PURPOSE: This study aimed to assess the agreement between 2 raters in evaluations of students on a prosthodontic clinical practical exam integrated with directly observed procedural skills (DOPS). METHODS: A sample of 76 students was monitored by 2 raters to evaluate the process and the final registered maxillomandibular relation for a completely edentulous patient at Mansoura Dental School, Egypt on a practical exam of bachelor’s students from May 15 to June 28, 2017. Each registered relation was evaluated from a total of 60 marks subdivided into 3 score categories: occlusal plane orientation (OPO), vertical dimension registration (VDR), and centric relation registration (CRR). The marks for each category included an assessment of DOPS. The marks of OPO and VDR for both raters were compared using the graph method to measure reliability through Bland and Altman analysis. The reliability of the CRR marks was evaluated by the Krippendorff alpha ratio. RESULTS: The results revealed highly similar marks between raters for OPO (mean= 18.1 for both raters), with close limits of agreement (0.73 and −0.78). For VDR, the mean marks were close (mean= 17.4 and 17.1 for examiners 1 and 2, respectively), with close limits of agreement (2.7 and −2.2). There was a strong correlation (Krippendorff alpha ratio, 0.92; 95% confidence interval, 0.79–0.99) between the raters in the evaluation of CRR. CONCLUSION: The 2 raters' evaluation of a clinical traditional practical exam integrated with DOPS showed no significant differences in the evaluations of candidates at the end of a clinical prosthodontic course. The limits of agreement between raters could be optimized by excluding subjective evaluation parameters and complicated cases from the examination procedure.
Centric Relation ; Dental Occlusion ; Education, Dental ; Educational Measurement ; Egypt ; Humans ; Methods ; Prosthodontics ; Schools, Dental ; Vertical Dimension

Extensive dental erosion and wear will cause serious loss of function and aesthetics in the mouth. In order to recover this condition, careful analysis of the patient's bite relationship is required. In particular, a treatment plan should be established considering the possibility of reproduction of the vertical dimension and centric relation, and appropriateness of the occlusal plane and anterior guidance. Also, the choice of prosthetic materials is an important consideration in patients with severe wear. In this case, patients with overall wear and erosion on tooth was established anterior guidance by orthodontic treatment and fully restored with monolithic zirconia, without increasing vertical dimension.
Centric Relation ; Dental Occlusion ; Esthetics ; Humans ; Mouth Rehabilitation* ; Mouth* ; Prostheses and Implants* ; Reproduction ; Tooth Erosion* ; Tooth Wear ; Tooth* ; Vertical Dimension

Centric Relation ; Dental Occlusion, Centric ; Humans ; Orthodontics

Nowadays, CAD/CAM is broadly used in dentistry for inlays, crowns, implant abutments and its spectrum is expanding to complete dentures. Utilizing CAD/CAM to fabricate complete dentures is expected to decrease chair time and the number of visits, thus decreasing total fabrication time, expenses and errors caused during fabrication processes. One of the systems using CAD/CAM, DENTCA(TM) CAD/CAM denture (DENTCA Inc. Los Angeles, USA) scans edentulous impressions, designs dentures digitally, fabricates try-in dentures by 3D printing and converts them into final dentures. Patients can wear final dentures after only 2 - 3 visits with satisfying adaptation. This case report introduces a 71-year-old male patient who visited to consult remaking of existing old dentures. Residual teeth with bad prognosis and root remnants were extracted and the patient used reformed existing mandibular denture for 2 months. And then DENTCA system started. One-step border molding was done using conventional tray of adequate size provided by DENTCA system and wash impression was taken. Gothic arch tracing was completed based on the vertical dimension of existing dentures. Both maxillary and mandibular trays were placed to the resultant centric relation and bite registration was taken. Then DENTCA scanned the bite registration, arranged the teeth, completed the festooning and fabricated the try-in dentures by 3D printing. The try-in dentures were positioned, occlusal plane and occlusal relations were evaluated. The try-in dentures were converted to final dentures. To create bilateral balanced occlusion, occlusal adjustment was done after clinical remounting using facebow transfer. The result was satisfactory and it was confirmed by patient and operator.
Aged ; Centric Relation ; Crowns ; Dental Occlusion ; Dentistry ; Denture, Complete ; Dentures* ; Fungi ; Humans ; Inlays ; Jaw Relation Record ; Male ; Occlusal Adjustment ; Prognosis ; Tooth ; Vertical Dimension

Centric Relation ; Dental Occlusion, Centric ; Humans ; Orthodontics ; Temporomandibular Joint

One of the ultimate goals for orthodontic treatment is to establish an esthetic, healthy, stable and efficient occlusion. Currently, however, most of the criteria are limited to static occlusion, with little attention to dynamic occlusion. During the therapy, the orthodontists may sometimes find the maximum intercuspation (MI) is remarkably inconsistent with the centric relation (CR), or the mandibular positions are different before and after the therapy. These definitely will influence the stability of the treatment, or even the health of temporomandibular joint (TMJ) and stomatognathic system. The functional occlusion theory emphasizes that the displacement of TMJ in the glenoid fossa is the reason for the inharmony between MI and CR, and the relapse. What is more, this theory also gives the orthodontists the ways to evaluate the relationships among the MI, CR and TMJ. In this paper, we will introduce the contents and methods of the functional occlusion theory.
Dental Occlusion ; Dental Occlusion, Centric ; Humans ; Mandible ; Temporomandibular Joint

Centric relation (CR) is one of the core research contents in orthodontics, prosthodontics, and gnathology, acting as an important physiological factor in reconstructing the occlusion and adjusting the occlusal relationship. For over a century, CR is still a controversial subject in dentistry. CR has been redefined for several times, and recently, its application has been widened in orthodontics, including orthodontic diagnosis, clinical examination and analysis, and treatment goals. The purpose of this article is to review the definition of CR, its relationship with malocclusion, and the application of this relationship in orthodontic treatment.
Centric Relation ; Dental Care ; Dental Occlusion, Centric ; Humans ; Malocclusion ; Orthodontics, Corrective

OBJECTIVE: To observe the changes of forward displacement of maxillary complete denture during centric occlusion, three different methods were used to record the changes of vertical overlap and the comfort level of patients before and after the selective grinding of the three dentures made according to maxillo-mandibular horizontal relationship record. METHODS: Twelve edentulous patients with normal stomatognathic system were recruited in this study. Three types of complete dentures for these 12 edentulous patients were made according to their different maxilla-mandibular horizontal relationship record methods. The amount of displacement of the maxillary complete denture, the vertical overlap of the anterior teeth as well as patient comfort level were recorded before and after selective grinding. Statistical analysis was performed using the SPSS 17.0 software package. RESULTS: Before selective grinding, the amount of displacement of denture A was significantly larger than those of dentures B and C (P<0.05). After selective grinding, there was no statistical difference among the three dentures (P>0.05). During selective grinding, the vertical overlap variation of denture A was significantly greater than those of dentures B and C (P<0.05). Before selective grinding, the comfort level of the denture A was the lowest (P<0.05), and no statistical difference was found between dentures B and C (P>0.05). After selective grinding, no statistical difference was found among the three dentures (P>0.05). CONCLUSIONS Among the complete dentures with anatomical teeth, the dentures whose horizontal relationship was recorded at 1 mm before the apex of the Gothic arch apex and with checkbite are more in line with clinical repair requirements. Complete dentures whose horizontal relationship was recorded at the apex of Gothic arch need to be adjusted with selective grinding to meet the clinical restoration requirements.
Dental Occlusion, Centric ; Denture, Complete ; Humans ; Mandible ; Maxilla ; Mouth, Edentulous

OBJECTIVEThis study investigates the differences in condylar position between centric relation (CR) and maximum intercuspation (MI) in Angle's Class II orthodontic patients before treatment.

METHODS80 cases, who were Angle's Class II pretreatment patients, and 50 cases, who were normal(ideal) occlusion were accepted. Dental casts were mounted on Panadent articulator with CR bite record, taken by bilateral manipulation and load testing. The differences in condylar position between CR and MI in all three spatial planes were measured using the Panadent condylar position indication (CPI).

RESULTS(1) The positive rate of CR-MI discrepancy was 92.50%(74 cases) in the group of Angle's Class II malocclusion and 10.00% (5 cases) in the group of normal occlusion(P< 0.001). 2)74.32% (55 cases) CR-MI discrepancy in 74 cases in the group of Angle's Class II pretreatment patients were coincidence discrepancy. (3)91.25% patients in the group of Angle's Class 11 malocclusion and 66.00% in the group of normal occlusion present occlusion interferences which located at the posterior teeth.

CONCLUSIONThe results suggested that orthodontists should be aware of a high incidence of condylar displacement in Angle's Class ii pretreatment patients, and measure condylar displacement before the start of comprehensive orthodontic treatment to unmask real jaw relationships and avoid possible misdiagnoses.

Adult ; Centric Relation ; Dental Arch ; Dental Articulators ; Dental Occlusion ; Female ; Humans ; Male ; Malocclusion ; Mandibular Condyle

OBJECTIVEThe aim of this study was to compare the mandibular position when speaking with the intercuspal position and to check the stability of phonetics when determining the horizontal jaw relation in healthy adults.

METHODSA total of 19 healthy volunteers were recruited. Seven Chinese letters, namely, /xi/, /er/, /yi/, /ci/, /mi/, /ni/, and /ri/, were chosen in the test. O-bite was used to record the mandibular position when speaking these letters. A full-adjusted articulator was used to find the mandibular position during speech, and the mandibular position was measured using a vernier caliper. The mandibular position during speech with intercuspal position was compared in both anterior-posterior and left-right directions of the horizontal plane. Multi-factor analysis of variance was conducted for the statistical analysis of the effect of objects and letters on the mandibular position.

RESULTS1) The mandibular position was in front of the intercuspal occlusion position when speaking all seven letters, and almost no deviation was observed in the left and right directions (the mandibular position value of 82% was in the range of 0.5 mm). 2) Different objects had different mandibular positions during speech, whereas different letters did not. The distance between the centric relation position and the intercuspal position had a positive correlation with the range of the mandibular position during speech.

CONCLUSIONThe mandibular position was in front of the intercuspal position when speaking all seven words in the test. In the same object, the mandibular position was stable during speech.

Adult ; Centric Relation ; Dental Articulators ; Dental Occlusion ; Humans ; Jaw Relation Record ; Mandible ; Phonetics ; Speech