Comparison Between Opg And Cbct For Implant Dentistry In Mandible Accurately

ObjectiveTo compare the measurements of the mandible associated with implant surgery between the OPG and CBCT. According to the data and images, the study would provides the objective suggestion for accurate measurement of mandibular structures and help to improve the safety of the surgery.MethodIn the study, choose30patients’OPG and CBCT randomly. For different areas of mandibular, the following indicators would be measured and compared on OPG and CBCT:1) The detection rates of mental foramen,anterior loop, additional mental foramen, incisive canel and lingual foramina on the mandibular midline.2) The root length in bone, the available bone height; Interradicular space on the level of the alveolar ridge crest and between the apical of two adjacent teeth;3) The tilt angle of the second premolar.4) Analysis the relationship between PMI on OPG and grey values on CBCT. All data was analyzed by statistical package of GraphPad Prism5software.the confidence interval is95%。ResultIn comparision of OPG and CBCT in measuring data about mandibular commonly needed, the results as following:1) On OPG, the detection rates of mental foramen,anterior loop, additional mental foramen, incisive canel and suprior genial spinal foramina were93.3%、46.7%、6.7%、0%and0%; On the CBCT, the detection rates of mental foramen,anterior loop, additional mental foramen, incisive canel and suprior genial spinal foramina were100%,16.1%、26.1%、83.8%and100%. The difference in the detection rates of anterior loop、incisive canel and suprior genial spinal foramina show statistical significance(p<0.05).2) Measuring the root length in bone and the available bone height:In anterior area the differences had statistical significance (p<0.05), difference of ABH in anterior area and molar area had statistically significant (p<0.05);In measurement of interradicular space on the level of the alveolar ridge crest and between the apical of two adjacent teeth, the difference had no statistical significance;3) The tilt angle of the second premolar was greater than the CBCT on OPG, and it had statistical significance (p=0.01).4) A statistically significant correlation was found between PMI and grey value on CBCT(p<0.05, r2=0.27).Conclusion1.It is better to observe the anatomical structure in mandibular on CBCT than OPG;2.There is difference in measuring height in anterior area and molar area;the title angle of the second premolar between OPG and CBCT;3. PMI can reflect the density of mandible to a certain extent.