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.

Glucocorticoids have remained important anti-inflammatory agents in the treatment of chronic kidney disease (CKD).However,the use of glucocorticoids can invoke or enhance insulin resistance,which is closely associated with renal injury and serves as an independent risk of the occurrence and progression of CKD.On the other hand,CKD patients may have insulin resistance,which hampers the use of glucocorticoids in these patients.

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 observe the effect of ultra-low frequency transcranial magnetic stimulation on cerebral blood flow in children with spastic diplegia cerebral palsy. Methods 36 cases of spastic diplegia cerebral palsy were divided into control group (n=21) and obsevation group (n=15), 19 healthy children were as normal group. The control group received conventional rehabilitation training. The obsevation group received the ultra-low frequency transcranial magnetic stimulation in addition. All the children received the check of transcranial color Doppler (TCD). Results Several arterials flow velocity was lower, several arterials pulsatility index and resistance index were higher in the obsevation group than in the normal group before treatment (P<0.05). Compared with the control group, the arterial flow of obsevation group improved, pulsatility index and resistance index decreased in some degrees in the obsevation group after treatment (P<0.05). Conclusion The cerebral blood flow is of low velocity and high resistance in spastic diplegia children, while ultra-low frequency magnetic stimulation could improve the condition of cerebral flow.

Objective To investigate the effect of serum CYFRA21-1 and SCCAg levels on the prognosis of patients with cervical cancer radiotherapy.Methods 100 cases of cervical cancer were diagnosed by pathological examination in our hospital from October 2008 and October 2011,Using radioimmunoassay(RIA) in detection of serum CYFRA21-1 and SCCAg level,Pearson and Spearman correlation is used to study the relationship between serum CYFRA21-1 and SCCAg level and cervical cancer patients with clinical features,using the Cox regression model of CYFRA21-1 and SCCAg level and uterine cervix cancer death or recurrence and metastasis of the relationship.Results 100 cases of patients with cervical cancer,endpoint events in 21 cases,LNR4 patients appear higher risk of endpoint events about 44.3%,CYFRA21-1 and SCCAg levels were with cervical cancer patients with CA-125 values,tumor staging,depth of tumor invasion into positive correlation,and the age of patients,no significant correlation,tumor differentiation(P=0.013),serum CYFRA21-1 levels(P=0.02),serum SCCAg levels(P=0.03),depth of tumor invasion(P=0.04) is cervical cancer patients with endpoint events independent risk factors.Conclusion CYFRA21-1 and SCCAg levels were closely related to the prognosis of patients with cervical cancer radiotherapy.

Objective:To measure the resting pressure of the tongue body on the sagittal and vertical dimensions of the tongue anchorage pad ( TAP) , and to investigate the proper position of TAP as an an-chorage. Methods:Nineteen volunteers with individual normal occlusion (4 males and 15 females, age 23-33 years) were recruited in the study. Individualized TAP was designed and made for each subject. On the sagittal dimension, the pressure along the midline at the level of the distal of the second premolar (PM2), the first molar (M1) and the second molar (M2) were measured. On the vertical dimension, pressures on TAPs with height of -3 mm, 0 mm, and 3 mm were measured, with 0 mm standing for the reference point recorded by the tongue position record. The tongue resting pressure of the volunteers in the upright position was measured by miniature sensors ( FSS1500NS, Honeywell, USA) embedded in TAP. Nonparametric analysis was applied with the significant level of 0. 05. Results:On the vertical di-mension, the pressure obtained at the height of -3 mm, 0 mm, and 3 mm were 105. 83 Pa, 167. 75 Pa, and 254. 25 Pa, respectively (P<0. 001). On the sagittal dimension, the pressure detected at the level of PM2, M1, and M2 were 177. 64 Pa, 126. 72 Pa, and 109. 37 Pa, respectively (P<0. 001). Con-clusion:Tongue pressure rises significantly with the increase of TAP height. On the sagittal dimension, pressure decreases along the palatal midline in an anteroposterior direction. But in the clinical practice, we should also put comfort into consideration.

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 study ultrasonic parameters characteristics of lactation mastitis,breast cancer by using color doppler flow imaging(CDFI)and ultrasonic elastography(UE),and to explore its clinical value.Methods Retrospective analysis was conducted in the clinical data of 85 female patients (a total of 85 breast lesions).All patients were confirmed by pathology,and according to the results of pathology,they were divided into non lactation mastitis group(group NLM,a total of 28 cases),breast cancer group(group Ca,a total of 57 cases).All patients accepted CDFI and UE before treatment,and compared ultrasound parameters between the two groups.Results The proportions of class 0~I(71.43%)and RI<0.7(82.14%)in group NLM were significantly higher than those in group Ca,while the proportions of classⅡ ~Ⅲ(28.57%)and RI≥0.7 (17.86%)were significantly lower than 75.44%,84.21% in group Ca(χ2 =17.185,35.217,all P<0.05).The UE ratings(1.75 ±0.97)and the strain rate ratio (1.64 ±0.83)in NLMgroup were lower than (4.19 ±0.74),(5.03 ±1.08)in group Ca(t=-12.873,-14.623,all P<0.05).The accuracy of CDFI +UE(89.41%)was higher than the accuracy of UE(76.47%)or the accuracy of CDFI(67.06%)(χ2 =12.337,P<0.05).Conclusion CDFI,UE have a certain diagnosis ability for non lactation mastitis and breast cancer,combining both can obtain better diagnostic value,which is worthy of clinical application.