A Pilot Study of Oral-Motor Dysfunction in “At-Risk” Infants

The purposes of this pilot study were to devise a neonatal oral-motor assessment scale (NOMAS), and to correlate oral-motor function with feeding histories, perinatal-neonatal complications, neurologic status, and polygraphic recording of sucking. The methods used to study the at-risk infants were polygraphic amplification and recording of intra-oral pressure waves; scoring of sucking behavior with the NOMAS occurred concurrently with instrumental measurement. Both non-nutritive (NNS) and nutritive sucking (NS) modes were tested. Oral-motor performance tended to be disorganized or dysfunctional in infants with intraventricular hemorrhage (IVH) and asphyxia neonatorum. Those infants with brain insults (IVH, hydrancephaly) showed slower sucking rates in NNS, and the degree of slowing of the rate when switched to NS was less in these higher-risk infants. The polygraphic data did not, however, distinguish those same infants who had abnormal NOMAS scores. Oral-motor dysfunction was identified only from 40 weeks corrected age (C.A.) and correlated with generalized hypotonia on neurological examination. Polygraphic data further substantiated that oral-motor dysfunction may be the result of deviant jaw movement. Deviant motor patterns observed between 35 and 37 weeks C.A. were not easily identifiable as oral-motor dysfunction and probably represented incoordination or disorganization because, although differences in oral-motor function were noted, normal movements of both the tongue and jaw were present. Further study is needed to determine if oral-motor disorganization noted between 35 and 37 weeks can be attributed to immaturity or whether oral-motor function deteriorates with loss of normal movement, so that by term age dysfunction is subsequently noted.