Although small in size, the eyeballs are extremely important in function, and are delicate and complex in structure. With the wide application of acupuncture for eye diseases and the high frequency of use of intra-orbital points, the incidence of acupuncture accidents increases accordingly in treatment. We reported two recent accident cases, retinal tear and ciliochoroidal detachment that occurred during the regular operation of acupuncture and acupoint injection at intra-orbital points, in order to strengthen people's awareness of acupuncture accidents caused by acupuncture at the points in the orbital region, and enhance the sound development and comprehensive promotion of acupuncture in treatment of eye diseases.
Humans ; Acupuncture Therapy/adverse effects* ; Acupuncture Points ; Male ; Adult ; Female ; Middle Aged ; Orbit ; Retinal Perforations/therapy*

OBJECTIVE: To explore the clinical characteristics, diagnosis, and treatment methods of one patient with idiopathic multicentric Castleman disease (iMCD), in order to strengthen the understanding of this rare disease. METHODS: The clinical manifestations, diagnosis and treatment process, and prognosis of one patient with iMCD admitted to our hospital were retrospectively analyzed. RESULTS: The patient was a 45-year-old female with swollen bilateral orbit, edema of lower limbs, multiple serosal cavity effusion, thrombocytopenia, renal insufficiency, and multiple lymph node enlargement. Lymph node biopsy suggested mixed type of Castleman disease. Combined with pathology, imaging and laboratory examination, the patient was finally diagnosed with mixed type of iMCD. After six cycles of R-COP regimen chemotherapy, the patient achieved complete remission. CONCLUSIONS Castleman disease with renal and orbit involvement is rare in clinic and easy to be misdiagnosed. It should be distinguished from lymphoma. The patient has been treated with R-COP regimen, and obtained good short-term efficacy.
Humans ; Castleman Disease/diagnosis* ; Middle Aged ; Female ; Retrospective Studies ; Orbit/pathology* ; Kidney/pathology*

OBJECTIVE: To evaluate the clinical and radiographic efficacy of micro crestal flap-alveolar ridge preservation following extraction of mandibular molars with severe periodontitis compared with natural healing, and to preliminarily propose the surgical indication. METHODS: A retrospective analysis was conducted on clinical data from patients with mandibular molars with severe periodontitis either receiving micro crestal flap-alveolar ridge preservation (MCF-ARP group) or undergoing natural healing in department of periodontology, Peking University School and Hospital of Stomatology from September 2013 to June 2021. Cone-beam computed tomography scannings performed before/immediately after extraction (as baseline) and repeated before implantation (after the extraction socket healing) were used to measure the ridge width, height and volumetric changes of the sockets, and the proportion of guided bone regeneration (GBR) during implant therapy were compared between the two groups. RESULTS: Between baseline and healing, significant differences in changes of MCF-ARP group [(8.34±2.81) mm] and natural healing group [(3.82±3.58) mm] in the distances from mandibular canal to center of the tooth socket were recorded (P < 0.001). The ridge width at 1 mm below the most coronal aspect of the crest increased by (3.50±4.88) mm in the MCF-ARP group but decreased by (0.16±5.70) mm in the natural healing group, respectively (P=0.019). After healing, the MCF-ARP group showed the distances from mandibular canal to center of the tooth socket >8 mm in all the cases, with 97.1% exceeding 10 mm. Natural healing group displayed 23.1% of the cases with center bone height < 8 mm and 61.5% exceeding 10 mm. Volume changes at the buccal and lingual aspect as well as the total socket were significantly greater in the MCF-ARP group compared with natural healing group (P < 0.001).At the time of implantation, GBR was performed in 5 out of 68 subjects (8.3%) in the MCF-ARP group, whereas 8 out of 26 subjects (30.8%) in the natural healing group required GBR, reflecting significant difference (P=0.003). CONCLUSION In the sites of mandibular molars with severe periodontitis, when the distances from mandibular canal to center of the tooth socket was not enough (less than 7 mm), clinicians could consider performing the micro crestal flap-alveolar ridge preservation to achieve augmentation for alveolar ridge and reduce the proportion of guided bone regeneration during implant therapy to reduce the difficulty and risk of injuries during implant therapy.
Humans ; Tooth Extraction ; Retrospective Studies ; Surgical Flaps ; Molar/surgery* ; Mandible/surgery* ; Female ; Periodontitis/surgery* ; Male ; Adult ; Middle Aged ; Cone-Beam Computed Tomography ; Alveolar Ridge Augmentation/methods* ; Alveolar Process/surgery* ; Tooth Socket/diagnostic imaging* ; Dental Implantation, Endosseous/methods*

OBJECTIVE: To compare the influence of different emergence profile of implants in mandibular molar on the peri-implant soft tissue. METHODS: Forty-four implants were divided into two equal groups by mucosal thickness, ≥2 mm (group A) or < 2 mm (group B), and were randomly included in the test group and the control group. In the control group, the patients were treated by a prosthesis with no transmucosal modifications (subgroups A1 and B1). In groups A1 and B1, the prostheses maintained the original emergence profile of the healing abutment. In the test group, the prostheses were designed based on a width-to-height ratio (W/H) of 1.3 ∶ 1 (subgroups A2 and B2). In group A2, the buccal transmucosal configuration design was slightly concave, and in group B2, the prostheses were designed with convex buccal transmucosal configuration. Assessments were made before delivery of the definitive restoration (T0), one month (T1) and 12 months (T2) after loading. The soft tissue and prosthesis information were obtained by intraoral scan and were converted to digital models. The digital models of different time were superimposed together. Buccal mucosal W/H, emergence angle (EA) and buccal mucosal margin recession (ΔGM) were measured. RESULTS: One year after loading, the buccal mucosal margin recession in the test group (groups A2 and B2) was significantly lower than that in the control group (groups A1 and B1). The ΔGM in group A2 was significantly lower than that in group A1 (P=0.033), but in groups B1 and B2, it was not significantly different. The W/H in group A2 increased significantly one month after loading, but remained stable at one year. In the A1 group, the W/H changed little from initial to one month, but increased significantly at one year after loading. The W/H in group B2 remained stable from the beginning to one year, while in group B1, it changed little one month after loading, but increased significantly by one year. CONCLUSION When the initial mucosal thickness was ≥2 mm, the slightly concave prosthesis designed based on the biological W/H significantly maintained the level of buccal mucosa. When the mucosal thickness was < 2 mm, the slightly convex prosthesis design maintained a more stable W/H over one year.
Humans ; Mandible/surgery* ; Molar/surgery* ; Male ; Female ; Adult ; Middle Aged ; Dental Prosthesis Design ; Dental Implants ; Dental Implantation, Endosseous/methods*

OBJECTIVE: To evaluate the clinical outcomes and define the indications for a one-stage mandibular reconstruction technique that combines iliac bone flaps with immediate implant-based dentures, and to assess both the accuracy of surgical planning and the long-term success of the procedure. METHODS: A total of ten patients underwent the procedure at Peking University Hospital of Stomatology between June 2020 and August 2023. The preoperative biopsy pathology of all the patients confirmed a benign tumor. In this technique, iliac bone flaps were used for mandibular reconstruction, and immediate implant-based dentures were placed during the same surgical session. Various outcome measures were evaluated, including the accuracy of the surgical reconstruction, implant placement deviations (entry point, apical point, depth, and angle), and long-term outcomes, such as cervical bone resorption, implant survival, and the cumulative survival rate. RESULTS: Thirty-eight implants were successfully inserted into the iliac flaps of the ten patients. The median follow-up duration was 23.5 months, and no significant complications occurred during the follow-up period, such as infections, titanium plate exposure, implant loosening, or damage to the implants and dentures. The accuracy of preoperative virtual surgical planning (VSP) was highly reliable. The repeatability of the VSP model compared to the postoperative reconstructed mandible was as follows: 67.82% ±10.16% within 1 mm, 82.14% ±6.58% within 2 mm, and 90.61% ±4.62% within 3 mm. The average maximum deviation from the plan was (6.10±0.89) mm, with an average overall deviation of (1.14±0.31) mm. For the implants, deviations in critical parameters were as follows: entry point deviation was (2.02±0.58) mm, apical point deviation was (2.25± 0.66) mm, depth deviation was (1.26±0.51) mm, and angular deviation was 1.84°±1.10°. The implant survival rate remained 100% during the follow-up, with a cumulative survival rate of 97.37% from 1 to 4 years. Average cervical bone resorption was 0.94 mm. CONCLUSION The combination of iliac bone flaps with immediate implant-based dentures for one-stage mandibular reconstruction demonstrated pro-mising clinical outcomes, including high implant survival and minimal complications. This technique proved to be safe and reliable for mandibular reconstruction. However, further studies with larger sample sizes and longer follow-up periods are necessary to confirm the long-term efficacy and optimal indications for this procedure.
Humans ; Mandibular Reconstruction/methods* ; Male ; Ilium/surgery* ; Female ; Middle Aged ; Surgical Flaps ; Adult ; Mandible/surgery* ; Aged ; Dental Implantation, Endosseous/methods* ; Immediate Dental Implant Loading/methods* ; Bone Transplantation/methods* ; Dental Implants

OBJECTIVE: To investigate the clinical application effect of the along-axis extraction method in the extraction of impacted mandibular third molars (IMTM) and to compare the biomechanical characteristics of different root extraction techniques through three-dimensional finite element analysis. METHODS: A total of 68 patients requiring IMTM extraction were enrolled and randomly divided into two groups: the experimental group underwent the along-axis extraction method, while the control group underwent the traditional buccal bone removal and root extraction method. The duration of the procedure, intraoperative and postoperative complications were recorded. Three-dimensional finite element analysis further revealed the stress distribution in the tooth root, jawbone, periodontal ligament, and mandibular canal during different root extraction methods. RESULTS: The duration of root extraction, pain score and swelling on the first postoperative day in the control group were (7.87±3.90) min, 4.62±1.90 and (11.37±5.12) mm, respectively, which were significantly higher than those in the experimental group [(5.74±2.37) min, 3.87±1.19 and (7.22±3.39) mm, respectively]. The root fracture rate and lingual bone plate fracture rate in the control group were significantly higher than those in the experimental group (P < 0.05). The results of finite element analysis showed that the control group ' s lingual al-veolar bone had the higher peak equivalent stress, and lingual bone plate fracture was prone to occur. The periodontal ligament of the experimental group had the higher equivalent stress value, making it more likely to rip and more likely to cause root displacement. When subjected to force, the experimental group' s instantaneous root displacement was higher, but the control group ' s root displacement was more pronounced in the lingual direction. CONCLUSION This study suggests that the along-axis extraction me-thod can not only effectively shorten the operative time but also reduce postoperative complications after extraction of impacted mandibular third molars, and enhance the safety of the operation and the patient' s comfort. Three-dimensional finite element analysis shows the biomechanical characteristics of various root extraction techniques visually, serves as a valuable guide for choosing and refining clinical surgical techniques, and confirms that extracting a tooth' s root along its long axis yields better clinical results.
Humans ; Finite Element Analysis ; Tooth, Impacted/surgery* ; Tooth Extraction/methods* ; Molar, Third/surgery* ; Mandible/surgery* ; Imaging, Three-Dimensional ; Female ; Adult ; Biomechanical Phenomena ; Male ; Tooth Root/surgery* ; Young Adult ; Adolescent

OBJECTIVE: To propose a new protocol for personalized mandibular reconstruction assisted by three-dimensional (3D) retrieval model based on fully connected neural network (FCNN) and a database of mandibles, and to verify clinical feasibility of the protocol. METHODS: A database of mandibles of 300 normal northern Chinese Han people was established. On the basis of cephalometry, the mandible landmarks with good stability were further screened. Mandibular landmarks were selected and geometric features of the mandible were extracted. A 3D retrieval algorithm was developed, which could retrieve the mandible most similar to a given mandible from the database. A FCNN was built to train the algorithm to improve accuracy of the 3D retrieval model. Using Geomagic Control 2014 software, matching accuracy of the 3D retrieval model was based on aforementioned mandible database and algorithm. From December 2019 to March 2021, a total of 5 patients underwent personalized mandibular reconstruction assisted by a 3D retrieval model based on mandible database and FCNN in the Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology. The most similar mandible was retrieved from mandible database through 3D retrieval algorithm. It was used to restore the premorbid morphology of defect area and guide mandibular reconstruction. For the 5 patients, mandible was reconstructed with iliac flap. Virtual surgical plan was transformed using individual surgical guides. RESULTS: Through screening, mandibular landmarks with high reproducibility and stability were identified and composed of mandibular landmarker protocols. After training, the average deviation between most similar mandible retrieved from the 300-case mandible database through 3D retrieval model based on FCNN and given mandible was (1.77±0.44) mm. And the root-mean-square deviation between the most similar mandible retrieved from the database and given mandible was (2.58±0.86) mm. The mandibular reconstruction surgery was successful in all the 5 patients. Their facial symmetry and occlusion were restored. All the patients were satisfied with postoperative appearance. The mean deviation between postoperative mandible and preoperative design was (0.98±0.17) mm. The area with a deviation ≤1 mm accounted for 61.34%±14. 13%, ≤2 mm accounted for 83.82%±7.35%, and ≤3 mm accounted for 93.94%± 2.87%. CONCLUSION The personalized mandibular reconstruction assisted by 3D retrieval model based on the 300-case mandible database and FCNN is feasible clinically.
Humans ; Neural Networks, Computer ; Mandibular Reconstruction/methods* ; Mandible/diagnostic imaging* ; Imaging, Three-Dimensional/methods* ; Adult ; Databases, Factual ; Female ; Male ; Algorithms ; Middle Aged ; Cephalometry

OBJECTIVE: To establish a three-dimensional finite element model of a digital wire loop space maintainer for the mandible and primary tooth loss, in order to investigate the stress, deformation, and shear force experienced by patients with the loss of the second primary molar when wearing the wire loop space maintainer. METHODS: Cone beam computed tomography (CBCT) scans were performed on the patients to create a digital model of the mandible with the absence of the second primary molar using Mimics 21.0 software. A digital model integrating the crown's retention and the wire loop structure of the full crown and ring wire loop space maintainer was constructed using pediatric space maintainer design software, utilizing three different materials: cobalt-chromium alloy, polyether ether ketone (PEEK), and titanium alloy. In ANSYS Work Beach 2023 R2 software, vertical loads of 70 N, tilted 45° along the long axis of the tooth loads of 70 N, and a 10 N load on the surface of the wire loop were applied to the occlusal surfaces of models 46 and 84, simulating centric and lateral occlusions during chewing with the wire loop space maintainer in place. The stress states of the wire loop space maintainer and supporting teeth were analyzed. RESULTS: Under various loading conditions, the maximum principal stress of the ring wire loop space maintainer was significantly lower than that of the full crown. Stress contour maps indicated that the peak of the maximum principal stress occurred at the junction of the wire loop and crown structure, indicating that this area was more susceptible to fracture. The ring wire loop space maintainer made from PEEK material exhibited the lowest maximum shear stress on the internal organizational surfaces, with equivalent stresses of 23.18 MPa and 36.35 MPa for models 46 and 84, respectively. Stress contour maps demonstrated that the maximum stress on tooth 46 was located at its mesial, while the maximum stress on tooth 84 was situated near the root area on its distal, in contact with the wire loop space maintainer. CONCLUSION In cases of second primary molar loss, wearing the digital ring wire loop space maintainer can effectively distribute stress, and the ring wire loop space maintainer made from PEEK material reduces the stress experienced by supporting teeth to some extent, demonstrating its superiority in clinical application.
Finite Element Analysis ; Humans ; Tooth, Deciduous ; Cone-Beam Computed Tomography ; Space Maintenance, Orthodontic/methods* ; Imaging, Three-Dimensional ; Orthodontic Wires ; Dental Stress Analysis ; Mandible ; Stress, Mechanical

Osteonecrosis of the mandible is also called avascular necrosis of the jaw, and it is a rare complication of bisphosphonates. It is characterized with pain, swelling, exposure of bone, local infection and pathologic fractures of the jaw. With the widespread usage of bisphosphonates in bone metastasis of malignant tumors and osteoporosis, this rare complication has received more attention in recent years. Here, we reported a case of bisphosphonates-related osteonecrosis of the jaw (BRONJ) caused by intravenous zoledronic acid for osteoporosis. A 62-year-old female patient with 7-year history of Sjögren's syndrome and 3-year history of osteoporosis developed BRONJ after 3-year treatment of zoledronic acid. Two months before she went to the Peking University International Hospital, she visited the dentist for periodontal purulent secretion and extracted one tooth from the right mandible. However, the condition was not improved and she felt persistent pain and swelling in the right mandible. Hence, she received repeated root curettage, but there was no improvement. Finally, she was diagnosed with osteonecrosis of the mandible based on the digital volume tomography scan, which showed right mandibular osteonecrosis bone destruction. She underwent surgical debridement of the necrotic bone and administered intravenous antibio-tics at the Peking University International Hospital. Histopathological analysis of the bone biopsy further confirmed the diagnosis of BRONJ. Her condition was improved successfully during a 3-year follow-up. Osteonecrosis of the mandible become more common with the increased use of bisphosphonates. Recent study has reported that osteonecrosis of the mandible is more likely to occur in patients with Sjögren's syndrome. In addition, age, long-term and irregular administration of glucocorticoids, irregular oral examination and treatment also might be the risk factors in the pathogenesis of osteonecrosis of the mandible. For the elder osteoporosis patients who would receive or had received bisphosphonate-related drugs, oral health status and the disease states associated with necrosis of the mandible such as Sjögren's syndrome should be comprehensively measured and fully evaluated during the whole process. Furthermore, to better understand and prevent or reduce the occurrence of this complication, we reviewed the patho-genesis, diagnosis, treatment, and prevention of BRONJ.
Humans ; Female ; Middle Aged ; Bisphosphonate-Associated Osteonecrosis of the Jaw/etiology* ; Diphosphonates/administration & dosage* ; Zoledronic Acid ; Imidazoles/administration & dosage* ; Bone Density Conservation Agents/adverse effects* ; Osteoporosis/drug therapy*

OBJECTIVE: To assess the osteogenesis height in maxillary sinus segment one year after zygomatic implantation by imaging methods, and evaluate the influence of patient factors, maxillary sinus anatomical factors and surgical factors on postoperative osteogenesis height. METHODS: This study is a retrospective study, including patients who underwent zygomatic implantation and whose zygomatic implants passed through the maxillary sinus at the Department of Implantology, Peking University School and Hospital of Stomatology from July 2017 to January 2022. Preoperative and postoperative cone beam CT (CBCT)was taken to measure and calculate the average osteogenesis height (AOH) in maxillary sinus segment of the zygomatic implants, then the residual bone height, the width and morphology of the maxillary sinus floor in the buccal and palatal directions were measured. Besides, the integrity of Schneiderian membrane during implant surgery, and the general information of the patients and zygomatic implants were recorded. By comparing anatomical situations and surgical characteristics, the differences of AOH under different conditions were analyzed. Then AOH was divided into two groups (obvious osteogenesis group and non-obvious osteogenesis group) using the median as the threshold, and the influencing factors of osteogenesis were evaluated using mixed effect generalized linear model univariable and multivariable analysis. RESULTS: A total of 47 zygomatic implants were implanted in 24 patients. During the average follow-up period of 12.1 months, there was no implant failure, and the implant survival rate was 100%. Postoperative CBCT showed that 43 zygomatic implants had osteogenic images in the maxillary sinus segment, most of which originated from the floor of the maxillary sinus, and the median AOH was 3.1 mm [interquartile range (IQR): 4.0 mm]. In terms of maxillary sinus width, there were 31 cases (66.0%) of wide type and 16 cases (34.0%) of narrow type. In the aspect of buccal and palatal morphology, 17 cases were taper (36.2%), 20 cases were round (42.6%), and 10 cases were flat (21.3%). The median of residual bone height was 2.8 mm (IQR: 2.2 mm) before operation. Univa-riate analysis of mixed effect generalized linear model showed that postoperative obvious osteogenic rate was related to the residual bone height (OR=2.09, P=0.006). Multivariate analysis showed that the resi-dual bone height (OR=2.55, P=0.022) and the shape of a taper maxillary sinus (OR=11.44, P=0.040) had a significant impact on the postoperative obvious osteogenic rate. CONCLUSION The maxillary sinus floor showed osteogenic images 1 year after the zygomatic implantation surgery. Larger residual bone height and the shape of a taper maxillary sinus may be favorable factors for osteogenesis.
Humans ; Maxillary Sinus/surgery* ; Cone-Beam Computed Tomography ; Retrospective Studies ; Zygoma/diagnostic imaging* ; Male ; Female ; Osteogenesis/physiology* ; Middle Aged ; Adult ; Dental Implants ; Aged ; Dental Implantation, Endosseous/methods*