ABSTRACT
Objective The method of bone lengthening by distraction of callus was used on dog mandible as a model to study the capability and changes of membranous bone during distraction osteogenesis. Methods 15 dogs aged 5～7 months were chosen as the subjects. The operation included a unilateral or bilateral periosteal preserving corti cotomy of mandibular bone, and an introral mini lengthening device were fixed to the buccal side of the mandible. After 7d, the mandible was lengthened lmm/d for 20d and then held in internal fixation for 7～ 140d (1 ～ 20 weeks). Results The dogs were killed at 3 times. Anthropometric measurements, X-ray examination and histological observa tion were conducted and conformed that the distracted bone had formed in the expanded zone successfully. Conclu sion The results suggested that we could use the DO technique in the area of craniofacial clinic. The strong ability of generating new bone in membranous skeleton by DO technique should be further demonstrated in the future.
ABSTRACT
ObjectiveTo introduce the progressing history of DO technique,and report the characteristics of the home-made type MS-1 internal mandibular distracter, and the effects of application of it in animal experiment. Methods15 Mongrel dogs were subjected to be lengthened of the unilateral or bilateral mandibles using the home-made type MS-1 mandibular distracter, and the regular X-ray ex aminations were made. ResultsAbout (20±5)mm in length of the andible had been achieved by the DO (distraction of osteogenesis)technique using the device. The accuracy of the distracter on lengthening would be attained to 98 % of the expectancy. The mineralization of the new bone fulfilled the gap zone about 5 weeks after the distraction had been finished during the consolidation period. ConclusionThe MS-1 type internal mandibular lengthening device has its special advantages on ap plication of cranio-maxillofacial surgery with a great expectancy.
ABSTRACT
Objective: To study the effect of palate repair operation on middle ear function. Methods: Cleft palate was repaired with double-opposing Z-plasty(DOZ) in 20 cases and with routin method (RM ) in 23 cases. Secretory otitismedia (SOM), high negative pressure (HNP), stapedial reflex(SR) and low acoustic compliance (LAC) were determined 3d before and 6 months after operation respectively. Results: Of the total 86 ears, before operation the persentages of SOM, HNP, SR and LAC were 61. 63, 75. 58, 29. 07 and 65. 15; after operation those were 31.39, 43.02, 66.28 and 33.72, respectively. Of the 40 ears of the cases treated with DOZ the persentages of those were 20.00, 27.50, 72.50 and 25.00) while of the 46 ears of the cases treated with RM those were 41.30, 56.52, 60.87 and 41.30 respectivellly. Conclusion: Middle ear function can be improved by palate repairs surgery, better results may be achieved with double opposing Z-plasty technique.