The Dahl Concept: Best Evidence Consensus Statement

Purpose: In a series of publications, Dahl and Krogstad promoted an orthodontic technique for the treatment of severe wear of the anterior teeth that reportedly could induce intrusion of the anteriors and extrusion of the posterior teeth to allow space to restore the worn anterior teeth. The purpose of this Best Evidence Consensus Statement was to evaluate the existing dental literature related to the Dahl Concept. Methods: A PubMed search limited to clinical studies, clinical trials, randomized controlled trials, systematic reviews, meta analyses, and journal articles, using the key words Orthodontics, Dahl appliance, Dahl concept and adult, revealed 11 citations, 9 of which were related. An additional 9 citations were culled from the reference lists in the aforementioned articles. Results: The 20 articles that met the initial search criteria were evaluated and rated. The literature largely focused on the restorative materials that are commonly used to apply the Dahl technique. Conclusions: While there is low-level evidence from a few case series that demonstrated the ability to achieve enough space in the anterior region for the restoration of lost anterior tooth structure, there is no compelling evidence to support any theories as to how that space was achieved. In addition, there is no evidence to support the long-term stability of that position and the restorations. Negative position and restorative outcomes have been reported.