Influence of Mandibular Prognathism (class III) on Speech, and Effects of Postoperative Articulation Training

我们研究了术后持续性发音失败和需要外科正畸治疗不良咬合的患者进行发音训练的必要性/有效性。术前不良咬合合并开牙合的患者往往比仅不良咬合的患者产生更多的牙间音，无论其覆盖值如何。从我们的研究结果来看，术后持续开牙合的患者没有一个能使他或她的发音恢复正常，而在一些通过手术改善咬合的患者中，明显的构音障碍变得正常，我们推测开牙合影响了牙间音的产生，但由于本研究中不良咬合合并开牙合的患者数量较少，因此无法得出决定性结论。通过术后发音训练，40%的患者发音得到改善。这一发现表明，即使手术治疗改善了咬合，齿间音仍然存在，并且习惯性的齿间音可以通过发音训练来解决。考虑到齿间音是由舌头运动产生的，舌头运动可能会使改善的咬合恢复到以前的状态，如果齿间音本身可能不会使谈话不清楚，那么术后的发音训练就非常重要。

We examined the postoperatively persisting articulation failure and the necessity/efficacy of articulation training in patients who had required surgical orthodontic treatment for adverse occlusion. Preoperatively the patients with adverse occlusion combined with open bite had tended to produce more interdental sounds than those with adverse occlusion only, regardless of their overjet values. From our findings that none of the patients with postoperatively persisting open bite improved his or her articulation to normal, and that conspicuous dysarthria became normal in some of the patients whose occlusion was improved by operation, we speculate that open bite influences the production of interdental sounds, although it is not decisively concluded since the patients with adverse occlusion combined with open bite were small in number in the present study. Articulation was improved in overall 40% of the patients by articulation training in the postoperative course. This finding suggests that interdental sounds persist even if surgical treatment has improved occlusion, and that the habituated inderdental sounds can be resolved by articulation training. Considering the fact that interdental sounds are produced by the tongue movements which may reverse the improved occlusion to its previous state, postoperative articulation training is significantly important, if interdental sounds themselves may not make conversation unclear.