The fibrosis under the impact of masticatory muscle and temporomandibular joint receiving radiation therapy, which leads to tighter lockjaw. Patients could have less flexibility when opening the mouth while the reduction of mouth-opening width will affect the performance of eating.

Lockjaw and difficulty with opening the mouth could occur during or after radiation therapy, which level depends on the received dose and fibrosis produced. 

Treatment Method

• Denture removal is suggested for removal during the radiation therapy.  
• Keep opening and clothing the mouth during the therapy period.

Prevention of Lockjaw

• The average person can open the mouth to the width of accommodating 3~4 fingers horizontally. Do it multiple days per day and multiple opening to the maximum extent. Avoid excess force to prevent displacement.
• The opening and closing and left/right exercise of jaw.
• Use the hand or spatula to help open the mouth and frequently measure the distance between the upper and lower incisor to observe the progress. 

• Engage in mouth-opening exercise during and after the therapy with routine return for follow-up. 

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