Tumor cell-intrinsic programmed death-ligand 1 (PD-L1) signals mediate tumor initiation, progression and metastasis, but their effects in ameloblastoma (AM) have not been reported. In this comprehensive study, we observed marked upregulation of PD-L1 in AM tissues and revealed the robust correlation between elevated PD-L1 expression and increased tumor growth and recurrence rates. Notably, we found that PD-L1 overexpression markedly increased self-renewal capacity and promoted tumorigenic processes and invasion in hTERT⁺-AM cells, whereas genetic ablation of PD-L1 exerted opposing inhibitory effects. By performing high-resolution single-cell profiling and thorough immunohistochemical analyses in AM patients, we delineated the intricate cellular landscape and elucidated the mechanisms underlying the aggressive phenotype and unfavorable prognosis of these tumors. Our findings revealed that hTERT⁺-AM cells with upregulated PD-L1 expression exhibit increased proliferative potential and stem-like attributes and undergo partial epithelial‒mesenchymal transition. This phenotypic shift is induced by the activation of the PI3K-AKT-mTOR signaling axis; thus, this study revealed a crucial regulatory mechanism that fuels tumor growth and recurrence. Importantly, targeted inhibition of the PD-L1-PI3K-AKT-mTOR signaling axis significantly suppressed the growth of AM patient-derived tumor organoids, highlighting the potential of PD-L1 blockade as a promising therapeutic approach for AM.
Ameloblastoma/metabolism* ; Humans ; B7-H1 Antigen/metabolism* ; Neoplasm Recurrence, Local/pathology* ; Signal Transduction ; Cell Proliferation ; Up-Regulation ; TOR Serine-Threonine Kinases/metabolism* ; Proto-Oncogene Proteins c-akt/metabolism* ; Telomerase/metabolism* ; Jaw Neoplasms/metabolism* ; Epithelial-Mesenchymal Transition ; Animals ; Cell Line, Tumor ; Female ; Male

Objective To evaluate the accuracy of different convolutional neural networks (CNN),representative deep learning models,in the differential diagnosis of ameloblastoma and odontogenic keratocyst,and subsequently compare the diagnosis results between models and oral radiologists. Methods A total of 1000 digital panoramic radiographs were retrospectively collected from the patients with ameloblastoma (500 radiographs) or odontogenic keratocyst (500 radiographs) in the Department of Oral and Maxillofacial Radiology,Peking University School of Stomatology.Eight CNN including ResNet (18,50,101),VGG (16,19),and EfficientNet (b1,b3,b5) were selected to distinguish ameloblastoma from odontogenic keratocyst.Transfer learning was employed to train 800 panoramic radiographs in the training set through 5-fold cross validation,and 200 panoramic radiographs in the test set were used for differential diagnosis.Chi square test was performed for comparing the performance among different CNN.Furthermore,7 oral radiologists (including 2 seniors and 5 juniors) made a diagnosis on the 200 panoramic radiographs in the test set,and the diagnosis results were compared between CNN and oral radiologists. Results The eight neural network models showed the diagnostic accuracy ranging from 82.50% to 87.50%,of which EfficientNet b1 had the highest accuracy of 87.50%.There was no significant difference in the diagnostic accuracy among the CNN models (P=0.998,P=0.905).The average diagnostic accuracy of oral radiologists was (70.30±5.48)%,and there was no statistical difference in the accuracy between senior and junior oral radiologists (P=0.883).The diagnostic accuracy of CNN models was higher than that of oral radiologists (P<0.001). Conclusion Deep learning CNN can realize accurate differential diagnosis between ameloblastoma and odontogenic keratocyst with panoramic radiographs,with higher diagnostic accuracy than oral radiologists.
Humans ; Ameloblastoma/diagnostic imaging* ; Deep Learning ; Diagnosis, Differential ; Radiography, Panoramic ; Retrospective Studies ; Odontogenic Cysts/diagnostic imaging* ; Odontogenic Tumors

Odontogenic tumors are rare lesions with unknown etiopathogenesis. Most of them are benign, but local aggressiveness, infiltrative potential, and high recurrence rate characterize some entities. The MAP-kinase pathway activation can represent a primary critical event in odontogenic tumorigenesis. Especially, the BRAF V600E mutation has been involved in 80-90% of ameloblastic lesions, offering a biological rationale for developing new targeted therapies. The study aims to evaluate the BRAF V600E mutation in odontogenic lesions, comparing three different detection methods and focusing on the Sequenom MassARRAY System. 81 surgical samples of odontogenic lesions were subjected to immunohistochemical analysis, Sanger Sequencing, and Matrix-Assisted Laser Desorption/Ionization-Time of Flight mass spectrometry (Sequenom). The BRAF V600E mutation was revealed only in ameloblastoma samples. Moreover, the presence of BRAF V600E was significantly associated with the mandibular site (ρ = 0.627; P value <0.001) and the unicystic histotype (ρ = 0.299, P value <0.001). However, any significant difference of 10-years disease-free survival time was not revealed. Finally, Sequenom showed to be a 100% sensitive and 98.1% specific, suggesting its high-performance diagnostic accuracy. These results suggest the MAP-kinase pathway could contribute to ameloblastic tumorigenesis. Moreover, they could indicate the anatomical specificity of the driving mutations of mandibular ameloblastomas, providing a biological rational for developing new targeted therapies. Finally, the high diagnostic accuracy of Sequenom was confirmed.
Ameloblastoma/pathology* ; Carcinogenesis ; Humans ; Mitogen-Activated Protein Kinases/genetics* ; Mutation ; Odontogenic Tumors/pathology* ; Proto-Oncogene Proteins B-raf/metabolism* ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

Objective: To analyse the quality of life of patients receiving repair of bone defect with folded fibula flap after removal of mandibular ameloblastoma. Methods: The case data of 39 patients with ameloblastoma admitted to the First Affiliated Hospital of Zhengzhou University from August 2013 to April 2016 were retrospectively analysed, including 21 males and 18 females, from 18 to 58 years old. 3D printing and digital technology were used in flap preparation before surgery in all patients. The folded fibular flaps were used to repair mandibular defects and the implants were placed between 6-9 months after surgery. The short form-36 health survey questionnaire (SF-36) and the university of Washington quality of life questionnaire (UW-QOL) were applied to evaluate the quality of life of patients before surgery and at 6 months and 24 months after surgery. The higher the score, the better the condition. SPSS 20.0 was adopted for statistical analysis. Results: The SF-36 survey showed that the mean score of body role before surgery (72.4±11.7) was significantly higher than that at 6 months after surgery (39.6±11.1, t=23.580, P<0.05) or that at 24 months after surgery (59.8±6.4, t=8.358, P<0.001). Compared with the preoperative mean scores of Physical Pain (73.0±11.0), General Health (73.4±10.4) and Health Changes (79.2±3.9) before surgery, the mean scores Physical Pain (53.1±7.7), General Health (53.5±7.5) and Health Changes (63.9±11.7) at 6 months after surgery were decreased significantly respectively (t=13.068, 13.756 and 10.880, respectively, all P<0.05), but the mean scores Physical Pain (78.8±14.0), General Health (80.9±12.6) and Health Changes (84.4±4.6) at 24 months after surgery were increased significantly respectively (t=-2.904, -4.027 and -7.586, respectively, all P<0.05), with significant differences in the mean scores of Physical Pain, General Health and Health Changes between 6 and 24 months after surgery (t=-14.241, -16.490, -14.294, respectively, all P<0.001). The UW-QOL survey showed that the mean scores of chewing, language and taste functions decreased at 6 months after surgery (53.1±6.7, 53.0±7.7 and 62.2±9.9, respectively), but improved at 24 months after surgery (67.9±3.9, 63.9±2.9 and 68.4±11.1, respectively), with statistically significant difference (t=-16.765, -11.675 and 2.498, respectively, all P<0.001). Conclusion: The application of folded fibula flaps to repair bone defects after sugery of mandibular ameloblastoma can better meet the needs of language and chewing functions and improve the quality of life of patients.
Adolescent ; Adult ; Ameloblastoma/surgery* ; Bone Transplantation ; Female ; Fibula/surgery* ; Free Tissue Flaps ; Humans ; Male ; Mandible/surgery* ; Mandibular Neoplasms/surgery* ; Middle Aged ; Quality of Life ; Reconstructive Surgical Procedures ; Retrospective Studies ; Young Adult

OBJECTIVES: This study aimed to determine the prevalence of odontogenic cysts, tumors, and other lesions among reports in the archives of the Department of Oral and Maxillofacial Surgery at the Faculty of Dentistry affiliated with Kocaeli University collected over a four-year period.MATERIALS AND METHODS: In this retrospective study, patient records from the archive of the Department of Oral and Maxillofacial Surgery from 2014 to 2018 were reviewed. Patient demographic information (age and sex) and lesion location were recorded and analyzed.RESULTS: From a total of 475 files reviewed, odontogenic cyst was confirmed in 340 cases (71.6%), and odontogenic tumor was confirmed in 52 cases (10.9%). Regarding odontogenic cyst type, the most common was radicular cyst (216 cases), followed by dentigerous cyst (77 cases) and odontogenic keratocyst (23 cases). Among odontogenic tumors, the most frequent was odontoma (19 cases), followed by ossifying fibroma (18 cases) and ameloblastoma (9 cases). Giant cell granuloma was also reported in 35 cases.CONCLUSION: The distribution pattern of odontogenic cysts and tumors in our retrospective study is relatively similar to that reported in the literature. Complete clinical reports for final diagnosis of these lesions and routine follow-up examinations are very important for treatment.
Ameloblastoma ; Archives ; Biopsy ; Dentigerous Cyst ; Dentistry ; Diagnosis ; Fibroma, Ossifying ; Follow-Up Studies ; Granuloma, Giant Cell ; Humans ; Jaw Neoplasms ; Odontogenic Cysts ; Odontogenic Tumors ; Odontoma ; Prevalence ; Radicular Cyst ; Retrospective Studies ; Surgery, Oral

Clear cell odontogenic carcinoma (CCOC), a rare tumor in the head and neck region, displays comparable properties with other tumors clinically and pathologically. In consequence, an incorrect diagnosis may be established. A 51-year-old male patient who was admitted to the Department of Oral and Maxillofacial Surgery at Pusan National University Dental Hospital was initially diagnosed with ameloblastoma via incisional biopsy. However, the excised mass of the patient was observed to manifest histopathological characteristics of ameloblastic carcinoma. The lesion was ultimately diagnosed as clear cell odontogenic carcinoma by the Department of Oral Pathology of Pusan National Dental University. Therefore, segmental mandibulectomy and bilateral neck dissection were performed, followed by reconstruction with fibula free flap and reconstruction plate. Concomitant chemotherapy radiotherapy was not necessary. The patient has been followed up, and no recurrence has occurred 6 months after surgery.
Ameloblastoma ; Ameloblasts ; Biopsy ; Busan ; Diagnosis ; Diagnostic Errors ; Drug Therapy ; Fibula ; Free Tissue Flaps ; Head ; Humans ; Male ; Mandibular Osteotomy ; Middle Aged ; Neck ; Neck Dissection ; Pathology, Oral ; Radiotherapy ; Recurrence ; Surgery, Oral

Ameloblastoma is a benign odontogenic epithelial tumor with high recurrence rate and requires extensive resection of the surrounding tissue and reconstruction of defect site. Because of the anatomical limitation of the reconstruction site, prosthetic treatment with implants is the first recommendation. This is a case of prosthetic restoration of the reconstruction site with implant fixed prosthesis in patient who underwent mandibular resection and iliac bone reconstruction due to ameloblastoma. However 14 months after completion of implant prosthesis, adjacent natural tooth erupted unexpectedly, resulting in 1mm infra-occlusion occurred including posterior implant prosthesis and anterior natural teeth. In adults, implant infra-occlusion may occur due to residual growth after placement of the maxillary anterior implant. But this case, hypo-occlusion of molar implant and open bite of anterior natural teeth is occurred due to extrusion of adjacent tooth, is rare. Thus we report the treatment process including orthodontic treatment with intrusion of the posterior tooth, and investigate the causes of sudden, unexpected tooth extrusion.
Adult ; Ameloblastoma ; Humans ; Mandibular Reconstruction ; Molar ; Open Bite ; Orthodontic Extrusion ; Prostheses and Implants ; Recurrence ; Tooth

Ameloblastoma in the tibia is rare. Limb reconstruction after tumor resection is challenging in terms of selection of the operative method. Here, we report a case of radical resection of an ameloblastoma in the mid-distal tibia combined with limb salvage using a three-dimensional (3D)-printed prosthesis replacement, with 1-year follow-up results. After receiving local institutional review board approval, a titanium alloy prosthesis was designed using a computer and manufactured with 3D-printing technology. During the operation, the stem of the prosthesis was inserted closely into the proximal tibial medullary cavity. Then, the metal ankle mortise and the talus were compacted closely. Radiographic results at 1-year follow up showed that the prosthesis was well placed, and no loosening was observed. The Musculoskeletal Tumor Society (MSTS) 93 functional score was 26 points, and the functional recovery percentage was 86.7%. Computer-assisted 3D-printing technology allowed for more volume and structural compatibility of the prosthesis, thereby ensuring a smooth operation and initial prosthetic stabilization. During the follow up, the presence of bone ingrowths on the porous surface of some segments of the prosthesis suggested good outcomes for long-term biological integration between the prosthesis and host bone.
Alloys ; Ameloblastoma ; Ankle ; Ethics Committees, Research ; Extremities ; Follow-Up Studies ; Limb Salvage ; Methods ; Prostheses and Implants ; Talus ; Tibia ; Titanium

BACKGROUND: The mandible is an important structure that is located in the lower third of the face. Large mandibular defects after tumor resection cause loss of its function. This study assessed the outcomes and tumor recurrence after immediate mandibular reconstruction using a free fibula osteocutaneous flap following radical resection of ameloblastoma. METHODS: This is a retrospective non-randomized study of outcomes and tumor recurrence of all patients diagnosed with mandibular ameloblastoma from August 1997 until August 2017 (20 years) requiring free fibula osteocutaneous flap reconstruction at a single institution. The patients were identified through an electronic operative database; subsequently, their medical records and photo documentation were retrieved. RESULTS: Twenty-seven patients were included in this study. Eighteen patients were male, while nine were female. The majority of the patients (48.1%) were in their third decade of life when they were diagnosed with ameloblastoma. All of them underwent radical resection of the tumor with a surgical margin of 2 cm (hemimandibulectomy in cases with a large tumor) and immediate mandibular reconstruction with a free fibula osteocutaneous flap. Two patients required revision of a vascular anastomosis due to venous thrombosis postoperatively, while one patient developed a flap recipient site infection. The flap success rate was 100%. There was no tumor recurrence during a mean follow-up period of 5.6 years. CONCLUSIONS: Mandibular ameloblastoma should be treated with segmental mandibulectomy (with a surgical margin of 2 cm) to reduce the risk of recurrence. Subsequent mandibular and adjacent soft tissue defects should be reconstructed immediately with a free fibula osteocutaneous flap.
Ameloblastoma ; Female ; Fibula ; Follow-Up Studies ; Free Tissue Flaps ; Humans ; Male ; Mandible ; Mandibular Osteotomy ; Mandibular Reconstruction ; Medical Records ; Recurrence ; Retrospective Studies ; Venous Thrombosis

OBJECTIVES: Endoscopic prelacrimal medial maxillectomy (EPMM) was previously reported to treat maxillary inverted papilloma. This study aimed to compare prelacrimal recess approach with the conventional Caldwell-Luc approach (CLA) to remove benign maxillary sinus tumors and to evaluate the usefulness of this approach based on our experience. METHODS: Ten patients who underwent EPMM at our hospital from January 2013 to December 2017 were reviewed. We also reviewed 30 patients who underwent benign maxillary sinus tumor resection via CLA during the same period. From medical records, postoperative pathological results, complications due to surgery, and recurrence rate were evaluated. RESULTS: There were eight inverted papilloma, one ameloblastoma, and one ossifying fibroma in the EPMM group. In the CLA group, all 30 cases were inverted papilloma. There were no cases of failure at gross total removal during surgery, and no recurrences were observed during follow-up in either groups. Mean follow-up period was 13.0 months in CLA group and 10.8 months in EPMM group. Regarding postoperative complications, 11 patients of the CLA group (37%) and three patients of the EPMM group (30%) had numbness around the cheek and upper lip area after surgery (P=0.715). In the CLA group, there were eight patients who had numbness lasting more than 3 months after surgery, and two patients had numbness for more than 1 year. However, facial numbness disappeared within 3 months in all patients in the EPMM group, in which epiphora was not observed. CONCLUSION: EPMM is the effective surgical approach for resecting benign maxillary sinus tumor compared with CLA. Although facial numbness was reported in EPMM, the duration of numbness was shorter than CLA.
Ameloblastoma ; Cheek ; Endoscopy ; Fibroma, Ossifying ; Follow-Up Studies ; Humans ; Hypesthesia ; Lacrimal Apparatus Diseases ; Lip ; Maxillary Sinus Neoplasms ; Maxillary Sinus ; Medical Records ; Papilloma, Inverted ; Postoperative Complications ; Recurrence