Bioscopic Planes of Prosthetic Interest to Establsh Occlusal Plane In Edentulous Patients - A Cephalometric Study.

Aims: To determine the parallelism of the occlusal plane to the different alatragal lines and to evaluate the parallelism of maxillary and mandibular residual ridges/ basal bone to the three ala tragal lines. Material and Methods:Forty dentulous and forty edentulous subjects were included in the study. Four radiological markers have been placed- one each on superior, middle, inferior position of tragus and one at the ala of the nose. Lead foil is placed on the intaglio surface of the maxillary and mandibular dentures . Then the Lateral cephalograms was made and traced. Statistical analysis: Was subjected to ANOVA test and post hoc test of Bonferroni. Results: The alatragal line passing through the inferior position of the tragus to the ala of the nose is relatively parallel to the reference planes studied and helps to establish occlusal plane during complete denture fabrication.

The effect of pre-operative maxillary occlusal plane angle to post-operative skeletal stability after two-jaw surgery

Factors affecting root curvature of mandibular first molar / 대한구강악안면방사선학회지

PURPOSE: To find the cause of root curvature by use of panoramic and lateral cephalometric radiograph. MATERIALS AND METHODS: Twenty six 1st graders whose mandibular 1st molars just emerged into the mouth were selected. Panoramic and lateral cephalometric radiograph were taken at grade 1 and 6, longitudinally. In cephalometric radio graph, mandibular plane angle, ramus-occlusal plane angle, gonial angle, and gonion-gnathion distance (Go-Gn distance) were measured. In panoramic radio graph, elongated root length and root angle were measured by means of digital subtraction radiography. Occlusal plane-tooth axis angle was measured, too. Pearson correlations were used to evaluate the relationships between root curvature and elongated length and longitudinal variations of all variables. Multiple regression equation using related variables was computed. RESULTS: The Pearson correlation coefficient between curved angle and longitudinal variations of occlusal planetooth axis angle and ramus-occlusal plane angle was 0.350 and 0.401, respectively (p<0.05). There was no significant correlation between elongated root length and longitudinal variations of all variables. The resulting regression equation was Y=10.209+0.208X1+0.745X2 (Y: root angle, X1: variation of occlusal plane-tooth axis angle, X2: variation of ramus-occlusal plane angle). CONCLUSION: It was suspected that the reasons of root curvature were change of tooth axis caused by contact with 2nd deciduous tooth and amount of mesial and superior movement related to change of occlusal plane.

Study on the changes of occlusal plane angle in mandible prognathism after orthognathic surgery

11degree). Three groups were compared with the change of anatomical landmarks and occlusal plane angle alteration of lateral cephalometric radiography at each period of preoperative to immediate postoperative stage, preoperative to postoperative stage and immediate postoperative to postoperative 6month stage. As a result of this study, The clinical correlation between preoperative occlusal plane angle and severity of mandibular prognathism wasn't found. there is no statistical correlation between postoperative occlusal plane angle and severity of mandibular prognathism, but postoperative occlusal plane angle was increased in group of lower occlusal plane angle preoperatively, and postoperative occlusal plane angle was decreased in group of higher occlusal plane angle preoperatively. And, there is no clinical correlation between the relapse of B point to vertical plane and degree of preoperative occlusal plane angle. Therefore, from the results obtained in this study, we should suggest that mandible was rotated to clockwise direction on mandibular prognathism patient with the low occlusal plane angle postoperatively, and mandible was rotated to anti-clockwise direction on mandibular prognathism patient with the high occlusal plane angle postoperatively.

The comparative study for occlusal plane between articulated cast model and cephalogram in orthogantihic surgery patients

The common errors in preoperative treatment plan for the orthognathic surgery can be occurred during cast impression, cast mounting procedure with face-bow transfer, surgical stent fabrication, and so on. One of the most common errors exists during mounting process of the model on the articulator. Accurate mounting of dental casts to articulator should be achieved by transferring the 3- dimensional spatial relationship of the maxillary arch to an articulator. A face-bow is used for transfer this relationship to articulator, usually by relating the face-bow to a plane of reference of maxillary cast. The purpose of this study is evaluation of the accuracy of face-bow transferring of maxillary model to the articulator. The maxillary casts of thirty patients for orthognathic surgery were mounted on articulator with an face-bow instrument. The relationship of occlusal plane angle to Frankfort horizontal plane relations were compared the cephalogram with the cast-mounted articulator. As a result of this study, the significant difference between the maxillary occlusal planes angle in the cephalogram and articulator were found . The results were followed,1. The mean occlusal plane angle in cast-mounted articulator was 13.5.(SD+/-5.4).2. The mean occlusal plane angle in cephalogram was 10.4.(SD+/-4.3).3. The mean difference of occlusal plane angle between cast-mounted articulator and cephalogram was 3.3.(SD+/-4.6).According to the result, we should suggest that the occlusal plane angle to Frankfort plane in cast-mounted articulator is more steeper than that of cephalogram.And then, maxillofacial surgeon should try to get a more predictable result by suggesting the proper correction method and mounting the cast accurately.