Inclusion criteria:  full - term infants born with an Apgar score of 8-10 points no visual causes of lactation difficulties (malocclusion, posterior and small jaw, cervical torticollis, significant positional asymmetry) parental consent  Exclusion criteria:  hypotrophy low birth weight perinatal complications congenital craniofacial defects neurological diseases visible genetic syndromes mother' unwilling to breastfeed no consent for vaccination against hepatitis B neonates born to HIV seropositive mothers