A novel intraoral injection technique for rat levator veli palatini muscle regeneration.

The levator veli palatini (LVP) muscle drives the elevation and retraction of the soft palate to facilitate speech and feeding, but undergoes atrophic changes in patients with cleft palate deformity. This study aimed to establish an effective drug delivery technique for LVP muscle regeneration. An intraoral injection technique for rat LVP muscle regeneration was developed based on careful examination of the rat craniofacial anatomy. The accuracy and reliability of this technique were tested by cone-beam computed tomography and nitrocellulose dye labeling. Recombinant human Wnt7a was delivered via this injection technique, and the subsequent responses of the levator veli palatini muscle were analyzed. Both the cone-beam computed tomography orientation of the needle tip and dye labeling suggested repeatable accuracy of the injection technique. Recombinant human Wnt7a delivery via this technique induced regeneration-related changes, including increased expression of centrally nucleated myofibers and Ki67^+ve nuclei. The intraoral injection technique is safe and efficient. It can be used for accurate drug delivery and to screen regenerative therapeutics for the LVP muscle. [ABSTRACT FROM AUTHOR]