Long‐term survival and complications of Quad Zygoma Protocol with Anatomy‐Guided Approach in severely atrophic maxilla: A retrospective follow‐up analysis of up to 17 years

Abstract

IntroductionThe objective of the study was to provide long‐term clinical outcomes and complications in the severely atrophic edentulous maxillae treated by means of the quad zygoma protocol (QZP) using the Anatomy‐Guided Approach (AGA).MethodsThis was a retrospective cohort study of all consecutive patients with severely atrophic edentulous maxilla and insufficient bone height and width in the anterior and posterior regions bilaterally, who underwent rehabilitation with the QZP between May 2006 and December 2021. All patients were followed for at least 1 year. All zygomatic implants (ZIs) were placed by the same surgeon. The primary endpoint of the study was the implant survival rate. Secondary endpoints were implant success rate, prosthesis success rate, complications, and Oral Health‐Related Quality of Life using the OHIP‐14 questionnaire.ResultsA total of 56 patients (men 16, women 40) with 224 ZIs (Nobel Biocare, n = 204; Straumann, n = 16; Southern Implant, n = 4) placement were included with a mean follow‐up period 8.8 ± 3.9 years (range, 1.2–17.0). The survival (success) rate was 97.7%. Five ZIs in four patients failed. The mean time between implant placement and failure was 8.6 years (range, 0.5–13.3). All patients received immediate loading with acrylic prosthesis. The successful rates for the definitive prosthesis were 98.2%. Forty‐two patients received posterior cantilever for rehabilitation of fixed definitive prosthesis. Local orofacial inflammation (35.7%) and Sinusitis (12.5%) were the most common complications, occurring at a mean follow‐up of 10.0 (range, 4.2–14.9) and 10.3 (range, 4.3–16.2) years, respectively. In 48 patients, the mean score of the OHIP‐14 questionnaire was 1.7 ± 2.6 with the follow‐up period of 9.0 ± 4.1 years.ConclusionsThe rehabilitation of severely atrophic edentulous maxilla using the QZP has shown a predictable and high survival rate in the long term. The implementation of an immediate loading protocol offers potential benefits in stabilizing ZIs with cross‐arch stabilization. Moreover, the use of a posterior cantilever in reconstruction can effectively establish functional occlusion through well‐distributed ZIs, eliminating the need for additional implant placement.

All-on-4 Hybrid with Extra-Long Transnasal Implants: Descriptions of the Technique and Short-Term Outcomes in Three Cases

“…The quad zygoma represents a highly demanding surgical technique that requires appropriate training, planning, and meticulous surgery. A recent long-term retrospective study on the quad zygoma concept [ 18 ] provided long-term evidence, registering a 97.8% implant survival rate, a 98.2% prosthesis success rate, and a mean score of 1.7 on oral health impact profile-14, translating as virtually “no impairment” on the patient’s quality of life self-assessment. Furthermore, a systematic review and meta-analysis by Aboul-Hosn Centenero et al evaluated the survival rates of two zygomatic implants combined with regular implants versus four zygomatic implants, with no significant differences between the two treatment modalities in survival [ 42 ].…”

“…Among the various treatment options, the use of zygomatic implants has proven to be an approach with high success rates over the last 30 years [ 15 , 16 , 17 , 18 ]. Depending on the degree of maxillary bone atrophy, the zygomatic implant may be used in combination with one to three conventional anterior implants (all-on-4 hybrid) [ 19 ], or in cases of inadequate bone volume preventing the insertion of conventional dental implants, using four zygomatic implants (quad zygoma; all-on-4 double zygoma) [ 20 , 21 ].…”

Evaluation of the zygomatic bone prior to the quad zygoma surgery: Virtual implant placement study on cone beam computed tomography

“…The quad zygoma protocol involves the placement of four zygoma implants strategically to distribute forces in the antero-posterior direction, particularly in cases where patients exhibit inadequate bone structure in this dimension of the maxilla [13]. This approach has undergone clinical testing, particularly in immediate loading techniques, demonstrating promising short-and long-term success [14,15]. However, despite its predictability and well-documented nature, there are several noteworthy limitations.One key prerequisite for successful implant placement is a minimum zygoma bone thickness of 1.8-2 mm [24].…”