Effect Of Sagittal/Vertical Ratio Of Snoring Stopper On Condylar Stress In Patients With Obstructive Sleep Apnea Hypopnea Syndrome

As a common sleep-breathing disease,Obstructive sleep apnea hypopnea syndrome(OSAHS)has always affected human health.The forward mandibular extensor stop snoring device is a simple and effective method for the treatment of patients with mild and moderate OSAHS.Its mechanism is to change the position of mandible during sleep,thus driving the movement of tongue,soft palate and other tissues,facilitating the removal or widening of pharyngeal airway stenosis in patients with speech,so as to achieve the purpose of treating OSAHS.The vertical opening distance of the jaw also has a great impact on the final therapeutic effect.If the mandibular sagittal/vertical ratio is not properly allocated,the treatment effect may be weakened,the condylar contact stress increases,and the burden of temporomandibular joint is aggravated,so that the patient can not tolerate the treatment and give up.The main content of this study is to guide the change of mandibular sagittal/vertical ratio and compare the stress of the subcondyle in different positions,so as to obtain better efficacy and comfort.Therefore,if the vertical opening distance and the amount of mandibular protraction can be known in advance for medical personnel to refer to when making a mandibular protraction snoring arrestor,it is of great significance in reducing treatment time,enhancing treatment effectiveness,and patient acceptance.The main work and results of this paper are as follows:(1)This paper analyzes and compares the advantages and disadvantages of triangular mesh modeling and parametric surface modeling in different application scenarios,and confirms that the heterogeneous model based on triangular mesh can model the complex geometric shape and structure of the tissue in biomedical application,so that it is closer to the real organization.(2)Set up including joint articular disc,maxilla,mandibular condylar cartilage and three-dimensional finite element model of temporomandibular joint,determine the grid size of each joint,for each part material properties,so as to further perfect the model,the results are more accurate and reliable.(3)In view of the movement state of the mandible,the change of the vertical amount of the patient’s opening was simulated by changing the rotation Angle of the mandible in the small opening state,and the movement of the mandible in different sagittal/vertical ratios was obtained.(4)Through the simulation analysis of mandible condyle stress under different sagittal/vertical proportions,the stress distribution law of condyle was analyzed by comparing the stress nebulogram distribution of mandibular condyle under different states,and the ideal sagittal/vertical proportions were determined by comparing and analyzing the simulation data under 25 different position states and combining with the actual situation.The sagittal displacement of the mandible was 66% of the maximum extension,and the condyle stress was uniform and small when the vertical distance of the opening was 6 mm.