Alveolar bone is the thickened ridge of jaw bone that supports teeth.It is subject to constant occlusal force and pathogens invasion,and is therefore under active bone remodeling and immunomodulation.Alveolar bone hol...Alveolar bone is the thickened ridge of jaw bone that supports teeth.It is subject to constant occlusal force and pathogens invasion,and is therefore under active bone remodeling and immunomodulation.Alveolar bone holds a distinct niche from long bone considering their different developmental origin and postnatal remodeling pattern.However,a systematic explanation of alveolar bone at single-cell level is still lacking.Here,we construct a single-cell atlas of mouse mandibular alveolar bone through single-cell RNA sequencing(scRNA-seq).A more active immune microenvironment is identified in alveolar bone,with a higher proportion of mature immune cells than in long bone.Among all immune cell populations,the monocyte/macrophage subpopulation most actively interacts with mesenchymal stem cells(MSCs)subpopulation.Alveolar bone monocytes/macrophages express a higher level of Oncostatin M(Osm)compared to long bone,which promotes osteogenic differentiation and inhibits adipogenic differentiation of MSCs.In summary,our study reveals a unique immune microenvironment of alveolar bone,which may provide a more precise immune-modulatory target for therapeutic treatment of oral diseases.展开更多
The aims of the study were to investigate the incidence of C-shaped root canal systems in mandibular second molars in a native Chinese population using radiography and clinical examination under microscope and to comp...The aims of the study were to investigate the incidence of C-shaped root canal systems in mandibular second molars in a native Chinese population using radiography and clinical examination under microscope and to compare the relative efficacies of these methods. For the recognition of C-shaped root canal system, 1 146 mandibular second molars were selected and examined. Teeth with C-shaped canal systems were categorized by using the radiographic classification criteria and the modified Melton＇s method. C-shaped canals were identified in 397 （34.64%） mandibular second molars by radiography （type I, 31.23%; type II, 38.29%; type III, 30.48%）. Clinical examination showed that 449 （39.18%） cases exhibited C-shaped canal systems （C1, 22.94%; C2, 48.11%; C3a, 15.59%; C3b, 13.36%）. As for the result of the radiographic and clinical combined examination, C-shaped root canals were found in 473 （41.27%） mandibular second molars （C1, 21.78%; C2, 45.67%; C3a, 16.70%; C3b, 15.86%）. The incidence of C-shaped root canal diagnosed by radiographic method was statistically different from that by clinical examination and the combined examination （P〈O.05）. The study indicated a high incidence of C-shaped canal system in a Chinese population. The combination of microscopic and radiographic examination is an effective method in identifying the C-shaped root canal system.展开更多
Kissing molars (KMs) is a condition of occlusal molar surfaces in a single follicular space with roots extending in opposite directions. Here, we have reported a case of KMs in a 58-year-old woman. The patient complai...Kissing molars (KMs) is a condition of occlusal molar surfaces in a single follicular space with roots extending in opposite directions. Here, we have reported a case of KMs in a 58-year-old woman. The patient complained of pain in the right mandibular molar region and was diagnosed with KMs consisting of the right mandibular second and third molars. Because of the patient’s pain having subsided at the time of the visit and her unwillingness to undergo tooth extraction, the patient was followed up. KMs is classified into three classes (I-III) and is either true-KMs or pseudo-KMs and presents with or without cystic variants of dental follicles. The presents as true-KMs class II without a cystic variant. With reference to the literature and based on our analysis, the mean age of patients affected by this specific case of KMs is 31.7 years and unilateral KMs is relatively more common (85.7%). Histopathological findings of dentigerous cysts are more often indicated (42.9%). The treatment policy for KMs should therefore be based on the classification of KMs. Importantly, the focus should be on preserving the first and second molars as much as possible. The treatment approach, such as the employment of surgical removal or orthodontics, should be determined by considering the associated factors such as the crowns, tissues, and age of the patient.展开更多
This study was to describe the use of inverted-L osteotomy of ramus and lilac bone graft for the management of mandibular deficiency in adult patients. From 2008 to 2010, 11 patients （aged 19 to 29 years） with mandi...This study was to describe the use of inverted-L osteotomy of ramus and lilac bone graft for the management of mandibular deficiency in adult patients. From 2008 to 2010, 11 patients （aged 19 to 29 years） with mandibular deficiency underwent intraoral or extraoral inverted-L osteotomy of ramus and lilac crest bone grafting. Data were collected from the patients＇ records, photographs and radiographs. The height and width of the ramus were successfully expanded by inverted-L osteotomy and lilac crest bone grafting with minimal complications in all patients, resulting in significant improvement in occlusion and facial appearance. Our early results showed that the inverted-L osteotomy of ramus and lilac crest bone grafting is safe and effective, and should be considered as a good alternative for the patients with mandibular deficiency.展开更多
The main goal of this study was to introduce a novel three-dimensional procedure to objectively quantify both inner and outer condylar remodelling on preoperative multi-slice computed tomography （MSCT） and postopera...The main goal of this study was to introduce a novel three-dimensional procedure to objectively quantify both inner and outer condylar remodelling on preoperative multi-slice computed tomography （MSCT） and postoperative cone-beam computed tomography （CBCT） images. Second, the reliability and accuracy of this condylar volume quantification method was assessed. The mandibles of 20 patients （11 female and 9 male） who underwent bimaxillary surgery were semi-automatically extracted from MSCT/CBCT scans and rendered in 3D. The resulting condyles were spatially matched by using an anatomical landmark-based registration procedure. A standardized sphere was created around each condyle, and the condylar bone volume within this selected region of interest was automatically calculated. To investigate the reproducibility of the method, inter- and intra-observer reliability was calculated for assessments made by two experienced radiologists twice five months apart in a set of ten randomly selected patients. To test the accuracy of the bone segmentation, the inner and outer bone structures of one dry mandible, scanned according to the clinical set-up, were compared with the gold standard, micro-CT. Thirty-eight condyles showed a significant （P〈O.05） mean bone volume decrease of 26.4%_ 11.4% （502.9 mm3＋ 268.1 mm3）. No significant effects of side, sex or age were found. Good to excellent （ICC〉 0.6） intra- and inter-observer reliability was observed for both MSCT and CBCT. Moreover, the bone segmentation accuracy was less than one voxel （0.4 mm） for MSCT （0.3 mm __. 0.2 mm） and CBCT （0.4 mm _ 0.3 mm）, thus indicating the clinical potential of this method for objective follow-up in pathological condylar resorption.展开更多
基金the National Natural Science Foundation of China(NSFC 81722014,81970913)State Key Laboratory of Oral Diseases(SKLOD202008)West China Hospital of Stomatology(RD-03-202010).
文摘Alveolar bone is the thickened ridge of jaw bone that supports teeth.It is subject to constant occlusal force and pathogens invasion,and is therefore under active bone remodeling and immunomodulation.Alveolar bone holds a distinct niche from long bone considering their different developmental origin and postnatal remodeling pattern.However,a systematic explanation of alveolar bone at single-cell level is still lacking.Here,we construct a single-cell atlas of mouse mandibular alveolar bone through single-cell RNA sequencing(scRNA-seq).A more active immune microenvironment is identified in alveolar bone,with a higher proportion of mature immune cells than in long bone.Among all immune cell populations,the monocyte/macrophage subpopulation most actively interacts with mesenchymal stem cells(MSCs)subpopulation.Alveolar bone monocytes/macrophages express a higher level of Oncostatin M(Osm)compared to long bone,which promotes osteogenic differentiation and inhibits adipogenic differentiation of MSCs.In summary,our study reveals a unique immune microenvironment of alveolar bone,which may provide a more precise immune-modulatory target for therapeutic treatment of oral diseases.
基金supported by the grant from the Independent Innovation Foundation of Shandong University of China (No. 2011JC019)the grant of Science and Technique Development Foundation of Shandong province(2010G0020230)
文摘The aims of the study were to investigate the incidence of C-shaped root canal systems in mandibular second molars in a native Chinese population using radiography and clinical examination under microscope and to compare the relative efficacies of these methods. For the recognition of C-shaped root canal system, 1 146 mandibular second molars were selected and examined. Teeth with C-shaped canal systems were categorized by using the radiographic classification criteria and the modified Melton＇s method. C-shaped canals were identified in 397 （34.64%） mandibular second molars by radiography （type I, 31.23%; type II, 38.29%; type III, 30.48%）. Clinical examination showed that 449 （39.18%） cases exhibited C-shaped canal systems （C1, 22.94%; C2, 48.11%; C3a, 15.59%; C3b, 13.36%）. As for the result of the radiographic and clinical combined examination, C-shaped root canals were found in 473 （41.27%） mandibular second molars （C1, 21.78%; C2, 45.67%; C3a, 16.70%; C3b, 15.86%）. The incidence of C-shaped root canal diagnosed by radiographic method was statistically different from that by clinical examination and the combined examination （P〈O.05）. The study indicated a high incidence of C-shaped canal system in a Chinese population. The combination of microscopic and radiographic examination is an effective method in identifying the C-shaped root canal system.
文摘Kissing molars (KMs) is a condition of occlusal molar surfaces in a single follicular space with roots extending in opposite directions. Here, we have reported a case of KMs in a 58-year-old woman. The patient complained of pain in the right mandibular molar region and was diagnosed with KMs consisting of the right mandibular second and third molars. Because of the patient’s pain having subsided at the time of the visit and her unwillingness to undergo tooth extraction, the patient was followed up. KMs is classified into three classes (I-III) and is either true-KMs or pseudo-KMs and presents with or without cystic variants of dental follicles. The presents as true-KMs class II without a cystic variant. With reference to the literature and based on our analysis, the mean age of patients affected by this specific case of KMs is 31.7 years and unilateral KMs is relatively more common (85.7%). Histopathological findings of dentigerous cysts are more often indicated (42.9%). The treatment policy for KMs should therefore be based on the classification of KMs. Importantly, the focus should be on preserving the first and second molars as much as possible. The treatment approach, such as the employment of surgical removal or orthodontics, should be determined by considering the associated factors such as the crowns, tissues, and age of the patient.
文摘This study was to describe the use of inverted-L osteotomy of ramus and lilac bone graft for the management of mandibular deficiency in adult patients. From 2008 to 2010, 11 patients （aged 19 to 29 years） with mandibular deficiency underwent intraoral or extraoral inverted-L osteotomy of ramus and lilac crest bone grafting. Data were collected from the patients＇ records, photographs and radiographs. The height and width of the ramus were successfully expanded by inverted-L osteotomy and lilac crest bone grafting with minimal complications in all patients, resulting in significant improvement in occlusion and facial appearance. Our early results showed that the inverted-L osteotomy of ramus and lilac crest bone grafting is safe and effective, and should be considered as a good alternative for the patients with mandibular deficiency.
基金the Coordination for the Improvement of Higher Education Personnel(CAPES)programmeScience without borders from Brazilian governmentthe Research Foundation Flanders(FWO)from Flemish government for the fellowship support
文摘The main goal of this study was to introduce a novel three-dimensional procedure to objectively quantify both inner and outer condylar remodelling on preoperative multi-slice computed tomography （MSCT） and postoperative cone-beam computed tomography （CBCT） images. Second, the reliability and accuracy of this condylar volume quantification method was assessed. The mandibles of 20 patients （11 female and 9 male） who underwent bimaxillary surgery were semi-automatically extracted from MSCT/CBCT scans and rendered in 3D. The resulting condyles were spatially matched by using an anatomical landmark-based registration procedure. A standardized sphere was created around each condyle, and the condylar bone volume within this selected region of interest was automatically calculated. To investigate the reproducibility of the method, inter- and intra-observer reliability was calculated for assessments made by two experienced radiologists twice five months apart in a set of ten randomly selected patients. To test the accuracy of the bone segmentation, the inner and outer bone structures of one dry mandible, scanned according to the clinical set-up, were compared with the gold standard, micro-CT. Thirty-eight condyles showed a significant （P〈O.05） mean bone volume decrease of 26.4%_ 11.4% （502.9 mm3＋ 268.1 mm3）. No significant effects of side, sex or age were found. Good to excellent （ICC〉 0.6） intra- and inter-observer reliability was observed for both MSCT and CBCT. Moreover, the bone segmentation accuracy was less than one voxel （0.4 mm） for MSCT （0.3 mm __. 0.2 mm） and CBCT （0.4 mm _ 0.3 mm）, thus indicating the clinical potential of this method for objective follow-up in pathological condylar resorption.
