?Objective: To examine the morphologic changes produced by extranueral injection of methylene blue around rat infraorbital nerve. Methods: Under direct vision, 50 ?l of methylene blue at the concentration of 20 g/L was injected extranuerally into the infraorbital foramen on one side of the maxillar bone of each of 32 rats; physiological saline was used as the control on the contralateral side of each animal. Animals were killed at 3 days, 2, 4, 8 and 14 weeks after the application of methylene blue respectively. The infraorbital nerve specimens were examined by light and electron microscopes. Results:Axolysis and demyelination were found in the outer zone of the nerve bundles, and a few of centrally located axons were damaged in 2 and 3 weeks. 4 weeks later,a few of regenerated fibers were observed. Wallerian degeneration still remained and more regenerated fibers were found in 14 weeks. The sheath of myelinated fibers became twisted, thick and dissolved. The axonal changes characterized by either swelling, shrinking or vacuolization of axoplasm. Lysosome could be seen in the axons. The changes of myelinated fibers were more evident than that of demyelinated fibers. At the later stage, the regularly regenerated fibers with thin sheath could be seen. No change was observed in the Schwann cells. Conclusion: 20 g/L methylene blue can result in the changes of the sheath and axons of nerve fibers

Objective: To investigate correlation between the expression of Fas antigen in hemangioma and vascular malformation.Methods: Anvidin-biotin complex immunohistochemical method was used to detect the expression of Fas antigen in 31 cases hemangioma and 10 cases of vascular malformaton. Results: The expresson of Fas antigen was positive in hemangioma and negative in vascular malformation. Conclusion: The expression of Fas antigen might be related to the natural involution of hemangioma.

To study the influence of different processing technigue in preparing allogeneic bone on proliferation rate and activity of rabbit osteoblasts in vitro, Osteoblasts were cultured combined with allogeneic bone prepared with different processing techniqne. Cell proliferation and activity were assessed 48 and 96h with MTT colorimetry and assay of alkaline phosphatase activity. The results showed that freezed bone (FB) and lyophilized bone (LB) inhibited cell growth and activity, while mineralized bone matrix (DBM),bone matrix gelatin (BMG), and autolyzed antigen extracted allogeneic bone(AAA) enhanced them. With the exception of FB and LB, the three others were biocompatible for osteoblasts.

砄bjective:To study the absorption of porous block ? tricalcium phosphate(? TCP) implanted in the defects of rabbit calvarium.Methods:Twenty four rabbits were randomly divided into four groups with six in each,a round piece of bone with the diameter of 8 mm was removed on left and right sides in the calvarium of each animal.? TCP samples were implanted in the left defects and hydroxyapatite(HA)in the right.Rabbits were sacrificed at 2,4,8,12 weeks after operation respectively,The implanted materials were quantitatively measured by "Point Counting".Results:Twelve weeks after operation,the amount of ? TCP and HA remained in the transplants were 34.54% and 49.28%,while the bone tissue comprised 24.43% and 19.67% of ? TCP and HA transplants respectively.Conclusion:Porous block ? TCP is more absorbable and more feasible for new bone tissue regeneration than HA.

Objective To determine the prevalence of dental anxiety in children patients before tooth extraction.Methods　A modified Children's Fear Survey Schedule-Dental Subscale (CFSS-DS) and Venham's clinical ratings of anxiety and cooperative behavior were used in 150 children patients ranging in age from 5 to 12 years olds before tooth extraction. The former scale was answered by parents on behalf of their children, and the latter ratings was assessed by the author. Results　CFSS-DS scores and clinical ratings of behavior of the children were significantly higher in the children whose oral hygiene condition, dental experience, tooth extraction experience, spirit status on that day and whose mother's educational background were bad or low. A step regression analysis showed that oral hygiene condition had most significant interrelationship with both of the two scales（P＜0.01）. The correlation of the two scales was high (r=0.67).Conclusion　Children’s oral hygiene condition, dental experience, tooth extraction experience, spirit status on that day and their mother’s educational background are closely related to the dental anxiety level. Oral hygiene condition is the most important predictor of anxiety level before extraction and clinical ratings of behavior during extraction.

OBJECTIVETo study the effects of cardiovascular function in dental extraction on hypertensive patients by inhalation 50% nitrous oxide.

METHODSThe 30 hypertensive patients were randomly allocated into two groups: A group inhalation the 50% nitrous oxide and oxygen, B group inhalation the air and O(2). To measured the HR, BP, and SpO(2) in dental extraction.

RESULTSIn a group the changes of blood pressure and heart rate are more smoother than B group. Two groups were significant in HR, BP and SpO(2) (P < 0.01).

CONCLUSIONSInhalation with 50% nitrous oxide can keep the stability of cardiovascular system and it is a valid method in dental extraction on hypertensive patients.

Administration, Inhalation ; Aged ; Anesthetics, Inhalation ; administration & dosage ; pharmacology ; Blood Pressure ; drug effects ; Female ; Heart Rate ; drug effects ; Hemodynamics ; drug effects ; Humans ; Hypertension ; physiopathology ; Male ; Middle Aged ; Nitrous Oxide ; administration & dosage ; pharmacology ; Oxygen ; blood ; Partial Pressure ; Time Factors ; Tooth Extraction