) were obtained from all patients. During an average 67 months of follow-up, no clinical or radiographic signs were found of recurrence or absorption of zygomatic arch defects. The mean visual analog scale score changed from 5.5 preoperatively to 0.6 postoperatively (P<0.001), while the mean maximum inter-incisal opening improved from 21.5 mm preoperatively to 38.7 mm postoperatively (P<0.001). Thus, managing infratemporal lesions using the modified transzygomatic approach may provide functional and esthetically established outcomes.

Mesenchymal Stem Cells Alleviate Moderate-to-Severe Psoriasis by Reducing the Production of Type I Interferon (IFN-I) by Plasmacytoid Dendritic Cells (pDCs).

The anti-inflammatory and immunomodulatory properties of mesenchymal stem cells (MSCs) have been proposed to be involved in some autoimmune diseases and have been successfully tested in patients and mice. But their contribution to psoriasis and the underlying mechanisms involved remains elusive. Here, we explored the feasibility of using human umbilical cord-derived MSC (hUC-MSC) infusion as a therapeutic approach in an imiquimod- (IMQ-) induced psoriasis mouse model. MSC infusion were found to significantly reduce the severity and development of psoriasis, inhibit the infiltration of immune cells to the skin, and downregulate the expression of several proinflammatory cytokines and chemokines. Our results provide an explanation for the therapeutic effects of MSC infusion by first suppressing neutrophil function and then downregulating the production of type I interferon (IFN-I) by plasmacytoid dendritic cells (pDCs). Therefore, we discovered a novel mechanism of stem cell therapy for psoriasis. In summary, our results showed that MSC infusion could be an effective and safe treatment for psoriasis.

External morphology of the mouthparts of the whitebacked planthopper Sogatella furcifera (Hemiptera: Delphacidae), with special reference to the sensilla.

The whitebacked planthopper, Sogatella furcifera (Horváth), is a major pest of rice in Asia, with the adults and larvae sucking the phloem sap and affecting plant growth. The ultrastructural morphology of the mouthparts, with distribution of sensilla located on the maxillae and labium in adult S. furcifera was observed using scanning electron microscopy and illustrated, with a brief discussion of their taxonomic and putative functional significance. The gross mouthparts comprising an uppermost small cone-shaped labrum, a three-segmented labium with a deep longitudinal groove on the anterior side, and a stylet fascicle consisting of two mandibular and two maxillary stylets, are consistent with the conventional piercing-sucking type of mouth parts found in Hemiptera. The mandibles bear 5 teeth on the external convex region on the distal extremity. Smooth maxillary stylets, interlocked to form a larger food canal and a smaller salivary canal, are asymmetrical only in the internal position of longitudinal carinae and grooves. Two dendritic canals are also found in each maxilla and one in each mandible. The cross-section of the stylet fascicle is oval. The labial tip is a rosette shape. Two types of sensilla trichoides, two types of uniporous peg sensilla, two pairs of sensilla basiconica and a pair of subapical labial sensory organs have been detected at different locations on the labium, specifically the labial tip is divided into dorsal paired sensory fields with 9 pairs of uniporous peg sensilla and 1 pairs of dome-shaped sensilla, and ventral paired sensory fields with 2 pairs of sensilla basiconica.