Abstract: ObjectiveTo observe the effect of forced expansion of occlusion on radiation ankylosis of tempormandibular joint of patients with nasopharynx cancer after radiotherapy.Methods166 patients with ankylosis of tempormandibular joint were randomly divided into the treatment group (83 cases, treated with forced expansion of occlusion) and control group (83 cases, with other treatment).ResultsThe absoluteness value of degree of mouth opening in the treatment group was significantly higher than that in the control group( P<0.01), and the course of ankylosis of tempormandibular joint in the treatment group was obviously delayed compared with the control group ( P<0.01).ConclusionThe forced expansion of occlusion can delay the course of ankylosis of tempormandibular joint, expand the degree of mouth opening, recover or partially recover the occlusion and chaw function.

Key words: radiation, ankylosis of tempormandibular joint, expansion of occlusion