Quantitative Evaluation of the Infrazygomatic Crest Thickness in Polish Subjects: A Cone-Beam Computed Tomography Study

Abstract

Infrazygomatic crest (IZC) mini-implants are frequently used as an absolute anchorage when intrusive or distally directed forces are required during orthodontic treatment. The aim of the present study was to evaluate the thickness of the IZC area in Polish patients as well as to assess dependency between bone availability, sex, and age. The study material was 100 cone beam computed tomography scans (CBCT) of the maxilla of patients of the University Dental Clinic in Krakow (50 men and women each). IZC bone thickness was measured at nine different points. The biggest bone thickness was recorded in the interdental space between the first and second molar at the height of 12 mm (6.03 ± 2.64 mm). The thinnest bone depth was localized at the level of the mesial root of the first molar, 16 mm above the occlusal plane (2.42 ± 2.16). There was a significant and negative correlation between bone thickness and age in the case of measurements taken buccally to the first molar. Only two out of nine measurements showed a sex dependency (points I2 and I3). Considering vertical and sagittal dimensions, the most favorable conditions for IZC mini-implant placement were found interdentally, between the first and second molar, 12 mm above the occlusal plane.

Should Cone-Beam Computed Tomography Be Performed Prior to Orthodontic Miniscrew Placement in the Infrazygomatic Crest Area?—A Systematic Review

“…The rest of the studies (n = 13) performed the measurements by means of CBCT. Seven papers evaluated the IZC bone availability in relation to sex [ 29 , 31 , 32 , 35 , 36 , 38 , 40 ] and five investigated age differences [ 29 , 32 , 36 , 38 , 40 ]. Five studies analyzed the IZC anatomy in relation to different vertical skeletal patterns [ 12 , 33 , 34 , 37 , 39 ] and one in relation to different sagittal skeletal patterns [ 39 ].…”

“…Five studies analyzed the IZC anatomy in relation to different vertical skeletal patterns [ 12 , 33 , 34 , 37 , 39 ] and one in relation to different sagittal skeletal patterns [ 39 ]. One study evaluated the bone availability in relation to regional anatomy—modified palatal height index [ 40 ].…”

“…There was no consensus about best insertion region among studies, which evaluated the bone depth in different sagittal insertion sites [ 33 , 34 , 36 , 38 , 40 ]. Two studies recommended distobuccal root of first molar [ 36 , 38 ], one study mesiobuccal root of first molar [ 34 ], one mesiobuccal root of second molar [ 33 ], and one region between maxillary first and second molars [ 40 ]. Concomitantly, Arango et al [ 36 ] recommended to place TADs in the region between second premolar and first molar in younger patients.…”

“…There was a tendency to bone depth decrease in the apical direction [ 12 , 35 , 38 , 39 , 40 ]. Concomitantly, in two studies which compared levels in proximity, not exceeding a distance of 2 mm between sites, no significant differences were found [ 12 , 39 ].…”

“…Concomitantly, in two studies which compared levels in proximity, not exceeding a distance of 2 mm between sites, no significant differences were found [ 12 , 39 ]. On the other hand, Gibas-Stanek et al obtained significant differences in the region of distobuccal roots of maxillary first molar and region between maxillary first and second molars [ 40 ]. Du et al [ 35 ] and Song et al [ 38 ] also obtained statistical significance.…”