ABSTRACT
Objective To design a new type of mouth opening training device.Methods The device had a semicircular structure,and was composed of upper and lower bite blocks,a spring and a regulation mechanism.The bite blocks were made by one-step injection molding,and the spring and regulation mechanisen were manufactured by metal forming.Totally 88 patients with restriction of mouth opening after mandible fracture surgery in the oral surgery department from January to December 2016 were randomly divided into two groups,and each group had 44 patients.The control group used the traditional bite block for mouth opening training,and the experimental group applied the developed training device.Training was started 10 d after surgery,and the training time lasted 3 to 6 months.Results The experiment group behaved significantly better than the control group in maximal mouth opening (P＜0.05) and patient comfort (P＜0.01).Conclusion The training device gains advantages in easy operation,patient comfort,flexibility for regulation,cleaning and maintenance and patient compliance,and thus is worthy promoting clinically.