Objective·To evaluate the relationships between disc-condyle distance and anterior disc displacement,as well as between disc-condyle distance and disc morphology,in patients with temporomandibular disorders(TMD)using magnetic resonance imaging(MRI)of the temporomandibular joint(TMJ).Methods·From September 2023 to March 2024,90 patients(180 TMJs)who visited the TMJ clinic of Department of Stomatology,The Second Affiliated Hospital of Anhui Medical University,with clinical symptoms of TMD and were diagnosed via MRI with either anterior disc displacement or no significant displacement,were included.Clinical data were collected,and MRI images were used to measure the angle of disc displacement,disc-condyle distance,disc length,and thickness.The degree of disc deformation was assessed.The relationships between clinical symptoms and anterior disc displacement,between anterior disc displacement and both disc morphology and disc-condyle distance,and between disc-condyle distance and disc morphology were analyzed.Results·Among the 90 patients,there were 16 males and 74 females,with a mean age of(28.1±14.5)years.Among the 180 TMJs,175 had clinical symptoms and 5 were asymptomatic.There were 40 joints with no displacement,78 with reducible anterior disc displacement,and 62 with irreducible anterior disc displacement.In the joints with irreducible anterior disc displacement,the proportion of those with two or more symptoms was slightly higher at 62.9%,but the difference was not statistically significant compared with the joints with no displacement or reducible anterior disc displacement.MRI assessment revealed that in the joints with irreducible anterior disc displacement,the proportion of disc deformation type Ⅲ or higher was significantly higher compared with the non-displaced joints(P<0.001).The disc length was significantly shorter(P<0.001),and the intermediate zone thickness was significantly greater(P<0.001)compared with the non-displaced joints.The disc displacement angles at centric closure and maximum opening were also significantly larger(P<0.001).The disc-condyle distance was 3.10(2.70,3.70)mm for non-displaced joints,3.40(3.00,4.00)mm for joints with reducible anterior disc displacement,and 6.60(4.78,7.90)mm for joints with irreducible anterior disc displacement,with significant differences(P<0.001).The disc-condyle distance was 3.10(2.80,3.60)mm for type Ⅰ discs,3.70(3.10,4.60)mm for type Ⅱ discs,5.10(4.00,7.30)mm for type Ⅲ discs,and 6.80(4.98,8.20)mm for type Ⅳ/Ⅴ discs,with significant differences(P<0.001).The disc-condyle distance was negatively correlated with disc length(rs=-0.469,P<0.001),positively correlated with intermediate zone thickness(rs=0.319,P<0.001),and positively correlated with disc displacement angle at centric closure(rs=0.626,P<0.001).Conclusion·With increasing severity of disc deformation,intermediate zone thickness,and disc displacement angle at centric closure,as well as decreasing disc length,the disc-condyle distance increases.The disc-condyle distance is an important indicator for MRI assessment of pathological changes in TMD.

Objective·To evaluate the relationships between disc-condyle distance and anterior disc displacement,as well as between disc-condyle distance and disc morphology,in patients with temporomandibular disorders(TMD)using magnetic resonance imaging(MRI)of the temporomandibular joint(TMJ).Methods·From September 2023 to March 2024,90 patients(180 TMJs)who visited the TMJ clinic of Department of Stomatology,The Second Affiliated Hospital of Anhui Medical University,with clinical symptoms of TMD and were diagnosed via MRI with either anterior disc displacement or no significant displacement,were included.Clinical data were collected,and MRI images were used to measure the angle of disc displacement,disc-condyle distance,disc length,and thickness.The degree of disc deformation was assessed.The relationships between clinical symptoms and anterior disc displacement,between anterior disc displacement and both disc morphology and disc-condyle distance,and between disc-condyle distance and disc morphology were analyzed.Results·Among the 90 patients,there were 16 males and 74 females,with a mean age of(28.1±14.5)years.Among the 180 TMJs,175 had clinical symptoms and 5 were asymptomatic.There were 40 joints with no displacement,78 with reducible anterior disc displacement,and 62 with irreducible anterior disc displacement.In the joints with irreducible anterior disc displacement,the proportion of those with two or more symptoms was slightly higher at 62.9%,but the difference was not statistically significant compared with the joints with no displacement or reducible anterior disc displacement.MRI assessment revealed that in the joints with irreducible anterior disc displacement,the proportion of disc deformation type Ⅲ or higher was significantly higher compared with the non-displaced joints(P<0.001).The disc length was significantly shorter(P<0.001),and the intermediate zone thickness was significantly greater(P<0.001)compared with the non-displaced joints.The disc displacement angles at centric closure and maximum opening were also significantly larger(P<0.001).The disc-condyle distance was 3.10(2.70,3.70)mm for non-displaced joints,3.40(3.00,4.00)mm for joints with reducible anterior disc displacement,and 6.60(4.78,7.90)mm for joints with irreducible anterior disc displacement,with significant differences(P<0.001).The disc-condyle distance was 3.10(2.80,3.60)mm for type Ⅰ discs,3.70(3.10,4.60)mm for type Ⅱ discs,5.10(4.00,7.30)mm for type Ⅲ discs,and 6.80(4.98,8.20)mm for type Ⅳ/Ⅴ discs,with significant differences(P<0.001).The disc-condyle distance was negatively correlated with disc length(rs=-0.469,P<0.001),positively correlated with intermediate zone thickness(rs=0.319,P<0.001),and positively correlated with disc displacement angle at centric closure(rs=0.626,P<0.001).Conclusion·With increasing severity of disc deformation,intermediate zone thickness,and disc displacement angle at centric closure,as well as decreasing disc length,the disc-condyle distance increases.The disc-condyle distance is an important indicator for MRI assessment of pathological changes in TMD.

Objective:To introduce the standard screw implantation methods and to analyze the biomechanical stability of the second-generation dynamic anterior plate-screw system for quadrilateral area (DAPSQ).Methods:Six adult formalin-preserved corpses were selected to make a complete pelvic specimen. Further, the left high double-column fracture models were made and randomly fixed with second-generation DAPSQ or anterior reconstruction titanium plate and 1/3 tube buttress-plate (ARTPB). The specimens of intact pelvis (IP) group, DAPSQ group and ARTPB group were fixed on a Zwick Z100 material machine and loaded vertically with 200 N, 300 N, 400 N, 500 N, 600 N, 700 N, and 800 N in a simulated sitting position, respectively. The axial displacement and strain changes in the anterior and posterior columns were tested in the three groups. The stiffness was calculated accordingly.Results:The axial compression displacement in the three groups showed an increase trend as well with the vertical load increased from 200 N to 800 N ( F=68.581, P<0.001; F=91.795, P<0.001; F=33.819, P=0.002). The axial displacement in ARTPB group was significantly larger than that in DAPSQ group and IP group ( P<0.05), while the difference between DAPSQ and IP groups was not significant ( P>0.05). Under the vertical load of 600 N, the pelvic axial stiffness of IP group, DAPSQ group, and ARTPB group were 220.72±70.33 N/mm, 185.68±48.49 N/mm and 135.83±60.58 N/mm, respectively. The axial stiffness of ARTPB group was significantly lower than that in DAPSQ group and IP group ( t=5.345, P=0.003; t=6.443, P=0.001), while the difference between DAPSQ and IP groups was not significant ( t=2.138, P=0.086). There were no significant differences of the strain values in anterior column among the three groups during the load increasing from 200 N to 800 N ( P>0.05). With the load increasing from 500 N to 800 N, the strain values of the posterior column in ARTPB group were significantly greater than those of IP and DAPSQ groups ( P<0.05). However, the differences between IP and DAPSQ groups were not statistically significant in strain values of the posterior column ( P>0.05). Conclusion:Compared with anterior reconstruction titanium plate and 1/3 tube buttress-plate, acetabular double-column fracture model fixed with the second-generation DAPSQ has less axial compression displacement but with greater axial stiffness. The stress change in the posterior columns of the acetabulum is like in IP. Therefore, the second-generation DAPSQ has reliable biomechanical stability.

Objective:To compare the clinical efficacy between our first generation and second generation dynamic anterior plate-screw system for quadrilateral area (DAPSQ) in the treatment of T-shaped acetabular fractures.Methods:A retrospective study was conducted of the 28 patients with T-shaped acetabular fractures who had been treated at Department of Orthopaedics, General Hospital of Central Theater Command from January 2008 to December 2019. They were divided into 2 groups according to fixation methods. Group A [15 patients, 11 males and 4 females, an age of (43.5±9.1) years] were treated with the first generation DAPSQ while Group B [13 patients, 8 males and 5 females, an age of (42.5±7.0) years] with the second generation DAPSQ. Operation time, intraoperative bleeding, fracture reduction, function of the affected hip and postoperative complications were recorded and compared between the 2 groups.Results:The 2 groups were comparable because there was no significant difference between them in the preoperative general data ( P>0.05). The 28 patients were followed up for 12 to 60 months (average, 35.0 months). The operation time [(193.9±33.3) min] and intraoperative bleeding [(830.8±177.4) mL] for Group B were significantly less than those for Group A [(231.3±40.0) min and (1,043.3±190.7) mL] ( P<0.05). In Group A, according to the Matta scoring, the fracture reduction was rated as excellent in 8 cases, good in 5 and poor in 2; in Group B, the fracture reduction was rated as excellent in 8 cases, good in 4 and poor in one. According to the modified Merle d'Aubigné & Postel scoring at the final follow-up, the function of the affected hip was rated as excellent in 9 cases, as good in 3, as fair in 2 and as poor in one in Group A while as excellent in 9 cases, as good in 2 and as fair in 2 in Group B. There were no statistically significant differences between the 2 groups in reduction quality or in the function of the affected hip ( P>0.05). Follow-up observed hip traumatic arthritis in 2 cases in Group A and in one in Group B. Conclusion:In the treatment of T-shaped acetabular fractures, compared with the first generation DAPSQ, the second generation DAPSQ can shorten operation time and decrease intraoperative bleeding significantly, though both achieve comparable functional outcomes.

Objective: To investigate the clinical efficacy of dynamic anterior plate-screw system (DAPSQ) assisted by preoperative digital design in the treatment of acetabular bi-column fractures. Methods: A retrospective case-control study was conducted to analyze the clinical data of 34 patients with acetabular bi-column fractures admitted to the General Hospital of Central Theater Command from January 2012 to January 2018. There were 24 males and 10 females, aged 21-65 years[(43.0±14.2)years]. According to the treatment method, the patients were divided into Group A treated with DAPSQ assisted by preoperative digital design and Group B treated with conventional DAPSQ.Group A was consisted of 17 patients, including 11 males and six females aged 22-64 years [(42.7±12.4)years]. Group B consisted of 17 patients, including 13 males and four females aged 21-65 years[(43.2±14.6)years]. The operation time, intraoperative blood loss, hospitalization time, fracture healing time, Matta radiological standard score of fracture reduction, Merle d'Aubignre-Postel score and complications were recorded and compared between the two groups. Results: All patients were followed up for 12-62 months [(32.8±9.1)months]. The operation time [(160.8±38.5)minutes] and intraoperative bleeding [(455.6±190.4)ml] in Group A were significantly less than those in Group B [(216.9±59.5)minutes] and [(780.2±211.6)ml] (P<0.05). There were no significant differences in hospitalization time, fracture healing time, Matta radiological standard score, modified Merle d'Aubignre-Postel score at the last follow-up between the two groups (P>0.05). In Group A, four patients had traumatic arthritis, with one patient receiving total hip replacement. In Group B, three patients were found with traumatic arthritis, and one with avascular necrosis of femoral head who underwent total hip replacement. None of the two groups had complications such as screws' entry into articular cavity, failure of internal fixation, and incision infection. Conclusions For acetabular bi-column fractures, DAPSQ can effectively maintain the stability of the fracture, without the risk of screws entering the joint cavity, and obtain satisfactory clinical effect. Compared with conventional DAPSQ, preoperative digital design can significantly shorten the operation time and reduce intraoperative bleeding.

Objective To explore associations between mental disorders and accidental death. Methods A case-control psychological autopsy study was conducted in Fengning county in Hebei province, Kailu county in Inner Mongolia, Meixian county in Shaanxi province, Chongzhou county in Sichuan province. One hundred and fifty-seven accidental death cases were identified, based on detailed interview and cause of death listed as"accidental death"(International Classification of Diseases 10th edition codes V01-X59),"suicide"(X60-X84) or"mental disorder"(F00-F98). We used 2008 census data for three of the four counties (Fengning county in Hebei Province stopped participating in the study in 2009), to select a multistage stratified random sample of adult community residents as the living controls. Finally, 140 living controls were randomly sampled. For each cases or controls, one family member and one associate (neighbor or friend) were interviewed separately by different interviewers. For each cases, socio-demographic data, quality of life, and psychiatric diagnosis 1 month prior to accidental death (or 1 month prior to interview for the living controls), and life events and social support 12 months prior to the death or interview (for controls) were evaluated during the interview. Axis Ⅰ mental disorders, Axis Ⅱ personality disorders were diagnosed based on Structured Clinical Interviews for DSM-Ⅳ-TR Axis Ⅰ Disorders (SCID-I) and Axis Ⅱ Personality Disorders (SCID-Ⅱ). Multivariate logistic regression was used to test the association between accidental death and mental disorders. Results The accidental death group was more likely being male (χ2=37.55, P<0.001) and unmarried (χ2=8.82, P=0.003). The prevalence of Axis Ⅰ mental disorder and of axis Ⅱpersonality disorder were higher in accidental death group than that in control group (19.7%( 31/157) vs. 3.6%(5/140), χ2=18.17, P<0.01; 11.5%(18/157) vs .3.6%(5/140), χ2=6.45, P=0.011; respectively). After adjusted for demographic variables, the adjusted OR was 1.78 (95%CI: 1.26-2.51, P=0.001) for mental disorders, and 1.48(95%CI: 1.02-2.15, P=0.040) for mental disorders other than substance use disorders. Conclusion Mental disorder is an independent risk factor for accidental death, whether or not substance use disorders were excluded.

Objective To explore associations between mental disorders and accidental death. Methods A case-control psychological autopsy study was conducted in Fengning county in Hebei province, Kailu county in Inner Mongolia, Meixian county in Shaanxi province, Chongzhou county in Sichuan province. One hundred and fifty-seven accidental death cases were identified, based on detailed interview and cause of death listed as"accidental death"(International Classification of Diseases 10th edition codes V01-X59),"suicide"(X60-X84) or"mental disorder"(F00-F98). We used 2008 census data for three of the four counties (Fengning county in Hebei Province stopped participating in the study in 2009), to select a multistage stratified random sample of adult community residents as the living controls. Finally, 140 living controls were randomly sampled. For each cases or controls, one family member and one associate (neighbor or friend) were interviewed separately by different interviewers. For each cases, socio-demographic data, quality of life, and psychiatric diagnosis 1 month prior to accidental death (or 1 month prior to interview for the living controls), and life events and social support 12 months prior to the death or interview (for controls) were evaluated during the interview. Axis Ⅰ mental disorders, Axis Ⅱ personality disorders were diagnosed based on Structured Clinical Interviews for DSM-Ⅳ-TR Axis Ⅰ Disorders (SCID-I) and Axis Ⅱ Personality Disorders (SCID-Ⅱ). Multivariate logistic regression was used to test the association between accidental death and mental disorders. Results The accidental death group was more likely being male (χ2=37.55, P<0.001) and unmarried (χ2=8.82, P=0.003). The prevalence of Axis Ⅰ mental disorder and of axis Ⅱpersonality disorder were higher in accidental death group than that in control group (19.7%( 31/157) vs. 3.6%(5/140), χ2=18.17, P<0.01; 11.5%(18/157) vs .3.6%(5/140), χ2=6.45, P=0.011; respectively). After adjusted for demographic variables, the adjusted OR was 1.78 (95%CI: 1.26-2.51, P=0.001) for mental disorders, and 1.48(95%CI: 1.02-2.15, P=0.040) for mental disorders other than substance use disorders. Conclusion Mental disorder is an independent risk factor for accidental death, whether or not substance use disorders were excluded.

Objective:To assess the possibility of suicide in setting condition among urban and rural residents samples in northern China.Methods:By randomly sampling,1007 persons aged 18 years or older were selected from 10 urban neighborhoods in Beijing and from 10 rural village in Hebei province.The Survey Schedule of Atti-tudes in China in which 24 negative life events were listed,and the possibility of committing suicide was asked to the subjects when they encountered the supposed events.Results:The rates of thinking about committing suicide when encountered the supposed life events were 65.2% of incurable illness,62.0% of burden on other and no future hope,61.2% of drug dependence,57.3% of large debt due to gambling,54.2% of being raped, 51.6% of severe depression,50.7% of being elderly and no family to provide support.Only 14.6% of the ur-ban and rural residents would not consider suicide when encountered any type of supposed problems.Conclusion:There is higher possibility of considering suicide in urban and rural residents when encountered negative life events, so it is important to give support to the residents with one or more life events.

OBJECTIVETo observe the effect of glycine on the discharge activities of inspiratory neurons in the medulla oblongata slices of neonatal rats.

METHODSNeonatal rat medulla oblongata slices including the medial region of the nucleus retrofacialis (mNRF) with the hypoglossal nerve rootlets retained were prepared. The activity of the inspiratory neurons in the mNRF and the respiratory rhythmical discharge activity (RRDA) of the hypoglossal nerve rootlets were simultaneously recorded using microelectrodes and suction electrodes, respectively. The effect of glycine on the rhythmical respiration was investigated by administration of glycine receptor agonist and its specific antagonist strychnine (STR) into a modified Kreb's perfusion solution (MKS).

RESULTSGlycine significantly shortened the inspiratory time (TI) and integral amplitude (IA) of the inspiratory neurons and decreased the peak frequency (PFn). By contrast, STR induced a decrease in the expiratory time (TE) and respiratory cycle (RC) of the inspiratory neurons, but the peak frequency was not significantly affected.

CONCLUSIONGlycine and its receptor play a role in the modulation of the rhythmical respiration, and glycine is probably involved in the phase-switching between expiration and inspiration by affecting the inspiratory neurons.

Animals ; Animals, Newborn ; Electrophysiological Phenomena ; Glycine ; pharmacology ; In Vitro Techniques ; Inhalation ; physiology ; Medulla Oblongata ; cytology ; physiology ; Neurons ; physiology ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo determine the role of glycine (Gly) in the generation and modulation of basic respiratory rhythm.

METHODSNeonatal (0-3 days) SD rats of either sex were used in this study. The medulla oblongata brain slice containing the medial region of the nucleus retrofacialis (mNRF) and the hypoglossal nerve rootlets was prepared, and the surgical procedure was performed in the modified Kreb's solution (MKS) with continuous carbogen (95% O(2) and 5% CO(2)) within 3 min. The rhythmical respiratory discharge activity (RRDA) of the hypoglossal nerve rootlets was recorded using suction electrode. Eighteen medulla oblongata slice preparations were divided into 3 groups and treated for 20 min with Gly receptor specific agonist Gly (10 micromol/L), Gly receptor antagonist strychnine (STR, 1 micromol/L), or Gly+STR after a 20 min Gly application. The changes in RRDA of the hypoglossal nerve rootlets were observed.

RESULTSGly significantly decreased the inspiratory time and integral amplitude (IA), but the changes of respiratory cycle (RC) and expiratory time (TE) were not statistically significant. STR induced a decrease in expiratory time and respiratory cycle without significantly affecting the inspiratory time or integral amplitud. The effect of Gly on the respiratory rhythm was partially reversed by additional application of STR.

CONCLUSIONGly may play an important role in the modulation of RRDA in the medulla oblongata slice of neonatal rats.

Animals ; Animals, Newborn ; Female ; Glycine ; pharmacology ; Hypoglossal Nerve ; physiology ; Male ; Medulla Oblongata ; physiology ; Rats ; Rats, Sprague-Dawley ; Respiration ; drug effects ; Respiratory Center ; physiology