Digital orthopantomograms in osteoporosis detection: mandibular density and mandibular radiographic indices as skeletal BMD predictors

Radiomorphometric indices of the mandible as indicators of decreased bone mineral density and osteoporosis - meta-analysis and systematic review

This review aims to evaluate the accuracy of various mandibular radiomorphometric indices in comparison with DEXA BMD measurements in the diagnosis of osteopenia and osteoporosis based on a meta-analysis of the sensitivity and specificity of the indices. PRISMA statement was followed. The materials for analysis were collected in August 2023 by searching three databases: PubMed Central, Web of Science, and Scopus. The selection of studies consisted of three selection stages, and 64 articles were finally obtained. Quality assessment was performed with the QUADAS-2 tool, and the general methodological quality of retrieved studies was low. Statistical analysis was performed based on 2 × 2 tables and estimated sensitivity and specificity were obtained using SROC curves. The most used indices were MCI, MCW and PMI. The best results in detecting reduced BMD obtained for MCW ≤ 3 mm, estimated sensitivity and specificity were 0.712 (95% CI, 0.477-0.870) and 0.804 (95% CI, 0.589-0.921), respectively. The most prone to the risk of bias is the MCI due to the examiner's subjectivism. Radiomorphometric indices of the mandible can be useful as a screening tool to identify patients with low BMD, but should not be used as a diagnostic method. Further research needs to focus on analysing the ability of the indices to detect osteoporosis and also in combination the indices with clinical parameters.

Effectiveness of Orthopantomograms as a Screening Tool for Osteoporosis: A Case-Control Study

Introduction Osteoporosis is a disease that is characterised by low bone mineral density (BMD), and loss of structural and biomechanical properties that are essential in maintaining bone homeostasis. Osteoporosis is diagnosed by clinical measurement of BMD and is the best predictor of osteoporosis. The study was conducted with the aim of assessing the effectiveness of orthopantomogram (OPG) as a screening tool for osteoporosis in postmenopausal women and chronic drug users. Objectives The primary objective of the current study was to assess the mandibular cortical width and antegonial index in postmenopausal women and chronic drug users, the secondary objective was to compare the mandibular cortical width and antegonial index of postmenopausal women and chronic drug users with that of the control group (healthy individual). Methods Three groups were taken in this study with a sample size of 300 with 100 OPG in each group. The groups categorised in the study were postmenopausal women, patients under drugs (glucocorticoids, proton pump inhibitor, anti-epileptic drugs, selective serotonin reuptake inhibitor) and the control group and the parameters assessed were antegonial index and mandibular cortical width. Results Results were tabulated and analysed using Statistical Package for the Social Sciences (IBM SPSS Statistics for Windows, IBM Corp., Version 26.0, Armonk, NY). The normality tests Kolmogorov-Smirnov and Shapiro-Wilks test results reveal that the variables (both indices) follow the normal distribution. The mandibular cortical width was 3.44, 2.66 and 2.96 in the normal, postmenopausal women and women on drugs respectively. The antegonial index was 163.5, 157.2 and 158.8 in the normal, postmenopausal women and women on drugs respectively. Conclusion From the above results, it is evident that there is a statistically significant reduction in antegonial index and mandibular cortical width in postmenopausal women compared to normal individuals. Alterations of this value are suggestive that early pre-clinical changes of osteoporosis can be detected in the high-risk group using OPG.

Oral and craniofacial research in the Generation R study: an executive summary

OBJECTIVES

Oral conditions are of high prevalence and chronic character within the general population. Identifying the risk factors and determinants of oral disease is important, not only to reduce the burden of oral diseases, but also to improve (equal access to) oral health care systems, and to develop effective oral health promotion programs. Longitudinal population-based (birth-)cohort studies are very suitable to study risk factors on common oral diseases and have the potential to emphasize the importance of a healthy start for oral health. In this paper, we provide an overview of the comprehensive oral and craniofacial dataset that has been collected in the Generation R study: a population-based prospective birth cohort in the Netherlands that was designed to identify causes of health from fetal life until adulthood.

METHODS

Within the multidisciplinary context of the Generation R study, oral and craniofacial data has been collected from the age of 3 years onwards, and continued at the age of six, nine, and thirteen. Data collection is continuing in 17-year-old participants.

RESEARCH OUTCOMES

In total, the cohort population comprised 9749 children at birth, and 7405 eligible participants at the age of seventeen. Based on questionnaires, the dataset contains information on oral hygiene, dental visits, oral habits, oral health-related quality of life, orthodontic treatment, and obstructive sleep apnea. Based on direct measurements, the dataset contains information on dental caries, developmental defects of enamel, objective orthodontic treatment need, dental development, craniofacial characteristics, mandibular cortical thickness, and 3D facial measurements.

CONCLUSIONS

Several research lines have been set up using the oral and craniofacial data linked with the extensive data collection that exists within the Generation R study.

CLINICAL RELEVANCE

Being embedded in a multidisciplinary and longitudinal birth cohort study allows researchers to study several determinants of oral and craniofacial health, and to provide answers and insight into unknown etiologies and oral health problems in the general population.

A retrospective comparative fractal and radiomorphometric analysis of the effect of 3 generations of anti-epileptic drugs on the mandible

OBJECTIVE

The present study investigated the possible impacts of anti-epileptic drugs (AEDs) on trabecular and cortical bone in the mandible.

STUDY DESIGN

Fractal dimension (FD) and the radiomorphometric parameters of mandibular cortical width (MCW), panoramic mandibular index (PMI), and mandibular cortical index (MCI) were assessed on 497 dental panoramic radiographs (DPRs) of patients in the case group and controls. AEDs were compared according to 3 generations, duration of use, and patient age and sex.

RESULTS

FD of the angle and body of the mandible and MCW were significantly lower in the case group than in the control group (P < .001). FD values in the ramus and angle were lower in first-generation and third-generation AEDs than in second-generation drugs (P ≤ .011). FD in the mandibular body was lower in first-generation and second-generation AED users than in third-generation drugs (P = .017). Drug use for at least 1 year resulted in significantly lower values for all FDs and MCW values and more class 3 MCI assessments than short-duration use, but PMI was higher with more than 1 year of AED use (P ≤ .020). Age and sex had no significant effects.

CONCLUSIONS

AEDs caused significant changes in bone compared with controls in some FD values, MCW, and MCI. The effect of drug generation is pronounced in trabecular bone. Anti-epileptic drug use for more than 1 year had a greater effect than short-term use.

Evaluation of the effect of antiepileptic drugs on mandibular bone quality by fractal analysis

OBJECTIVES

Antiepileptic drugs (AEDs) are used to control seizures in epilepsy and their long-term use is common. AED use has been associated with decreased bone mineral density. The aim of this study is to determine the effect of AEDs on mandibular bone quality using fractal analysis and panoramic morphometric indices.

METHODS

In this study, dental and medical records of 132 patients (66 AED users and 66 control group) were used. Fractal analysis (FA), the panoramic mandibular index (PMI), mandibular cortical width (MCW), and Klemetti index (KI) measurements were performed on panoramic radiographs.

RESULTS

In all metrics, the mean values of the study group were significantly lower than the control group (p < 0.000). There is a statistically significant difference between the study and control groups in terms of KI distribution (p < 0.000). The mean fractal dimension (FD) values in each measured region of the female patients in the study group were found to be significantly lower than the female patients in the control group (p < 0.05). The mean FD values measured in ROI-2 and ROI-3 of male patients in the study group were found to be significantly lower than male patients in the control group (p < 0.05).

CONCLUSION

The side effects of AEDs on bone metabolism were shown in this study. Dentists examining patients with epilepsy should be careful about osteoporotic changes in the jaws.

Evaluation of temporomandibular joint components and mandibular bone structure in ankylosing spondylitis patients

OBJECTIVES

The study aimed to investigate the mandible and temporomandibular joint (TMJ) in patients with ankylosing spondylitis (AS) who had no signs or symptoms of TMJ-related disease and compare them with a control group.

STUDY DESIGN

In total, 128 panoramic radiographs (63 patients with AS, 65 controls) were evaluated. Fractal analysis was conducted on the mandibular condyle (ROI1), angle of the mandible (ROI2), and the area adjacent to the mental foramen (ROI3). Articular eminence inclination (AEI) values were measured. Klemetti index (KI) evaluation of the mandibular cortex was also performed.

RESULTS

Fractal dimension (FD) values were significantly lower in the patients with AS than the controls in ROI1 and ROI2 (P = .001), but there were no significant differences between groups for FD in ROI3, AEI, or KI (P ≥ .09). No significant differences were found in any parameters between patients with AS with different disease durations (P ≥ .06).

CONCLUSIONS

Patients with AS displayed significantly lower FD values in condyles and the angle of the mandible and slightly lower AEI values; therefore, they should be examined routinely for TMJ disorders. Clinicians should be aware of the possibility of secondary osteoporosis in patients with AS and consider its probable effects on the mandible.

The effect of Rutin hydrate on Glucocorticoids induced osteoporosis in mandibular alveolar bone in Albino rats (Radiological, histological and histochemical study)

Background

Glucocorticoids are used in different conditions such as autoimmune disorders and organ transplantation and their administration is the most common cause of secondary osteoporosis. Rutin is a flavonoid found in many plants. Flavonoids are natural products with various therapeutic and biological effects.

Objective

Is to investigate the effect of Rutin Hydrate as a form of Rutin on glucocorticoid induced osteoporosis in mandibular alveolar bone radiologically, histologically and histochemically.

Methods

Twenty-one adult male Albino rats were randomly divided into three groups. Group I (control), group II (osteoporotic) and group III (Rutin Hydrate treated). In both group II and III rats received 21 mg/kg of methylprednisolone daily for four weeks. Then group III received 50 mg/kg of rutin hydrate in distilled water daily for another four weeks. At the end of the experiment, mandibles were dissected for radiographic assessment, then processed for histological and histochemical examination and statistical analysis.

Results

Radiologically, administration of Rutin Hydrate was able to enhance bone density than osteoporotic group. Histological examination revealed preserved cortical bone thickness that had been statistically proved. Apparently normal sized marrow cavities, some plump osteoblasts and normal osteocytes were seen in group III. Histochemical examination showed statistical increase in the area percentage of newly formed collagen in group III than group II.

Conclusions

Rutin Hydrate was able to modify the radiological and histological picture of osteoporotic alveolar bone. This was achieved by the ability of Rutin Hydrate to increase bone density, preserve cortical plates thickness and enhance new collagen formation that was proved histochemically.

Relation between panoramic mandibular index and disease activity in patients with rheumatoid arthritis

Background

DEXA scan could be unavailable at some health centers, and radiologic examination of the mandible and oral cavity is considered more commonly used radiologic test that can predict, diagnose, or even follow-up on any defect in bone mineralization. The aim of this study was to elucidate the ability of panoramic radiograph to detect osteoporosis in rheumatoid arthritis patients and correlate panoramic mandibular index with RA disease activity and severity parameters.

Results

The sensitivity of panoramic mandibular index for diagnosis of osteoporosis was 96% in group Ι (primary OP) and 70% in group ΙΙ (RA patients). The positive predictive value of PMI was 67% in group Ι and 55% in group ΙΙ. The negative predictive value of PMI was 34% in group Ι and was 46% in group ΙΙ. The cutoff value of PMI for diagnosis of OP was ≤ 0.31 in group Ι and ≤ 0.17 in group ΙΙ. In group I, there were significant correlations between panoramic mandibular index and patient’s ages, weights, T score at L1-4, T score at femoral neck, and T score at forearm while there were insignificant correlations between PMI and patients’ heights. In group ΙΙ, there were significant correlations between PMI, patients’ ages, weights, disease durations, SHARP score, ESR, RF, T score at L1-4, T score at femoral neck, and T score at forearm, while there were insignificant correlations between PMI and patients’ heights, DAS, and CRP.

Conclusions

Panoramic radiography could have a potential usability in the diagnosis of osteoporosis in rheumatoid arthritis patients regardless of displaying insignificant correlation with disease activity.

In vivo evaluation of mandibular trabecular and cortical bone quality in psoriasis vulgaris

OBJECTIVE

The aim of this study was to evaluate the effects of psoriasis vulgaris on mandibular structure by calculating fractal dimension (FD) and radiomorphometric indices.

STUDY DESIGN

Panoramic radiographs of 58 patients with psoriasis and 58 healthy participants were assessed. FD was used to analyze trabecular bone architecture in the condyle, angle, and 2 sites in the alveolar bone. Five radiomorphometric indices based on cortical thickness and the mandibular cortical index (MCI) for structure were used to assess cortical bone porosity. Comparisons were made between sites in trabecular and cortical bone. Quantitative and categorical data were statistically analyzed with the significance level at P < .05.

RESULTS

FD was significantly lower in the patients with psoriasis than in the controls in the alveolar bone sites (P ≤ .035). Differences between measurement sites were insignificant in psoriasis (P ≥ .617), but the FD values of some measurement sides in the control group differed significantly (P ≤ .004). All quantitative radiomorphometric indices were significantly lower in patients with psoriasis (P ≤ .034) with significant differences between some sites in both groups. No significant difference was found in MCI frequency distribution between the groups (P = .782).

CONCLUSIONS

Trabecular architecture and cortical thickness were negatively affected in patients with psoriasis, but no differences in cortical porosity were detected between groups.

Proton pump inhibitors and mandibular bone quality: A preliminary study

OBJECTIVES

Proton pump inhibitors (PPI) provide a long-lasting anti-acidic effect by inhibiting the proton pump, and they are one of the most commonly prescribed drugs worldwide. PPIs adversely affect the bone structure via deficiency of vitamins and minerals. The aim of this study was to investigate the possible PPI-induced bone changes in the mandible on panoramic radiographs with the methods of fractal analysis and panoramic morphometric indices.

METHODS

Panoramic radiographs of 402 patients were used (201 PPI users, 201 control group). Fractal analysis was performed on 4 regions of interests (ROI): 1- upper part of the ramus, 2- angulus, 3- anterior of the mental foramen, 4- distal of the middle ramus. Also, the panoramic mandibular index (PMI), mandibular cortical width (MCW), and Klemetti index (KI) were performed on radiographs.

RESULTS

There were significant differences in terms of ROI3, MCW, and KI between the control and study groups (p < 0.05) while there was no significant difference for ROI1, ROI2, ROI4, and PMI (p > 0.05). Males were severely affected than females.

CONCLUSIONS

Osteoporotic changes were detected in the trabecular and cortical bone in the mental foramen region in PPI users with fractal analysis and morphometric indices, while there were no differences for mandibular ramus and angulus regions according to fractal analysis.

Correlations between periodontal disease, mandibular inferior cortex index and the osteoporotic fracture probability assessed by means of the fracture risk assessment body mass index tool

Background

The aim was to examine correlations between radiological signs of chronic periodontitis, Mandibular Inferior Cortex (MIC) index and osteoporotic fracture probability based on the FRAX BMI tool.

Methods

The material comprised 422 panoramic radiographs taken in patients aged 40–89, 270 females and 152 males. The severity of chronic periodontitis and resorption of mandibular inferior cortex based on MIC index were assessed. A diagnostic survey was conducted to estimate 10-year major and hip osteoporotic fracture probability (MOFP, HOFP) by means of the FRAX BMI tool - an algorithm that allows to calculate osteoporotic fracture probability based on assessing bone fracture risk factors knowing only BMI value.

Results

The conducted analysis based on U Mann-Whitney test revealed that mean 10-year MOFP was significantly higher (p = 0.00) in women than in men. Mean 10-year MOFP in females was 4.8% (SD = 3.95%) and in males 3.21% (SD = 2.35%). Mean 10-year HOFP in women was 1.35% (SD = 2.07%) and was significantly higher (p = 0.03) than in men – 0.79% (SD = 1.18%).MOFP is significantly higher in patients with moderate and severe periodontitis than in those with mild periodontitis. Significant difference between MIC values and MOFP (p = 0.00) and HOFP (p = 0.00) was found. Osteoporotic fracture probability was significantly higher in patients with MIC stages C2 and C3 than C1.

Conclusions

The FRAX BMI tool with radiological evaluation of periodontal disease severity and MIC index may be used in dental practice in determining individual risk of osteoporotic fracture in females and provide new opportunities of selecting those potentially more prone to such fractures.

Trial registration

The approval of the local bioethics committee was obtained (KE-0254/107/2017).

Usefulness of measuring radiographic density of axis vertebra in patients at risk of osteoporosis: A cone-beam computed tomography study

Objective:

Using cone-beam computed tomography (CBCT) images, the aim of the study was to evaluate the usefulness of measuring radiographic density of the axis vertebra (RDAV) in patients at risk of osteoporosis.

Materials and Methods:

Two hundred and forty-seven old patients (109 males and 138 females) aged between 50 and 80 years (mean age: 59.68 ± 7.27) were examined by CBCT. Using InVivoDental, v. 5.0 (Anatomage Inc., San Jose, CA), RDAV and mental index (MI) were measured twice and correlated using Pearson's correlation coefficients. Patients were divided into two categories: high risk and low risk of osteoporosis using 3.1 mm of MI as a cutoff value, and the mean value of RDAV was compared and correlated using independent samples’ t-test and regression analysis. Receiver-operating characteristic (ROC) curve analysis was also used to examine the predictive power of RDAV.

Results:

The mean value of RDAV was moderately correlated with MI (r = 0.32), and in patients at low risk of osteoporosis, the mean value of RDAV was significantly higher than in patients at high risk of osteoporosis. In multivariate binary logistic regression, the odds of being at risk of osteoporosis decreased by 1% with one unit increase in RDAV (odds ratio = 0.988, 95% confidence interval: 0.983–0.993; P < 0.005). ROC analysis showed that the mean value of RDAV had a high predictive power for predicting patients at risk of osteoporosis (area under the curve = 0.761 for females and 0.649 for males).

Conclusions:

Measuring RDAV is considered useful in predicting patients at risk of osteoporosis.

Dental Panoramic Radiographic Indices as a Predictor of Osteoporosis in Postmenopausal Saudi Women

Background

Many oral presentations of osteoporosis-a bone metabolic disease-were recorded. Thus, we aimed to assess panoramic radiomorphometric indices with bone mineral density (BMD) values among Saudi postmenopausal women and its importance in the prediction of osteoporosis.

Methods

A total of 431 Saudi women were enrolled in this study. Panoramic radiographs were obtained at the time of BMD measurement. Subjects were fatherly classified into; normal BMD, osteopenia, and osteoporosis groups. Serum follicle-stimulating hormone, luteinizing hormone (LH), estradiol (E2), 25-hydroxy-vitamin D (25[OH]D) and intact-parathyroid hormone were measured. Moreover, serum creatinine, calcium, and phosphate, together with serum osteocalcin (s-OC), procollagen type I N-terminal propeptide (s-PINP) and cross-linked C-terminal telopeptide of type 1 collagen (s-CTX) were measured. Receiver-operator curve (ROC) curve analysis for use of mandibular cortical width (MCW), panoramic mandibular index (PMI), and maxillary-mandibular ratio (M/M ratio) to differentiate women with osteoporosis or osteopenia from normal subjects was calculated. Cut off values of 4.6 at T score <−1 and 4.1 at T score ≤−2.5 were used.

Results

Body mass index is significantly low in the osteoporotic group. There is no significant difference in serum levels of LH, E2, calcium, phosphate, and 25(OH)D between the studied groups. Moreover, s-OC, C-terminal propeptide of procollagen type I, s-PINP, s-CTX, and urinary-CTX are significantly higher in osteoporosis than normal and osteopenia groups. ROC curve analysis revealed that MCW and PMI showed significant data while M/M ratio is non-significant.

Conclusions

It could be concluded that MCW as an important panoramic radiographic parameter can be used for prediction and diagnosis of osteoporosis in postmenopausal Saudi women with low BMD.

Association of Condylar Bone Quality with TMJ Osteoarthritis

The etiology and treatment of temporomandibular joint (TMJ) osteoarthritis (TMJOA) remain complex and unclear. Based on clinical observations, we hypothesized that low condylar bone quality is significantly correlated with TMJOA and explored this association in a cross-sectional study with human patients. A total of 254 postmenopausal female participants were included in this study. Radiographic findings from cone beam computed tomography (CBCT) and clinical symptoms were used to classify each TMJ data sample as healthy control ( n = 124) or TMJOA ( n = 130). Condylar bone mineral density (BMD) (computed tomography Hounsfield unit [CT HU]) and bone volume fraction (BV/TV) were measured and modeled as predictors of healthy control versus TMJOA status in multilevel logistic regression analyses. Both CT HU (adjusted odds ratio [AOR] = 0.9989, interquartile odds ratio [IOR] = 0.4206) and BV/TV (AOR= 0.8096, IOR = 0.1769) were negatively associated with TMJOA ( P = 0.049, 0.011, respectively). To assess the diagnostic performance of CT HU and BV/TV for identification of TMJOA, receiver operating characteristic (ROC) curves were plotted. The estimated areas under the curve (AUC) were 0.6622 for BV/TV alone, 0.6074 for CT HU alone, and 0.7136 for CT HU and BV/TV together. The model incorporating CT HU and BV/TV together had a significantly higher AUC than the models using BV/TV alone ( P = 0.038) or HU alone ( P = 0.021). In conclusion, we found that low condylar bone quality was significantly correlated with TMJOA development and that condylar CT HU and BV/TV can be used together as a potential diagnostic tool for TMJOA. Careful clinical evaluation of the condyle coupled with appropriate radiographic interpretation would thus be critical for the early detection of TMJOA.

IDIOS: An innovative index for evaluating dental imaging-based osteoporosis screening indices

Purpose

The goal of this study was to develop a new index as an objective reference for evaluating current and newly developed indices used for osteoporosis screening based on dental images. Its name; IDIOS, stands for Index of Dental-imaging Indices of Osteoporosis Screening.

Materials and Methods

A comprehensive PubMed search was conducted to retrieve studies on dental imaging-based indices for osteoporosis screening. The results of the eligible studies, along with other relevant criteria, were used to develop IDIOS, which has scores ranging from 0 (0%) to 15 (100%). The indices presented in the studies we included were then evaluated using IDIOS.

Results

The 104 studies that were included utilized 24, 4, and 9 indices derived from panoramic, periapical, and computed tomographic/cone-beam computed tomographic techniques, respectively. The IDIOS scores for these indices ranged from 0 (0%) to 11.75 (78.32%).

Conclusion

IDIOS is a valuable reference index that facilitates the evaluation of other dental imaging-based osteoporosis screening indices. Furthermore, IDIOS can be utilized to evaluate the accuracy of newly developed indices.

The osseous and dental changes of patients with chronic renal failure by CBCT

OBJECTIVES

The aim of the present study was to evaluate the osseous changes of the jaws of patients with chronic renal failure (CRF) by CBCT.

METHODS

On CBCT scans obtained from 15 patients with CRF and 15 control patients (7 males and 8 females), the mean was calculated for the antegonial index (AI), mental index (MI), panoramic mandibular index (PMI) and mandibular cortical index (MCI). The MI, AI and PMI, pulp chamber size, number of teeth with pulp calcification and lamina dura loss were compared using the paired t-test, and the MCI values were analysed using the χ(2) test.

RESULTS

There were no statistically significant differences in the PMI, MI and AI values in patients with CRF and the control group. With regard to MCI, the cortical margins of the mandible were more porous in patients with CRF than in the control group, and also soft-tissue calcifications, lamina dura loss and radiolucent defects were more common in patients with CRF. There were no statistically significant differences in pulp chamber size and pulp calcifications between patients with CRF and the control group.

CONCLUSIONS

Radiographic changes in the jawbones of patients with CRF may be commonly seen. CBCT is a valuable diagnostic tool for the evaluation of osseous findings, pulp chamber, soft-tissue calcifications and MCIs and allows indices measurement in three dimensions without any superposition.

The transforming growth factor-β1 (TGF-β1) gene polymorphisms (TGF-β1 T869C and TGF-β1 T29C) and susceptibility to postmenopausal osteoporosis: a meta-analysis

The aim of the present study was to integrate all the eligible studies and investigate whether the transforming growth factor-β1 (TGF-β1) gene polymorphisms (TGF-β1 T869C and TGF-β1 T29C) are correlated with postmenopausal osteoporosis (PMOP) risk. PMOP is a common skeletal disease and several genetic factors play an important role in the development and progression of PMOP. Significant associations between TGF-β1 gene polymorphisms (TGF-β1 T869C and TGF-β1 T29C) and PMOP risk have been reported; however, some of these results are controversial. A systematic online search was performed using PubMed, EMBASE, Web of Science, and the Cochrane Library to identify case-control studies investigating the relationship between TGF-β1 T869C and TGF-β1 T29C polymorphisms and the susceptibility of PMOP. The pooled odds ratio (OR) with 95% confidence interval (95% CI) was calculated to assess the associations, and subgroup meta-analyses were performed according to the ethnicity of the study populations. Eight studies involving 1851 cases and 2247 controls met the inclusion criteria after assessment by 2 reviewers. Overall, there were significant associations between TGF-β1 T869C and TGF-β1 T29C polymorphisms and PMOP (TGF-β1 T869C—C vs T: OR = 1.18, 95% CI = 1.02-1.36, P = 0.030; CC vs TT: OR = 1.38, 95% CI = 1.01-1.88, P = 0.042; CC vs

CT/TT

OR = 1.39, 95% CI = 1.09-1.76, P = 0.008; TGF-β1 T29C—CT vs TT: OR = 1.25, 95% CI = 1.02-1.53, P = 0.032; CT/CC vs TT: OR = 1.37, 95% CI = 1.02-1.84, P = 0.035). In the subgroup analysis of ethnicity, significant association was observed between TGF-β1 T869C polymorphism and PMOP risk in Asian population (C vs T: OR = 1.18, 95% CI = 1.01-1.38, P = 0.043; CC vs TT: OR = 1.41, 95% CI = 1.01-1.97, P = 0.047; CT/CC vs TT: OR = 1.31, 95% CI = 1.03-1.66, P = 0.026; CC vs

CT/TT

OR = 1.35, 95% CI = 1.03-1.75, P = 0.028); however, there was no significant association between TGF-β1 T869C polymorphism and PMOP risk in Caucasian population. With regard to TGF-β1 T29C polymorphism, significant association was also observed in Asian population (CT vs TT: OR = 1.37, 95% CI = 1.07-1.75, P = 0.013; CT/CC vs TT: OR = 1.54, 95% CI = 1.16-2.05, P = 0.003), while there was no significant association in Caucasian population. The TGF-β1 T869C and TGF-β1 T29C polymorphisms may be involved in susceptibility to PMOP, particular in Asian patients.