Is there is a consensus that a tongue thrusting pattern is “normal”/typical up to a certain age?

Hello, Is  there is a consensus that a tongue thrusting pattern is “normal”/typical up to a certain age?  I have read that it is normal for babies.  I have also read that it is “normal” until the age of 6.  I have also read that it is never normal, and even infants that are breastfeeding do not exhibit a forward tongue motion.  I feel a little confused.  I have an evaluation of a 4 year old who just had a frenectomy.  If I see a thrust when he drinks, how do I determine if that is normal for his age?  It seems like when I look at babies and young kids (maybe the age of 2, 3, 4, or even 5, they do seem to thrust when eating/drinking).  Ahhh….please help clarify! Thanks so much!!!

Dr. Robert Mason responds: The information can be found in the Hanson and Mason text, Orofacial Myology: International Perspectives (pages 11-12), but I will also include some information here since you may not have a copy of the text. First, a brief review of early oral maturation:  Every infant can protrude the tongue – even children with severe neuromotor retardation issues have no difficulty in protruding the tongue, while infants cannot elevate the tongue under control. Protrusion of the tongue is the most primitive neuromotor response of the tongue while tongue elevation requires a greater level of neuromotor maturation, and takes place over time.  As a result, all infants are tongue thrusters. The progression from tongue thrusting in sucking to an adult swallow involves up to 10 transitional swallow patterns that occur between infancy and adulthood. These changing swallow patterns are related to morphologic changes in the oral cavity and pharynx, such as the size of tonsils and adenoids, the length of the mandibular ramus, increases in the length of the pharynx, and the differential growth of the tongue as related to the growth of the maxilla and mandible, to name a few (see our website article For Dentists and Physicians for a longer list of factors involved). https://orofacialmyology.com/wp-content/uploads/2017/10/orofacial-myology-for_dentists_and_physicians.pdf Also, tongue patterns change according to oral sensory feedback, and this involves the distribution of high density sensory nerve endings in the lips and tongue.  Yes, tongue thrusting tends to spontaneously regress over time as neuromotor development results in the tongue elevating under control and as the dimensions of the oral cavity and pharynx are adapted to by the tongue. For 2, 3, 4, and even 5 year olds, it is not abnormal to see a tongue thrust, and when noted, this does not automatically indicate the need for treatment. In some cases, it is important NOT to treat such children. It is important to evaluate the oral isthmus area when a tongue thrust is seen in a child. Where the oral isthmus is restricted by large faucial tonsils, a long soft palate, or a high-riding tongue that is related to a short ramus of the mandible, (i.e., the tongue is attached relative to the mandible), a child may appropriately tongue thrust as a way of moving food easily through the oral isthmus area since a forward movement of the tongue can serve to enlarge the isthmus as food is passed through this area. For many children, a tongue thrust is the most appropriate adaptation to a small oral isthmus and should not be modified. This affirms, once again, that a tongue thrust or a forward rest posture of the tongue in a young child should signal the need to evaluate the oral isthmus area and pharynx, as there may be an unresolved airway issue or allergic rhinitis. I hope that these comments will clarify the questions you pose. Thanks for asking – and feel free to ask again as the need arises.