Reply

Abstract

Sir:FigureWe enjoyed reading the letter written by Dr. Tebbetts regarding our article1 and are pleased with the opportunity given by the Editor to respond to this letter. Dr. Tebbetts deals with an important issue in plastic surgery, namely, the term “form stable” with respect to breast implants. This term has been circulating in plastic surgery articles for almost a decade, including several interesting articles written by Dr. Tebbetts.2,3 Although one might intuitively have an opinion on what the term implies, until 2007, when the Style 410 U.S. Core Clinical Study Group published their article by Bengtson et al. in the Journal,4 there were to our knowledge no scientific articles that provided a definition of form stability related to breast implants. The study group defined form stability as the maintenance of implant dimensions and form in any position. We would like to quote Dr. Tebbetts from an earlier letter to the Editor.5 Here, he states that “if we are scientific, we must insist that conclusions and statements in peer-reviewed articles and presentations must be based on data.” We could not find any data that supported the definition given by Bengtson et al. The results from our study clearly showed that there is a marked increase in implant projection when the body position is changed from supine to prone. Support for these findings is given in the elegant pilot study by Dr. Hammond in his discussion of our article.6 Dr. Tebbetts criticizes the use of magnetic resonance imaging in our study. Magnetic resonance imaging is an established imaging method that gives excellent visualization of breast implants and body tissue, and its use is well documented in the literature. It is interesting that the implant dimensions as provided by the manufacturer are almost identical to those obtained from the magnetic resonance imaging examinations in the supine position. This provides an indication of the accuracy of the measurements based on the magnetic resonance images. The measurements obtained in the prone position were completely different. We explain this as a result of the implant's plasticity that allows significant changes in dimensions as a response to gravity and changes in the surrounding soft tissues. From a clinical point of view, such plasticity could in fact be considered as an advantage. In the prone position, a normal breast would also show an increase in projection when compared with the supine position. An augmented breast with the Style 410 breast implant appears to behave in a natural way. It is the opinion of Dr. Tebbetts that the magnetic resonance imaging examinations show “what any surgeon who has ever held a 410 in hand should be able to see with the naked eye” and that the patients were examined unnecessarily with magnetic resonance imaging. However, it is of little clinical value to know how the implant behaves in your hand without knowing how it behaves after implantation. Of course, everyone is entitled to have an opinion. However, we are surprised that Dr. Tebbetts came up with such a statement. In a former letter to the Editor, he writes that “opinions are interesting, and we all have them, but ‘conclusions’ based on opinions instead of data are also just opinions, not scientifically valid conclusions.”5 It is interesting that the term “form-stable implant” has been used for a long period without knowledge of how the implant behaves after implantation. As we see from our results, the implant is not form stable with respect to maintaining its dimensions in all positions. It has never been our intention to provide a scientific definition of the term form stable. Given the results from our study, we do not feel that there is a need to come up with a more accurate definition. We feel that the use of the term form stable as related to the Style 410 should be avoided, as it may cause confusion. One of the characteristics of the Style 410 breast implant is lower pole fullness, which gives the implant its anatomical shape. We see from our study that the lower pole fullness is maintained in both the supine and prone positions. In addition, the pilot study by Dr. Hammond shows that lower pole fullness is maintained also in the upright position. In that regard, it is perhaps enough to say that the Style 410 is an anatomically shaped breast implant that keeps its lower pole fullness in at least three body positions: supine, prone, and upright. We see no reason to comment on the statements made by Dr. Tebbetts regarding the motives, rhetoric, and marketing policies of the manufacturer of the Style 410 implant. Sven Weum, M.D. Department of Radiology Louis de Weerd, M.D., Ph.D. Department of Plastic Surgery and Hand Surgery Bente Kristiansen, M.S. Department of Radiology, University Hospital North Norway, Tromsø, Norway