A Comparative Study Of Magnetic Resonance Imaging Of Velopharyngeal Structure Between The Patinets After The“之”-Pattern Palatoplasty On Nasal Cavity Muscularis And Normal People

Objective:To compare the structure and function of the velopharyngeal structure between the cleft palate and the normal people through the “之”-pattern palatoplasty on nasal cavity muscularis by magnetic resonance imaging,and evaluate the effect of the operation.Methods: 20 adults were included as subjects(6 patients with cleft palate and 14 normal people).In the cleft palate group,the change of the length of soft palate,the effective soft palate,the thickness of soft palate,hard palate length,the depth of pharyngeal cavity in resting state and the length of soft palate in pronunciation state were measured by magnetic resonance scanning at 3 months after operation.The change of the length of levator veli palatini muscle,origin distance,insertion distance and origin angle,muscle volume and the circumference of each maker at rest and the length of levator veli palatini muscle at pronunciation state were also measured.The images were measured using Mimics research 20.0 software,and the three-dimensional reconstruction of the levator veli palatini muscles was performed using 3-Matic research version 12.0 software to observe the differences in the structure of velopharyngeal and levator veli palatini muscles between normal people and the patients after the “之”-pattern palatoplasty on nasal cavity muscularis and then statistical analysis.Results: 1.Measurement of velopharyngeal and levator veli palatini muscles at rest:(1)The soft palate length,effective soft palate length,hard palate length and VP ratio were higher in normal group than cleft palate group(P<0.05).(2)The average length of the levator veli palatini muscle.The extravelar segment length,intravelar segment length,origin distance,insertion distance and origin angle were not significantly different between normal and cleft palate patients(P>0.05).(3)Normal people levator veli palatini muscles were measured after three-dimensional reconstruction show that the circumference of the each points was larger than the patients with cleft palate(P<0.01).2.Measurement of velopharyngeal and levator veli palatini muscles during pronunciation:(1)The changes of effective soft palate length in the normal group were significantly greater than those in the cleft palate group(P<0.001);(2)There was no significant difference in stretch ratio of velar between normal group and cleft palate group(P>0.05).(3)There was no significant difference in length and stretch ratio of levator veli palatini muscles between the two groups(P>0.05).Conclusion: The“之”-pattern palatoplasty on nasal cavity muscularis can restore the normal shape of the levator veli palatini muscles in the soft palate and maintain its contractile function.Meanwhile,this study provides an imaging method for visualizing the structure and function of the velopharyngeal region of patients with cleft palate.