Augmentation of oral tissues in rabbit using autogenous fat

Patients with mild velopharyngeal incompetence (VPI) may have speech disorders, which are not sufficiently severe to warrant extensive surgical intervention, yet may not be amenable to correction by speech therapy alone. Augmentation of the posterior pharyngeal wall to aid in closure of the velopharyngeal sphincter may be beneficial in establishing better speech patterns, especially when combined with speech therapy. A variety of materials and techniques have been used in the past for this purpose. In this setting, autogenous fat may be transplanted without the risks incurred by augmentation with synthetic materials and involves very little donor site morbidity. The literature is somewhat contradictory, however, regarding the stability of the augmentation achieved using autogenous fat and there are no histologic studies describing the fate of fat injected into tissues of the oral cavity. Prior to introduction of this technique into clinical practice, this study was designed to investigate the fate of autogenous fat injected submucosally in the oropharyngeal region. Autogenous fat was injected into the anterior soft palate using the rabbit as a model. Histologic and gross inspections were performed at 2 days, 1, 2, and 4 weeks after injections. At the end of 4 weeks, at least 50% of the injection sites had visible evidence of augmentation, and 90% had histologic evidence of submucosal fat. In some instances most of the fat was resorbed; however, there were no instances of clinical infection or necrosis of the injection site. We conclude that submucosal injection of autogenous fat is a feasible alternative to using synthetic or other biologic materials for augmentation in the oral cavity.