Patient-specific Finite Element Analysis of Immediate Loading in the Edentulous Maxilla: Comparison of Three Implant Configurations Using Digital Twins.

Rehabilitation of severely atrophic edentulous maxillae with dental implants pose a significant clinical challenge. Immediate loading in grafted bone is often debated due to concerns about stress distribution and osseointegration. This study aimed to compare stress distribution in the maxilla using three full-arch implant configurations-all-on-four, all-on-six, and quad-zygomatic implants-in a single patient, to determine the safest and most favorable approach for immediate loading in grafted bone. Two CBCT scans from a 64-year-old female patient, before and after bone grafting (allograft with onlay grafting and sinus augmentation), were used to generate three patient-specific finite element models. Each model included the maxilla, implants in the respective configuration, abutments, and a full-arch prosthesis. Von Mises stresses in cortical and cancellous bone, implants, abutments, and prosthesis, as well as maximum bone displacement, were analyzed. Our results demonstrated that the all-on-six configuration provided the most favorable biomechanical outcome, with homogeneous cortical stress distribution, reduced stress in implants and prosthesis, and bone displacement fully compatible with immediate loading in grafted bone. The all-on-four model showed stress peaks at tilted abutments and cantilevers, whereas the quad-zygomatic model distributed implant and abutment stresses efficiently but induced higher cortical bone stresses, still within physiological limits.This patient-specific digital twin study demonstrates that immediate loading in full-arch grafted bone is biomechanically safe and optimal, with the all-on-six configuration providing superior stress distribution. These findings support clinical decision-making for immediate loading protocols and highlight the value of patient-specific FEA in planning complex maxillary rehabilitations.

Study Overview

• Status: Completed
• Conditions: Atrophic Edentulous Maxilla
• Intervention / Treatment: Other: numerical study

• Study Type: Observational
• Enrollment (Actual): 1

Contacts and Locations

Study Locations

• France
  • Alpes Maritimes
    • Nice, Alpes Maritimes, France, 06000
      • CHU de Nice

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Edentulous maxillae, have had full-arch bone reconstruction in order to use the scanner before the bone graft and the scanner after the bone graft and simulate two configurations (all on four and quad zygomatic) on the digital model from the first scanner, and one implant configuration (all on six) on the digital model from the second scanner.

Description

Inclusion Criteria:

• Edentulous maxillae, have had full-arch bone reconstruction

Exclusion Criteria:

• None

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Stress distribution in the Maxillary Bone	Finite element analysis (FEA) a numerical simulation method that models how mechanical forces affect anatomical structures. This technique visualizes stress, tension, compression and displacement zones in the maxillary bone. Stress values are expressed in megapascals (MPa) and displacements in microns (μm).	At inclusion
Stress distribution in the Implants	Finite element analysis (FEA). This technique visualizes stress, tension, compression and displacement zones in the implant. Stress values are expressed in megapascals (MPa) and displacements in microns (μm).	At inclusion
Stress distribution in the Prosthesis	Finite element analysis (FEA). This technique visualizes stress, tension, compression and displacement zones in the prosthesis. Stress values are expressed in megapascals (MPa) and displacements in microns (μm).	At inclusion

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Accuracy of the digital model digital twin of real patient	Scan of his edentulous maxilla	At inclusion

Collaborators and Investigators

• Sponsor: Centre Hospitalier Universitaire de Nice

Study record dates

Study Major Dates

• Study Start (Actual): November 2, 2023
• Primary Completion (Actual): November 2, 2023
• Study Completion (Actual): November 2, 2023

Study Registration Dates

• First Submitted: November 25, 2025
• First Submitted That Met QC Criteria: November 25, 2025
• First Posted (Actual): December 5, 2025

Study Record Updates

• Last Update Posted (Actual): December 5, 2025
• Last Update Submitted That Met QC Criteria: November 25, 2025
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Bone Resorption; Bone Diseases; Musculoskeletal Diseases; Stomatognathic Diseases; Jaw Diseases; Maxillary Diseases; Atrophic Maxilla
• Other Study ID Numbers: 25Odonto07

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No