Obstructive sleep apnea hypopnea syndrome(OSAHS) has been the main research area of the Dental Therapy Center for Sleep Apnea,Peking University School and Hospital of Stomatology.The basic research in the center includs: epidemic survey of OSAHS and snoring in a Beijing population,setting up the cephalometrc and MRI standard of airway and surrounding structures for non-snoring Chinese,aetology exploring OSAHS from views of airway size,craniofacial form,neck circumference and genioglossus muscle activity.Clinically,different dental appliances were developed.The treatment effects of the oral appliances for OSAHS patients were evaluated quantitatively.Two and three dimension changes of the airway and surrounding structures,genioglossus muscle activity,as well as snoring loudness following mandible advancing and opening were studied.Besides,research was expended to OSAHS in children recently.Under the support of National Nature Science Foundation 7 PhD and 3 MS students have graduated.More than 60 papers were published domestically and abroad and two awards were received from the National Ministry of Education and Chinese Medical Association in the past 10 years.This paper is a review of the past and current situation of dental research on OSAHS in China.

Objective: To design and develop a preadjusted appliance based on Chinese normal occlusion, and to apply it in treatment of malocclusion cases.Methods: According to the results of the research performed in Department of Orthodontics, School of Stomatology of Peking University about teeth position and morphology of 67 Chinese with normal occlusion, the preadjusted appliance with the optimal prescription for Chinese has been designed and developed (Z1 appliance). Z1 appliance has been used in treatment of malocclusion cases. The efficiency of Z1 appliance was evaluated. Results:The treatment of 30 non-extraction cases and 16 extraction cases has been completed with Z1 appliance. A quite good result of clinical application of Z1 appliance was represented. Conclusion: Z1 appliance could be used in treatment of Chinese malocclution. The bracket base for anterior teeth was too thick and need more improvement.

Objective:To study the effect of surrounding tissues on the minimum cross-section area(minCSA) of upper airway in non-snoring males.Methods: Upper airway scanning by magnetic resonance imaging(MRI) was conducted in 83 non-snoring males aged 22 to 57 years. The correlation between the minCSA of upper airway and the linear, area and volume measurement items about the morphology of the surrounding tissues was analyzed. Results: The minCSA was in velopharynx or glossopharynx. In non-snoring males,the main relative factors to minCSA were transverse dimension/ transverse distance between mandible(r=0.700), transverse dimension/ pharyngeal wall thickness(r=0.680), and parapharyngeal fat volume(r=-0.290). The velopharynx was more prone to be affected by the surrounding tissues than the glossopharynx. The location of the parapharyngeal fat, the lateral pharyngeal wall and parapharyngeal fat volume had the most obvious influence on the velopharyngeal size in sequence. While the thickness of the lateral pharyngeal wall was the main factor which influenced the size of glossopharynx. Conclusion: The feature of surrounding tissues has certain influence on minCSA of upper airway in non-snoring males.

Objective: To obtain the data about morphology of upper airway and surrounding tissues of non-snoring males from three age groups. Methods: Through questionnaires and clinic examinations, 83 non-snoring males (20-60 years) were selected from 453 volunteers and involved in the following research. There were 30 volunteers aged from 22 to 29 (mean 23.60?2.58 years), 31 volunteers aged from 36 to 45 (mean 40.10?2.64 years) and 22 volunteers aged from 46 to 57 (mean 49.55?3.45 years). Magnetic resonance imaging (MRI) of upper airway of each volunteer was acquired under strict posture-control conditions. The dimensions and cross-section area of nasopharynx, velopharynx, glossopharynx, hypopharynx and whole upper airway with its surrounding tissues were measured with MRI intrinsic software. Volumes of upper airway and surrounding tissues were also calculated. Results: There were 93 items about morphology of the upper airway and surrounding tissues of non-snoring males from the three age groups.With increase in age, some nasopharynx items showed increase tendency, while little change showed in velopharynx, glossopharynx and hypopharynx. Fat volume, tongue volume, anterior and posterior pharyngeal dimension showed age-related increase tendency, but fat deposition rate slowed down in elder age in non-snoring males, which supplies the reason why non-snoring males avoided becoming sleep apnea patients. Conclusion:We provide age-related reference data of upper airway and its surrounding tissues for further sleep and respiration research.

Objective:To investigate changes in the circum-maxillary sutures during alternate maxillary expansions and constrictions in a rat model.Methods:Twenty-two male Sprague-Dawley rats (6 weeks old)were used and divided into three groups.In maxillary expansion (ME)group (n=9),an expander was activated for 5 d,and then sacrificed.In alternate maxillary expansions and constrictions (Alt-MEC) group (9 animals),an alternate expansion and constriction protocol (5 d expansion and 5 d constriction for one cycle)was conducted for 2.5 cycles (25 d total),and then sacrificed.The control group com-prised 4 animals with no appliances used,each of two sacrificed on day 5 and day 25 ,respectively.Cir-cum-maxillary sutures (mid-palatal,maxillopalatine,premaxillary,zygomaticotemporal,and frontonasal suture)in each group were characterized histologically.Results:Histological findings of circum-maxil-lary sutures:in control group,the normal sutures were divided into 5 zones,the center was polygon mesenchyme zone,the lateral was mature chondrocyte zone,the next lateral was bone tissue.In ME group,the mid-palatal suture was expanded after ME,the fibre and connective tissue were extracted and invaded into cartilage zone.Osteoblast hyperplasia and new bone formation occurred.The orientation of the new bone trabecula was consistent with force.The osteoclast appeared in some area.Findings of other sutures were similar with those of control group,osteogenesis was active in some area without obvious re-construction in Alt-MEC group,mid-palatal suture and other sutures in some area were widened after Alt-MEC with much more osteoblast hyperplasia and new bone formation.Fibre and connective tissue were extracted,distorted or even broken.Sutures in some areas were narrowed with osteoblast cytopenia and osteoclast hyperplasia.Fibre and connective tissue compressed because of the different force and orienta-tion.Osteoclast count results showed that compared with the control group,the number of the osteoclast was increased only in the palatal suture in ME group (P<0.05 ).Other sutures did not show obvious changes (P>0.05).In Alt-MEC group,the numbers of the osteoclast in circum-maxillary sutures were the most,and had statistical significances (P<0.05 ).Conclusion:These results suggested that cir-cum-maxillary sutures were actively reconstructed after Alt-MEC.while only midpalatal suture had active reaction after ME.

Objective:To investigate the effectiveness and safety of early combined with tirofiban in the treatment of elderly patients with acute ischemic stroke after intravenous thrombolysis with alteplase.Methods:Elderly (60-75 years old) patients with acute ischemic stroke received intravenous alteplase thrombolysis in the Department of Neurology, Traditional Chinese Medicine Hospital of Huangdao District, Qingdao from January 2018 to May 2020 were enrolled prospectively. According to whether tirofiban is combined or not, they were divided into tirofiban group and non-tirofiban group. Tirofiban was pumped intravenously 2 h after intravenous thrombolysis, first 0.4 μg/(kg·min) for 30 min, then 0.1 μg/(kg·min) for 24 h. The efficacy endpoints included National Institutes of Health Stroke Scale (NIHSS) score at 7 d after treatment and modified Rankin Scale (mRS) score at 90 d after onset. 0-2 was defined as good outcome, and >2 was defined as poor outcome. The safety endpoints included the incidence of hemorrhagic transformation, symptomatic intracranial hemorrhage (sICH) and mortality within 90 days after onset.Results:A total of 124 patients with acute ischemic stroke were enrolled. The median age was 68 years (range, 60-75 years). There were 73 males (58.9%) and 51 females (41.1%). There were 62 patients (50%) in the tirofiban group and 62 (50%) in the non-tirofiban group. The median baseline NIHSS score was 14. Hemorrhagic transformation occurred in 7 patients (5.6%), of which 2 were sICH (1.6%). The follow-up at 90 d after onset showed that 68 patients (54.8%) had a good outcome, 56 (45.2%) had a poor outcome, of which 4 (3.2%) died. The NIHSS score at 7 d after treatment (5.52±4.79 vs. 7.35±3.80; t=2.357, P=0.020) and the rate of good outcome at 90 d after onset (64.5% vs. 45.2%; χ2=4.689, P=0.030) in the tirofiban group were significantly better than those of the non-tirofiban group, and there were no significant differences among the incidence of hemorrhagic transformation (4.8% vs. 6.5%; P=1.000), sICH (1.6% vs. 1.6%; P=1.000), and 90 d mortality (3.2% vs. 3.2%; P=1.000). Conclusion:After intravenous thrombolysis with alteplase, the early combined treatment with tirofiban in elderly patients with acute ischemic stroke can significantly improve the efficacy and outcome, and will not increase the risk of hemorrhagic transformation, sICH and death.

Objective To summarize our experience with surgical management of renal neoplasm involving inferoir veno cava.Methods We review the data of 115 patients,including 74 male patients and 41 female patients,with renal neoplasm involving venous system between March 1993 and December 2015.The mean age was 52 years old,ranging 22 to 77 years old.The tumor was found in right side in 77 cases and left side in 38 cases.There were 15 patients (13.0％) with renal vein thrombus,38 (33.1％) with infrahepatic thrombus,29 (25.2％) with low retrohepatic thrombus,20 (17.4％) with high retrohepatic thrombus,and 13 (11.3％) with supradiaphragmatic thrombus.The mean age was 52 years old,ranging 22 to 77 years old.The tumor was found in right side in 77 cases and left side in 38 cases.All patients accepted the radical nephrectomy.Primary outcomes were overall survival (OS),and cancer special survival (CSS) in patients with renal cell carcinoma (RCC) estimated by Kaplan-Meier method.Secondary outcome included operative and oncological features,past-operative complications and hospital mortality.Cox proportional hazard model was used to univariate and multivariate analysis for risk factor impacting on OS of RCC patients.Results Complete resections of renal neoplasm with tumor thrombus were achieved in 113 patients (98.3％),2 patients died intraoperatively due to the dropping of thrombus.Postoperative complication rate was 16.8％.Hospital mortality was 2.6％.Mean follow-up interval was 48 months.OS rates at 5-,and 10-year in RCC patients were 66.5％,and 61.8％,respectively.Metastasis was an independent risk factor affecting on OS (P =0.000).However,the level of thrombus was not an risk factor affecting the prognosis.Conclusions Radical resection of renal tumor and caval thrombus is an effective treatment for prolonging survival in patients with RCC extending into venous system.Retrohepatic caval tumor thrombus below or above the main hepatic vein should be dichotomized and managed respectively with diverse techniques.Metastatic rather than the level of thrombus was a risk factor impacting on RCC patient survival.

OBJECTIVETransesophageal echocardiography was performed during closed-chest cardiopulmonary resuscitation (CPR) in in-hospital cardiac arrest to further explore the hemodynamic mechanism of CPR.

METHODSCPR attempts were performed according to advanced cardiovascular life support guidelines in 6 cases of in-hospital cardiac arrest. Multi-plane transesophageal echocardiography was carried out within 15 min of initiation of CPR. Throughout CPR, the motion of the mitral, tricuspid and aortic valves, the changes in the left ventricular cavity size and the thoracic aortic diameter were observed. Trans-mitral and trans-aortic Doppler files of blood flow were also documented.

RESULTSA closure of the mitral and tricuspid valves with simultaneous opening of the aortic valve occurred exclusively during chest compression, resulting in forward blood flow in the pulmonary and systemic circulation. Peak forward aortic flow at a velocity of 58.8 +/- 11.6 cm/s was recorded during the compression phase. Whereas, a closure of the aortic valve and rapid opening of the atrioventricular valves associated with ventricular filling during relaxation of chest compression was noted in all 6 patients. Peak forward mitral flow at a velocity of 60.6 +/- 20.0 cm/s was recorded during the release phase. Mitral regurgitation during the chest compression period was detected in 5 patients, reflecting a positive ventricular-to-atrial pressure gradient. A reduction in the left ventricular chamber and an increase in the thoracic aortic diameter during the compression phase was found in all patients, indicating that direct cardiac compression contributed to forward blood flow.

CONCLUSIONThese observations favor the cardiac pump theory as the predominant hemodynamic mechanism of forward blood flow during CPR in human beings.

Aged ; Aged, 80 and over ; Cardiopulmonary Resuscitation ; Echocardiography, Transesophageal ; Female ; Heart Arrest ; diagnostic imaging ; physiopathology ; therapy ; Hemodynamics ; Humans ; Male ; Middle Aged

BACKGROUND: The silk fibroin/type II collagen composite scaffold has been prepared by low-temperature bio-3D printing technology in the previous study and the scaffold has good mechanical properties. Studies have shown that mechanical stimulation is beneficial to bone remodeling, and gradient loading strain is beneficial to the activation of osteoblasts and osteoclasts. OBJECTIVE: To co-culture silk fibroin/type II collagen composite scaffolds with chondrocytes under compression loading, to observe the proliferation of cells, and to observe the preliminary repair effect of silk fibroin/type II collagen composite scaffold on cartilage defects. METHODS: The silk fibroin/type II collagen composite scaffold was prepared by low-temperature 3D printing to detect the porosity of the scaffold. The passage 3 mouse chondrocytes ADTC-5 were inoculated on the silk fibroin/type II collagen composite scaffold and cultured under static culture and mechanical load respectively. (1) Static culture: blank scaffold was set as control, and cell proliferation was detected by MTT assay at 1, 3, 5, 7, 10, 14 days of inoculation. (2) Culture under mechanical load: blank scaffold was set as control. At 1 day after inoculation, 0％, 1％, 5％, 10％, 15％, 20％ compressive strains were applied to the cell-scaffold complex, and continued to load for 3 days. Cell proliferation was detected by MTT assay, and the distribution, adhesion and morphology of the cells on the scaffold were observed by scanning electron microscopy and hematoxylin-eosin staining. A cartilage defect of 3.5 mm in diameter was made in the bilateral knee joint of New Zealand rabbits. The silk fibroin/type II collagen composite scaffold was implanted onto the left side, and no material was implanted onto the right side. The repair site was observed at 8 weeks after surgery. RESULTS AND CONCLUSION: (1) The porosity of the scaffold was (89.3±3.26)％, which was conducive to cell attachment. (2) After 5 days of static culture, the chondrocytes proliferated well on the surface of the composite scaffold. Under 0％, 1％, 5％, 10％, 15％, 20％ compressive strains, the cell proliferation on the scaffold first increased and then decreased, wherein the cell proliferation was highest under 10％ compressive strain, and lowest under 20％ compressive strain. (4) Under the scanning electron microscopy, the chondrocytes in the 0％ load group were distributed in the surface of the scaffold with irregularities, the cell morphology was obvious, and the cell protrusions were fully extended. There were few or no chondrocytes on the contact surface of the 10％ load group, and more cells distributed on the lateral and internal surfaces of the first layer, but the cell morphology was flat with obvious protrusions. (5) Hematoxylin-eosin staining showed that the chondrocytes in the 0％ load group were concentrated on the surface of the scaffold, and there were almost no cells in the pores, while the chondrocytes in the 10％ load group were distributed in the scaffold pores. (6) There was still a circular defect model with no scaffold implantation, and no obvious repair appeared; similar hyaline cartilage appeared in the defect after scaffold implantation, but there was no adhesion to the surrounding defected cartilage, and the new hyaline cartilage was independent. Overall, the adsorption, proliferation and growth of chondrocytes on the silk fibroin-type II collagen scaffolds is better when the compressive strain is 10％, and the composite scaffold can be used as a repair material for cartilage defects.

Mouth breathing in children are increasingly concerned by the physicians and the society. Incompetent lip closure can be classified as oral habit and pathological mouth breathing. Pathologic mouth breathing due to hypertrophy of adenoids and tonsils is often the cause of obstructive sleep apnea in children, which may lead to craniofacial deformities and other consequences. At present, there are many problems in the definition, diagnosis and treatment of mouth breathing, which need to be clarified.