Mouth opening limitation induced by scarring in the supporting ligaments of the temporomandibular joint following maxillectomy: a 3D simulation study

Purpose: Mouth opening limitation following maxillectomy significantly has great influence on the quality of life.The purpose of this study was to analyze the effect of scarring in the supporting ligaments of the temporomandibular joint that is recognized as one of the causes of mouth opening limitation using a three-dimensional computer simulation.Materials and Methods: Based on the CT data from a healthy adult, a computer musculoskeletal model with a maxillary palatal defect was developed.The geometry from patient's CT data was imported into the biomechanical simulation platform Artisynth to reproduce mandibular movement.Four simulations including scar tissue in the capsular and temporomandibular ligament were established.Forty and 60 percent of the maximum voluntary muscle contraction (MVC) were applied to evaluate the mouth opening limitation.Distance between maxillary and mandibular central incisors were evaluated.Results: In all simulations, the model that had scarring in the capsular ligament showed the most significant mouth opening limitation.The simulation with scarring only in the temporomandibular ligament also showed reduced mouth opening compared to the non-scarred condition.However, the effect was less than that of the capsular ligament.Conclusion: When the capsular ligament that plays a great role in mandibular movement is scarred, it might be the one of the most important factors in mouth opening limitation.Therefore, in the surgical treatment around the temporomandibular joint, the biomechanical characteristics of the joint supporting ligaments has to be considered.(