PURPOSE: The first aim of this study is to compare the outcomes in rehabilitating the atrophic maxilla using zygomatic implants (ZIs) and regular implants (RIs) using the classical zygomatic technique (CZT) versus the zygomatic anatomy-guided approach (ZAGA). The second goal of this paper is to propose a standardized system to report rhinosinusitis diagnosis. MATERIALS AND METHODS: Twenty-two consecutive zygomatic patients operated on from 1998 to 2002 and 80 consecutive zygomatic patients operated on from 2004 to October 2009 were selected. All included patients were in a maintenance program. Survival rates (SRs) of ZI and RI were recorded. Implants were individually tested using Periotest® (Periotest value [PTv], Siemens AG, Bensheim, UK). Sinus health was radiographically and clinically assessed according to Lund-Mackay system and Lanza and Kennedy survey recommended by Task Force on Rhinosinusitis for research outcomes. A satisfaction questionnaire (Oral Health Impact Profile for assessing health-related quality of life in Edentulous adults) and different anatomical measurements were also performed. RESULTS: No significant differences (p = .602) were observed with respect to SR between the two groups (95.12% vs 96.79%). Significant differences (p = .000) were found comparing measurements of ZI head distance to the alveolar crest (5.12 ± 2.38 mm vs 2.92 ± 2.30 mm). With the CZT, more palatal emergence of ZI was observed. PTv gave significantly greater stability for the CZT compared with the ZAGA group in both measurements (-4.38 ± 1.75 vs -2.49 ± 4.31, p = .000; -4.94 ± 1.46 vs -3.11 ± 5.06, p = .000). Lund-Mackay score was significantly lower for the ZAGA group (2.38 ± 3.86 vs 0.56 ± 1.26, p = .042). Statistically significant difference (p = .047) regarding the percentage of patients with no signs or symptoms of rhinosinusitis (Lanza and Kennedy test negative and Lund-Mackay score zero) was observed between groups (54.55% vs 76.25%, p = .047). CONCLUSIONS: Both procedures had similar clinical outcomes with respect to implant survival. The ZAGA concept is able to immediately rehabilitate the severely atrophic maxillae, minimizing the risk of maxillary sinus-associated pathology. Moreover, less bulky, more comfortable, and easy to clean prostheses are achieved.