Abstract: The number and distribution of occlusal contacts in centric occlusion (CO) and centric relation have been studied by a number of authors All these studies have one thing in common-they define the greatest number of occlusal contacts between the molars The purpose of the present study was to register the maximum clenching forces in CO, as well as to analyze the anatomic and functional factors that determine their localization on teeth Method and Materials: The study included 42 subjects, aged 19 to 26 years, with intact dentition and Class I Angle occlusion; 38 persons had 1 to 4 restorations on the premolars and molars The occlusal contacts were investigated in CO by the T-Scan system (Sentek) on wax and silicone impressions The force loads in different sections of the dentition were differentiated by an additionally developed computer program Results: The T-Scan analysis and the developed computer program revealed that the maximum values of the clenching forces were recorded on the third molars The strongest contacts found by the T-Scan system were successfully visualized in wax and silicone impressions Conclusion: The maximum clenching forces of the masticatory muscles recorded by the T-Scan system were located in CO at the third molars in a dentition of 32 teeth and at the second molars in a dentition of 28 teeth If the above-mentioned phenomenon is not taken into consideration in clinical practice, occlusal contacts may be created that will unfavorably transfer the specific clenching forces to a more medially located molar in cases of occlusal restoration of the same molar by a restoration or a single crown

Abstract: The rationale of recording Centric Relation records is to establish guidelines as starting point to develop occlusion with artificial teeth in harmony with the various structures of masticatory apparatus including TMJ. It aids to maintain physiologic as well as anatomic health of tissues. When maximum intercuspation is coinciding with centric position, it provides stability to the prosthesis thereby preserving the health of remaining tissues (edentulous foundation, remaining natural teeth, musculature and TMJ) is accomplished.

Abstract: Aim This study was conducted in order to assess the changes in the occlusal position of the mandible after ULF (Ultra Low Frequency)-TENS relaxing procedure in subjects in pubertal growth phase with diagnosed Angle Class II division 1 and mandibular dentoalveolar retrusion. Materials and methods This study was performed on 19 patients (13 females, 6 males) with an Angle Class II division 1, aged between 10 and 15 years old (mean age 12.26, SD 1.32), characterised by mandible dentoalveolar retrusion and optimal vertical facial dimension, diagnosed by clinical and cephalometric evaluation. Diagnostic neuromuscular registrations were made for all subjects. The casts were mounted on articulator in habitual intercuspal position with a tooth-guided wax bite registration. Reference points were chosen at molar level. Subsequently the same casts were mounted in myocentric position and compared to the habitual intercuspal position, assessing the sagittal shift after TENS procedure. Statistics Mean and standard deviation were calculated on the amount of shifting at the left molar reference point after TENS procedure. Analysis of variance (ANOVA), using STATA statistics package, was carried out in order to evaluate the influence of sex and age on the amount of molar shift. Results Nine subjects showed, in the sagittal plane, a forward mandibular shift in neuromuscular myocentric position compared to habitual intercuspal position. Six subjects showed no differences between habitual and myocentric position in the sagittal plane. Four individuals showed a backward mandible shift after TENS indicating worsening of the II molar class in the sagittal plane. Conclusion This study suggests that TENS recorded occlusion in subjects with Class II division 1 with mandible dentoalveolar retrusion allows to visualise an unusual trend of growth. The advancements of the mandible were not taken into account. These results could offer new diagnosis and prognosis methods for Class II malocclusions.

Abstract: Functional rehabilitation of a completely edentulous patient with removable prostheses is a clinical challenge. A patient with an edentulous maxilla and mandible received 6 endosseous implants in the maxilla and 5 implants in the mandible using CAD/CAM surgical templates. Definitive maxillary and mandibular implant-supported fixed complete dentures were connected immediately after implant placement using a CAD/CAM-guided implant surgical placement protocol. (J Prosthet Dent 2008;99:416-420)

Abstract: Introduction: Recording the maxillomandibular relation is one of the important procedures in prosthodontic treatments. The centric relation (CR) of occlusion is the most important of these records. Body posture of the patient is one of the factors influencing the CR. In this study, we investigated the influence of patient's body position in CR recording by extra-oral tracing method. Materials & Methods: In this cross-sectional study, 18 edentulous Patients were randomly selected. After patient education, the extra-oral tracing device was attached to patient's dentures. Then the Gothic arch tracing was accomplished in supine, semi supine and upright position. The CR achieved by bimanual manipulation method was also recorded. Then the horizontal, anterior-posterior and straight distances of each point to point achieved by Dawson method, were calculated. Data were statistically analyzed using the one-way ANOVA and t-test. The level of significance was set at 95. Results: In edentulous subjects, there was no significant difference between horizontal distances of points registered in various body positions and the point registered in Dawson method, but with a view to ant-post and direct distances, the points registered in supine position were significantly nearer to that of Dawson method rather than the points registered in upright position. Conclusion: In edentulous subjects, and in comparison to upright position, the CR obtained in supine position by extraoral tracing method, was significantly similar to bimanual manipulation.

Abstract: PURPOSE: This study was performed to determine the most reproducible of three routinely used centric relation registration methods. MATERIALS AND METHODS: Three commonly used centric relation recording methods were investigated: a) the Gothic arch, b) the light-cured resin base plate with resin detail paste, and c) the anterior flat plane with lateral wax stripes. The handling principle used with all three methods was the gentle chin control. After a complete clinical and model analysis and axis-mounted casts, 99 centric relation records (33 times for each method) were performed by the same operator in a healthy 26-year-old individual. Registrations were performed after muscle deprogramming and using of well defined protocols. Every morning was determined the centric relation with all three methods and articulated the same lower jaw cast to the same axis-mounted upper jaw cast to 0 incisal pin position at the first contact point between the casts. The changes in space of three selected points in the lower jaw cast were evaluated with a 3D Digitizer in the X, Y, and Z axes. RESULTS: The maximum differences between the average values of the methods at the selected points were in the range of 0.26–0.34 mm for the X axis, 0.05–0.06 mm for the Y axis, and 0.05–0.33 mm for the Z axis. CONCLUSIONS: The light cured resin base plate method yielded the most retral position of the mandible in the most reproducible way while the least consistent method was the Gothic arch technique. The anterior flat plane was between the afore-mentioned methods. Working with the same gentle chin control all three methods were highly reproducible and can be used reassuringly in different clinical cases as required.

Abstract: A patient who visited our department after job relocation was reexamined, and a marked discrepancy was found in mandibular position between centric occlusion and centric relation. Although the patient was originally scheduled to undergo orthodontic treatment only, the results of comprehensive tests indicated that surgery would be needed to resolve this discrepancy. Surgery was performed with the patient's consent, yielding favorable results. Although the entire orthodontic treatment lasted 3 years and 11 months, including treatment prior to transfer, it was clear that long-term use of intermaxillary elastics would not have corrected the discrepancy and that surgery was the right decision.