Tooth Movements Adjacent to Single-Implant Restorations After More Than 15 Years of Follow-up

Purpose: To analyze the prevalence and magnitude of tooth movements adjacent to single-implant crowns in a long-term study, and to discuss these changes in relation to changes in cephalometric measurements of a reference group after 10 years. Materials and Methods: Twenty-five of an original group of 39 patients, consecu-tively restored with single-implant crowns in the anterior maxilla, were included. The mean age was 25.4 years (SD: 10.0) at inclusion. Clinical photographs were taken at implant crown placement and at the final examination an average of 15.9 years (SD: 0.74) later. The reference group comprised 134 dental students with a mean age of 22.9 years (SD: 1.20) at inclusion. Cephalograms and study casts were made at inclusion and after 10 years. Study casts were also made after 20 years (n = 61). Tooth movements were assessed adjacent to the implant crowns according to a clinical index. For the reference group, cephalometric measurements were performed for anterior and posterior face height and gonion and nasion-sella line/mandibular line (NSL/ML) angles. Vertical overbite measurements were collected from the study casts. Results: Altogether, 28 implant crowns were included in the test group. Male patients presented a clinically stable situation without any signs of vertical tooth movement adjacent to the single-implant restorations in 11 of 20 implant sites, compared to none in female patients (P .05). With regard to horizontal tooth movements, 55% of the sites showed palatal tooth movements, which were relatively more common in females. Both males and females presented a significant average increase of anterior and posterior face height (P .05), but only females presented a significant increase of the NSL/ML angle. Average vertical overbite was basically stable for 20 years, but individual variations were obvious. Conclusions: A possible relationship between significantly higher incidence of tooth movements adjacent to implants in females in the study group and significantly greater increase of anterior face height and posterior rotation of the mandible in the female reference group was observed