Objective:This study aimed to evaluate whether intra-articular delivery of conditioned medium(CM)derived from stem cells of human exfoliated deciduous teeth(SHED)could influence the progression of condylar cartilage degeneration in a rat model of temporomandibular joint osteoarthritis(TMJ OA).Methods:Sixty 8-week-old male SD rats were randomly divided into control group(CON group),intraarticular injection of MIA induced TMJ OA model group(MIA group),and injection of SHED condi-tioned medium 1 week after MIA modeling for treatment group(SHED-CM group),with 20 animals in each group.Histological sec-tions,HE,Safranine O-solid green staining,Col Ⅱ immunohistochemical staining,and TUNEL staining were performed 2 and 4 weeks after the start of treatment.Western blotting and RT-qPCR were used to detect the key molecules of apoptosis,cleaved-CASP3,BAX and BCL2,pro-inflammatory related factors IL-1β,IL-6,TNFα,MMP3,ADAMTS5,and the MAPK pathway-related molecules p-ERK,ERK,p-P38 and P38.Results:Compared with the CON group and SHED-CM group,the condyle chondrocytes in the MIA group had disordered arrange-ment,interrupted layers,significantly thickened fibrous layers(P＜0.001),and significantly increased Mankin's OA histological score(P＜0.001).In the MIA group,both the Safranin O-positive area ratio and the proportion of ColⅡ-positive regions were markedly reduced compared with the CON and SHED-CM groups(P＜0.001).Conversely,the proportion of TUNEL-positive cells was substantially higher than in the other two groups(both P＜0.001).Western blot analysis further demonstrated that apoptotic markers(cleaved-CASP3,BAX/BCL2)and MAPK pathway-related proteins(p-ERK,ERK,p-P38,P38)were expressed at significantly elevated levels in the MIA group relative to CON and SHED-CM groups(BAX/BCL2:P＜0.05;cleaved-CASP3:P＜0.01;p-P38/P38:P＜0.001;p-ERK/ERK:P＜0.01).Similarly,qRT-PCR revealed upregulated expression of inflammatory mediators,including IL-1 β(P＜0.001),IL-6(P＜0.01),TNFα(P＜0.01),MMP3(P＜0.001),and ADAMTS5(P＜0.05),in the MIA group compared with the CON and SHED-CM groups.Conclusion:SHED-CM treatment can ef-fectively reverse MIA-induced condylar cartilage degeneration of TMJ OA in rats.

Objective:This study aimed to evaluate whether intra-articular delivery of conditioned medium(CM)derived from stem cells of human exfoliated deciduous teeth(SHED)could influence the progression of condylar cartilage degeneration in a rat model of temporomandibular joint osteoarthritis(TMJ OA).Methods:Sixty 8-week-old male SD rats were randomly divided into control group(CON group),intraarticular injection of MIA induced TMJ OA model group(MIA group),and injection of SHED condi-tioned medium 1 week after MIA modeling for treatment group(SHED-CM group),with 20 animals in each group.Histological sec-tions,HE,Safranine O-solid green staining,Col Ⅱ immunohistochemical staining,and TUNEL staining were performed 2 and 4 weeks after the start of treatment.Western blotting and RT-qPCR were used to detect the key molecules of apoptosis,cleaved-CASP3,BAX and BCL2,pro-inflammatory related factors IL-1β,IL-6,TNFα,MMP3,ADAMTS5,and the MAPK pathway-related molecules p-ERK,ERK,p-P38 and P38.Results:Compared with the CON group and SHED-CM group,the condyle chondrocytes in the MIA group had disordered arrange-ment,interrupted layers,significantly thickened fibrous layers(P＜0.001),and significantly increased Mankin's OA histological score(P＜0.001).In the MIA group,both the Safranin O-positive area ratio and the proportion of ColⅡ-positive regions were markedly reduced compared with the CON and SHED-CM groups(P＜0.001).Conversely,the proportion of TUNEL-positive cells was substantially higher than in the other two groups(both P＜0.001).Western blot analysis further demonstrated that apoptotic markers(cleaved-CASP3,BAX/BCL2)and MAPK pathway-related proteins(p-ERK,ERK,p-P38,P38)were expressed at significantly elevated levels in the MIA group relative to CON and SHED-CM groups(BAX/BCL2:P＜0.05;cleaved-CASP3:P＜0.01;p-P38/P38:P＜0.001;p-ERK/ERK:P＜0.01).Similarly,qRT-PCR revealed upregulated expression of inflammatory mediators,including IL-1 β(P＜0.001),IL-6(P＜0.01),TNFα(P＜0.01),MMP3(P＜0.001),and ADAMTS5(P＜0.05),in the MIA group compared with the CON and SHED-CM groups.Conclusion:SHED-CM treatment can ef-fectively reverse MIA-induced condylar cartilage degeneration of TMJ OA in rats.

Objective:To investigate the effects of intra-articular injection of exosomes derived from dental pulp stem cells from hu-man exfoliated deciduous teeth(SHED-EXO)on subchondral bone homeostasis in rat temporomandibular joint osteoarthritis(TMJ OA)process.Methods:36 male SD rats were randomly divided into 3 groups(n=12):control(CON),sodium iodoacetate(MIA)-induced TMJ OA(MIA),and SHED-EXO injection into TMJ OA(SHED-EXO)groups.At 2 and 6 weeks post-treatment,Micro-CT,Double labeling,TRAP staining,and immunohistochemical staining were employed to detect osteoclasts and osteoblasts in the subchondral bone.Additionally,the mRNA expression levels of ADAMTs5,IL-1β,OCN and OPG/RANKL were analyzed by qRT-PCR.Results:The MIA group exhibited significant bone loss and an enlarged bone marrow cavity.In comparison with the CON group,BV/TV and Tb.Th were lower(P＜0.001),while BS/BV,Tb.Sp,and Tb.N were higher(P＜0.01).Additionally,the bone formation rate within 5 days was low-er than that of the control group(P＜0.001).When compared to the MIA group,the SHED-EXO group showed a significant increase in bone morphology and bone mass.BV/TV and Tb.Th were increased(P＜0.01),while BS/BV,Tb.Sp and Tb.N were decreased(P＜0.05).The bone formation rate was higher(P＜0.01).Compared with both the control and treatment groups,the MIA group exhibited a significant increase in the number of osteoclasts in the subchondral bone(P＜0.01),along with a notable decrease in H-type blood vessels and OCN-positive areas(P＜0.01).Conclusion:Intra-articular injection of SHED-EXO can reg-ulate condylar subchondral bone homeostasis in TMJ OA of rats by promoting osteogenesis and inhibiting osteoclasts.

30 patients with chronic periodontitis and Type 2 diabetes mellituse were included.By a split-mouth design,the teeth in the left side were served as the experiment group and given Nd∶YAG and Er∶YAG laser therapy adjunctive to conventional periodontal treatment;the teeth in the right side were served as the control group and given conventional periodontal treatment alone.Before and after treatment perio-dontal and CBCT image indexes were examinde and compare between the 2 groups.Before treatment all the indexes were not statistically dif-ferent between the 2 groups(P＞0.05).3 months after treatment,the bleeding index(BI)and probing depth(PD)of the experimental group were significantly lower than those of the control group(P＜0.05).6 months after treatment,BI,PD and attachment loss(AL)in the experi-mental group were significantly lower than those in the control group,and the surface area and volume of the root in the alveolar bone were significantly higher than those in the control group(P＜0.05).Nd∶YAG and Er∶YAG laser therapy adjunctive to conventional periodontal treatment is more effective than conventional periodontal treatment alone in the treatment of chronic periodontitis with type 2 diabetes melli-tus.

Objective:To provide references for further improving the oral health of Air Force pilots by investigating the periodontal health status and oral hygiene behavior of Air Force pilots.Methods:A total of 182 active-duty Air Force pilots who underwent physical examinations at the Air Force Medical Center were randomly selected for periodontal examination and oral hygiene behavior questionnaires survey. They were grouped by age (<35 years and ≥35 years), hometown (urban-originated and rural-originated), and aircraft type (fighter or other aircraft types like bomber, helicopter, transporter, and trainer).Results:Among the 182 Air Force pilots, the detection rate of gingival bleeding, dental calculus, periodontal pocket and loss of periodontal attachment was 86.81%, 75.27%, 6.59%, 9.89%, respectively. There was 82.42% of the pilots brushed their teeth at least twice a day, 35.16% used dental floss every day, 80.22% alternately used different toothpastes, and only 9.34% used toothpastes containing fluoride. There was 56.04% of the pilots brushed their teeth up and down, 8.24% brushed horizontally, 70.88% brushed their teeth for 2-3 min, and 53.30% smoked. In the past 6 months, 48.35% of the pilots had experienced gingival bleeding, but 67.58% had not undergone tooth cleaning treatment in the past 12 months. The detection rates of periodontal pockets, loss of periodontal attachment and the rates of flossing use in ≥35 years group were higher than those in <35 years group, with significant differences ( χ2=6.04, 4.68, 11.00, P=0.014, 0.031, 0.012), and there was also a significant difference in brushing method between the 2 groups ( χ2=17.75, P<0.001). There were significant differences in the detection rates of dental calculus, brushing frequency, brushing method, and the treatment of dental cleaning in the past 12 months between the rural-originated group and the urban-originated group ( χ2=6.25, 7.20, 13.81, 4.02, P=0.012, 0.007, 0.003, 0.045). The smoking rate in the fighter group was lower than that in the other aircraft types group, with significant difference ( χ2=10.10, P=0.018). Conclusions:The periodontal health status of Air Force pilots is still not optimistic, and the oral hygiene behavior still needs to be further improved. It is necessary to further strengthen oral hygiene education for pilots, improve their oral hygiene behavior, and enhance the support capabilities to their oral health.

Objective:To provide references for further improving the oral health of Air Force pilots by investigating the periodontal health status and oral hygiene behavior of Air Force pilots.Methods:A total of 182 active-duty Air Force pilots who underwent physical examinations at the Air Force Medical Center were randomly selected for periodontal examination and oral hygiene behavior questionnaires survey. They were grouped by age (<35 years and ≥35 years), hometown (urban-originated and rural-originated), and aircraft type (fighter or other aircraft types like bomber, helicopter, transporter, and trainer).Results:Among the 182 Air Force pilots, the detection rate of gingival bleeding, dental calculus, periodontal pocket and loss of periodontal attachment was 86.81%, 75.27%, 6.59%, 9.89%, respectively. There was 82.42% of the pilots brushed their teeth at least twice a day, 35.16% used dental floss every day, 80.22% alternately used different toothpastes, and only 9.34% used toothpastes containing fluoride. There was 56.04% of the pilots brushed their teeth up and down, 8.24% brushed horizontally, 70.88% brushed their teeth for 2-3 min, and 53.30% smoked. In the past 6 months, 48.35% of the pilots had experienced gingival bleeding, but 67.58% had not undergone tooth cleaning treatment in the past 12 months. The detection rates of periodontal pockets, loss of periodontal attachment and the rates of flossing use in ≥35 years group were higher than those in <35 years group, with significant differences ( χ2=6.04, 4.68, 11.00, P=0.014, 0.031, 0.012), and there was also a significant difference in brushing method between the 2 groups ( χ2=17.75, P<0.001). There were significant differences in the detection rates of dental calculus, brushing frequency, brushing method, and the treatment of dental cleaning in the past 12 months between the rural-originated group and the urban-originated group ( χ2=6.25, 7.20, 13.81, 4.02, P=0.012, 0.007, 0.003, 0.045). The smoking rate in the fighter group was lower than that in the other aircraft types group, with significant difference ( χ2=10.10, P=0.018). Conclusions:The periodontal health status of Air Force pilots is still not optimistic, and the oral hygiene behavior still needs to be further improved. It is necessary to further strengthen oral hygiene education for pilots, improve their oral hygiene behavior, and enhance the support capabilities to their oral health.

Objective:To investigate the correlation between three-dimensional histogram analysis of dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)and Gleason score(GS)in prostate cancer(Pca)from two hospital, and its diagnostic efficacy for discriminating low-grade from high-grade Pca.Methods:A total of 102 pathologically confirmed Pca patients in the First Affiliated Hospital of Zhejiang Chinese Medical University and Hangzhou Traditional Chinese Medical Hospital(TCM Hospital)Affiliated to Zhejiang Chinese Medical University from January 2017 to October 2020 were retrospectively analyzed.The quantitative parameters of Pca, including transport constant(K trans), rate constant(K ep), percent volume of the extravascular extracellular space(V e)and fraction of the Intraplasmic contrast volume(V p), were obtained by manually layer by layer delineating of interested regions of all lesions on the original DCE-MRI imaging.Then the three-dimensional histogram analysis of the above parameters were performed to obtain the minimum, maximum, median, mean, area, 10 thpercentile, 25 thpercentile, 75 thpercentile and 90 thpercentile.The correlations between quantitative parameters and GS, and diagnostic efficiencies were analyzed. Results:102 Pca patients were divided into low-grade prostate cancer group(GS≤3+ 4)(n=44)and high-grade Pca group(GS≥4+ 3)(n=58). There were no statistically significant differences in age and location of lesions between the two groups( P>0.05), but there were statistically significant differences in Gleason score, PSA level and lesion diameter between the two groups( U=0.000, 730.000, 711.000, all P<0.05). The median, mean, 10 thpercentile, 25 thpercentile, 75 thpercentile, 90 thpercentile derived from K trans, and K ep(median, mean, 10%, 25%, 75%, 90%)together with maximum of K transand mean for V e were positively correlated with GS( r=0.405 to 0.583, P<0.05), in which mean of K transhad the highest positive correlation( r=0.583, P=0.000). The histogram parameters derived from V pwere negatively correlated with GS( r=-0.301 to 0.341, P<0.05). The area under ROC of 75th percentile derived from K transwas the highest(0.832). When the cut-off value of 75 thpercentile derived from K transwas ≥0.680/min, its Youden index, sensitivity, and specificity were 0.594, 0.776, 0.818, respectively. Conclusions:The three-dimensional histogram of DCE-MRI quantitative parameters has correlation with GS in Pca patients, can be used to discriminate low-grade from high-grade Pca.

Objective To investigate the incidence rate of aerodontalgia in fighter pilots and analyze the related factors . Methods The cross-section study was used . The invasion of aerodontalgia was obtained upon a questionnaire survey from 192 fighter pilots , including the occurrence time ,degree ,and location and the incidence rate was calculated .The flying hours and the dental disease were compared between the pilots with and without aerodontalgia . Results The incidence rate of aerodontalgia in fighter pilots was 4 .17% (8/192) .In 8 aerodontalgia cases 7 pilots had dental disease .But in 184 pilots who felt free of aerodontalgia ,53 pilots (28 .80% ) were diagnosed as dental disease .There were significant difference between the incidence rates (χ2＝ 109 .634 , P＜0 .01) .In 8 pilots with aerodontalgia ,5 cases had toothache during taking-off and 3 landing .The flying altitude was 500-1 000 m .Two of 8 aerodontalgia cases appeared the toothache on maxillary teeth and jaw ,5 on lower jaw and 1 on maxillary teeth .There was no significant difference among them (P＞0 .05) .The average flying hours of 8 pilots with aerodontalgia were (2 425 .00 ± 1 445 .93) h while the average flying hours of 184 pilots without aerodontalgia was (1 703 .56 ± 1 331 .08) h .There was no significant difference between them (P＞0 .05) . Conclusions The incidence rate of aerodontalgia was higher in the fighter pilots with dental disease .But the incidence rate has no correlation to the location of toothache and flying hours .It is suggested that pilots should conduct oral examinations every 6-12 months in order to detect and treat dental diseases in time .

Objective To investigate the influence of high + Gzenvironment on receptor activator of nuclear factor κB ligand (RANKL) and osteoprotegerin (OPG) messenger RNA (mRNA ) expression in the peri-implant bone tissue by an animal model. Methods Thirty New Zealand white rabbits were randomly and averagely divided into 3 control groups and 3 experimental groups corresponding to the investigation for 3 weeks ,5 weeks and 12 weeks respectively.Rabbits′ mandible incisors of both sides were extracted and im planted with 1 implant in each socket immediately.After 1 week of rest ,the experimental rabbits were exposed to high + Gzenvironment 3 times a week (Monday ,Wednesday ,Friday) ,The exposure scheme choose the + Gzprofile with 4～9 G for 10～45 s with 1 G/s onset rate and with the intervals of 1 min.The rabbits of control groups were not exposed to + Gzenvironment and normally fed.One control group and one experimental group rabbits were respectively sacrificed at the 3rd week (+Gzexposure for 2 weeks) , 5th week (+Gzexposure for 4 weeks) and 12th week (+Gzexposure for 4 weeks and normal feeding for 7 weeks) after the implanting surgery.The specimens were obtained to find the mRNA expression of RANKL and OPG by real-time polymerase chain reaction (RT-PCR) examination. Results The mRNA expression of RA NKL and OPG were the highest 3 weeks after the surgery in both groups , and then decreased gradually.The RANKL mRNA expression and the RANKL/OPG ratio of the experimental group were significantly higher than those of the control group 3 weeks after the surgery (P＜0.05).Five weeks after the surgery ,the OPG mRNA expression of the experimental group was significantlylowerthanthatofthecontrolgroup(P＜0.05),buttheRANKLmRNAexpressionand RANKL/OPG ratio were still higher than that of control group (P＜0.05).Twelve weeks after the surgery ,the differences on RANKL and OPG mRNA expressions was not obvious between two groups. Conclusions High +Gzexposure could increase the expression of RA N K L ,raise RA N K L/OPG ratio and promote bone resorption ,but may be not conducive to implant bone bonding.

Objective To investigate the incidence rate of aerodontalgia in fighter pilots and analyze the related factors . Methods The cross-section study was used . The invasion of aerodontalgia was obtained upon a questionnaire survey from 192 fighter pilots , including the occurrence time ,degree ,and location and the incidence rate was calculated .The flying hours and the dental disease were compared between the pilots with and without aerodontalgia . Results The incidence rate of aerodontalgia in fighter pilots was 4 .17% (8/192) .In 8 aerodontalgia cases 7 pilots had dental disease .But in 184 pilots who felt free of aerodontalgia ,53 pilots (28 .80% ) were diagnosed as dental disease .There were significant difference between the incidence rates (χ2＝ 109 .634 , P＜0 .01) .In 8 pilots with aerodontalgia ,5 cases had toothache during taking-off and 3 landing .The flying altitude was 500-1 000 m .Two of 8 aerodontalgia cases appeared the toothache on maxillary teeth and jaw ,5 on lower jaw and 1 on maxillary teeth .There was no significant difference among them (P＞0 .05) .The average flying hours of 8 pilots with aerodontalgia were (2 425 .00 ± 1 445 .93) h while the average flying hours of 184 pilots without aerodontalgia was (1 703 .56 ± 1 331 .08) h .There was no significant difference between them (P＞0 .05) . Conclusions The incidence rate of aerodontalgia was higher in the fighter pilots with dental disease .But the incidence rate has no correlation to the location of toothache and flying hours .It is suggested that pilots should conduct oral examinations every 6-12 months in order to detect and treat dental diseases in time .