(Y in the diagram at right), and research reveals that it is approximately 1.4 mm. Horizontal component affecting crestal bone loss between adjacent implants Because of this established mean horizontal dimension of the immediate crestal bone loss around dental implants, an issue arises when implants are placed into adjacent sites in the mouth. If the implants are placed too closely together, the overlap of the horizontal components of each implant's biologic width serves to increase the effective vertical crestal bone loss between the implants. This was first reported by Dennis Tarnow et al. in 2000 in a study that demonstrated that the distance between the most coronal aspect of the inter-implant bone and an imaginary line drawn between the implant platforms was greater when adjacent implants were placed ≤3 mm apart. Increased loss of inter-implant bone in the vertical dimension due to this overlap of horizontal components of the adjacent implants' biologic width can have ramifications in the anterior esthetic zone because it decreases bony support for the interproximal papilla between implants. By platform switching, implants can be placed closer to teeth and to each other while maintaining more crestal bone. Horizontal component affecting buccal plate in narrow alveolar crests Another clinical example in which the horizontal extent of crestal bone loss due to biologic width formation can negatively affect the peri-implant bony architecture is a situation in which the buccal plate of the alveolar process is very thin and lies wholly or substantially within the halo of the horizontal component of the biologic width. If an implant is placed within 1.5 mm of the facial aspect of the buccal plate, it will be obliterated for a vertical distance of approximately 1.5-2 mm by the formation of the biologic width on the body of the implant fixture, which can lead to complications related to esthetics and long-term maintenance. Platform switching and the vertical component of biologic width Because the abutment is narrower in diameter than the implant fixture, a certain amount of the implant platform is exposed when an implant is platform switched, and this exposed area of the platform can allow for the tissues of the biologic width -- junctional epithelium and soft connective tissue—to begin forming here, requiring less bone to be resorbed to make room for attachment on the lateral surface of the implant fixture. Platform switching has been shown to have the potential to reduce the