Abstract: Objective　 To study the application of medical examination and treatment of occult submucous cleft palate (OSMCP). Methods Eight individuals of hypernasality without visible cleft palate who had been performed physical examination outside the hospital ruling out the systemic disease or any syndrome, were confirmed as subjects of velopharyngeal incompetence(VPI) after they were performed the speech assessment(scored by hypernasality severity）and the electronic nasopharyngoscopy inspection. Subjects who showed abnormal anatomy of levator veli palatine muscle (LVP) in the velum on the magnetic resonance imaging(MRI) were diagnosed as OSMCP. Operations were performed on OSMCP subjects to explore structures of LVP with reconstructions of LVP muscles and Furlow technique. Operated subjects received hypernasality assessment and inspection of velopharyngeal closure using electronic nasopharyngoscopy again three months after surgery. Results Six of eight VPI subjects showed disconnecting of LVP structures in the velum by the MRI examination. The surgery course verified that all six operated subjects lost continuity of the LVP in the soft palate and had levator muscles abnormal attachment forward. The six subjects’ hypernasality and their rates of VPI recovered obviously after the operations. Conclusion MRI can help diagnosis of OSMCP in an effective way. The operation of reconstruction of LVP muscles plus the Furlow technique has a potentiality to improve the velar function of OSMCP patients.

Key words: occult submucous cleft palate, velopharyngeal incompetence, magnetic resonance imaging, levator veli palatine muscle