The Clinical Study On The Effect Of Occlusal Splint On Stomatognathic Function In Patients With Severe Tooth Wear

The patients with severe tooth wear often suffer from stomatognathicsystem disorder Occlusal reconstruction, especially by occulusal splint, isusually to treat this kinds of patients. Occlusal splint can improve lots ofstomatognathic system diseases,and is widely used in clinic.In the past,therecovery of occlusal vertical dimension, the subjective feeling of patientsabout occlusion, mastication and pronunciation, the improvement of thesymptoms in masticatory muscle and temporomandibular joint, were usuallyused to evaluate the effect of occlusal reconstruction.But all these subjectiveindex can not be used to evaluate treatment efficacy objectively.Nowadays, T-ScanⅢocclusal analysis system,Bio-EMGⅢelectromyograph,and JT-3D jawtracker can be used to evaluate the effect occlusal reconstruction’ effectobjectively. In clinic, the response of masticatory system should be observedfrequently, after recovering OVD for the patients. The observation periodusually1-2months. Another study showed that the optimal mandibularposition was determined after ш months from wearing occlusal splint. Howthe effect of occlusal splint on stomatognathic function in patients changewith time, remains unclear. Up to now, there is no uniform standard inevaluating the treatment efficacy after wearing occlusal splint.The presentstudy was to investigate the effect of occlusal splint on stomatognathicfunction objectively in10patients with severe tooth wear, and to providesome evidence for clinical treatment.Objective:The present study was to detect the changes of pain in masticationmuscle or temporomandibular joint, the electromyography amplitude ofmasseter and anterior bundle of temporalis, the stability of mandibularposition and occlusion, the smoothness and symmetry changes in maximalmandibular movement, and to investigate the effect of occlusal splint onstomatognathic function in patients with severe tooth wear.Methods:After routine oral examination,and basic treatment,occlusal splint wasused to recover the occlusal vertical dimension.Before the recovery and1,3,6months after that, T-ScanⅢ occlusal analysis system was used to analyzethe balance of occlusal force distribution.The Bio-EMG Ⅲ electromyography was used to detect theelectromyography amplitude of masseter and anterior bundle oftemporalis.The JT-3D jaw tracker was used to analyze the stability of mandibular position and occlusion, and the smoothness and symmetrychanges in maximal mandibular movement.Result:Before treatment, all10patients all have different levels of pain intemporomandibular joints or mastication muscles. The level of paindidn t change significantly in the first month after wearing occlusalsplints（P>0.05），but decreased significantly in3and6months groupsthan pretreatment group(P<0.05).Before treatment, the balance of occlusal force distribution in all10patients didn’t reach the first level. Hoever, that in80%of patients reachedthe first level after6months.3. The EMG amplitude of the masseter and anterior bundle of temporalisat rest position reduced significantly after treatment (P<0.05), while that atclenching intercuspal postion increased significantly in3months and6months groups compared to pretreatment group(P<0.05).4. The stability of mandibular position and occlusion,and, thesmoothness and symmetry changes in maximal mandibular movement,improved gradually after wearing occlussal splints. After6months treatment80%of patients recoverd to normal state.Conclution:Within the observational period of6months, occlusal splint canimprove stomatognathic function of patients with severe tooth wear.