Survival rates and periimplant soft tissue evaluation of extraoral implants over a mean follow-up period of three years

Abstract

The use of implants with extraoral prostheses provides excellent support, stability, and retention, thereby offering the potential for improving a patient's appearance and quality of life. However, few studies have examined cumulative survival rates of extraoral implants, nor have these reports documented long-term aspects of treatment, such as soft tissue health around abutments. The purpose of this study was to evaluate the survival rates and the periimplant soft tissue responses of extraoral implants used to retain facial prostheses. Thirty-three patients with auricular, nasal, and orbital anatomical compromise were treated with 98 craniofacial and dental implants. Of the 33 patients, 14 had auricular, 9 had nasal, and 10 had orbital defects. After a 3-month osseointegration period, implant-retained prostheses were fabricated. Following completion of treatment, each patient was seen at 6-month intervals. These examinations were recorded for this patient cohort from 25 to 50 months. Data were analyzed using Kaplan-Meier survival analysis. A 5-point scale was used to record the health of periimplant soft tissues. The unit of measure as a visit/site unit was assigned for each instance and implant site. Periimplant soft tissue reactions were assessed for auricular, nasal, and orbital defects, for each implant site used for these patients' treatments. The overall cumulative survival rates were 100% for auricular, 83.3% for nasal, and 77.4% for orbital implants, respectively. The survival rates of the implants were 72.7% for those placed in irradiated sites treated without adjunctive HBO therapy, and 93.4% for implants placed in nonirradiated sites. To evaluate the response of the periimplant soft tissues to the implants, a total of 524 visits/sites were recorded. Absence of inflammation (grade 0) of the periabutment soft tissues was observed in 73.3% of the visits/sites. The anatomical site into which the implant is placed has an effect on success rate. The auricular site is the most predictable implant site. Survival rates of nasal and orbital implants were found to offer promising results in achieving reliable implant prognoses in these regions. Regardless of the implant site, a decreased survival rate was observed in the irradiated sites. Periimplant soft tissue reactions were most commonly associated with lapses in hygiene.