Cooperation between physicians and dentists for osteonecrosis of the jaw: a 2022 Japanese survey.

INTRODUCTION: A 2015 survey of the Japan Osteoporosis Society (JOS) on medication-related osteonecrosis of the jaw (MRONJ) revealed that cooperation between physicians and dentists was poor. Discontinuation of antiresorptive agents before tooth extraction was found to increase adverse events without preventing MRONJ. We compared this 2015 survey with a new survey conducted in 2022 to investigate cooperation between physicians and dentists for MRONJ. MATERIALS AND METHODS: A web-based structured questionnaire including 13 key queries was sent to 3813 physicians who were members of JOS, and 1227 (32.2%) responses were received. RESULTS: Of the 1227 respondents, 909 (74.1%) had complied with a discontinuation request from a dentist before tooth extraction, although 25.4% of medications were not related to the incidence of MRONJ. Of these, 177 respondents reported 252 adverse events including 10 (1.3%) cases of MRONJ. The prevalence of fractures increased from 4.8% in 2015 to 8.2% in 2022. The rates of respondents who requested oral health care by a dentist before antiresorptive agent therapy and reported cooperation between physicians and dentists were 72.7% and 42.4% in 2022 compared with 32.9% and 24.8% in 2015, respectively. The rates of cooperation among the 47 prefectures in Japan were significantly different, ranging from 10.0 to 83.3% (p = 0.02). CONCLUSION: This study confirmed increased cooperation between physicians and dentists for MRONJ in Japan. However, a more equal distribution of cooperation across Japan is necessary to optimally manage MRONJ. Discontinuation of antiresorptive agents is no longer necessary because fractures during discontinuation continue to increase in Japan.

Reliability of early stage symptoms/clinical findings of osteonecrosis of the jaw: Japanese Osteoporosis Intervention Trial-05 (JOINT-05).

INTRODUCTION: To investigate the differences in the incidence rates of suspected stage 0/1 osteonecrosis of the jaw (ONJ) and incidence risk of relevant clinical findings of suspected stage 0 ONJ between patients treated with sequential therapy comprising weekly teriparatide for 72 weeks followed by alendronate for 48 weeks vs. those who received monotherapy with alendronate for 120 weeks. MATERIALS AND METHODS: Suspected stage 0/1 ONJ was defined by non-specific symptoms. Tooth mobility and periodontal symptoms (gingival bleeding, swelling, and/or pain) were selected as clinical findings of suspected stage 0 ONJ. Poisson regression models were applied to calculate the incidence rate ratios of suspected stage 0/1 between the teriparatide group (TG) and alendronate group (AG). Generalized linear models were used to calculate the risk ratios of clinical findings between groups. RESULTS: Two hundred and sixty-one participants in the TG and 344 in the AG answered a structured questionnaire on oral health and were included in this study. There were no significant differences between the groups in the incidence rate of suspected stage 0/1 ONJ at both 72 and 120 weeks. The risk ratio of the TG to AG for tooth mobility was 0.34 (95% confidence interval [CI] 0.13-0.88, p = 0.02) at 72 weeks and 0.90 (95% CI 0.40-2.03, p = 0.83) at 120 weeks. The incidence rate of tooth mobility related to periodontal symptoms decreased in the TG and increased in the AG during the study. CONCLUSION: Tooth mobility accompanied by clinical periodontal symptoms may be a useful early sign of stage 0 ONJ.

Association of pentosidine and homocysteine levels with number of teeth present in Japanese postmenopausal women.

INTRODUCTION: Little is known about whether substances inducing tissue protein degeneration in the oral cavity are associated with the number of teeth present in postmenopausal women. We sought to investigate the association of urinary pentosidine and serum homocysteine levels with the number of teeth and subsequent tooth loss in Japanese postmenopausal women. MATERIALS AND METHODS: Among participants in the Nagano Cohort Study, 785 postmenopausal women (mean age, 68.1 years) participated in the present study. The number of teeth was re-counted at the time of follow-up in 610 women. Poisson regression analysis was used to investigate differences in the number of teeth among quartiles of pentosidine or homocysteine, adjusting for covariates that correlated with the number of teeth. A Cox proportional hazard model was used to evaluate the association of subsequent tooth loss with pentosidine or homocysteine levels. RESULTS: Pentosidine quartiles were not associated with the number of teeth at baseline. Participants in the highest homocysteine quartile had significantly fewer teeth at baseline than those in the third and lowest quartiles (p < 0.001 for both). Those in the second quartile had fewer teeth than those in the third (p = 0.001) and lowest (p < 0.001) quartiles. An increased risk of tooth loss during follow-up was significantly associated with higher urinary pentosidine (hazard ratio = 1.073 for 10 pmol/mgCre; p = 0.001). CONCLUSION: Postmenopausal women with higher homocysteine levels had fewer teeth at baseline. A higher pentosidine concentration increased the risk of subsequent tooth loss. High pentosidine or homocysteine concentrations may be associated with tooth loss in postmenopausal women.

Fragility fractures and delayed wound healing after tooth extraction in Japanese older adults.

INTRODUCTION: Fragility fractures can cause delayed wound healing after tooth extraction, which contributes to an increased risk of osteomyelitis of the jaw. We evaluated whether a history of fragility fracture was associated with increased risk of delayed wound healing after tooth extraction in older adults in Japan. MATERIALS AND METHODS: Of 5352 people aged 50-89 years in the 2014 basic resident registry of the town of Obuse, the present study included 376 subjects (190 men and 186 women) who completed a structured questionnaire and measurement of the bone mineral densities (BMDs) of the bilateral femoral neck. Delayed wound healing after tooth extraction was self-reported. Fragility fractures were confirmed via examination of hospital medical records. Logistic regression analyses adjusted for age and gender were used to evaluate association of clinical variables with delayed would healing after tooth extractions. Odds ratios (ORs) and the 95% confidence intervals (CIs) of all possible associated variables for the presence of delayed wound healing were calculated. RESULTS: Subjects with a history of fragility fractures had a significantly higher risk of delayed wound healing compared with those without previous fragility fractures (OR 2.68; 95% CI 1.11-6.46, p = 0.028). This association still remained after adjusted for all other variables (OR 2.70; 95% CI 1.10-6.60, p = 0.030). Delayed wound healing was not significantly associated with the BMD of the femoral neck. CONCLUSIONS: History of fragility fracture may be associated with increased risk of delayed wound healing after tooth extraction in Japanese men and women aged 50-89 years.

Incidence of osteonecrosis of the jaw in Japanese osteoporosis patients taking minodronic acid.

Osteonecrosis of the jaw (ONJ) associated with bisphosphonate therapy is a rare but severe side effect in osteoporosis patients. Recently, the number of osteoporosis patients with ONJ has dramatically increased in Japan. This has contributed to an increase in the number of patients avoiding extractions. However, there has been no prospective study providing definitive incidence data for ONJ in Japanese patients. The purpose of this study was to elucidate the true as well as suspected incidence of ONJ. A total of 3229 subjects (1612 subjects in the minodronic acid group and 1617 subjects in the raloxifene group) in the Japanese Osteoporosis Intervention Trial protocol number 4 participated in this study. ONJ was diagnosed by experienced dentists. Suspected Stage 0 and 1 (bone exposure of the jaw) ONJ was assessed by a structured questionnaire at baseline and at 6, 12, 18, and 24 months. No established ONJ cases were diagnosed during the study. The incidence of suspected Stage 0 and/or Stage 1 ONJ was 6.14 per 1000 patient-years in the minodronic acid group and 3.38 per 1000 patient-years in the raloxifene group [hazard ratio (95% confidence interval) = 1.82 (0.84-3.93), P = 0.13]. Approximately 50-60% of bone exposures that appeared during the study had disappeared at the next observation. Although the subjects in this study may have developed a greater interest in the health of the oral cavity, the incidence of ONJ after minodronic acid treatment would be lower than the expected incident rate.

Study design of multi-center, open-label randomized controlled, head-to-head trial comparing minodronic acid and raloxifene: Japanese Osteoporosis Intervention Trial (JOINT)-04.

We planned to conduct multi-center, open-labeled, blinded-endpoints, head-to-head randomized trial of minodronate and raloxifene to compare incidences of vertebral and non-vertebral fractures. The study is the Japanese Osteoporosis Intervention Trial protocol number 4 (JOINT-4). Here, we present the pre-fixed study design. The inclusion criteria are ambulatory older women with osteoporosis, aged > 60 years, and without pre-specified risk factors for secondary osteoporosis and dementia. The subjects who meet selection criteria will be randomly allocated to the raloxifene (60 mg/day) or minodronate (1 mg/day or 50 mg/4 weeks) groups using the central registry. The co-primary endpoints are osteoporotic (vertebral, humeral, femoral, and radial), vertebral, and major osteoporotic (clinical vertebral, humeral, femoral, and radial) fractures. Furthermore, we plan to use the Hochberg procedure to preserve an overall type 1 error rate. In addition, changes in bone mineral density (BMD), hip-structure analysis (HSA) variables, height, bone turnover markers, serum cholesterol and triglyceride concentrations, dental health questionnaire, fall frequency, fall risk index, nursing care level, physical function, quality of life (QOL), and safety profiles were assessed as secondary endpoints. To detect 24% reduction of major osteoporotic fractures with 80% power and a two-sided significance level of 5% with a 2-year observation period, 1734 patients/treatment arm would be required. Subgroup analysis stratified to the following factors age, body mass index, BMD, 25-hydroxyvitamin D concentration, estimated glomerular filtration rate (eGFR), prevalent vertebral fracture number, hypertension status, and diabetes mellitus is pre-specified. The protocol is registered in the trial registry system, and the trial identification number is UMIN000005433.

Antiresorptive agent-related osteonecrosis of the jaw: Position Paper 2017 of the Japanese Allied Committee on Osteonecrosis of the Jaw.

Antiresorptive agent-related osteonecrosis of the jaw (ARONJ) is an intractable, though rare, complication in cancer patients with bone metastases and patients with osteoporosis who are treated with antiresorptive agents, including bisphosphonates and denosumab. Despite the more than 10 years that have passed since the first cases of bisphosphonate-related osteonecrosis of the jaw (BRONJ) were reported, our understanding of the epidemiology and pathophysiology of ARONJ remains limited, and data supported by evidence-based medicine are still sparse. However, the diagnosis and staging of ARONJ, identification of risk factors, and development of preventive and therapeutic approaches have advanced significantly over the past decade. The Position Paper 2017 is an updated version of the Position Paper 2010 of the Japanese Allied Committee on Osteonecrosis of the Jaw, which now comprises six Japanese academic societies. The Position Paper 2017 describes a new diagnostic definition for ARONJ, as proposed by the American Association of Oral and Maxillofacial Surgeons (AAOMS), summarizes our current understanding of the pathophysiology of ARONJ based on a literature search, and suggests methods for physicians and dentists/oral surgeons to manage the disease. In addition, the appropriateness of discontinuing antiresorptive medications (drug holiday) before, during, and after invasive dental treatments is discussed extensively. More importantly, the manuscript also proposes, for the first time, the importance of interactive communication and cooperation between physicians and dentists/oral surgeons for the successful treatment of ARONJ. The Position Paper 2017 is intended to serve as a guide for improving the management of ARONJ patients in Japan.

Case-Based Review of Osteonecrosis of the Jaw (ONJ) and Application of the International Recommendations for Management From the International Task Force on ONJ.

Osteonecrosis of the jaw (ONJ) has been associated with antiresorptive therapy in both oncology and osteoporosis patients. This debilitating condition is very rare and advances in diagnosis and management may now effectively reduce the risk of its development and offer valuable treatment options for affected patients. This paper provides a case-based review of ONJ and application of the International Task Force on ONJ (referred to as the "Task Force") recommendations for the diagnosis and management of ONJ. The Task Force was supported by 14 international societies and achieved consensus from representatives of these multidisciplinary societies on key issues pertaining to the diagnosis and management of ONJ. The frequency of ONJ in oncology patients receiving oncology doses of bisphosphonate (BP) or denosumab is estimated at 1%-15%, and the frequency in the osteoporosis patient population receiving much lower doses of BP or denosumab is estimated at 0.001%-0.01%. Although the diagnosis of ONJ is primarily clinical, imaging may be helpful in confirming the diagnosis and staging. In those with multiple risk factors for ONJ for whom major invasive oral surgery is being planned, interruption of BP or denosumab therapy (in cancer patients) is advised, if possible, before surgery, until the surgical site heals. Major oral surgery in this context could include multiple extractions if surgical extractions are required, not simple forceps extractions. ONJ development may be reduced by optimizing oral hygiene and postoperatively using topical and systemic antibiotics as appropriate. Periodontal disease should be managed before starting oncology doses of BP or denosumab. Local debridement may be successful in disease unresponsive to conservative therapy. Successful surgical intervention has been reported in those with stage 3 disease; less severe disease is best managed conservatively. Teriparatide may be helpful in healing ONJ lesions and may be considered in osteoporosis patients at a high fracture risk in the absence of contraindications. Resumption of BP or denosumab therapy following healing of ONJ lesions is recommended, and there have not been reports of subsequent local recurrence.

[Bisphosphonate and osteonecrosis of the jaw.]

Marx first reported avascular osteonecrosis of the jaw(ONJ)in oncology patients who had used high dose intravenous bisphosphonate(BP)at 2003. Ruggiero et al. also reported BP-related ONJ in osteoporosis patients who had used low dose oral BP at 2004. Since tooth extraction was considered one of risk factors for ONJ, discontinuation of BP before and after tooth extraction was recommended as one of preventive strategy for ONJ, especially in osteoporosis patients. However, recent studies showed that discontinuation of BP did not prevent ONJ, but increased the occurrence of adverse events such as fracture. Best strategies for preventing ONJ include elimination of oral disease such as periodontal and/or periapical diseases prior to initiation of BP, as well as maintenance of good oral hygiene. Development of a strategy for sharing information about ONJ among physicians, dentists, and patients is required to reduce the incidence of ONJ.

Impact of Osteonecrosis of the Jaw on Osteoporosis Treatment in Japan: Results of a Questionnaire-Based Survey by the Adequate Treatment of Osteoporosis (A-TOP) Research Group.

Dentists request a discontinuation of antiresorptive agents, such as bisphosphonate, before and after tooth extractions to prevent osteonecrosis of the jaw (ONJ). However, little is known about how this affects ONJ and osteoporosis treatment and how medical professionals and dentists cooperate to treat ONJ in patients with osteoporosis. This study aimed to clarify the impact of ONJ on osteoporosis treatment in Japan. A structured questionnaire including 14 key clinical queries was sent to 488 medical professionals as part of the Japanese Osteoporosis Intervention Trial (JOINT)-04, and 206 responses were received. A total of 173 respondents had received discontinuation requests from dentists. Of these, 28 respondents experienced 30 adverse events including ten fractures and one incidence of ONJ. The respondents who refused discontinuation requests observed no cases of ONJ. Approximately 16 % of respondents had patients who discontinued osteoporosis treatment, following a requested drug discontinuation, after tooth extraction. Dentists requested discontinuations for many medications that were not associated with the incidence of ONJ. Approximately 76 % of respondents had never requested oral health care from dentists before osteoporosis treatment and 72 % reported no cooperation between dentists and medical professionals in their region. Our results suggest that drug discontinuation may increase adverse events and disturb osteoporosis treatment without completely preventing ONJ. Currently, both medical professionals and dentists in Japan still continue to recommend their own treatment position. A forum to share information about ONJ among medical professionals, dentists, and patients is required.

Poor oral health, that is, decreased frequency of tooth brushing, is associated with endothelial dysfunction.

BACKGROUND: Poor oral health is an independent predictor of cardiovascular outcome. Endothelial dysfunction is the initial step of atherosclerosis, resulting in cardiovascular outcomes; but there is no information on the association between oral health and endothelial function. The purpose of this study was to determine the relationships between oral health and endothelial function. METHODS AND RESULTS: A total of 190 subjects who underwent health examinations (mean age, 57±18 years), including patients with cardiovascular disease, completed a questionnaire on oral health and frequency of tooth brushing, and underwent measurement of vascular function, flow-mediated vasodilation (FMD) and nitroglycerine-induced vasodilation. The subjects were divided into 2 groups according to frequency of tooth brushing (≥twice/day and

Association between oral health and the risk of lacunar infarction in Japanese adults.

BACKGROUND: Poor oral health is associated with an increased risk of dementia in the elderly. One possible pathway linking these two phenomena is lacunar infarction, a potential cause of dementia. An association between poor oral health and an increased risk of ischaemic stroke has been recognised through the oral infection-inflammation pathway. However, little is known about whether poor oral health is associated with the progression of lacunar infarction. OBJECTIVE: We examined the association between variables related to oral health and lacunar infarction, as detected by magnetic resonance imaging (MRI). METHODS: A total of 110 subjects (52 men, 58 women), aged 27-76 years, who visited our periodontology clinic participated in this study. The subjects underwent dental radiography, periodontal examinations and brain MRI. One experienced specialist in cardiovascular disease and one experienced neurosurgeon determined the number of lacunar infarctions on brain MRI. Periodontologists performed clinical periodontal examinations. Variables related to oral health were determined from the radiographs by an oral radiologist. Information on the subjects' lifestyles and disease histories were obtained using a structured questionnaire and confirmed by clinical records. Adjacent categories logit regression analysis with backward elimination was used to determine variables associated with three groups based on the number of lacunar infarctions. RESULTS: Of the 110 subjects, 61 had lacunar infarctions. Nineteen had multiple (≥7) lesions. Aging (p = 0.0004), increased time spent in physical activity per day (p = 0.042), the presence of hypertension (p = 0.006), the absence of hyperlipidaemia (p = 0.045), the presence of diabetes mellitus (p = 0.025) and low alveolar bone height (p = 0.026) were significantly associated with an increased number of lacunar infarctions in the final regression model. The significance of hyperlipidaemia and alveolar bone height disappeared in an unadjusted model. An increased pocket depth, which indicates current periodontal disease progression, tended to be associated with an increased number of lacunar infarctions (p = 0.058). This tendency did not disappear in an unadjusted model. CONCLUSION: Our results suggest that lacunar infarction may be associated with current periodontal disease in Japanese adults.

Effects of open mouth and rubber dam on upper airway patency and breathing.

OBJECTIVES: Rubber dams increase the quality and safety of dental treatment. However, the condition of a rubber dam over an open mouth may also obstruct the route for respiration. We tested whether an open mouth with or without a rubber dam would affect upper airway patency and breathing pattern. MATERIALS AND METHODS: Twenty young healthy volunteers were imaged with a magnetic resonance (MR) system under three conditions: mouth closed, mouth open, and rubber dam with mouth open. Respiration was concurrently monitored with plethysmography. MRI slices of the upper airway were obtained at 5-mm thicknesses, and the size of the cross-sectional area of the upper airway was measured by image analysis software. Respiratory cycle duration and tidal volume were also measured with digital signal analysis software. RESULTS: The volume of the upper airway became significantly decreased with the mouth open. Analysis of each cross-sectional area of the upper airway revealed that while the oropharyngeal area was significantly narrower with an open mouth, the retropalatal and hypopharyngeal areas were not affected. Placing a rubber dam had no additional influence on upper airway patency but was seen to significantly shorten mean respiratory duration and decrease tidal volume. CONCLUSIONS: Open mouth position plays the largest role in decreased upper airway patency, and open mouth position with a rubber dam may further disrupt breathing pattern. CLINICAL RELEVANCE: Breathing pattern may become deteriorated by airway obstruction during dental treatments requiring a rubber dam.

Morphological changes in the temporomandibular joint before and after sagittal splitting ramus osteotomy of the mandible for skeletal mandibular protrusion.

Changes of temporomandibular joint (TMJ) morphology were analyzed in 21 patients with mandibular protrusion corrected using bilateral sagittal split ramus osteotomy (SSRO) and mini-plate fixation with TMJ cephalometric laminographs. The condylar pass angle, eminence to the FH plane angle, and total height of fossa and lower height of fossa in both left and right sides, significantly decreased after surgery. The width of the condyle, in both left and right sides, significantly increased after treatment. However, in the joint spaces, there were no significant differences before and after treatment. The amount of change in the eminence to the FH plane angle, total height of fossa and lower height of fossa, before and after surgery, showed significant positive correlations with that of SNB, before and after surgery. These results suggest that adaptive bone remodeling of the TMJ might occur due to the correction of occlusion and craniofacial morphology by SSRO in patients with mandibular protrusion.

Increased Risk of Tooth Loss in Postmenopausal Women With Prevalent Vertebral Fractures: An Observational Study.

The association between prevalent fractures and tooth loss in postmenopausal women remains unclear. Herein, we investigated the association between prevalent vertebral and nonvertebral fractures, the number of teeth present at baseline, and the number of teeth lost during follow-up in postmenopausal Japanese women. This cross-sectional study enrolled 843 participants (mean age 68.3 years). The number of teeth at follow-up was evaluated in 655 women in this longitudinal study. The participants were divided into four groups according to their prevalent fracture status: no fractures, vertebral fractures alone, nonvertebral fractures alone, and both fracture types. After adjusting for covariates, Poisson regression analyses were performed to investigate differences in the number of teeth at baseline and that lost during the follow-up period among the four groups. Participants with prevalent vertebral fractures alone had significantly fewer teeth at baseline than those in participants without fractures or nonvertebral fractures alone (p < 0.001 for both). Furthermore, they lost more teeth during the follow-up period than did those with no fractures (p = 0.021) and tended to lose more teeth than did those with nonvertebral fractures alone or both prevalent fracture types. We observed no significant difference in the number of teeth lost between the participants with nonvertebral fractures alone and those with no fractures. Postmenopausal women with prevalent vertebral fractures may be at a higher risk of tooth loss. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Association between clinical manifestations of occlusal trauma and magnetic resonance imaging findings of periodontal ligament space.

OBJECTIVES: The purpose of this study was to evaluate the association between clinical manifestations of occlusal trauma of the teeth and maximum signal intensity of periodontal ligament space on MRI. METHODS: 20 subjects (males: 9, females: 11, mean age: 35.9 ± 14.0 years, range: 22-65 years) participated in this study. Subjective symptoms of bruxism, tooth mobility, fremitus, occlusal contact area, occlusal force, widening of the periodontal ligament space, and thickening of the lamina dura were defined as clinical manifestations of occlusal trauma. The total number of clinical manifestations was used to evaluate the degree of clinical occlusal trauma, with a score of 7 indicating the highest degree of occlusal trauma. The maximum signal intensity in the periodontal ligament space was evaluated by a specific T2 weighted MRI sequence: IDEAL image. RESULTS: Spearman's rank correlation between the total clinical occlusal trauma score and maximum signal intensity in the periodontal ligament space was 0.529 for all teeth, 0.517 for anterior teeth, and 0.396 for molar teeth (p < 0.001 for all). CONCLUSIONS: A significant correlation between the degree of occlusal trauma and the signal intensity of the periodontal ligament space suggests a new potential MRI-based method for objectively determining occlusal trauma.

Diagnosis of osteoporosis from dental panoramic radiographs using the support vector machine method in a computer-aided system.

BACKGROUND: Early diagnosis of osteoporosis can potentially decrease the risk of fractures and improve the quality of life. Detection of thin inferior cortices of the mandible on dental panoramic radiographs could be useful for identifying postmenopausal women with low bone mineral density (BMD) or osteoporosis. The aim of our study was to assess the diagnostic efficacy of using kernel-based support vector machine (SVM) learning regarding the cortical width of the mandible on dental panoramic radiographs to identify postmenopausal women with low BMD. METHODS: We employed our newly adopted SVM method for continuous measurement of the cortical width of the mandible on dental panoramic radiographs to identify women with low BMD or osteoporosis. The original X-ray image was enhanced, cortical boundaries were determined, distances among the upper and lower boundaries were evaluated and discrimination was performed by a radial basis function. We evaluated the diagnostic efficacy of this newly developed method for identifying women with low BMD (BMD T-score of -1.0 or less) at the lumbar spine and femoral neck in 100 postmenopausal women (≥50 years old) with no previous diagnosis of osteoporosis. Sixty women were used for system training, and 40 were used in testing. RESULTS: The sensitivity and specificity using RBF kernel-SVM method for identifying women with low BMD were 90.9% [95% confidence interval (CI), 85.3-96.5] and 83.8% (95% CI, 76.6-91.0), respectively at the lumbar spine and 90.0% (95% CI, 84.1-95.9) and 69.1% (95% CI, 60.1-78.6), respectively at the femoral neck. The sensitivity and specificity for identifying women with low BMD at either the lumbar spine or femoral neck were 90.6% (95% CI, 92.0-100) and 80.9% (95% CI, 71.0-86.9), respectively. CONCLUSION: Our results suggest that the newly developed system with the SVM method would be useful for identifying postmenopausal women with low skeletal BMD.

Osteoporosis screening support system from panoramic radiographs using deep learning by convolutional neural network.

OBJECTIVES: This study was performed to develop computer-aided screening systems that could predict osteoporosis. The systems were constructed using panoramic radiographs of women aged ≥ 50 years through three types of deep convolutional neural networks (CNNs): Alexnet, VGG-16, and GoogLeNet; the performances of the constructed systems were evaluated. METHODS: One oral radiologist classified 1500 panoramic radiographs into three types. In C1, the endosteal margin of the cortex was smooth and sharp, whereas porosities were observed in C2 and C3. The risks of osteoporosis were higher in C2 and C3 than in C1; C3 had the highest risk. This information was included with the images as training data; three CNNs were transfer trained. Using each trained CNN, the diagnostic accuracy was assessed using panoramic radiographs and bone mineral density inspection findings in the lumbar spine and femoral neck of 100 additional patients. RESULTS: All CNNs exhibited relatively good agreement with the oral radiologist's judgement (86.0%-90.7%). The predictive results of the three systems for osteoporosis of the lumbar spine showed sensitivities of 78.3%-82.6%, specificities of 71.4%-79.2%, and accuracies of 74.0%-79.0%. The predictive results for osteoporosis of the femoral neck showed sensitivities of 80.0%-86.7%, specificities of 67.1%-74.1%, and accuracies of 70.0%-75.0%. CONCLUSIONS: The constructed systems were generally more accurate than the previously developed conventional system. The new systems may facilitate osteoporosis prediction and prevent subsequent fractures by encouraging patients with suspected osteoporosis to undergo further inspections (e.g., dual-energy X-ray absorptiometry) and treatment.