Graftless Solutions for Rehabilitation of Atrophied Maxilla: Zygomatic Versus Subperiosteal Implants — A Systematic Review

V. S. Sudhir, Rajendra B. Prasad, Niranjani Krothapalli, Perukasrujan Kumar

Full text link: https://pubmed.ncbi.nlm.nih.gov/40511161/

Graftless Solutions for Rehabilitation of Atrophied Maxilla: Zygomatic Versus Subperiosteal Implants — A Systematic Review

1. Scientific reference

• Study title: Graftless Solutions for Rehabilitation of Atrophied Maxilla – Zygomatic Versus Subperiosteal Implants – A Systematic Review
• Authors: M. V. S. Sudhir, Rajendra B. Prasad, Niranjani Krothapalli, Perukasrujan Kumar
• Scientific journal: Journal of Pharmacy and Bioallied Sciences
• Year of publication: 2025
• DOI: 10.4103/jpbs.jpbs_1802_24
• Publication type: Systematic review

2. Scientific context

Severe maxillary atrophy remains one of the most demanding situations in advanced implant dentistry because reduced bone availability can compromise conventional implant placement strategies. When bone augmentation procedures are unsuitable, alternative graftless approaches have gained attention as potential solutions for complex implant-supported rehabilitation.

Among these approaches, zygomatic implants and subperiosteal implants represent two different treatment concepts. Zygomatic implants rely on anchorage in the zygomatic bone to bypass deficient alveolar bone, whereas modern subperiosteal implants have evolved through digital technologies, allowing patient-specific designs adapted to individual anatomical conditions.

The growing interest in these techniques reflects a broader evolution in oral rehabilitation, where clinicians seek predictable alternatives that may reduce the need for extensive grafting procedures. However, differences in clinical experience, available evidence, complications, and long-term validation remain important considerations when evaluating these strategies.

This systematic review contributes to the discussion by comparing reported outcomes of these two graftless implant solutions in severely atrophic maxilla rehabilitation.

3. Study objective

The primary objective of this systematic review was to compare clinical outcomes associated with zygomatic implants and subperiosteal implants in the management of severely atrophic maxillae.

The authors specifically evaluated implant survival, reported complications, and patient satisfaction outcomes in order to provide a clearer understanding of the clinical performance of both approaches and their potential role in graftless implant rehabilitation.

4. Methodology

This study was conducted as a systematic review following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines.

A structured literature search was performed using PubMed, Scopus, Web of Science, and the Cochrane Library databases. Studies evaluating zygomatic implants or subperiosteal implants in patients with severe maxillary atrophy were considered eligible.

The review included different types of clinical studies, including systematic reviews, randomized controlled studies, cohort studies, and case reports. Eight studies were analyzed in total.

The reviewed population included 623 patients treated with zygomatic implants and 257 patients treated with subperiosteal implants. Follow-up periods varied among included studies, ranging from 12 months to more than 6 years.

The main evaluated parameters were implant survival rates, complications, patient satisfaction, procedural considerations, and the influence of digital technologies such as CAD/CAM and additive manufacturing.

5. Main results

The reviewed evidence showed favorable survival outcomes for both graftless implant approaches.

Zygomatic implants demonstrated a reported survival rate of 96.1%, with immediate loading protocols showing a survival rate of 98.1% in the analyzed data. Their main reported complication was related to sinus involvement, with sinusitis identified as a notable adverse event.

Subperiosteal implants showed a reported short-term survival rate of 97.8%. The review highlighted that digital workflows, particularly CAD/CAM-based customization, improved implant adaptation and contributed to reducing surgical complexity.

However, soft tissue complications remained an important concern for subperiosteal implants, with soft tissue dehiscence reported at 25.6% in the included data.

Both treatment approaches were associated with positive patient outcomes, although the authors emphasized that zygomatic implants currently benefit from greater long-term clinical documentation, whereas subperiosteal implants represent a developing personalized solution requiring further validation.

6. Clinical analysis

This systematic review highlights two distinct strategies for managing patients with severe maxillary bone deficiency who require implant-supported rehabilitation.

Zygomatic implants appear to represent a more established therapeutic option, supported by longer clinical follow-up and extensive experience in severely resorbed maxillae. Their ability to obtain anchorage outside the compromised alveolar region can provide an alternative when conventional implant placement or graft-based procedures are difficult to perform.

Nevertheless, their clinical success depends on accurate surgical planning and appropriate management of anatomical risks, particularly sinus-related complications. The technique requires specific expertise because implant positioning involves complex three-dimensional anatomical considerations.

Subperiosteal implants illustrate the impact of digital transformation in oral implantology. Patient-specific designs generated through CAD/CAM technology and additive manufacturing allow customized adaptation to challenging anatomical situations. However, compared with zygomatic implants, the available evidence remains more limited, particularly regarding long-term outcomes.

From a clinical perspective, this review does not establish one universal superior technique. Instead, it suggests that treatment selection should be individualized according to anatomical conditions, clinician experience, available technology, and the objectives of the prosthetic rehabilitation.

The findings support the importance of multidisciplinary planning involving surgical and prosthetic considerations when treating patients with advanced maxillary atrophy.

7. Clinical applications

The findings of this review are particularly relevant for patients presenting severe maxillary atrophy where conventional implant placement may be compromised.

Zygomatic implants may be considered within advanced implant rehabilitation protocols requiring alternative anchorage strategies. Their use is mainly discussed in relation to severely resorbed maxillae and fixed implant-supported prosthetic rehabilitation.

Subperiosteal implants may represent an option for anatomically challenging cases where individualized implant design is required. Their development is closely associated with digital planning workflows, CAD/CAM design, and additive manufacturing technologies.

These approaches illustrate the expanding role of personalized solutions in oral surgery and implant dentistry, while emphasizing the importance of careful patient selection and evidence-based clinical decision-making.

8. Level of evidence, limitations, and transparency

This publication is a systematic review, providing a higher level of evidence compared with isolated clinical reports. However, the strength of its conclusions depends on the quality, consistency, and follow-up duration of the included studies.

The authors reported important limitations related to heterogeneity among study designs and evaluation criteria, which restrict direct comparisons between zygomatic and subperiosteal implants. They also highlighted the limited availability of long-term evidence concerning subperiosteal implants.

The review was funded by Continuum Oral Health Inc., Framingham, Massachusetts, United States. The authors declared that there were no conflicts of interest.

9. Key points of the study

• Study type: Systematic review following PRISMA guidelines
• Evidence level: Systematic review
• Number of included studies: 8 studies
• Population analyzed: 623 zygomatic implant patients and 257 subperiosteal implant patients
• Follow-up duration: 12 months to more than 6 years depending on the included studies
• Main outcomes assessed: Implant survival, complications, patient satisfaction
• Main finding: Both approaches demonstrated favorable outcomes for severely atrophic maxilla rehabilitation
• Scientific conclusion: Zygomatic implants currently have stronger long-term clinical validation, while subperiosteal implants represent an emerging personalized alternative
• Main limitations: Study heterogeneity and limited long-term evidence for subperiosteal implants

10. Scientific impact

This systematic review provides a comparative overview of two important graftless approaches used in advanced implant rehabilitation.

Its main contribution is the synthesis of evidence surrounding a well-established technique, zygomatic implants, and a more recently developed personalized approach, digitally manufactured subperiosteal implants.

The study reflects the ongoing evolution of implant dentistry toward customized treatment strategies supported by digital technologies. The increasing use of CAD/CAM workflows and additive manufacturing may expand therapeutic possibilities for patients with complex anatomical limitations.

However, the review also underlines the need for stronger long-term clinical evidence, particularly for subperiosteal implants. Current findings should therefore be interpreted as supportive evidence rather than definitive proof of superiority between the two approaches.

The study contributes to clinical decision-making by emphasizing that graftless rehabilitation should be guided by patient-specific factors rather than by a single universal protocol.

11. Editorial conclusion

The rehabilitation of severely atrophic maxillae remains a complex challenge in implant dentistry. This systematic review indicates that zygomatic implants currently benefit from greater clinical maturity and longer-term validation, while customized subperiosteal implants represent a promising alternative supported by advances in digital technologies.

Both approaches may provide valuable solutions in selected cases where conventional implant placement or graft-based strategies are unsuitable. Future research, particularly with longer follow-up periods and standardized evaluation methods, will be essential to further define their respective roles in complex implant rehabilitation.