Implant fracture is rare, but one of the most serious problem in implantation. Treatment of implant fracture can be different according to the extent of the fracture and on the state of the surrounding prosthetic restoration. Maintaining or submerging implant after treatment of peri-implantitis can be useful options for cases of tear-like fracture on the coronal area of an implant.

PURPOSE: The purpose of this study was to utilize cone-beam computed tomography (CBCT) image analysis to obtain anatomical information related to the morphology of the incisive foramen to provide useful data regarding implant placement and clinical procedures such as anesthesia. METHODS: The study included 167 patients who underwent CBCT scans over 20 years. Three components were measured: 1) the anteroposterior and mediolateral diameter of the incisive foramen, 2) the horizontal bone thickness anterior to the incisive foramen, and 3) the vertical bone height coronal to the incisive foramen. All measurements were expressed as mean±standard deviation and were analyzed by a single examiner. RESULTS: The anteroposterior diameter of the incisive foramen was wider than the mediolateral diameter (P<0.001). The diameter of the incisive foramen in patients in whom the central incisors were present was smaller than that in those in whom at least one central incisor was absent, but no statistically significant difference between the groups was observed. The horizontal bone thickness in the patients with central incisors was statistically significantly larger than that in the patients without at least one central incisor (P<0.001). The same pattern was observed with regard to vertical height, but that difference was not statistically significant. CONCLUSIONS The buccal bone thickness anterior to the incisive foramen was significantly decreased after central incisor loss. It is necessary to identify the morphology of the bone and the location of the incisive foramen via CBCT to avoid invasion of the incisive foramen and nasopalatine canal.

Purpose: The purpose of this study was to evaluate severe periodontitis with tooth loss as a modifiable risk factor for Alzheimer dementia (AD), vascular dementia (VaD), and mixed dementia (MD) using the National Health Insurance Service-National Health Screening Retrospective Cohort database with long-term follow-up over 14 years. Methods: Multivariate Cox hazards regression analysis was applied to a longitudinal retrospective database, which was updated in 2018, to evaluate the association between severe periodontitis with few remaining teeth and dementia after adjusting for potential risk factors, including sociodemographic factors and comorbid diseases. Results: Among 514,866 individuals in South Korea, 237,940 (46.2%) participants satisfying the inclusion criteria were selected. A total of 10,115 age- and sex-matched participants with severe periodontitis and 10,115 periodontally healthy participants were randomly selected and evenly assigned. The results showed that the risks of AD (hazard ratio [HR], 1.08), VaD (HR, 1.24), and MD (HR, 1.16) were significantly higher in patients with severe periodontitis with 1–9 remaining teeth after adjustment for sociodemographic factors, anthropomorphic measurements, lifestyle factors, and comorbidities. Conclusions Severe periodontitis with few remaining teeth (1–9) may be considered a modifiable risk factor for the development of AD, VaD, and MD in Korean adults.

PURPOSE: This study investigated the association between health status and tooth loss based on data from the National Health Insurance Service-Health Examinee Cohort in 2002–2015. METHODS: Multivariate Cox proportional hazards regression analyses were applied to a longitudinal retrospective database, which was updated and newly released in 2018, to assess the association between health status and tooth loss while adjusting for potential confounders among sociodemographic and economic factors (sex, age, household income, insurance, and presence of disability), general and oral health status (body mass index [BMI], smoking and drinking status, periodic dental visits and scaling, and brushing before sleep), and comorbid disease (hypertension, diabetes mellitus [DM], and Charlson comorbidity index [CCI]). RESULTS: Among 514,866 participants from a South Korean population, 234,247 (45.5%) participants satisfying the inclusion criteria were analyzed. In the adjusted multivariate analysis, sex, age, household income, insurance, presence of disability, BMI, smoking and drinking status, periodic scaling, tooth brushing before sleep, DM, and CCI showed statistically significant associations with the loss of at least 1 tooth. The risk of experiencing a loss of ≥4 teeth was associated with an increase in age (in those 50–59 years of age: hazard ratio [HR], 1.98; 95% confidence interval [CI], 1.93–2.03; in those 60–69 years of age: HR, 2.93; 95% CI, 2.85–3.02; and in those 70–79 years of age: HR, 2.93; 95%, CI 2.81–3.05), smoking (HR, 1.69; 95% CI, 1.65–1.73), and DM (HR, 1.43; 95% CI, 1.38–1.48). CONCLUSIONS: The results of this study showed that the risk of experiencing tooth loss was related to multiple determinants. DM and smoking were especially significantly associated with tooth loss.
Adult ; Cohort Studies ; Comorbidity ; Dental Caries ; Diabetes Mellitus ; Drinking ; Family Characteristics ; Humans ; Insurance ; Multivariate Analysis ; National Health Programs ; Oral Health ; Periodontal Diseases ; Retrospective Studies ; Smoke ; Smoking ; Tooth Extraction ; Tooth Loss ; Tooth

This article describes cases of applying non-surgical treatment including scaling and root planing, occlusal adjustment and tooth splinting of periodontally compromised lower anterior incisors Clinical and radiographic evaluations were performed over a 1–3-year period. All clinical parameters and radiographic bone levels improved in both cases. Dramatic regeneration of alveolar bone and lamina dura were observed on radiographic images, and no specific complications occurred during the follow-up period. Within the limitations of this study, these cases demonstrated the possibility of tooth rescue through non-surgical treatment and splinting of periodontally compromised teeth typically considered for extraction.
Bone Regeneration ; Dental Occlusion, Traumatic ; Follow-Up Studies ; Incisor ; Occlusal Adjustment ; Periodontal Splints ; Regeneration ; Root Planing ; Splints ; Tooth

PURPOSE: The aim of the current study was to develop a computer-assisted detection system based on a deep convolutional neural network (CNN) algorithm and to evaluate the potential usefulness and accuracy of this system for the diagnosis and prediction of periodontally compromised teeth (PCT). METHODS: Combining pretrained deep CNN architecture and a self-trained network, periapical radiographic images were used to determine the optimal CNN algorithm and weights. The diagnostic and predictive accuracy, sensitivity, specificity, positive predictive value, negative predictive value, receiver operating characteristic (ROC) curve, area under the ROC curve, confusion matrix, and 95% confidence intervals (CIs) were calculated using our deep CNN algorithm, based on a Keras framework in Python. RESULTS: The periapical radiographic dataset was split into training (n=1,044), validation (n=348), and test (n=348) datasets. With the deep learning algorithm, the diagnostic accuracy for PCT was 81.0% for premolars and 76.7% for molars. Using 64 premolars and 64 molars that were clinically diagnosed as severe PCT, the accuracy of predicting extraction was 82.8% (95% CI, 70.1%–91.2%) for premolars and 73.4% (95% CI, 59.9%–84.0%) for molars. CONCLUSIONS: We demonstrated that the deep CNN algorithm was useful for assessing the diagnosis and predictability of PCT. Therefore, with further optimization of the PCT dataset and improvements in the algorithm, a computer-aided detection system can be expected to become an effective and efficient method of diagnosing and predicting PCT.
Area Under Curve ; Artificial Intelligence ; Bicuspid ; Boidae ; Dataset ; Diagnosis ; Learning ; Machine Learning ; Methods ; Molar ; Periodontal Diseases ; ROC Curve ; Sensitivity and Specificity ; Supervised Machine Learning ; Tooth ; Weights and Measures

PURPOSE: The aims of the present study were to quantitatively assess graft height changes after sinus lift procedures and to analyze the factors that influenced graft height changes, including the residual bone height before surgery, surgical approach, and tooth type. METHODS: A total of 39 maxillary posterior implants placed during a simultaneous sinus lift procedure were evaluated. Panoramic radiographs of all patients were taken immediately after implant installation and at 3 months, 6 months, 1 year, 2 years, and 3 years. To analyze graft height changes over time, we measured the distance between the implant platform and the base of the grafted sinus floor at 3 locations. The radiographs were analyzed by a single examiner. RESULTS: Graft height tended to decrease over time, and a statistically significant difference was observed at 2 years compared to baseline (P < 0.05). There was no statistically significant difference in graft height change according to the surgical approach or tooth type. For residual bone height, a statistically significant difference in graft height change was found between those with 4–7 mm of residual bone height and those with ≥7 mm (P < 0.05). CONCLUSIONS: Graft height after sinus lift procedures significantly decreased at 2 years compared to baseline after sinus augmentation. Further studies should be done with controlled variables, and prospective studies with 3-dimensional images are needed to clarify the factors that influence graft height changes.
Alveolar Bone Grafting ; Dental Implants ; Humans ; Maxillary Sinus ; Prospective Studies ; Sinus Floor Augmentation ; Tooth ; Transplants

PURPOSE: To retrospectively evaluate the relationship between the vertical position of the implant-abutment interface and marginal bone loss over 3 years using radiological analysis. METHODS: In total, 286 implant surfaces of 143 implants from 61 patients were analyzed. Panoramic radiographic images were taken immediately after implant installation and at 6, 12, and 36 months after loading. The implants were classified into 3 groups based on the vertical position of the implant-abutment interface: group A (above bone level), group B (at bone level), and group C (below bone level). The radiographs were analyzed by a single examiner. RESULTS: Changes in marginal bone levels of 0.99±1.45, 1.13±0.91, and 1.76±0.78 mm were observed at 36 months after loading in groups A, B, and C, respectively, and bone loss was significantly greater in group C than in groups A and B. CONCLUSIONS: The vertical position of the implant-abutment interface may affect marginal bone level change. Marginal bone loss was significantly greater in cases where the implant-abutment interface was positioned below the marginal bone. Further long-term study is required to validate our results.
Alveolar Bone Loss ; Bone-Implant Interface ; Dental Implants ; Humans ; Retrospective Studies*

PURPOSE: This study evaluated trends in tooth extraction due to acute and chronic periodontal disease (PD) using data from the National Health Insurance Service-National Sample Cohort for 2002–2013. METHODS: A random sample of 1,025,340 individuals was selected as a representative sample of the population, and a database (DB) of diagnostic and prescription codes was followed up for 12 years. We used multivariate logistic regression analysis to assess the incidence of total extraction (TE), extraction due to periodontal disease (EPD), and immediate extraction due to periodontal disease (IEPD) according to sociodemographic factors (sex, age, household income, health status, and area of residence). RESULTS: The incidence of tooth extraction was found to be increasing, and at a higher rate for TE in PD patients. In 2002, 50.6% of cases of TE were caused by PD, and this increased to 70.8% in 2013, while the number of cases of IEPD increased from 42.8% to 54.9% over the same period. The incidence rates of extraction due to acute and chronic PD increased monotonically. We found that the incidence rates of TE, EPD, and IEPD were all 2-fold higher among patients with high income levels and those who were not beneficiaries of health insurance. CONCLUSIONS: The rates of TE, EPD, and IEPD have been steadily increasing despite dental healthcare policies to expand public health insurance coverage, increasing the accessibility of dental clinics. Moreover, the effects of these policies were found to vary with both income and education levels. Consistent patient follow-up is required to observe changes in trends regarding tooth extraction according to changes in dental healthcare policies, and meticulous studies of such changes will ensure optimal policy reviews and revisions.
Cohort Studies* ; Delivery of Health Care ; Dental Clinics ; Education ; Family Characteristics ; Follow-Up Studies ; Humans ; Incidence* ; Insurance Coverage ; Insurance, Health ; Korea* ; Logistic Models ; National Health Programs ; Periodontal Diseases* ; Prescriptions ; Public Health ; Retrospective Studies ; Tooth Extraction* ; Tooth Loss ; Tooth*

PURPOSE: To investigate the healing pattern of the mucous membrane after tooth extraction necessitated by periodontal disease in the maxillary sinus. METHODS: One hundred and three patients with 119 maxillary sinuses were investigated. Before implant placement, cone-beam computed tomography (CT) scanning was performed. The causes of extraction, the time elapsed since extraction, smoking, periodontal disease in adjacent teeth, and gender were recorded. In addition, the thickness of the mucous membrane of the maxillary sinus and the height of residual alveolar bone at the extracted area were calculated from CT images. RESULTS: The thickness of the mucous membrane in the periodontal disease group (3.05+/-2.71 mm) was greater than that of the pulp disease group (1.92+/-1.78 mm) and the tooth fracture group (1.35+/-0.55 mm; P<0.05). The causes of extraction, the time elapsed since extraction, and gender had relationships with a thickening of the mucous membrane of the maxillary sinus (P<0.05). In contrast, the height of the residual alveolar bone at the extracted area, periodontal disease in adjacent teeth, and smoking did not show any relation to the thickening of the mucous membrane of the maxillary sinus. CONCLUSIONS: The present study revealed distinct differences in healing patterns according to the causes of extraction in the maxillary sinus, especially periodontal disease, which resulted in more severe thickening of the mucous membrane.
Cone-Beam Computed Tomography ; Humans ; Maxillary Sinus ; Mucous Membrane ; Periodontal Diseases ; Smoke ; Smoking ; Tooth ; Tooth Extraction ; Tooth Fractures