Stress Appraisal with Simulation of en masse Absolute Intrusion of Maxillary Anteriors deploying Strategic Mini-implant Locations: A Finite Element Analysis

Abstract

One of the major challenges of fixed clinical orthodontics is the correction of deep overbite. Mini screw implants are ideally suited for absolute intrusion because they make it possible to apply light continuous forces of known magnitudes without producing any reciprocal reactionary effect on posterior teeth. The purpose of this FEM study was to evaluate and compare the stresses generated in maxillary anterior region during absolute en masse intrusion of six maxillary teeth using mini-implants at strategic locations. Materials and methods: Finite element model was generated using FEM software ANSYS and, on the same model, two different analyses were carried out for two groups with different points of force application as Group I consisted of two bilateral implants for en masse intrusion of maxillary anteriors and Group II consisted of a single mid implant. Results: Soft and hard bones showed significantly high stress distribution in Group I as compared to Group II. The total tooth deformation was found to be more with single point of force application which produced oblique force vectors. Conclusion: Stresses on the teeth are higher and distributed more evenly, when the point of force application is bilateral rather than a single source. Bilateral implants generate less stresses which are evenly distributed with minimum detrimental effect on the teeth during absolute intrusion.

The effects on pdl, tooth and alveolar bone with intrusion of anteriors using round wire utility arch: finite element model analysis

“…Maximum stress was found along cervical region of labial side of central incisor followed by laterals similar to study by Sagar S Padmawar et al 8,10 probably because the point of force application is between central incisors and away from the lateral incisors.…”

“…Studies have also shown that range of stresses exerted by the blood in capillary vessels (0.0026N/mm 2 ) help us to determine the changes in tooth structure at apex leading to root resorption. 8,10 Few literature consider 0.0047 MPa as the range of capillary blood pressure 26 .All the values of Von Mises stress on tooth in above method are found to be above the capillary blood hydrostatic pressure suggesting the possibility of root resorption.…”

“…Young's modulus (n/mm 2 ) value as per average values reported in literature for tooth, PDL, alveolar bone, stainless steel and implant. [8][9][10][11][12][13][14] (Tooth -20300, PDL-0.667, Alveolar bone-13700, Stainless steel-19200) POISSON'S RATIO VALUES as per average values reported in literature for tooth 8,10,15 PDL, alveolar bone, [12][13][14][15][16][17] Stainless steel 14 and implant 18 (Tooth-0.3,PDL-0.45, Alveolar bone -0.3, Stainless steel -0.3)…”

Revolution in Orthodontics: Finite element analysis

“…At the center of resistance and 2 mm above and below it, teeth moved bodily by 0.013 mm Padmawar et al . [ 18 ] evaluated and compared the stresses generated in the maxillary anterior region during absolute en masse intrusion of six maxillary teeth using mini-implants at two different points of force applications. The study found that use of bilateral implants was more efficient and less detrimental for the teeth during absolute intrusion of the maxillary anterior teeth Chetan et al .…”

Evaluating the effects of consolidation on intrusion and retraction using temporary anchorage devices—a FEM study

“…Many studies evaluated the stress in the bone [10, 11], PDL [12–18], implants [19–22] in mini-implant-assisted retraction [23] with different height of implants and retraction hooks [24, 25] and materials [26, 27]. But there are no studies which evaluated the stresses on the bone and PDL in two implant and three implant combinations.…”