The reciprocal influence of body postures on the oral structures, but also of the oral structures on body postures, has been proposed by clinicians and is taken into consideration when treating children with poor postural control and moderate to severe eating impairments. However, this relationship has not been rigorously investigated. The purpose of this study was to document the possible relationships among oral-motor, postural, and ambulatory control. Ambulatory skills [exclusive use of wheelchair (w/c) vs w/c and ambulation], postural control when sitting, "pathologic" reflexes, and lip and tongue posture were recorded before and after one year of therapy with an intraoral appliance (ISMAR) in 20 children with cerebral palsy and moderate eating impairment. Significant improvement occurred in sitting (head-trunk-foot control) following one year of ISMAR therapy. Ambulatory status also significantly improved above the level of maturation. Half of the children showed marked improvement in oral posture, i.e., their resting mouth posture was closed rather than open. These results support an hypothesis of interaction between oral structures and postural control of the "whole body." Further studies are needed to determine the controls of such a relationship.