Abstract: Objective: To understand variations in blood flow of the temporomandibular joint （TMJ） after loosing one side posterior teeth.Methods: On various periods before and after extracting one side posterior teeth the quantitative changes of the blood flow of the TMJ in miniature pigs were observed by using Tc-99m MDP bone scanning.Results: After 1 month of extracting the values of the time activity curve of blood flow decreased and blood flow arriving was postponed on loosing teeth side TMJ. The more uptake of radionuclide occurred in the blood pool image and the static image in the extracting side TMJs. In this side joints there were less blood flow and more uptake of Tc-99m MDP in postextracting 3 monthes than in postextracting 1 month. Radionuclide activity count of non extracting sides TMJs increased in postoperative 1 month and remained not to go up in 3 mnthes in blood pool image.Conclusion: Loosing one side posterior teeth has an influence over bloodb flow of both sides TMJs. The extracting side joint is more deeply affected and worse as time going on.