1.Impact of cold spells on hospitalizations of residents in Hengyang City from 2017 to 2023: A time series study based on different definitions of cold spells
Xiaoming DENG ; Guanxiang ZOU ; Weixiong PENG ; Bin LI
Journal of Environmental and Occupational Medicine 2025;42(7):808-813
Background The impact of cold spells on population health can be categorized into an independent main effect of extreme low temperatures and an added effect of prolonged low temperatures. However, studies on the added effects of cold spells on hospitalizations remain limited. Objective To investigate the added effects of cold spells on hospitalizations of residents in Hengyang City, Hunan Province, and to provide a scientific basis for establishing a cold spell early warning system. Methods Daily meteorological data, air pollutant data, and hospitalization data from six tertiary hospitals of four districts in Hengyang City from 2017 to 2023 were collected. A generalized linear model (GLM) combined with a distributed lag nonlinear model (DLNM) was used to assess the added effects of cold spells on non-accidental hospitalizations, as well as hospitalizations for circulatory system diseases and respiratory system diseases, after controlling the main effect of temperature. The modifying effects of cold spell characteristics (intensity and duration) and individual characteristics (gender and age) were also analyzed. Results Compared with non-cold spell periods, the relative risks (RRs) of total non-accidental hospitalizations and hospitalizations across disease categories, genders, and age groups were elevated during cold spells of varying intensities and durations. However, the total effects of cold spells exhibited a "U-shape" nonlinear relationship with intensity and decreased with prolonged duration. During high-intensity cold spells (daily average temperature < P5 and lasting ≥ 2 d), the RR (95%CI) for non-accidental hospitalizations was 1.71 (1.21, 2.42); the RRs (95%CIs) for males and females were 1.99 (1.38, 2.84) and 1.47 (1.00, 2.16), respectively; for individuals < 65 years and ≥ 65 years, the RRs (95%CIs) were 1.59 (1.12, 2.26) and 1.93 (1.27, 2.92), respectively; and for circulatory and respiratory system diseases, the RRs (95%CIs) were 1.84 (1.22, 2.79) and 1.07 (0.71, 1.60), respectively. No statistically significant differences were observed between the above subgroups. The single-day lagged effects of cold spells displayed a two-peaked pattern. The single-day lag RR for total non-accidental hospitalizations peaked at lag 1 d after cold spell exposure, declined thereafter, and began to rise again after lag 5 d, reaching a second peak at lag 12–13 d before gradually decreasing. The lagged effects remained statistically significant during lag 8–18 d. The lag patterns of cold spell associations across disease categories, genders, and age groups were largely consistent with those of total hospitalizations. Conclusion Cold spells have a significant impact on non-accidental hospitalizations of residents in Hengyang City, with notable lagged effects. The findings provide important theoretical support for establishing a more targeted cold spell early warning system.
2.Analysis of factors correlating with the initial seizure threshold in modified electroconvulsive therapy for patients with mental disorders
Yingyin LI ; Peng YANG ; Meijie WANG ; Yajie SHI ; Yanfei LI ; Kun LI ; Xiaoming ZHANG
Sichuan Mental Health 2025;38(4):302-307
BackgroundModified electroconvulsive therapy (MECT) is a common front-line strategy widely used in psychiatric practice, and the optimal first stimulus dosage in MECT is usually estimated clinically based on the factors influencing the patient's initial seizure threshold (IST). However, previous studies on the influencing factors of IST have mostly suffered from limitations such as small sample sizes and single-dimensional research perspectives. ObjectiveTo explore the factors influencing IST in MECT for patients with mental disorders, so as to provide references for stimulus dosing strategies in MECT for the patients. MethodsA retrospective study was used to include 1 446 inpatients fulfilling the diagnostic criteria for any specific mental disorder listed in the ICD-10 and receiving MECT at Shandong Daizhuang Hospital from January 1, 2021 to August 1, 2023. Their general and clinical data were collected, including IST, psychiatric diagnostic categories, gender, ethnicity, age, body weight, body mass index (BMI), course of disease, family history of psychiatric disorders, first episode status, use of antiepileptic drugs the day before treatment, use of benzodiazepines the day before treatment, and previous MECT treatment history. Pearson correlation analysis was utilized to test the correlation of IST with age, height, body weight, BMI, and course of disease, and stepwise multivariate linear regression analysis was performed to identify the factors affecting IST. ResultsIST yielded statistical difference among patients in terms of gender, first episode status, use of antiepileptic drugs the day before treatment, and use of benzodiazepines the day before treatment (t=2.256, -3.059, -2.136, -3.006, P<0.05 or 0.01). IST in patients of different ages and psychiatric diagnostic categories also demonstrated statistical difference (F=913.120, 6.212, P<0.01). Within young population, IST varied significantly based on the psychiatric diagnostic categories (F=2.986, P<0.05). Correlation analysis indicated that IST was positively correlated with age, body weight, BMI and course of disease (r=0.886, 0.055, 0.184, 0.456, P<0.05 or 0.01), and negatively correlated with height (r=-0.183, P<0.01). Stepwise multivariate linear regression analysis revealed that age, gender, and body weight were influencing factors of IST (β=0.888, -0.049, -0.035, P<0.01). ConclusionsAge, gender and body weight may be factors influencing IST in MECT for patients with mental disorders. [Funded by Key R&D Plan Projects of Jining City in 2024 (number, 2024YXNS202)]
3.The influence of microvessel density and microlymphatic vessel density on prognosis in hypopharyngeal carcinoma and the construction.
Cong XU ; Lanzhen CUI ; Xiaoxiao LIU ; Jing BAI ; Lijun ZHANG ; Yu PENG ; Xiaoming LI
Journal of Clinical Otorhinolaryngology Head and Neck Surgery 2025;39(12):1143-1149
Objective:This study aims to investigate the influence of microvessel density(MVD) and microlymphatic vessel density(MLVD) on the prognosis of patients with hypopharyngeal squamous cell carcinoma(HPSCC) and to develop a nomogram prediction model for prognosis based on pathological characteristics. Methods:A retrospective analysis was conducted on clinicopathological and follow-up data from HPSCC patients who underwent surgical treatment at our institution between June 2010 and June 2020. Immunohistochemical staining was performed on tumor tissues and adjacent normal margin tissues to evaluate MVD and MLVD. The associations among MVD, MLVD, and clinicopathological features were analyzed. Univariate and multivariate Cox regression analyses were conducted to identify independent risk factors affecting overall survival(OS). Based on these findings, a nomogram model was constructed and its predictive accuracy was assessed using C-index, receiver operating characteristic(ROC) curve, and calibration curve. Results:Both MVD and MLVD were significantly higher in HPSCC tumor tissues compared to normal tissues. Patients in the high MVD and high MLVD groups exhibited significantly lower OS rates than those in the low MVD and low MLVD groups. Multivariate Cox regression analysis revealed that N stage, recurrence, nerve invasion, lymph node capsule invasion, MVD, and MLVD were independent prognostic factors of OS. Based on these factors, a nomogram prognosis model was successfully constructed. The nomograms demonstrated superior performance in terms of C-index, area under the ROC curve, and calibration, outperforming the AJCC TNM staging system. Conclusion:Elevated MVD and MLVD levels are associated with poorer prognosis in HPSCC patients. The nomogram model based on pathological features provides valuable insights for clinical assessment and decision-making.
Humans
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Hypopharyngeal Neoplasms/blood supply*
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Prognosis
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Retrospective Studies
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Microvascular Density
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Nomograms
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Lymphatic Vessels/pathology*
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Male
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Female
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Middle Aged
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Carcinoma, Squamous Cell/blood supply*
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Microvessels/pathology*
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Lymphatic Metastasis
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Survival Rate
4.Analysis of urban cancer screening results in Qinghai Province from 2019 to 2024
Peng WENGANG ; Jin SHENGYAN ; Qiao WENJIE ; Cai BAOJIA ; Yu PENGJIE ; Zhu SHENGMAO ; Han JINGJUN ; Li XILING ; Chang HAODONG ; Sun DEXIAN ; Song YINGHENG ; Rong QINGXI ; Zhang CHENGWU ; Ma XIAOMING
Chinese Journal of Clinical Oncology 2025;52(18):944-949
Objective:To analyze the screening results of the Urban Cancer Early Diagnosis and Treatment Project in Qinghai Province from 2019 to 2024.Methods:A summary and statistical analysis were conducted on six years of screening data from the Urban Cancer Early Dia-gnosis and Treatment Program in Qinghai Province,with the high-risk rate,screening rate,and detection rate calculated separately for each type of cancer.Results:From 2019 to 2024,56,882 high-risk individuals were identified.The high-risk rates for lung,colorectal,breast,up-per gastrointestinal,and liver cancer were 22.02%,21.57%,14.23%,13.52%,and 6.10%,respectively.Overall,13,592 individuals com-pleted clinical screening,with detection rates of 0.32%for lung cancer,0.41%for liver cancer,0.08%for precancerous gastric lesions,3.63%for precancerous colorectal lesions,0.08%for esophageal cancer,0.16%for gastric cancer,and 0.14%for colorectal cancer.Conclusions:The implementation of the Urban Cancer Early Diagnosis and Treatment Program in Qinghai Province aids in the early detection of cancer,improves early diagnosis and survival rates,and reduces mortality.Nevertheless,due to low public awareness and limited participation,en-hancements in program management and public outreach are required.
5.Experience analysis of therapeutic effects on 75 cases of infantile vascular rings
Xiaoming ZHOU ; Shunyang FAN ; Yuge PENG ; Yanli CHEN ; Yuqi YANG ; Lin LIN ; Haitao GUO ; Jinghao ZHENG
Chinese Journal of Thoracic and Cardiovascular Surgery 2025;41(8):453-459
Objective:To investigate the operation opportunity for vascular rings in infants and assess the impact of prenatal and postnatal integrated management strategies on treatment outcomes.Methods:A retrospective analysis was conducted on the clinical data of 75 infants with vascular rings who underwent surgical treatment at the Third Affiliated Hospital of Zhengzhou University from January 2016 to December 2023. Among them, 54 were males and 21 were females, with a median age at surgery of 1.7 (0.7-6.9) months and a median weight of 5.3 (3.5-8.0) kg. Vascular rings malformation was diagnosed by real-time three-dimensional color doppler echocardiography during pregnancy in 51 cases. Preoperatively, 28 cases presented with respiratory or digestive system-related symptoms, and 26 cases had a history of hospitalization due to related symptoms. All patients underwent preoperative cardiac CTA+ CTVE and three-dimensional reconstruction examinations, and 56 cases showed varying degrees of airway compression and stenosis on imaging. Among them, 10 patients presented with preoperative stridor and respiratory distress; fiberoptic bronchoscopy performed after anesthesia induction confirmed significant tracheal compression/stenosis. One patient was ventilator-dependent preoperatively, and bronchoscopy revealed main bronchomalacia. The cohort included: Complete vascular rings (62 cases of double aortic arch, 10 cases of right aortic arch with aberrant left subclavian artery and left-sided ductus arteriosus/ligamentum) and incomplete vascular rings (3 cases of pulmonary artery sling). Additionally, 5 cases had associated Kommerell’s diverticulum, and 12 had intracardiac malformation. All patients successfully completed surgery, and those with intracardiac malformation underwent extracorporeal circulation and primary radical surgery concurrently. Based on prenatal diagnosis and implementation of prenatal and postnatal integrated management, patients were divided into an observation group (prenatal and postnatal integrated management group) and a control group (postnatally diagnosed group). The perioperative data of the two groups were compared to analyze the surgical outcomes and the advantages of prenatal and postnatal integrated treatment.Results:All 75 patients successfully completed surgery. Preoperatively, 56 cases (74.66%) presented with varying degrees of tracheal stenosis. Except for 1 case that died after abandoning treatment and 1 case that underwent tracheal surgery due to repeated failed ventilator weaning, all other patients were successfully discharged from the hospital. The overall mortality rate was 1.33%, and the rate of tracheal surgery was 1.35%. The age and weight at surgery in the observation group were lower than those in the control group ( P<0.05), and the proportion of preoperative hospitalization history was lower in the observation group ( P<0.05). No significant differences were observed between the two groups in terms of tracheal compression and stenosis, postoperative monitoring time, operation time, ventilator time, and risk of postoperative complications ( P>0.05). Conclusion:Tracheal stenosis is a common complication in children with vascular rings. Early surgical intervention is recommended for complete vascular rings and pulmonary artery slings (as an incomplete ring). Timely prenatal diagnosis of vascular ring anomalies combined with the implementation of an integrated prenatal-postnatal management strategy can significantly reduce the risk of preoperative hospitalization due to related symptoms and may lower the risk of subsequent tracheal surgery, potentially improving long-term prognosis.
6.A preliminary study on the effect of transcranial magnetic stimulation on refractory migraine and brain network mechanism
Xiyue FAN ; Jingya DENG ; Xiaoming WANG ; Dan YANG ; Chen GOU ; Tingting PENG ; Shuangfeng YANG
Chinese Journal of Neurology 2025;58(4):372-379
Objective:To explore the clinical efficacy, safety and possible neuroimaging mechanism of deep transcranial magnetic stimulation (dTMS) and repetitive transcranial magnetic stimulation (rTMS) in the treatment of refractory migraine.Methods:Thirty patients with refractory migraine were selected from the Department of Neurology, Affiliated Hospital of North Sichuan Medical College from October 2022 to August 2023. The patients were randomly divided into dTMS group ( n=10), rTMS group ( n=10) and sham stimulation group ( n=10). The dTMS group was treated with H7 coil and the rTMS group with "8" coil, and the sham stimulation group was treated with sham stimulation rTMS with the frequency of 10 Hz. The stimulation site was the contralateral primary motor cortex (M1) of headache, which was treated for 2 weeks (3 600 pulses per time, 5 times per week, 10 times in total). Visual Analogue Scale (VAS) and Headache Impact Test-6 (HIT-6) evaluations were performed before treatment, on the first day after treatment, and 1, 3 and 6 months after treatment. The resting-state functional magnetic resonance images of the 3 groups of patients before and after treatment were collected and analyzed by MATLAB2018b, SPM12 and RESTPLUS softwares, and the brain regions with different regional homogeneity (ReHo) before and after treatment were obtained. The general clinical data and scale scoring data were analyzed and processed by SPSS 26.0 version software. Results:There were significant differences in VAS scores among the dTMS group (before treatment 6.70±0.68, the first day after treatment 5.60±0.70, 1 month after treatment 5.00±0.82, 3 months after treatment 3.50±0.85, 6 months after treatment 3.90±1.45), the rTMS group (before treatment 6.90±0.74, the first day after treatment 5.90±0.74, 1 month after treatment 5.30±0.82, 3 months after treatment 5.30±0.82, 6 months after treatment 6.80±0.63) and the sham stimulation group (before treatment 6.60±0.97, the first day after treatment 6.70±0.95, 1 month after treatment 6.90±1.10, 3 months after treatment 6.70±0.68, 6 months after treatment 7.10±0.88; F=16.054, P<0.001), VAS scores among different time points ( F=34.292, P<0.001), and the interaction between groups and time ( F=24.136, P<0.001). Compared with those before treatment, VAS scores in the dTMS group and the rTMS group decreased on the first day after treatment, 1 month and 3 months after treatment (all P<0.05); VAS scores decreased in the dTMS group 6 months after treatment ( P<0.05). Compared with the sham stimulation group, the VAS scores of the dTMS group were lower at the same time points after treatment (all P<0.05), and the VAS scores of the rTMS group were lower on the first day after treatment, 1 month and 3 months after treatment (all P<0.05). Compared with the rTMS group, VAS scores were lower at 3 and 6 months after dTMS treatment (both P<0.05). There were significant differences in HIT-6 scores among groups ( F=13.173, P<0.001), HIT-6 scores among different time points ( F=60.788, P<0.001), and interaction between groups and time ( F=35.576, P<0.001). Compared with those before treatment, the HIT-6 scores in the dTMS group decreased on the first day after treatment ( P<0.05); the HIT-6 scores in the dTMS group and the rTMS group decreased 1 month and 3 months after treatment (both P<0.05); the HIT-6 scores decreased in the dTMS group 6 months after treatment ( P<0.05). Compared with the sham stimulation group, the HIT-6 scores were lower in the dTMS group at the same time points after treatment (all P<0.05), and the HIT-6 scores were lower in the rTMS group at 1 and 3 months after treatment (both P<0.05). Compared with the rTMS group, HIT-6 scores were lower at 3 and 6 months after dTMS treatment (both P<0.05). Analysis of ReHo results: compared with those before treatment, the ReHo values of the right cerebellar angle area 1 increased in the dTMS group and the sham stimulation group, decreased in the rTMS group. The ReHo values of the right middle occipital gyrus, left dorsolateral superior frontal gyrus and right cerebellar area 8 increased in the dTMS group, but decreased in the rTMS group and the sham stimulation group. The ReHo values of the left precentral gyrus and left superior temporal gyrus decreased in the dTMS group, while those in the rTMS group and the sham stimulation group increased. There were no obvious adverse reactions in the 3 groups during the treatment and follow-up period. Conclusions:dTMS and rTMS may help to improve the headache degree and quality of life of patients with refractory migraine, and they are safe, which may be related to the changes of brain network in the right cerebellar angle area 1, right middle occipital gyrus, left dorsolateral superior frontal gyrus, left precentral gyrus, left superior temporal gyrus and right cerebellar area 8.
7.A case of type I sialidosis presenting with myoclonic seizures
Peiwen DENG ; Xiaoming RONG ; Hongxuan WANG ; Jingrui PAN ; Ruowei HUANG ; Ying PENG ; Lei HE
Chinese Journal of Neurology 2025;58(2):175-178
The clinical characteristics, diagnosis and treatment process of a patient with type Ⅰ sialidosis (ST-1) caused by a homozygous mutation in the NEU1 gene who was missed diagnosis for 5 years were retrospectively analyzed to improve the understanding of the disease. A 16-year-old female patient presented with episodic limb shaking for more than 5 years and single generalised tonic-clonic seizure. Electroencephalogram (EEG) tests conducted at external hospital did not show any abnormalities, and head magnetic resonance imaging (MRI) showed general normality. Multiple antiepileptic drugs could not control the attack and the symptoms gradually worsened. After admission, the patient was found to have symptoms of easy wrestling and decreased vision, as well as signs of nystagmus and ataxia. The reexamination of the EEG showed extensive spike-and-slow complexes, and the brain MRI showed cerebellar atrophy. Furthermore, the whole-exome gene testing revealed the c.544A>G homozygous mutation in the NEU1 gene, leading to the diagnosis of ST-1. Levetiracetam tablets and clonazepam were given to improve the patient′s symptoms. During the follow-up, sleep improved compared to before, and myoclonus was significantly reduced. Therefore, patients with recurrent myoclonus, ataxia, and visual impairment without cognitive impairment should be aware of the possibility of sialidosis. Genetic testing plays an important role in the diagnosis of sialidosis.
8.Analysis of factors influencing mortality in critically ill neonates undergoing continuous renal replacement therapy
Rong ZHANG ; Yan ZHUANG ; Xiaoming PENG ; Fan ZHANG ; Junshuai LI ; Zhuojun XIAO ; Jingjing XIE ; Qiong GUO
Chinese Journal of Perinatal Medicine 2025;28(4):280-287
Objective:To investigate the risk factors influencing mortality in neonates undergoing continuous renal replacement therapy (CRRT).Methods:This retrospective study included 34 neonates with a corrected age of≤28 days who received CRRT at the Affiliated Children's Hospital of Xiangya School of Medicine, Central South University, from January 2019 to December 2023. The neonates were divided into a mortality group ( n=16) and a survival group ( n=18) based on whether they died during CRRT. Pre-CRRT blood biochemical indices, general condition, CRRT treatment modes, parameters, and related complications were analyzed using t-tests, Wilcoxon signed-rank tests, and Chi-square tests. Logistic stepwise regression analysis was used to screen for risk factors associated with CRRT mortality. Results:The mortality rate among the 34 neonates was 48.6% (16/34), with a median CRRT age of 17 days (range: 2-33 days). Eleven neonates (32.3%) were preterm, with the youngest gestational age being 27 weeks and the lowest weight before CRRT initiation being 1 700 g. The mortality group had lower urine output 6-12 hours before CRRT initiation and lower critical illness scores compared to the survival group [0.05 (0.02-1.00) ml/(kg·h) vs. 0.50 (0.20-1.05) ml/(kg·h), (64.50±7.10) scores vs. (77.67±3.65) scores, Z or t values were 10.97 and 3.91, respectively]. However, the vasoactive inotropic score (VIS), proportion of coma, and levels of blood potassium, alanine aminotransferase, aspartate aminotransferase, blood ammonia, blood lactic acid, and activated partial thromboplastin time (APTT) were higher in the mortality group compared to the survival group [ (86.88±15.80) scores vs. (55.56±24.31) scores, 11/16 vs. 1/18, (7.02±1.73) mmol/L vs. (5.88±1.53) mmol/L, 274.55(132.50-664.98) U/L vs. 31.10(19.03-110.70) U/L, 688.20 (449.73-3 618.13) U/L vs. 96.65 (44.15-439.00) U/L, 232.75 (70.33-1 310.85) μmol/L vs.77.70 (49.78-919.05) μmol/L, (11.17±3.36) U/L vs. (7.99±2.67) U/L, and (99.57±39.74) s vs. (60.97±31.25) s, with t, χ2, or Z values of-4.39, 14.81,-2.03,-2.72,-11.81,-3.89,-3.06, and-3.17, respectively] (all P<0.05). Logistic regression analysis revealed that pre-treatment VIS value ( OR=1.150, 95% CI: 1.035-1.278), and blood ammonia level ( OR=1.004, 95% CI: 1.002-1.009) were independent risk factors for mortality (both P<0.05). Conclusions:Neonatal CRRT mortality is associated with pre-treatment VIS scores and blood ammonia levels. Attention should be paid to a rapid decreases in urine output, the intensity of vasopressor support, and elevated levels of blood ammonia, blood lactic acid, transaminases, and APTT at the initiation of treatment.
9.Dihydroartemisinin suppresses cancer-associated fibroblast-mediated tumor angiogenesis and lymphangiogenesis in hypopharyngeal squamous cell carcinoma
Lanzhen CUI ; Cong XU ; Xiaoxiao LIU ; Jing BAI ; Lijun ZHANG ; Yu PENG ; Xiaoming LI
Chinese Archives of Otolaryngology-Head and Neck Surgery 2025;32(6):341-347
OBJECTIVE To explore the effects of dihydroartemisinin(DHA)on the functions of cancer-associated fibroblasts(CAFs)in the tumor microenvironment in hypopharyngeal squamous cell carcinoma(HPSCC).METHODS The influence of conditioned media from CAFs and normal fibroblasts(NFs)on tube formation was assessed using a tube formation assay.Secreted protein levels of IL-6,VEGFA,and VEGFC were measured by immunofluorescence and ELISA.Western blotting was used to evaluate the expression of α-SMA,p-STAT3,STAT3,VEGF-A,and VEGF-C within the STAT3 signaling pathway.After treatment with DHA,the optimal concentration for DHA's effect was determined using CCK8 assays and morphological observations of cells.The impact of DHA on angiogenesis was analyzed through tube formation assays,changes in IL-6 expression were detected using ELISA and immunofluorescence,and alterations in α-SMA,p-STAT3,and STAT3 expression were examined by Western blot.RESULTS Both CAFs and NFs exhibited pro-angiogenic and pro-lymphangiogenic effects,with CAFs showing a more pronounced impact.Activated CAFs overexpressed and secreted high levels of IL-6,VEGF-A,and VEGF-C.The concentration of IL-6 in the conditioned medium supernatants of CAF1 and CAF2 was significantly higher than that of NF1 and NF2(P1<0.001,P2<0.05).Similarly,the concentration of VEGF-A was significantly increased(P1<0.05,P2<0.01),and the concentration of VEGF-C was also significantly increased(P1<0.05,P2<0.01).Treatment with DHA inhibited the activated state of CAFs,reducing the expression and secretion of IL-6 and p-STAT3,thereby suppressing tube formation.CONCLUSION Our findings indicate that CAFs promote angiogenesis and lymphangiogenesis in HPSCC via activation of the STAT3 pathway.DHA effectively inhibits this process,suggesting a potential new therapeutic strategy for the treatment of HPSCC.
10.The root canal morphology of mandibular anterior teeth and its correlation with the occurrence of three-rooted mandibular first molars
Peng ZHU ; Yongchun GU ; Yihan WU ; Xiaoming XU
STOMATOLOGY 2025;45(1):58-63,74
Objective To study the root canal morphology of permanent mandibular anterior teeth and explore its correlation with the occurrence of three-rooted mandibular molars using cone beam computed tomographic(CBCT)imaging.Methods CBCT image data of 200 subjects were randomly collected from dental clinics.The root canal morphology of the mandibular anterior teeth was identified and classified by Vertucci's classification,and the root length and labio-lingual dimension at the tooth neck level were measured.The occurrence of three-rooted mandibular first molars was examined as well.The concurrence rates of double-canaled anterior teeth and three-rooted mandibular first molars at each side,and concurrence rates of bilateral double-canaled anterior teeth and three-rooted man-dibular first molars were calculated.Spearman correlation tests were applied to analyze the correlation between the double-canaled ante-rior teeth and three-rooted mandibular first molars,as well as the bilateral antimetric teeth.Results The incidence of double-canaled system was 10.4%,18.6%and 6.5%in mandibular central incisors,lateral incisors and canines,respectively;the bilateral concur-rence rates were 5.7%,11.1%and 3.0%,respectively,and Spearman correlation coefficients(rho)were 0.487,0.505 and 0.440(P<0.01),respectively;gender difference and side difference were not detected(P>0.05).The frequency of three-rooted mandibular first molars was 24.6%;gender difference was not detected(P>0.05),while the incidence was significantly higher at the right side(29.0%)than the left side(20.3%)(P<0.05).The bilateral concurrence rate was 17.4%,and a moderate correlation was detected(rho=0.666,P<0.01).The concurrence rates between the double-canaled anterior teeth and three-rooted mandibular first molars at each side were very low(2.6%-7.6%),and Spearman correlation tests demonstrated that no correlation(P>0.05)could be detected between them.Conclusion The lateral incisors exhibited the highest incidence of two root canals among the mandibular anterior teeth.Ad-ditionally,there was no significant corr-elation between three-rooted mandibular first molars and double-canaled mandibular anterior teeth.

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