Improper tongue position is a frequent problem in orthodontics and likely to interfere on a long-term basis with the beneficial effects of an orthodontic treatment. Therefore, an atypical tongue resting position can lead to functional problems such as an open bite or a Class II malocclusion brought about by an overly posterior lingual position through lingual propulsion (Dr. Balters), or yet a Class III malocclusion brought about by a sagged lingual position that overly develops the lower arch.
The N.L.W not only serves as a barrier but also as an appliance that conditions the tongue to correct its position, and to acquire new automatisms and reflexes that may eliminate the need for orthodontic treatment altogether (if prescribed to children early enough) or help maintain the benefits of such treatment.
Once the problem is corrected, the tongue modifies the buccal environment by creating natural palatal expansion through constant radicular pressure.
The N.L.W. can also be used as a retainer following a first expansion stage in the treatment of Class II or Class III cases or worn together with fixed orthodontic apparatus.