Objective: To study the influence of tongue position and movement pattern on the phonation of cleft palate patients.
Methods: The standard lateral cephalometric roentgenographic recordings were performed at rest and functional position. Computer scanning system was used to measure and analyse the graphs.
Results: At rest position, A/F ratio in pre-operation group is smaller than in post-operation and control groups; C/H ratio in post-operation group is greater than in pre-operation and control groups; S/V ratio in post-operation group is smaller than in control group. During phonation of /a:/, D/F, A/P, A/F and a/p ratios in post-operation group are smaller, but P/B, C/H ratios are bigger than in control group. A/F ratio in post-operation group is smaller and C/H ratio is bigger than in control group. D/F, A/P, a/p ratios in pre-operation group are smaller than in post-operation group.
Conclusion: Significant abnormalities of tongue position and movement pattern exist in pre-operation group. After operation for cleft palate, most abnormalities disappeared, but some still persist. It is necessary for the patients to have phonetic training to eliminate these abnormalities and achieve clear phonation.