Citation Information :
Kumar A, Kumar MS, Mathew S, Shivamurthy PG. Three-dimensional Comparison of Infra-zygomatic Crest Thickness in Different Facial Patterns: A Cross-sectional Study. World J Dent 2023; 14 (6):552-558.
Aim: Infra-zygomatic crest (IZC) mini-screws are an important advancement for anchorage reinforcement. There are numerous studies measuring IZC bone thickness (BT), but there is less evidence regarding the choice of a specific site for this screw placement among adults with different facial types and among periodontally compromised individuals. In the case of periodontitis, since there is alveolar bone loss, the site of choice for mini-screws will be on the extra alveolar region. This study aims to measure the IZC thickness among different growth patterns and give an optimal site for mini-implant placement.
Materials and methods: This is a cross-sectional study conducted on 48 cone-beam computed tomography (CBCT) files with 24 horizontal and 24 vertical growers. The IZC thickness and insertion height (IH) in relation to the maxillary occlusal plane were measured at 70°, considering it an ideal insertion angle according to the literature. The data were recorded and statistical analysis was performed.
Results: At all the three coronal slices measured, the horizontal grower group had the maximum thickness of the IZC at the measured angulation and the results were statistically significant. Regarding IH, both groups had an IH of 13–15 mm at 70° angulation with slightly more height in the vertical grower group to the occlusal plane as per our measurement parameters. At all three coronal slices within horizontal growers and within vertical growers, IZC thickness was maximum above the distal root of the first molar.
Conclusion: The ideal site for the insertion of mini-implants in the IZC lies above the distal root of the maxillary first molar at an IH of 13–15 mm from the maxillary occlusal plane at an insertion angulation of 70°. Individuals with horizontal growth patterns have a thicker crestal bone when compared to individuals with vertical growth patterns.
Clinical significance: Above the distal root of the maxillary first molar at an IH of 13–15 mm from the maxillary occlusal plane at an insertion angulation of 70° can be considered as an optimal insertion site for mini-screws. CBCT should be considered a significant diagnostic aid for measuring the same.
Costa A, Pasta G, Bergamaschi G. Intraoral hard and soft tissue depths for temporary anchorage devices. Sem Orthodont 2005;11(1):10–15. DOI: 10.1053/j.sodo.2004.11.003
Sato H, Kawamura A, Yamaguchi M, et al. Relationship between masticatory function and internal structure of the mandible based on computed tomography findings. Am J Orthodont Dentofacial Orthop 2005;128(6):766–773. DOI: 10.1016/j.ajodo.2005.05.046
Liou EJ, Chen PH, Wang YC, et al. A computed tomographic image study on the thickness of the infrazygomatic crest of the maxilla and its clinical implications for miniscrew insertion. Am J Orthodont Dentofacial Orthop 2007;131(3):352–356. DOI: 10.1016/j.ajodo.2005.04.044
Farnsworth D, Rossouw PE, Ceen RF, et al. Cortical bone thickness at common miniscrew implant placement sites. Am J Orthodont Dentofacial Orthop 2011;139(4):495–503. DOI: 10.1016/j.ajodo.2009.03.057
Chaimanee P, Suzuki B, Suzuki EY. “Safe zones” for miniscrew implant placement in different dentoskeletal patterns. Angle Orthod 2011;81(3):397–403. DOI: 10.2319/061710-111.1
Baumgaertel S. Cortical bone thickness and bone depth of the posterior palatal alveolar process for mini-implant insertion in adults. Am J Orthodont Dentofacial Orthop 2011;140(6):806–811. DOI: 10.1016/j.ajodo.2011.05.020
Marquezan M, Mattos CT, Sant'Anna EF, et al. Does cortical thickness influence the primary stability of miniscrews? a systematic review and meta-analysis. Angle Orthodont 2014;84(6):1093–1103. DOI: 10.2319/093013-716.1
Liu H, Wu X, Yang L, et al. Safe zones for miniscrews in maxillary dentition distalization assessed with cone-beam computed tomography. Am J Orthodont Dentofacial Orthop 2017;151(3):500–506. DOI: 10.1016/j.ajodo.2016.07.021
Niwlikar KB, Khare V, Nathani R, et al. Bone mapping for mini-implant placement with various facial growth patterns using three dimensional volumetric tomography. J Clin Diagnos Res 2018;12(12):13–18. DOI: 10.7860/JCDR/2018/32796.12343
Ghosh A. Infra-zygomatic crest and buccal shelf-Orthodontic bone screws: a leap ahead of micro-implants–Clinical perspectives. J Indian Orthodont Soc 2018;52(4_suppl 2):127–141. DOI: 10.4103/jios.jios_229_18
Elshebiny T, Palomo JM, Baumgaertel S. Anatomic assessment of the mandibular buccal shelf for miniscrew insertion in white patients. Am J Orthodont Dentofacial Orthop 2018;153(4):505–511. DOI: 10.1016/j.ajodo.2017.08.014
Vargas EO, de Lima RL, Nojima LI. Mandibular buccal shelf and infrazygomatic crest thicknesses in patients with different vertical facial heights. Am J Orthodont Dentofacial Orthop 2020;158(3):349–356. DOI: 10.1016/j.ajodo.2019.08.016
Murugesan A, Jain RK. A 3D comparison of dimension of infrazygomatic crest region in different vertical skeletal patterns: a retrospective study. Int Orthodont 2020;18(4):770–775. DOI: 10.1016/j.ortho.2020.09.002
Matias M, Flores-Mir C, de Almeida MR, et al. Miniscrew insertion sites of infrazygomatic crest and mandibular buccal shelf in different vertical craniofacial patterns: a cone-beam computed tomography study. Korean J Orthod 2021;51(6):387–396. DOI: 10.4041/kjod.2021.51.6.387
Tavares A, Montanha-Andrade K, Cury PR, et al. Tomographic assessment of infrazygomatic crest bone depth for extra-alveolar miniscrew insertion in subjects with different vertical and sagittal skeletal patterns. Orthod Craniofac Res 2022;25(1):49–54. DOI: 10.1111/ocr.12485