A Comparative Study on Measurement of Maxillary Occlusal Cant Obtained through Facebow Transfer and Using Lateral CEPH.: An in vivo Study

Purpose: The purpose of the study was tocompare measurements of maxillary occlusal cant obtained through facebow transfer and through lateral cephalogram.Method:40 subjects were included in this study according to inclusion and exclusion criteria and divided into two groups: dentulous and edentulous. For edentulous subjects, all the steps of complete denture fabrication were carried out and finished dentures weredelivered. Alginate impressions were now made for all the subjects (with complete denture worn in edentulous cases) for both upper and lower arches. The study was conducted in two parts. Facebow transfer was done next and casts were mounted. In first partof the study, sagittal inclination was measured after facebow transfer. After mounting of the casts, four points were marked to measure the inclination of the occlusal plane. In second part, cephalometric evaluation of occlusal plane and Frankfurt horizontal plane was carried out. Angle between Frankfurt horizontal plane and the occlusal plane was maxillary occlusal cant. which was evaluated by tracing.Paired t test was used to compare mean facebow values and lateral ceph values in edentulous subjects. Intergroup comparison between lateral ceph and mean facebow values between dentulous and edentulous subjects was evaluated using independent t test.Results:Facebow measurements gave comparatively higher values in both dentulous and edentulous patients and are subjected to less variation as compared to the lateral cephalogram values p<0.0001.Conclusion:The occlusal plane angle of lateral cephalogram was found to be significantly different from angle obtained through facebow transfe

Utility of facebow in the fabrication of complete dentures, occlusal splints and full arch fixed dental prostheses: A systematic review

The objective of this study is to assess the utility of facebow transfer in the fabrication of occlusal splints, complete dentures and full arch fixed dental prosthesis. Materials and Methods: A systematic review protocol was registered at PROSPERO registry, University of York, UK (CRD42016041919). Following databases were explored: PubMed, CINAHL, Cochrane, and Web of knowledge. The PICO model included participants who received occlusal splint or complete denture or full arch fixed dental prosthesis at the centric relation position. The intervention was the use of facebow transfer. Comparators were prosthesis made without using a facebow. Outcomes were the patient satisfaction of the prosthesis and the need for laboratory adjustments. Only randomized clinical trials were included in the present review. A customized data extraction pro forma was used to extract the data and assess its quality. Results: A total of 505 articles were retrieved. On excluding duplicates, protocols, case reports, case series, narrative reviews, etc., only eight studies were selected for review. Six clinical trials on 249 complete dentures and two clinical trials on 65 occlusal splints were reviewed. No study on full arch crown and bridge work satisfied the inclusion criteria. Conclusions: The use of facebow did not yield a superior fit or comfort of the complete dentures or occlusal splints. Therefore, there is no evidence of the utility facebow transfer for these prostheses. However, no inference could be drawn for its utility in full arch fixed dental prosthesis as there were no studies to draw an inference.

Single step approach to make diagnostic impressions of both the arches and face bow transfer: A novel technique.

Context: Mounting the maxillary and mandibular dentulous casts for Diagnostic purpose requires many steps (including making maxillary and mandibular impressions, face-bow transfer, and bite registration) or many appointments. A simple new technique of doing all of this together without compromising on the accuracy can save time over the conventional mounting procedure. Aim: To compare the accuracy of a new technique of a single-step diagnostic mounting procedure with that of the conventional diagnostic mounting procedure. Materials and Methods: Ten dentulous patients with the full complement of teeth and without any history of temporomandibular disorder and orthodontic treatment were selected for this study. A detachable metal triple tray to replace the fork part of the face bow fork that further could be attached to face bow was fabricated. Dual-arch impressions and face-bow transfer were made in these subjects using this modified triple tray. These mountings were compared with the ones done with the conventional mounting procedure. Five linear measurements (using stable reference points on the articulator and the cast) were made and the values obtained by both the methods were compared. Statistical Analysis: The Student's 't' test for statistical analysis was used in this study. Results: The measurement values obtained by the single-step method were almost similar to the ones obtained by the conventional method. The various mean measurements for the single step and conventional methods were 37.7 ± 6.8 and 38.5 ± 6.5 mm; 70.0 ± 4.4 and 70.1 ± 4.2 mm; 57.0 ± 4.9 and 57.3 ± 4.2 mm; 71.3 ± 4.5 and 71.0 ± 4.6 mm; and 58.7 ± 2.5 and 58.3 ± 2.3 mm; respectively. The differences between the values obtained by the conventional and single-step methods were not statistically significant. Conclusion: The single-step procedure of diagnostic mounting can be used as an alternative to the conventional method, without compromising the quality of mounting.

A prediction of bony interference between proximal and distal segment of the mandible with integrated 3d solid model and dental cast in orthognathic surgery

Three-dimensional solid model has not been widely used in surgical prediction of orthognathic surgery because freque from occlusal restorations or prosthesis limited the usefulness of simulated surgery involving occlusion. We prepared three-dimensional(3D) solid model from CT data and integrated the 3D solid model with dental cast using a face-bow transfer technique combined with skeletal reference measurement and confirmation with cephalometric radiographs. With this simple and easy method, it was possible to predict bony interference between the proximal and distal segment of the mandible so that we can prevent condylar displacement after sagittal split ramus osteotomy of the mandible with prominent asymmetry. The method error was within 2mm and it seemed to be useful in preoperative planning for maxillofacial surgery with maxillo-mandibular occlusal change

A three-dimensional FEM comparison study about the force, displacement and initial stress distribution on the maxillary first molars by the application of various asymmetric head-gear / 대한치과교정학회지

The purpose of this study was to compare the force, the displacement and the stress distribution on the maxillary first molars altered by the application of various asymmetric head-gear. For this study, the finite element models of unilateral Cl II maxillary dental arch was made. Also, the finite element models of asymmetric face-bow was made. Three types of asymmetric face-bow were made : each of the right side 15mm, 25mm and 35mm shorter than the left side. We compared the forces, the displacement and the distribution of stress that were generated by application of various asymmetric head-gear. The results were as follows. 1. The total forces that both maxillary first molars received were similar in all groups. But the forces that mesially positioned tooth received were increased as the length of the outer-bow shortened, and the forces that normally positioned tooth received were decreased as the length of the outer-bow shortened. 2. In lateral force comparison, the buccal forces that normally positioned tooth received were increased as the length of the outer-bow shortened, and the buccal forces that mesially positioned tooth received were decreased as the length of the outer-bow shortened. Though the net lateral force moved to the buccal side of normally positioned tooth as the length of the outer-bow shortened, both maxillary first molars received the buccal force. That showed "Archial Expansion Effect" 3. The distal forces, the extrusion forces and the magnitudes of the crown distal tipping that mesially positioned tooth received were increased as the length of the outer-bow shortened, and the forces that normally positioned tooth received were decreased as the length of the outer-bow was shortened. 4. The magnitude of the distal-in rotation that normally positioned tooth received were increased as the length of the outer-bow was shortened. But, mesially positioned tooth show two different results. For the outer-bow 15mm shortened, mesially positioned tooth showed the distal-in rotation, but for the outer-bow 25mm and 35mm shortened, mesially positioned tooth showed the distal-out rotation. Thus, the turning point exists between 15mm and 25mm. 5. This study of the initial stress distribution of the periodontal ligament at slightly inferior of the furcation area revealed that the compressive stress in the distobuccal root of the normally positioned tooth moved from the palatal side to the distal side and the buccal side successively as the length of the outer-bow shortened. 6. This study of the initial stress distribution of the periodontal ligament at slightly inferior of the furcation area revealed that the magnitudes of stress were altered but the total stress distributions were not altered in the mesiobuccal root and the palatal root of normally positioned tooth, and also three roots of mesially positioned tooth as the length of the outer-bow shortened.