Stress Distribution During Infra Zygomatic Crest-Supported Full-Arch Distalization with Intrusion Using Single and Dual TAD Configurations: A Finite Element Study

AimTo evaluate stress distribution and displacement patterns during infrazygomatic crest (IZC)–supported full‑arch distalization with intrusion and to compare the biomechanical performance of single versus dual anterior temporary anchorage device (TAD) configurations using finite element analysis.Methods A CBCT‑based three‑dimensional finite element model of the maxillary dentoalveolar complex was constructed, including teeth, periodontal ligament (PDL), cortical and cancellous bone, archwire, IZC screws, and TADs. Two anchorage configurations were simulated: a single anterior TAD placed between the maxillary central incisors and dual anterior TADs placed bilaterally between the central and lateral incisors, both combined with IZC screws. Distalization forces ranging from ۵۰ to ۷۰۰ g were applied with a constant intrusive force of ۵۰ g. Von Mises stress distribution and displacement patterns were evaluated in the cortical bone, PDL, dental roots, and anchorage components.ResultsFourteen loading conditions (۵۰–۷۰۰ g distalization combined with ۵۰ g intrusion) were analyzed. At low force levels (۵۰–۲۵۰ g), stresses remained within physiologic limits, with root stress ranging from ۱.۴۰ to ۱.۸۰ MPa and PDL stress from ۰.۰۱۵ to ۰.۰۲۰ MPa. With moderate forces (۳۰۰–۴۷۵ g), stresses increased, and root stress reached ۲.۸۸–۳.۰۳ MPa while PDL stress ranged from ۰.۰۲۶ to ۰.۰۳۰ MPa. At higher forces (۵۰۰–۷۰۰ g), stress levels further increased, with root stress ranging from ۴.۱۸ to ۴.۳۸ MPa and PDL stress from ۰.۰۴۱ to ۰.۰۴۴ MPa, indicating a potential overload region. Overall, stress and displacement values increased proportionally with increasing distalization force. The dual TAD configuration consistently demonstrated more favorable biomechanical behavior than the single‑TAD model, showing lower stress concentrations in cortical bone and the periodontal ligament, more uniform stress distribution, and reduced displacement of the maxillary teeth.ConclusionDual anterior TAD reinforcement during IZC-supported full-arch distalization with intrusion demonstrated a more uniform stress distribution and lower displacement values compared with the single TAD configuration, suggesting differences in biomechanical behavior between the two anchorage systems. Careful regulation of distalization force magnitude may help minimize localized stress within the dentoalveolar structures during skeletal anchorage–supported maxillary distalization.

کلیدواژه ها:

Finite element study ، Full-arch distalization ، Infrazygomatic crest ، Intrusion ، Temporary Anchorage Device