| Purpose:In order to provide a basis for clinical assessment of alveolar bone lose andimprove the success rate of clinical operations, patients’ digital panoramicradiograph (OPG) and cone beam computerized tomography (CBCT) imageswere analyzed retrospectively. The alveolar horizontal distance and vertical distancewere measured in the anterior region, premolar region and molar region of the maxillaand mandible. The distortion rate of OPG was analyzed in every region while CBCTmeasurements were standard.Methods:1. In this study,60cases were randomly selected from the patients in Henanstomotology hospital who have taken CBCT and OPG during September2012toDecember2013. In which,30cases were in maxilla, and30cases were in mandible.The interval between OPG and CBCT was not more than three weeks. Images weretook at the standard postural and head position by the same experienced radiologist tomake sure the images were clear.2. There were three regions in mandible and they were anterior region,premolar region and molar region as same as the maxilla. The alveolarbone linear distance in every region were measured by using the in-built software inOPG and CBCT. Measurement content in each area included:①the horizontal distance on the alveolar ridge crest②the horizontal distance between the apical of two adjacent teeth in the samearea③the vertical root length-the length inside alveolar bone of each tooth3. The distortion rate was calculated on the formula followed while CBCTmeasurement was took as standard:Distortion rate=(OPG value－CBCT value)／CBCT value×100％ The horizontal distortion rate and vertical distortion rate of alveolar ridge crestand apical areas on OPG was Computed. The statistical analysis of the results wastaken by using software SPSS17.0, and the confidence interval was95%.Results:1. The horizontal and vertical distortion rate in different areas are as follows:Maxillary molar area: the mean of horizontal distortion ratios of the alveolarridge crest and apical are2.16±9.83%and3.24±12.02%, and the mean of verticaldistortion ratios is0.55±13.51%.Maxillary premolar area: the mean of horizontal distortion ratios of the alveolarridge crest and apical are8.38±9.98%and-3.40±11.22%, and the mean of verticaldistortion ratios is4.44±10.76%.Maxillary anterior area: the mean of horizontal distortion ratios of the alveolarridge crest and apical are-0.38±12.12%and8.48±14.34%, and the mean of verticaldistortion ratios is-1.23±8.46%.Mandibular molar area: the mean of horizontal distortion ratios of the alveolarridge crest and apical are3.14±8.14%and-3.23±12.06%, and the mean of verticaldistortion ratios is1.88±9.50%.Mandibular premolar area: the mean of horizontal distortion ratios of thealveolar ridge crest and apical are1.17±9.48%and4.76±13.10%, and the mean ofvertical distortion ratios is-0.36±6.67%.Mandibular anterior area: the mean of horizontal distortion ratios of the alveolarridge crest and apical are1.87±10.78%and12.15±18.35%, and the mean of verticaldistortion ratios is-7.84±8.78%.2. Except the maxillary molar area, each alveolar ridge crest areas in maxillaand mandibular, the differences of horizontal distortion ratios are not statisticallysignificant(P﹥0.05).Each alveolar ridge apical areas in maxilla and mandibular, the differences ofhorizontal distortion ratios are statistically significant(P﹤0.05).Each areas in maxilla and mandibular, the differences of vertical distortion ratios are statistically significant(P﹤0.05).3. The statistical analysis results of distortion ratios in different groups ofmaxillary and mandibular: the difference is not statistically significant in three groupsof maxillary, mandibular molar area and mandibular premolar area(P﹥0.05), thedifference is statistically significant in three groups of maxillary, mandibular anteriorarea and maxillary premolar area(P﹤0.05).Conclusions:1. The larger distortion rate of OPG is mostly in the maxillary premolar andmandibular anterior area.2. The vertical distortion rate is less than the horizontal distortion rate of OPGexcept individual areas.3. Both the horizontal and vertical distortion rates are stable and small inmaxillary and mandibular molar areas of OPG.4. The horizontal distortion rate changes greatly on different alveolar boneheight in maxillary and mandibular, and it is larger and less stable at the apical areasthan the alveolar ridge crest areas. |
PDF Full Text Request