Dataset Information

Effects of cortical bone thickness and trabecular bone density on primary stability of orthodontic mini-implants.

ABSTRACT:

Background/purpose

Mini-implant screws are now routinely used as anchorage devices in orthodontic treatments. This study used synthetic bone models to investigate how the primary stability of an orthodontic mini-implant (OMI) as measured by resonance frequency (RF) is affected by varying cortical bone thickness and trabecular bone density.

Materials and methods

Three synthetic cortical shells (thicknesses of 1, 2, and 3 mm) and three polyurethane foam blocks (densities of 40, 20, and 10 pound/cubic foot) were used to represent jawbones of varying cortical bone thicknesses and varying trabecular bone densities. Twenty-five stainless steel OMIs (2 × 10 mm) were sequentially inserted into artificial bone blocks to depths of 2, 4, and 6 mm. Five experimental groups of bone blocks with OMIs were examined by Implomates® RF analyzer. Statistical and correlation analyses were performed by Kruskal-Wallis test, Wilcoxon rank-sum test, and simple linear regression.

Results

As trabecular bone density decreased, RF decreased; as cortical bone thickness decreased, RF also decreased. Simple linear regression analysis showed highly linear correlations between trabecular bone density and RF (R ² > 0.99; P < 0.0001) and between cortical bone thickness and RF (R ² > 0.98; P < 0.0001).

Conclusion

The stability of an OMI at the time of placement is influenced by both cortical bone thickness and trabecular bone density. Both cortical bone thickness and trabecular bone density have strong linear correlations with RF.

SUBMITTER: Pan CY

PROVIDER: S-EPMC6921117 | biostudies-literature | 2019 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Effects of cortical bone thickness and trabecular bone density on primary stability of orthodontic mini-implants.

Pan Chin-Yun CY Liu Pao-Hsin PH Tseng Yu-Chuan YC Chou Szu-Ting ST Wu Chao-Yi CY Chang Hong-Po HP

Journal of dental sciences 20190720 4

<h4>Background/purpose</h4>Mini-implant screws are now routinely used as anchorage devices in orthodontic treatments. This study used synthetic bone models to investigate how the primary stability of an orthodontic mini-implant (OMI) as measured by resonance frequency (RF) is affected by varying cortical bone thickness and trabecular bone density.<h4>Materials and methods</h4>Three synthetic cortical shells (thicknesses of 1, 2, and 3 mm) and three polyurethane foam blocks (densities of 40, 20, ...[more]

PMID: 31890126

Similar Datasets

Project description:PurposeThe purpose of this study was to assess the anatomical size of proximal femur in South Korea. This study measured cortical thickness and cortical thickness index (CTI) based on computed tomography (CT) and additionally, evaluated the T-score and trabecular bone score (TBS) based on the dual energy X-ray absorptiometry (DXA).Materials and methodsThis retrospective study is a cross-sectional study based on data from 600 patients aged from 20 to 93 years during the time from 2011 to 2021 were enrolled and selected the patients who did the examination of both pelvic CT and DXA scan. Age, sex, BMI, T-score, TBS, cortical thickness, CTI and the size of proximal femur were analyzed. Among these patients, 200 patients each corresponding to femoral neck fracture group(N = 200), trochanteric fracture group(N = 200), and non-fracture group(N = 200) were randomly selected and studied. The differences of three groups were compared statistically.ResultsMean outer diameter of proximal femur was 24.34 mm, inner diameter of proximal femur was 15.28 mm, cortical thickness was 4.55 mm and CTI was 0.37 at the lesser trochanter (LT) level. The outer diameter was 24.00 mm, inner diameter of proximal femur was 13.04 mm, cortical thickness was 4.97mm and CTI was 0.44 at 3cm below LT. In the hip fracture group, T-score of hip, outer diameter of proximal femur and cortical thickness at LT were lower than non-fracture group. BMI, T-score of spine, T-score of hip, inner diameter at 3cm below LT, CTI of LT and TBS were lower in femoral neck fracture group compared to the trochanteric fracture group.ConclusionAnalysis of 600 patients of pelvic CT might be a representative of real size of proximal femur in South Korea. Outer diameter of proximal femur at LT and cortical thickness at LT level were significantly lower in hip fracture group. Narrower outer diameter of proximal femur and thinner cortical thickness at LT level from the CT might be a risk factor of hip fracture.

Project description:The study aimed to clinically estimate an influence of a 635 nm diode laser on the stability of orthodontic mini-implants, to assess mini-implants loss, and to evaluate a pain level after the treatment. The randomized clinical split-mouth trial included 20 subjects (13 women and 7 men; age: 32.5 ± 6.1 years), 40 implants (RMO, West Colfax Ave., Denver, CO, USA) with a diameter 1.4 mm and length of 10 mm. Mini-implants were placed in the area of the attached gingiva between the second premolar and first molar teeth, 2 mm below the mucogingival junction of both sides of the maxilla. Each implant on the right side (G1, n = 20) of the maxilla was irradiated with a diode laser, and the implants on the opposite side (left, G2, n = 20) were a control group (without laser irradiation). The 635-nm laser parameters; dose: 10 J per point (20 J/cm2), time: 100 s per point, two points (irradiation on a buccal, and a palatal side of the alveolus/implant), the total energy per session 20 J. Laser application protocol: immediately and 3, 6, 9, 12, 15, and 30 days after surgery. The total energy after all therapeutic sessions was 140 J. The implants' stability was measured employing a Periotest device (Periotest Test Value-PTV) immediately and 3, 6, 9, 12, 15, 30, and 60 days after the insertion of the mini-implants. We found significantly higher secondary stability, lower mean PTV (6.18 ± 5.30) and (1.51 ± 2.25), for self-drilling mini-implants (G1, test group) in contrast to the control, G2 group (9.17 ± 8.25) and (5.00 ± 3.24), after 30 (p = 0.0003) and 60 days (p = 0.0000). Moreover, the analysis of the mini-implants stability after 635-nm diode laser application revealed significant higher stability in comparison with none irradiated implants (G2 group) after 3 days. (p = 0.0000) There was no significant difference in pain level measured on the NRS-11 scale on both sides of the maxilla. (p = 0.3665) An important finding was that all inserted mini-implants survived during a two-month observation period. 635-nm diode laser at laser irradiation increases the secondary stability of orthodontic mini-implants.

Dataset Information

Effects of cortical bone thickness and trabecular bone density on primary stability of orthodontic mini-implants.

Background/purpose

Materials and methods

Results

Conclusion

Publications

Effects of cortical bone thickness and trabecular bone density on primary stability of orthodontic mini-implants.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets