Rehabilitation of severely resorbed maxillae with zygomatic implants: an evaluation of implant stability, tissue conditions, and patients' opinion before and after treatment.

PURPOSE: The aim of the present study was to describe experiences of 11 consecutively treated patients who received zygomatic implants. Patient results were assessed through clinical and radiographic evaluations of tissue conditions, including resonance frequency analysis (RFA). MATERIALS AND METHODS: Eleven patients were treated with implant-retained fixed prostheses. A total of 64 implants were placed, 22 of which were placed in the zygoma. Fixed prostheses were removed to allow clinical and radiographic evaluations at a follow-up visit 18 to 46 months following implant placement. RFA was performed on all implants. A visual analog scale was used to assess patient satisfaction before and after treatment. RESULTS: All patients received implant-supported prostheses. All zygomatic implants demonstrated clinical signs of osseointegration. One anterior implant was lost during follow-up. Mean ISQ values for the zygomatic and anterior implants were 65.9 (range, 42 to 100) and 61.5 (range, 48 to 71), respectively. Twenty-four implants showed moderate inflammation, with 3 exhibiting severe inflammation. Most anterior implants (75.6%) showed a marginal bone recession of 1 thread or less. Four zygomatic implants showed bone loss of 4 to 5 threads, and 5 zygomatic implants exhibited no marginal bone support. Patients described significant improvement in chewing ability and esthetics but did not describe changes in speech. DISCUSSION: The use of zygomatic implants can help the clinician avoid the need for bone grafting and reduce morbidity. In addition, it can shorten the treatment time considerably. CONCLUSION: This preliminary report demonstrates that zygomatic implants can provide posterior support to fixed prostheses in patients who lack bone volume to place conventional implants without encroaching upon the maxillary sinus.

Implant stability, tissue conditions, and patient self-evaluation after treatment with osseointegrated implants in the posterior mandible.

BACKGROUND: Implant treatment in the posterior mandible is considered challenging because of bone resorption and the presence of the inferior alveolar nerve, which may result in the use of short implants. PURPOSE: To evaluate implant stability, tissue conditions, and patient opinion after treatment with implant-supported bridges in the posterior mandible. MATERIALS AND METHODS: Thirty-four patients treated with implant-supported bridges in the posterior mandible according to a two-stage protocol were clinically and radiographically examined and interviewed after a mean functional time of 3.9 years. One hundred five Brånemark implants (Nobel Biocare AB, Gothenburg, Sweden) were placed in premolar and molar regions to support 40 bridges. Twenty-eight implants were placed anterior to the mental foramen, and 77 implants were placed posterior to the mental foramen. Bridges were supported either by two or by three implants. After 2 to 6 years, the bridges were removed to analyze the resonance frequency of the implants with the use of a special instrument (Osstell instrument, Integration Diagnostics AB, Gothenburg, Sweden), and an implant stability quotient (ISQ) was recorded for each implant. RESULTS: One implant was lost. An ISQ range of 59 to 90 (mean, 70.05) expressed stability of fully integrated implants in the posterior mandible. Significantly higher (p < .024) ISQ values were found in implants in three-implant bridges when compared with implants in two-implant bridges. There were no differences in ISQ values between molars/premolars, implant types, implant widths, implant lengths, anchoring depth, or uni- or bilateral mandibular bridges. Good mucosal health in the periimplant soft tissue and minor bone resorption around the implants were observed. Patients were generally very satisfied with the treatment outcome. CONCLUSIONS: High implant stability can be reached in the posterior mandible. The implants were more stable in three-implant bridges than in two-implant bridges. The patients were highly satisfied with the treatment, and few complications were seen.