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

Deep overbite patients who do not have proper occlusal relationship may cause problems such as teeth wear and antagonist extrusion. These lead to the collapse of occlusal plane and esthetic problem. Increasing vertical dimension is frequently essential to resolve those problems. This case report demonstrates a full-mouth rehabilitation for a patient with severe deep bite that contacts surface to surface by increasing vertical dimension. Treatment procedures included diagnosis, treatment planning, implant surgery, and prosthodontic rehabilitation. Satisfactory results were obtained in functional and esthetic aspects.
Dental Occlusion ; Diagnosis ; Humans ; Overbite* ; Rehabilitation* ; Tooth ; Vertical Dimension

OBJECTIVETo analyze changes of myoelectrical activity of anterior funicle of temporal muscle (TA) and masseter muscle (MM) after raising vertical distance of occlusion by flat bite plate during treatment of deep overbite in order to approach an optimal raised vertical distance.

METHODSA total of 70 persons were selected and divided into two groups: Experiment group (36 patients) with deep overbite and control group (34 persons) with individual normal occlusion. The experiment group was subdivided into three groups that were respectively raised D, D+2 mm and D+4 mm (D means free way space, mm). Electromyologram (EMG) was utilized to measure the average peak potential of TA and MM on quiescent condition before treatment and two weeks after wearing flat bite plate.

RESULTS1) Before treatment, the average peak potential of experiment group was obviously higher than that of the control group (P<0.05). 2) After two weeks the potential of TA and MM of all persons in experiment group was obviously lower than before (P<0.05), the degree between the group D+2 mm and the group D+4 mm was not manifestly different, but both of the two groups were more obvious than the group D.

CONCLUSIONThe raised vertical distance of occlusion by flat bite plate, which exceeded free way space, was favourable to the functional recovery of masticatory muscles.

Dental Occlusion ; Humans ; Masseter Muscle ; Masticatory Muscles ; Overbite ; Vertical Dimension

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

OBJECTIVETo assess occlusal balance of normal occlusion in intercuspal position with maximal bite force.

METHODSMaximal bite force was recorded in intercuspal position by use of T-Scan II system from 123 subjects with normal intact dentitions. Occlusal balance of normal occlusion was quantitatively analyzed from center of force, percentage of bite force, and occlusal contacts.

RESULTSThe relative position of the center of bite force, the difference in bilateral force percentage, and unsymmetrical coefficient followed normal distributions. The 95% reference ranges for corresponding testing items were -6.60 to 6.68 mm, -15.50% to 12.10%, and 0.65 to 1.39. There was no statistic difference (P = 0.915) in occlusal contacts between left and right sides. The 98.4% of normal occlusion subjects had the center of bite force locating in posterior region of dentition when biting with maximal force in intercuspal position.

CONCLUSIONSOcclusal balance could be evaluated by T-Scan II system. Occlusion of normal subjects biting with maximal force was stable and bilaterally balanced in intercuspal position.

Adolescent ; Bite Force ; Dental Occlusion, Balanced ; Dental Stress Analysis ; instrumentation ; Female ; Humans ; Image Processing, Computer-Assisted ; Jaw Relation Record ; Male ; Reference Values ; Young Adult

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

OBJECTIVETo investigate the relationship between wedge-shaped defects and occlusal interference.

METHODSFollowing examination from 46 patients, a total of 157 teeth were identified to have the criteria set for wedge-shaped defects and regarded as the experiment group. Also, 157 adjacent teeth exhibiting no such noncarious cervical lesions were randomly selected from the same group of patients and regarded as the control group. The distribution of occlusal force and time were examined with T-Scan II system in 46 patients with wedge-shaped defects in intercuspal occlusion position, protrusive movement and lateral movement. Occlusal interference and premature contact were evaluated and compared between the two groups.

RESULTSThe proportion of the teeth with premature contact in experiment group was 6.37%, while the control group was 2.55%, there was no significant difference between the two groups (P > 0.05). The total proportion with occlusal interferences in experiment group was 23.57%, which was significantly higher than that of the control group (10.19%, P < 0.05), in experiment group the proportion with working side interferences was 15.92%, and in control group, the proportion was 3.82%, there was significant difference between the two groups (P < 0.01). At the same time, the teeth with occlusal interferences had more serious degree of the wedge-shape defects than those with no occlusal interference.

CONCLUSIONThe increased occlusal force has relation to the formation as well as severity of wedge-shaped defects.

Bicuspid ; Bite Force ; Dental Occlusion ; Humans ; Male ; Tooth Abrasion

Loss of posterior support may cause extrusion of antagonistic teeth and excessive wear of remaining teeth which often leads to the destruction of the occlusal plane. In such cases, it is critical to verify the need to increase vertical dimension of occlusion (VDO). Should you increase VDO, provisionalization is crucial in evaluating function and esthetics. Double scanning technique is a useful method when fabricating definitive restoration that mimic provisional restoration. In this case, a patient with apparently no loss of VDO and insufficient interocclusal space for dental materials due to loss of posterior support and extrusion of antagonistic teeth was rehabilitated using double scanning technique.
Dental Materials ; Dental Occlusion ; Esthetics ; Humans ; Methods ; Rehabilitation* ; Tooth ; Vertical Dimension