OBJECTIVETo investigate the insertion position of the levator veli palatini in the soft palate with SMCP comparing normal group and find out reliance diagnosis methods for SMCP.

METHODSExperimental group: lateral skull radiography film were taken in 50 patients with SMCP at rest and "i" phonation. Five parameters were measured which are relative length of soft palate and hard palate; levatorveli palatini insertion in the soft palate; elongation and angle of soft palate when lifting up on phonation.

CONTROL GROUPTen sets (rest and pronouncing "i") of lateral skull radiography were used as control group. X-rays were taken for ten normal subjects without speech disorder or other abnormal physical situations. All data were subjected to the t-test of statistical significance.

RESULTSThe difference of measures between patients with SMCP and normal control was significant (P

CONCLUSIONIt was obvious that both absolute and relative length of soft palate are short and levator muscle insert into soft palate arterially in patients with SMCP comparing with normal group, which caused VPI and become one of the criterias for SMCP.