Clinical Research Of Bone Mineral Dentisy Analiysis By Radiovisiograph, Bone Quality Index And Mandibular Cortical Index Of Dental Implants

Objective: To establish whether a relationship exists between the bone quality index (BQI), the mandibular cortical index (MCI) and bone mineral density (BMD) as measured by RadioVisioGraphy (RVG). To assess clinical utility of bone mineral dentisy analiysis by RVG,measurement by RVG,BQI,MCI in evaluation of jaws quality of implantodontics.Methods: 138 implants were planed to be placed in the jaws of 116 cases. Each patient underwent RVG examination by altering the exposure intensity three times and panoramic radiographic examination before implants placing. BMD of the jaws was observed and measured by RVG,.Jaws quality was assessed using the BQI by RVG. The appearance of the lower border of mandibular cortex distal to the mental foramina were classified according to the MCI by orthopantomography. The images made by RVG and oral pantomography in 65 posterior mandible or posterior maxilla cases, the height of the crest of ridge to the mandibular nervous canal or maxillary sinus was measured by the two images above.All measurements and assessments were performed by two observers having similar experience independly . The variation of measurement of BMD during different exposure intensity groups and different region of interest(ROI) was analyzed by SPSS13.0 software. The relationships between the BMD and the radiographic indices (BQI and MCI) were assessed using the same SPSS13.0 software. Agreement of two indices assessed by two observer was analyzed by calculation of the kappa (k) statistic.Variation of the height of the alveolar bone measured by the two methods above was analyzed by calculation of paired-sample t-test. Results: 1:The results of F test showed there was statistical difference among three groups of different exposure intensity(p<0.01),and the BMD values were declined following the increasing of the exposure intensity.There was no statistical difference among the different gray scales in the same group(p>0.05).2:There was no statistical difference of the BMD measured by RVG among the four regions within the mouth, with posterior mandible > anterior mandible > posterior maxilla > anterior maxilla.3:Repeated assessments of BQI inter-observer had "moderate" to "substantial" agreement(Kappa value=0.509-0.749). There was moderate agreement between repeated assessments of MCI inter-observer(Kappa value=0.532-0.598).4:For assessments by both observers there were significant differences in BMD among different BQIs and MCIs in the same region of jaws. (p<0.05).5:BQI and MCI assessments, made by both observers, were significantly correlated with BMD measured by RVG in the same region of jaws.(p<0.05) 6:There was no statistical difference of height of alveolar bone measurement using RVG and pantomography.(p> 0.05). The height of jaws can be measured directly by RVG.Conclusions: The BMD analiysis of RVG is a useful method to analyze the bone density of the jaws before dental implants surgery,for its advantage of objective,economy,quickness,less radiation exposure and direct-viewing.Both BQI and MCI assessments were significantly correlated with BMD measured by RVG.There are limitations in reproducibility of assessments which might considerably diminish their usefulness in clinical practice. The height of the alveolar bone can be measured directly by RVG,but there are limitations in the posterior mandibular sites.