The investigators propose a randomized clinical trial on a sample of 90 babies (45 in each group), under six weeks, presenting sucking dysfunctions, in Quebec city (Canada). The control group will receive usual care with a lactation consultant and the intervention group will receive usual care plus an osteopathic treatment. It is a simple blind clinical trial: the osteopath finds out, prior to evaluating the patient, what intervention should be delivered to the baby (assessment alone or standardized osteopathic treatment for infant).