Comprehensive 3-dimensional Positional and Morphological Analyses of Condyle and Glenoid Fossa in Patients with Skeletal Class II Malocclusion following Bimaxillary Orthognathic Surgery.

This study aimed to comprehensively and quantitatively characterize 3-dimensional (3D) positional and morphological changes of the condyle and glenoid fossa in patients with skeletal Class II malocclusion treated with bimaxillary orthognathic surgery. Twenty eligible patients treated at our institution from January 2016 to December 2021 with more than 12 months of postoperative follow-up were retrospectively enrolled. Radiographic data of cone-beam computed tomography (CBCT) for each patient were collected at 3 stages: 1 week preoperatively (T0), immediately after surgery (T1), and at least 12 months postoperatively (T2). Positional changes, surface and volumetric alterations of condyle, and bone remodeling in glenoid fossa were measured and compared based on voxel- and surface registrations in visual 3D methods. Most patients exhibited a tendency for condyles to shift posteriorly, laterally, superiorly, and rotated outward, downward, and forward immediately after surgery. Posterior, medial, superior movement and outward, upward, and backward rotation of condyles were observed during follow-up (T1-T2). Bone resorption frequently occurred in the posterior area of condylar surfaces, while bone remodeling was more common in the anterior region of the glenoid fossa. Reduced volume of the condyle was found in most cases, which was not associated with the amount of mandibular advancement. Overall, the condyle and its corresponding glenoid fossa remained relatively stable during the follow-up. Our results reveal positional and morphological alterations in the condyle and the glenoid fossa after bimaxillary orthognathic surgery in patients with skeletal class II malocclusion. These changes predominantly fall within the spectrum of physical adaption.

CBCT study on the positional relationship between marginal points of pterygomaxillary junction and anterior nasal spine.

PURPOSE: This study aimed to locate the inferior end (Pti) and the superior end (Pts) of pterygomaxillary junction (PMJ) relative to anterior nasal spine (ANS) so as to provide references for pterygomaxillary separation. METHODS: The study was based on CBCT images of 109 Chinese patients. We projected Pti and Pts to the frontal plane and measured the distance as well as the positional relationship between the projection points and ANS via three-dimensional reconstruction image. RESULTS: On average, the ANS was 5.18 mm above the Pti and the horizontal distance between the Pti and ANS was 21.86 mm. The horizontal and vertical distances between Pts and ANS was 20.41 mm and 10.91 mm, respectively. The vertical height of PMJ was 16.09 mm. Scatter plots diagrammatic centered on ANS showed that 73% (160/218) Pti and 64% (140/218) Pts appeared in a 45° fan shape ranged from 20 to 25 mm radius in bilateral inferior and superior quadrant, respectively. There was no significant difference in the distance between both sides (P > 0.05). CONCLUSION: During the pterygomaxillary disjunction, it exists a risk of injuring neurovascular bundle of the pterygopalatine fossa 16.09 mm above the lowest border of the pterygomaxillary junction. The region within a 45° fan shape ranged in 20-25 mm radius in inferior quadrant centered on ANS might be suitable for the osteotome position. The positional relationship especially between the ANS and Pti found in this study provides a reference for surgeons during pterygomaxillary disjunction.

The top 100 highly cited articles on surgery-first orthognathic surgery between 2009 and 2022: a bibliometric and visualized analysis.

OBJECTIVES: To reveal research focuses on surgery-first orthognathic surgery by a bibliometric and visualized analysis of the top 100 highly cited articles. STUDY DESIGN: Published papers related to surgery-first orthognathic surgery were retrospectively retrieved from the Web of Science Core Collection from 2009 to 2022. The number of articles, journals, countries/regions, institutions, authors, and keywords were assessed and visualized using CiteSpace software. RESULTS: The top 100 cited articles included 89 research papers and 11 reviews. The average total citation was 21. The most influential article with 146 citations was published by Dr. Liou E.J.W. in 2011. The most common level of evidence was level IV (36 articles). The Journal of Oral and Maxillofacial Surgery had the largest number of papers and the highest total citation frequency. The most productive countries and institutions were Korea/China and Chang Gung Memorial Hospital, respectively. Chen Yu-ray and Choi Jong Woo published 13 and 11 articles with 434 and 299 total citations, respectively. Research interests shifted from skeletal class III malocclusion, accuracy, stability, and relapse to quality of life and virtual surgical planning. CONCLUSION: Our bibliometric analyses provide a comprehensive landscape of the influential topics and developmental trends in surgery-first orthognathic surgery and inspire future studies in this booming field.

Impaired autophagy-mediated macrophage polarization contributes to age-related hyposalivation.

Age-related dysfunction of salivary glands (SGs) leading to xerostomia or dry mouth is typically associated with increased dental caries and difficulties in mastication, deglutition or speech. Inflammaging-induced hyposalivation plays a significant role in aged SGs; however, the mechanisms by which ageing shapes the inflammatory microenvironment of SGs remain unclear. Here, we show that reduced salivary secretion flow rate in aged human and mice SGs is associated with impaired autophagy and increased M1 polarization of macrophages. Our study reveals the crucial roles of SIRT6 in regulating macrophage autophagy and polarization through the PI3K/AKT/mTOR pathway, as demonstrated by generating two conditional knock out mice. Furthermore, triptolide (TP) effectively rejuvenates macrophage autophagy and polarization via targeting this pathway. We also design a local delivery of TP-loaded apoptotic extracellular vesicles (ApoEVs) to improve age-related SGs dysfunction therapeutically. Collectively, our findings uncover a previously unknown link between SIRT6-regulated autophagy and macrophage polarization in age-mediated hyposalivation, while our locally therapeutic strategy exhibits potential preventive effects for age-related hyposalivation.

SIRT6-regulated macrophage efferocytosis epigenetically controls inflammation resolution of diabetic periodontitis.

Rationale: Diabetes exacerbates the prevalence and severity of periodontitis, leading to severe periodontal destruction and ultimately tooth loss. Delayed resolution of inflammation is a major contributor to diabetic periodontitis (DP) pathogenesis, but the underlying mechanisms of this imbalanced immune homeostasis remain unclear. Methods: We collected periodontium from periodontitis with or without diabetes to confirm the dysfunctional neutrophils and macrophages in aggravated inflammatory damage and impaired inflammation resolution. Our in vitro experiments confirmed that SIRT6 inhibited macrophage efferocytosis by restraining miR-216a-5p-216b-5p-217 cluster maturation through ''non-canonical'' microprocessor complex (RNA pulldown, RIP, immunostaining, CHIP, Luciferase assays, and FISH). Moreover, we constructed m6SKO mice that underwent LIP-induced periodontitis to explore the in vitro and in vivo effect of SIRT6 on macrophage efferocytosis. Finally, antagomiR-217, a miRNA antagonism, was delivered into the periodontium to treat LIP-induced diabetic periodontitis. Results: We discovered that insufficient SIRT6 as a histone deacetylase in macrophages led to unresolved inflammation and aggravated periodontitis in both human and mouse DP with accumulated apoptotic neutrophil (AN) and higher generation of neutrophil extracellular traps. Mechanistically, we validated that macrophage underwent high glucose stimulation resulting in disturbance of the SIRT6-miR-216/217 axis that triggered impeded efferocytosis of AN through targeting the DEL-1/CD36 axis directly. Furthermore, we demonstrated the inhibitory role of SIRT6 for MIR217HG transcription and identified a non-canonical action of microprocessor that SIRT6 epigenetically hindered the splicing of the primary miR-216/217 via the complex of hnRNPA2B1, DGCR8, and Drosha. Notably, by constructing myeloid-specific deletion of SIRT6 mice and locally delivering antagomir-217 in DP models, we strengthened the in vivo effect of this axis in regulating macrophage efferocytosis and inflammation resolution in DP. Conclusions: Our findings delineated the emerging role of SIRT6 in mediating metabolic dysfunction-associated inflammation, and therapeutically targeting this regulatory axis might be a promising strategy for treating diabetes-associated inflammatory diseases.

Clinical management of primary odontogenic sarcoma in the mandible: a case report after WHO nomination.

Ameloblastic fibro-odontosarcoma (AFOS) now designated as odontogenic sarcoma is an extremely rare odontogenic tumor, which histologically presents as a biphasic neoplasm with a malignant mesenchymal component plus ameloblastic epithelium. Here we report a 27-year-old Chinese female with the complaint of a painful swelling for half a month in the right mandible. A segmental mandibulectomy, with an immediate mandibular reconstruction using a free vascularized osteocutaneous fibular flap was performed using surgical guide models. Histological analysis revealed a primary odontogenic sarcoma. The postoperative period was uneventful, and no clinical indication of recurrence or metastasis was observed during the 3-year follow-up. No adjuvant therapy was proposed. This is the first odontogenic sarcoma case reported in China after the new World Health Organization classification of odontogenic lesions.

Comprehensive characterization of pleomorphic adenoma at intraoral unusual sites.

OBJECTIVE: The present study aimed to comprehensively characterize the epidemiologic characteristics, clinicopathologic characteristics, clinical treatments, and prognoses of pleomorphic adenoma (PA) identified at unusual intraoral sites. STUDY DESIGN: Patients diagnosed with PA in oral and maxillofacial regions at our institution in the past 16 years (2005-2020) were screened from the inpatient disease registry. All data concerning patients with PA found at unusual intraoral sites (defined as intraoral locations except sublingual gland and palate) were retrieved. Previously published cases with adequate clinicopathologic data were collected from PubMed and Embase. Eligible cases were further reviewed and included for statistical analyses. RESULTS: Among 1039 cases of PA diagnosed at our institution, 52 lesions were found at unusual intraoral sites. A literature review identified another 63 eligible cases from 32 articles. The upper lip was the most common sites for these lesions (n = 57), followed by buccal mucosa (n = 34), tongue (n = 8), lower lip (n = 8), and retromolar area (n = 2). Recurrence and malignant transformation after surgical resection were extremely rare for these lesions. CONCLUSIONS: PA might rarely develop at uncommon intraoral sites with atypical presentations, thus complicating its early diagnosis. Surgical resection is the major therapeutic strategy for this rare entity and has a favorable prognosis.

Computer-aided design-based preoperative planning of screw osteosynthesis for type B condylar head fractures: A preliminary study.

OBJECTIVE: To investigate the clinical application of a new computer-aided design - (CAD) based planning method for the treatment of type B condylar head fractures without fragmentation. METHODS: A total of 13 adult patients (19 sides) with type B condylar head fractures were included in the study. In all cases, imaging was performed using cone bean computed tomography (CBCT) preoperative, and Digital Imaging and Communications in Medicine (DICOM) files were imported into Simplant 11.04 software. The fracture of the mandibular condyle was reconstructed by a three-dimensional reconstruction module, and the simulation of reduction was achieved according to the morphological characteristics. Preoperative design was performed based on the CAD technology, and the three-dimensional interface was used to determine the length, location, and orientation of the positional screw. Osteosynthesis was performed with a single positional screw according to the optimum direction assessed in the preoperative planning CBCT, and the result was confirmed with postoperative CBCT scans and clinical follow-up. RESULTS: Preoperative computer-aided design was able to predict the length, location, and direction of the positional screw. Postoperative CBCT results demonstrated that 12 cases (18 sides) were consistent with preoperative design with exception of one case (one side) due to unexpected rupture of the fragment. Six-month follow-up showed the condylar fractures were anatomically repositioned and that healing was excellent in 12 cases (18 sides) with minor displacement and resorption in one case (one side). Postoperative occlusion in all cases was excellent, and the maximum mouth opening improved from mean 1.2 cm preoperatively to a of mean 4.3 cm at 6 months postoperatively. The data for mandibular movements at 6 months postoperatively demonstrated the recovery of protrusion, without higher grade limitations for laterotrusion. In one case, there appeared to be mandibular deviation (<0.5 cm) with mouth opening. CONCLUSION: The new preoperative design provides relevant data for screw osteosynthesis to enhance the precision and effectiveness of open reduction and internal fixation type B condylar head fractures.