Most of the maxillary first premolar are single-rooted,there are also two-rooted and three-rooted ones.A case of three-rooted maxillary first premolar was diagnosed by CBCT.CBCT has the advantage in the observation of the variation root number,root canal bending and the variation of root canal morphology.

Objective:To analyze the 3D changes of pharyngeal airway in patients with skeletal Class Ⅲ malocclusion after rapid maxillary expansion(RME)and maxillary protraction.Methods:53 patients underwent orthodontic treatment with Hyrax palatal ex-panders and maxillary protraction.Cone-Beam computed tomography(CBCT)scan was taken before treatment(T0),after 1 6 d RME (T1 )and after about 5 month maxillary protraction(T2).Data were reconstructed into 3D model,sagittal and transversal measure-ments,cross sectional areas,volumes of the pharyngeal airway were computed.Results:After RME,the transversal measurements, cross sectional areas,volumes of nasal passage were increased(P <0.05).After maxillary protraction,the 4 nasopharyngeal measure-ments were increased(P <0.05).Conclusion:RME and maxillary protraction may increase pharyngonasal airway.

OBJECTIVE:To study the anti-coagulation effect and mechanism of fibrinolytic enzyme SNFE in sipuculus nudus, and provide reference for further development of SNFE. METHODS:40 mice were randomly divided into blank control group(nor-mal saline),Xueshuantong group(positive control,15 mg/kg)and SNFE low-dose,high-dose group(15,30 mg/kg),10 in each group. After intravenous injection in tail,tail bleeding time (BT) and clotting time (CT) were respectively determined to investi-gate the anti-coagulation effect of SNFE. After taking blood in abdominal aorta of rats,test was divided into blank control group, positive control group and SNFE low-mass concentration,medium-mass concentration,high-mass concentration groups (0.25, 0.50,1.00 mg/mL). Prothrombin time(PT),re-calcium time(PRT)(using orokinase as positive drug,100000 U/mL),and max-mum platelet aggregation rate (PAG) in 5 min under adenosine diphosphate (ADP) inducer (using asprin as positive drug,0.50 mg/mL) were respectively determined,and anti-coagulation effect mechanism of SNFE was analyzed. RESULTS:Compared with blank control group,BT,CT of mice in each group were prolonged,with statistical significance in Xueshuantong group and SNFE high-dose group (P<0.05 or P<0.01). Plasma PT of rats in positive control group,SNFE medium-dose,high-dose groups and PRT in each administration group were significantly prolonged(P<0.05 or P<0.01);and PAG in administration group was signifi-cantly reduced(P<0.01). CONCLUSIONS:The fibrinolytic enzyme SNFE in sipuculus nudus can play its anti-coagulant effect by inhibiting the activity of coagulation factors in internal and external sources and ADP-induced platelet aggregation.

OBJECTIVESTo evaluate the naso-maxillary complex width and pharyngeal airway volume changes after rapid maxillary expansion (RME).

METHODSThirty-five patients were selected (18 males, 17 females, mean age, 12.1 ± 1.1 years). All patients underwent orthodontic treatment with Hyrax palatal expanders. Cone-beam CT (CBCT) scan was taken before treatment (T0), 16 days (T1) and three months (T3) after RME. Naso-maxillary complex width and pharyngeal airway volume were measured.

RESULTSAfter treatment the width of piriform aperture and maxillary width were significantly increased compared with that before treatment (P < 0.05). Three months after RME, no statistical difference was found in maxillary width compared with that before treatment. The nasopharyngeal volume significantly increased by 29.9% compared with that before treatment (P < 0.05), and the volume remained relatively stable after three months.

CONCLUSIONSRME resulted in a significant increase in the naso-maxillary complex width and nasopharyngeal volume.

Cone-Beam Computed Tomography ; Female ; Humans ; Imaging, Three-Dimensional ; Male ; Maxilla ; diagnostic imaging ; Nose ; diagnostic imaging ; Palatal Expansion Technique ; Palate ; diagnostic imaging ; Pharynx ; diagnostic imaging