Measurement And Analysis Of Cancellous Bone Density And Cortical Bone Thickness In Posterior Pre-planting Areas By CBCT

ObjectiverSuccessful implant denture not only requires adequate jawbone, but also depends on good bone quality. Evidences from many domestic and foreign researches, cancellous bone density and cortical bone thickness in the planting areas both have important effect on the initial stability of implant and osseointe-gration. cancellous bone density and cortical bone thickness also have the guid-ing sense to the implants for immediate loading and early loading. In this study 72 patients who with posterior teeth losing and quasi planting operation been scanned by cone beam CT, quantitative measurement and analysis of posterior pseudo planting area of cancellous bone density and cortical bone thickness with OnDemand 3D software. Comparing the difference of the cancellous bone density and cortical bone thickness in the posterior area between the different positions.Analysis the influence of bone density and cortical bone thickness in age and sex on the posterior teeth missing areas, in order to providing theoretical guidance for the design of clinical molar implant operation posterior areas,predicting the implant primary stability,and providing a theoretical basis for immediate load and the early load.Methods:72 patients (37males and 35females)with posterior teeth losing from 2011.2 to 2013.12 in the oral hospital affiliated to Luzhou Medical College Department repair planting implants of the CBCT image data, using the OnDemand 3D professional software for image reconstruction, were measured on 107posterior pre planting sites of cancellous bone density and cortical bone thickness. Application of SPSS20.0 software for statistical data analysis, respectively in posterior region of cancellous bone density and cortical bone thickness in each of the following: ① the difference between maxilla posterior region and mandibular posterior region; ﹖he difference between eath teeth position in mandibular posterior area or maxillary posterior area;②the difference between mandibular posterior area and maxillary posterior area at a same position;④ difference with age;⑤ the difference with gender. Result:1. Cancellous bone density:1.1 The average cancellous bone density of posterior maxilla and posterior mandibular were 229.76 ±113.53HU and 502.86±114.06HU, p<0.01, Significant difference between the two groups and mandibular is greater than the maxilla.1.2The comparison between different teeth position in posterior region:there was a significant difference in density of cancellous bone between earth posterior teeth of mandibular (F= 11.244, P<0.01), wherein the first premolar maximum, minimum second molars; there was no significant difference between different teeth position of cancellous bone density in maxillary posterior region (F=1.219, P=0.320).1.3 The comparison of bone density between the maxillary and mandibular in the same teeth position:there is obvious difference in the maxillary and mandibular density of cancellous bone in the same tooth position (P4<0.01; P5<0.01; P6<0.01; P7=0.02), and all of them are greater in mandibular than maxillary.1.4 The patients over 50 years old and 50 years old of the following with posterior area average density of cancellous bone were 318.12±189.29HU and 441.17±200.81HU, P=0.03, cancellous bone density of posterior area is decreasing with increasing age.1.5 Male patients and female patients with posterior mean density was 398.04±213.48HU and 376.78± 191.75HU, P=0.095,the cancellous bone density in posterior area can be considered asexuality difference.2.Cortical bone thickness:2.1 The average thickness of cortical bone in posterior maxilla and mandibular area were 1.29± 0.08mm and 2.18±0.15mm, p<0.01, Significant difference between the two groups and mandibular is greater than the maxillary.2.2The comparison between different teeth position in posterior region:there was a significant difference in cortical bone thickness between maxillary posterior region and mandibular posterior region (F=9.739, P<0.01),wherein the first premolar minimum, maximum second molars; there was no significant difference between different teeth position of cortical bone thickness in maxillary posterior region(F=1.600, P=0.210).2.3 Comparison of cortical bone thickness in same teeth position between maxillary and mandibular:cortical bone thickness in the same teeth position in the maxillary and mandibular have significant difference (P<0.01; P5<0.01; P6<0.01; P7<0.01), and it is greater in mandibular than maxillary.2.4The average value of patients over the age of 50 and under the age of 50 patients with posterior cortical bone thickness was 1.39±0.09mm and 1.48±0.11mm, P= 0.17, no difference is visible in posterior cortical bone thickness.2.5Posterior cortical bone thickness of male patients and female patients were 1.57±0.13m m and 1.49±0.18mm, P=0.293, can be considered in posterior cortical bone thickness asexuality difference.Conclusion:1.There is a significant difference in trabecular bone mineral density between maxillary and mandibular posterior, mandibular is greater than maxillary.2. There is a significant difference in trabecular bone mineral density between maxillary and mandibular posterior, mandibular is greater than maxillary.3. Cancellous bone density of mandibular posterior area in each of tooth position significantly, and decreased gradually from front to back, namely first premolar> second premolars> first molars> second molar;there is no significant difference between each-tooth position in maxillary.4.Mandibular posterior area of pine, cortical thickness differences in each tooth bit is remarkable, and gradually increased from front to back, namely the first premolar< second premolar< first molar< second molar; maxillary posterior region between each tooth of cortical bone thickness had no obvious difference.5.The same tooth posterior area of cancellous bone density was significant differences in the maxillary and mandibular, mandibular is greater than maxillary in the all.6.The same tooth posterior area of cortical bone thickness was significant differences in the maxillary and mandibular, mandibu-lar is greater than maxillary in the all.7.Cancellous bone density of posterior region decreased significantly after the age of 50,but no significant differences in gender; cortical bone thickness had no significant difference in age and sex.