The diagnosis of medication-related osteonecrosis of the jaw (MRONJ) currently lacks a globally unified "gold standard", with discrepancies existing among the consensus statements or guidelines of various academic societies. This diagnostic challenge is particularly pronounced for MRONJ cases without clinically evident bone exposure. According to the 2022 position paper of the American Association of Oral and Maxillofacial Surgeons (AAOMS), the diagnosis of MRONJ includes "intraoral or extraoral fistula that probes to bone" as a clinical manifestation in the absence of overt bone exposure. However, in clinical practice, MRONJ presenting with periapical fistula closely resembles periapical periodontitis, making differentiation difficult. Moreover, some MRONJ cases without bone exposure exhibit concealed drainage pathways located in periodontal pockets or the maxillary sinus, without typical fistula formation, increasing the risk of misdiagnosis or underdiagnosis. To address these issues, this article defines "non-exposed" MRONJ as a subtype of MRONJ characterized by the absence of overt bone exposure but the presence of fistulae that probe to bone or other concealed purulent drainage pathways, with non-specific symptoms and characteristic imaging changes. This article systematically analyzes the diagnostic challenges of this variant, synthesizes key differentiating features from medical history, clinical manifestations, and imaging findings to differentiate from odontogenic infections, and discusses the role of diagnostic treatment. Finally, a clinical pathway is proposed to facilitate the early identification of "non-exposed" MRONJ. It should be emphasized that "non-exposed" MRONJ is distinct from the AAOMS-defined stage 0 disease and does not represent an early phase of MRONJ. Clarifying the concept of "non-exposed" MRONJ may improve the overall diagnostic rate of MRONJ and reduce medicolegal disputes arising from misdiagnosis and inappropriate treatment.
The skeleton is a dynamically changing organ, and its homeostasis is maintained through the precise perception and response of osteocytes to mechanical load. The Ca2+ signal, as an early key signal in this process, can convert external mechanical signals into intracellular biochemical signals, and then maintain bone homeostasis by influencing bone formation and bone resorption. In recent years, some studies have explored the normal calcium dynamics of osteocytes and found that the occurrence of bone-related diseases such as osteoporosis were closely related to the abnormal calcium dynamics of osteocytes. Therefore, this article aims to systematically review the calcium dynamics homeostasis of osteocytes and its imbalance in pathological states, in order to deeply understand the physiological regulatory basis of bone homeostasis, and provide important evidence for analyzing the pathological mechanisms of related bone diseases from the perspective of calcium dynamics of osteocytes.
With the application of digital technology in dentistry, three-dimensional reconstruction, virtual surgical planning, and intraoperative navigation are gradually being applied to the clinical practice of orthognathic surgery, driving a transformation in the treatment paradigm from traditional experience-based to precise and personalized approaches. Digital technology has demonstrated significant advantages in improving surgical quality and safety, and has enormous development potential in the field of modern orthognathic surgery. This article reviews the current application status and research progress of digital technology in orthognathic surgery based on domestic and international literature.
Objective: To investigate the effects of cathepsin K (Ctsk) on the proliferation, migration, and osteogenic differentiation of murine periosteal mesenchymal cells. Methods: Primary periosteal mesenchymal cells were isolated from mice and cultured in vitro, and their surface markers were characterized by flow cytometry. Following osteogenic induction for 0, 3, 7, 14, and 21 days, the expression levels of Ctsk, Runx2, and ALP were evaluated using real‑time quantitative polymerase chain reaction (RT‑qPCR). Ctsk expression was knocked down by transfecting periosteal mesenchymal cells with small interfering RNA (siRNA), and knockdown efficiency was confirmed by RT‑qPCR. The expression of Ctsk and osteogenic markers (Runx2, ALP, BMP2, Sp7, COL1A1) was then examined on days 3, 7, and 14 of osteogenic induction. Cell proliferation was assessed using CCK-8 and EdU staining assays, while cell migration was evaluated by Transwell and wound‑healing assays. The impact of Ctsk knockdown on osteogenic differentiation was determined by alkaline phosphatase (ALP) staining and Alizarin red S (ARS) staining. Results: The isolated cells highly expressed CD90.2 (92.5%), CD200 (98.8%), and SCA1 (92.0%), while showing low expression of CD34 (2.5%), CD45 (3.2%), and CD105 (5.0%). Following osteogenic induction, the expression of Ctsk, ALP, and Runx2 in periosteal mesenchymal cells was significantly upregulated. After siRNA transfection, the Ctsk knockdown efficiency reached 62%. Knockdown of Ctsk resulted in decreased expression of osteogenic markers (Runx2, ALP, BMP2, Sp7, COL1A1), reduced cell proliferation capacity, enhanced migration ability, significantly lighter ALP and ARS staining, and fewer mineralized nodules formed after osteogenic induction. Conclusion: Ctsk promotes proliferation and osteogenic differentiation of periosteal mesenchymal cells while inhibiting their migration.
Objective: To investigate the in vivo and in vitro transdifferentiation capacity of murine CD11c-positive dendritic cells (CD11c+DCs) into osteoclasts, and to compare their osteoclastogenic differentiation potential with that of CD11b-positive monocytes (CD11b+MNs) and bone marrow monocytes (BMMs). Methods: A periodontitis model was established in C57BL/6 mice using silk ligation. Immunofluorescence staining was performed to examine the expression of CD11c and CD11b on cathepsin K (CTSK)-positive multinucleated cells in alveolar bone tissue on days 1, 3, and 7 post-surgery. Primary murine CD11c+DCs and CD11b+MNs were isolated using immunomagnetic beads, and the expression of relevant cell surface markers was detected by flow cytometry. CD11c+DCs, CD11b+MNs, and BMMs were separately cultured and induced to differentiate into osteoclasts. Tartrate-resistant acid phosphatase (TRAP) staining and real-time quantitative polymerase chain reaction (RT-qPCR) were employed to assess the number of osteoclasts formed and the mRNA expression levels of osteoclast-related genes (Ctsk, Mmp9, Trap, and Nfatc1). Results: Immunofluorescence showed that CD11c expression was significantly upregulated in alveolar bone following periodontitis surgery, with a faster rate and greater trend of upregulation compared to CD11b. On day 7 post-surgery, the proportion of CD11c+CTSK+ multinucleated cells among CTSK+ multinucleated cells was significantly higher than that of CD11b+CTSK+ multinucleated cells. Flow cytometry revealed that sorted CD11c+ DCs exhibited low expression of CD80, CD86, and MHC-Ⅱ, while CD11b+ MNs highly expressed Ly6C and F4/80 and did not express B220. In vitro experiments demonstrated that CD11c+ DCs formed a significantly greater number of TRAP-positive multinucleated cells compared to CD11b+ MNs and BMMs, with significantly elevated mRNA expression levels of osteoclast-related genes, including Ctsk, Mmp9, and Trap. Conclusion: Murine CD11c+DCs possess significant osteoclastogenic differentiation capacity and participate in the formation of CTSK+ multinucleated cells in periodontitis.
Objective: To investigate the effects of elongated third molars on the temporomandibular joint function, masticatory muscle electromyographic activity, and joint space. Methods: A total of 24 patients with elongated third molars who attended the outpatient clinic of the Department of Oral and Maxillofacial Surgery at the First Affiliated Hospital of Xinjiang Medical University from April 2024 to February 2025 were selected. Among them, 14 had unilateral elongation and 10 had bilateral elongation. The following parameters were compared before and 3 months after the extraction of the elongated third molars: Maximum mouth opening, range of mandibular border movements (protrusion, lateral movement, retrusion), tenderness threshold of the temporomandibular joint area, mean amplitude of surface electromyography (sEMG) of the bilateral anterior temporalis (TA) and masseter muscles (MM), asymmetry index (AsI) of the masticatory muscles, and bilateral temporomandibular joint space (anterior, superior, and posterior joint spaces). Results: Three months after tooth extraction, the patients' maximum mouth opening increased. In the maxillary elongation group, the range of mandibular protrusion and retrusion increased, while in the mandibular elongation group, the range of mandibular protrusion increased. The tenderness threshold of the bilateral TMJ area in both the unilateral and bilateral elongation groups was higher than that before extraction (all P<0.05). In patients with unilateral elongated third molars, the mean sEMG amplitudes of the TA on the elongated side were significantly higher than that on the non-elongated side before extraction. After extraction, there was no statistically significant difference in the mean sEMG amplitude of the TA and MM between the two sides (P>0.05). Compared with before extraction, the mean sEMG amplitudes of the TA and MM on both the elongated and non-elongated sides increased after extraction in patients with unilateral elongation, and the AsI of the bilateral TA decreased. In patients with bilateral elongation, there were no statistically significant differences in the mean sEMG amplitudes and AsI of the bilateral TA and MM before and after extraction (P>0.05). In patients with unilateral elongation, the anterior joint space of the bilateral TMJ decreased and the posterior joint space increased after extraction compared with that before extraction (all P<0.05). In patients with bilateral elongation, there were no statistically significant differences in the anterior and superior joint spaces before and after extraction (P>0.05). Conclusion: Unilateral elongation of the third molar can lead to asymmetry in the electromyographic activity of the masticatory muscles, an increase in the anterior joint space, and a decrease in the posterior joint space of the TMJ. Extraction of the elongated third molar can effectively improve these abnormalities.
Objective: To investigate the clinical efficacy of autologous platelet-rich plasma (PRP) combined with hyaluronic acid (HA) injection in the treatment of temporomandibular joint osteoarthritis (TMJOA). Methods: Eighty-two TMJOA patients admitted to our hospital from March 2023 to March 2024 were enrolled and randomly assigned to either the HA group or the combination group (n=41 per group) using a random number table. The HA group received HA injection, while the combination group received PRP in addition to HA. The following parameters were compared between the two groups before treatment (T0) and one week after the final injection (T1): maximum mouth opening (MMO), change in MMO, pain intensity and pain relief, degree of mandibular functional limitation, status of temporomandibular joint disorders, and levels of inflammatory factors. Results: At T1, the MMO in both groups had increased significantly compared to T0 (P<0.05), and the MMO in the combination group was significantly higher than that in the HA group (P<0.05). The change in MMO and pain relief in the combination group were significantly greater than those in the HA group (P<0.05). At T1, visual analogue scale (VAS) scores, jaw functional limitation scale (JFLS) scores, craniomandibular index (CMI) scores, interleukin-1β (IL-1β) levels, and tumor necrosis factor-α (TNF-α) levels were significantly reduced in both groups compared to T0 (P<0.05), and these values in the combination group were significantly lower than those in the HA group (P<0.05). Conclusion: PRP combined with HA injection is an effective treatment for TMJOA, as it significantly improves joint function and alleviates pain, providing a reference for clinical practice.
Objective: To investigate the factors influencing the operative time for the removal of a single impacted supernumerary tooth in the maxillary incisor region, and to provide a reference for pre-operative difficulty assessment. Methods: Clinical data were collected from 154 patients who underwent extraction of a single impacted supernumerary tooth in the maxillary incisor region at the Hospital of Stomatology, Hebei Medical University, from January to December 2023. All patients received a pre-operative cone beam CT (CBCT) examination, and surgeries were performed under general anesthesia. Patient age, sex, tooth morphology, orientation, position, root development status, surgeon's years of experience, and operative time were recorded. Multiple linear regression analysis was used to identify independent factors influencing operative time. Results: Patients' ages ranged from 4 to 21 years, with a mean of (9.03±3.11) years. Operative time ranged from 5 to 70 minutes, with a mean of (26.00±12.15) minutes. Multivariate analysis showed that patient age (B=1.175, P<0.05), vertical position (B=-5.417, P<0.05), orientation (B=2.236, P<0.05), root development of the supernumerary tooth (B=-2.266, P<0.05), and surgeon's years of experience (B=-2.849, P<0.05) were significantly associated with operative time. A regression equation was established: T=24.667+1.175A-5.417B+2.236C-2.266D-2.849E (T: operative time; A: age; B: vertical position; C: orientation; D: root development; E: surgeon's experience). Conclusion: The operative time for the removal of a single impacted supernumerary tooth in the maxillary incisor region is closely related to patient age, the tooth's vertical position, orientation, root development, and the surgeon's experience. The regression equation established in this study may serve as a quantitative reference for pre-operative difficulty assessment and clinician-patient communication.
Osteoclasts are bone-resorbing cells that play essential roles in both physiological bone remodeling and pathological bone resorption. Inflammation serves as a significant inducer of pathological bone resorption. Studies have shown that osteoclasts differentiated in the inflammatory microenvironment originate from specific marked osteoclast precursors and also exhibit enhanced bone-resorbing capacity compared with those under physiological conditions. Moreover, these inflammation-derived osteoclasts further regulate bone destruction processes through crosstalk with stromal and immune cells. Therefore, osteoclasts in the inflammatory microenvironment are crucial for understanding the pathogenesis of inflammatory bone loss and developing targeted therapeutic strategies. This article reviews the differentiation mechanisms and functional properties of osteoclasts in the inflammatory microenvironment.
The nasopalatine canal is located centrally in the anterior maxilla, originating from the Stenson's foramen at the nasal floor and coursing anteroinferiorly to the incisive foramen on the palatal aspect of the maxillary central incisors. It contains neurovascular bundles that provide innervation and blood supply to the anterior palate. The morphology of the nasopalatine canal is highly variable in the population and is influenced by multiple factors. These factors may lead to maxillary atrophy and enlargement of the nasopalatine canal, making it inevitable that the ideal implant placement site involves the nasopalatine canal. Recent studies have indicated that implant contact with the nasopalatine canal region does not significantly increase failure rates. However, to maximize bone-to-implant contact, most research advocates avoiding direct contact between the implant surface and the contents of the nasopalatine canal. This can be achieved by optimizing implant design or by actively managing the nasopalatine canal to ensure complete bone-to-implant contact. Nevertheless, the key factors influencing nasopalatine canal morphology and corresponding clinical management strategies require further investigation. Therefore, a comprehensive review of the morphological characteristics of the nasopalatine canal, its influencing factors, along with a summary of clinical management approaches for different nasopalatine canal types and relevant clinical recommendations, is of significant clinical importance. This article provides a literature review on these aspects and discusses corresponding clinical decision-making strategies.
Cemento-ossifying fibroma (COF) is a rare benign odontogenic tumor of mesenchymal origin, predominantly occurring in the tooth-bearing areas of the mandible. This article reports a case of COF located in the right mandible, focusing on its clinical manifestations and digital navigation-assisted surgical treatment. A review of the literature is also conducted to discuss the key points of diagnosis and management, aiming to provide reference for the clinical diagnosis and treatment of this disease.
The parotid gland is the most common site for salivary gland tumors, and its complex anatomy demands high surgical precision. This article reports a case of precise resection of a deep lobe parotid tumor using a surgical navigation system. With the surgical navigation system, the critical neurovascular structures surrounding the tumor were successfully preserved during the operation, and the patient achieved a favorable postoperative recovery. This case demonstrates that the surgical navigation system holds promising clinical value in the resection of deep lobe parotid tumors.
In clinical practice, patients often present with oral foreign bodies, but these are typically located in the esophagus, gingiva, and pharynx. Foreign bodies in the tongue are relatively rare, and inflammatory masses caused by foreign body-induced surrounding tissue inflammation are even rarer. Moreover, their imaging findings can be easily confused with neoplasms, leading to misdiagnosis. This article reports a case of a tumor-like mass on the dorsal tongue caused by a fishbone. In combination with relevant literature, its diagnosis, differential diagnosis, and treatment are discussed to enhance clinicians' understanding of such lesions and reduce misdiagnosis.
Carotid body tumor (CBT) is a neuroendocrine tumor originating from the carotid body chemoreceptor. Although it typically presents as a benign lesion clinically, it possesses malignant transformation potential. Malignant CBT can develop lymph node metastasis, distant metastasis, or local recurrence. Therefore, early detection, accurate diagnosis, and timely treatment are crucial. This article reports a case of malignant CBT in a child managed by our oral and maxillofacial surgery team. This case is rare, and its diagnosis, treatment process, and follow-up outcomes are of significant value for a deeper clinical understanding of this disease.
