OBJECTIVE: To verify the consistency between the digital manufacturing simple intraoral Gothic arch-tracing device and the traditional intraoral Gothic arch-tracing device in determining the centric relation of complete dentures restoration. METHODS: Ten outpatients with edentulous jaws were selec-ted, and the centric relation of the patients was determined by digital manufacturing of simple intraoral Gothic arch-tracing device (T1) and traditional intraoral Gothic arch-tracing device (T2); the difference of clinical operation time between the two methods was recorded; the upper and lower edentulous jaw plaster models were scanned with two kinds of centric relation, the Standard Triangle Language (STL) files imported into Geomagic studio software to apply the best fitting of multiple points of the both upper jaw models, the fitted STL files imported into the 3 shape viewer software, and the maximum position deviations of the vertical, labial (buccal) and lingual directions of the mandibular midline area and molar areas in T1 and T2 groups measured. During the clinical complete dentures try-in, we observed whether there was midline deviation in the mouth of T1 group and T2 group, and whether the occlusion of posterior teeth was stable or not. RESULTS: The mean time spent on determining the centric relation of T1 and T2 groups was (41.90±2.64) min, (57.50±2.37) min respectively. Paired t test was conducted in the two groups, P < 0.01 with significant statistical difference; The mean maximum position deviation between T1 group and T2 group of the midline mandibular region in labial lingual direction was (0.32±0.14) mm, that was (0.40±0.23) mm in vertical direction; the mean maximum position deviation of molar area in buccal lingual direction was (0.35±0.23) mm and that was (0.33±0.20) mm in vertical direction. In the vertical and horizontal directions, the maximum position deviation of mandibles between group T1 and group T2 was controlled within 0.5 mm. In the process of clinical complete dentures try-in, there was no deviation from the center line of dentures. There was not warping, swinging and other poor stability phenomena in T1 and T2 groups. CONCLUSION The digital manufacturing of simple intraoral Gothic arch-tracing device can be used to determine the centric relation of complete dentures, which can not only save time of clinical operation, but also ensure the accuracy of the centric relation.
Humans ; Centric Relation ; Jaw Relation Record/methods* ; Denture, Complete ; Mouth, Edentulous ; Jaw, Edentulous

Patients with collapsed occlusal support and unilateral chewing show parafunctional mandibular movements, which can be complicated in older patients. Gothic arch tracing and split cast technique are used to confirm the deviation between centric relation and anterior habitual bite in patient who has oral dyskinesia and collapsed occlusion. Temporary denture as occlusal stabilization appliance was provided for stable occlusion and reproducible mandibular movement. Definitive denture was fabricated by lingualized occlusion concept.
Centric Relation ; Dentures ; Humans ; Mandible ; Mastication ; Mouth Rehabilitation ; Mouth ; Movement Disorders ; Prostheses and Implants

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

Recently, many patients undergo anterior prosthetic treatment for esthetic reasons. In some patients complain about functional reasons such as inaccurate pronunciation and occlusal discomfort after the treatment. Anterior teeth are important esthetically but in the occlusal point of view, anterior guidance is the second most important factor in occlusion, next to centric relation. Failure to determine an appropriate anterior guidance might lead to posterior occlusal interference, which can highly affect the stability of the posterior teeth. Also, discomfort might occur if the customized interior guidance is not in harmony with the patient's envelope of function. The patient in this case complained of overall discomfort in the maxillary anterior area after prosthetic treatment. The expressed difficulty in pronunciation, unstable occlusion due to lack of stable holding contact and discomfort of the facial muscles. Maxillary anterior prostheses were refabricated through systematic diagnosis and treatment and thus, this case presents esthetical and functional satisfaction to both the patient and the dentist.
Centric Relation ; Dentists ; Diagnosis ; Facial Muscles ; Humans ; Prostheses and Implants ; Tooth

Excessive tooth wear can cause irreversible damage to the occlusal surface and can alter the anterior occlusal relationship by destroying the structure of the anterior teeth needed for esthetics and proper anterior guidance. The anterior deep bite is not a morbid occlusion by itself, but it may cause problems such as soft tissue trauma, opposing tooth eruption, tooth wear, and occlusal trauma if there are no stable occlusal contacts between the lower incisal edge against its upper lingual surface. The most important goal of treatment is to form stable occlusal contact in centric relation. In this case report, patients with decrease in vertical dimension and anterior deep bite due to maxillary posterior tooth loss and excessive tooth wear were treated full mouth rehabilitation with increased vertical dimension to regain the space for restoration and improve anterior occlusal relationship and esthetics. The functional and aesthetic problems of the patient could be solved by the equal intensity contact of all the teeth in centic relation (CR), anterior guidance in harmony with the functional movement, and restoration of the wear surface beyond the enamel range.
Centric Relation ; Dental Enamel ; Esthetics ; Humans ; Mouth Rehabilitation ; Mouth ; Overbite ; Tooth Eruption ; Tooth Loss ; Tooth Wear ; Tooth ; Vertical Dimension

Increased anterior teeth mastication following posterior teeth loss leads to greater anterior occlusal force. It may cause greater attrition of anterior teeth, traumatic force occlusion (TFO), also often followed by antagonist extrusion and occlusal disharmony. This clinical report describes the treatment for a 67-year-old female patient diagnosed with loss of both maxillary and left mandibular posterior teeth, severe attrition of maxillary and mandibular anterior teeth and extrusion of multiple teeth. A diagnostic cast was mounted on articular in centric relation (CR) position to evaluate vertical dimension (VD) and interspace. To provide adequate space for the prosthetic reconstructions, VD was increased by 3 mm on the anterior pin. And then diagnostic wax-up was completed upon that VD. Wax-up was converted to provisional restorations and verified in the patient's mouth and the final restorations were delivered. Clinical follow up examination held 3 months after temporary restoration owing to changes in vertical dimension revealed proper function in mastication without evidence of temporo-mandibular joint (TMJ) disorders. This clinical report presents successfully restoring severe attrition case with increasing vertical dimension resulting in satisfaction in esthetics and function.
Aged ; Bite Force ; Centric Relation ; Esthetics ; Female ; Follow-Up Studies ; Humans ; Joints ; Mastication ; Mouth ; Tooth ; Vertical Dimension

Flabby ridges adversely affect the stability of complete dentures. For the management it is suggested that soft tissues reconditioned before making definitive dentures, and modified impression techniques used for the flabby ridges. Also, correct record of centric relation is important in complete dentures. This case of 67-year-old edentulous female patient had atrophied ridges on the mandible and the flabby ridge on the maxilla. Treatment dentures were fabricated using gothic arch tracing method and tissue conditioner. Definitive dentures were made using window opening impression technique, the gothic arch tracing method, and lingualized occlusion. The patient was satisfied with the function and esthetic quality of the new prostheses.
Aged ; Centric Relation ; Denture, Complete ; Dentures ; Female ; Humans ; Mandible ; Maxilla ; Methods ; Mouth, Edentulous ; Prostheses and Implants ; Rehabilitation

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

In edentulous patients, implant - supported fixed prosthesis treatment has been proved to be useful, but involves complex treatment process. On the other hand, in the modern dentistry, digital technology has been developed day by day and it has expanded its range to the implant restoration of edentulous patients. In this case, a digital system was used for all stages of diagnosis, surgery, design and fabrication of provisional implants fixed prosthesis restoration in 66-year-old mandibular edentulous patients. In the preoperative diagnosis stage, a provisional restoration was designed based on the mucosal scan using the intraoral scanner and the stable occlusion of prefabricated complete denture of the patient. After flapless implant surgery using the surgical guide, the prefabricated interim restoration was connected to the implant and used as immediate provisional restoration. The final restoration was designed and fabricated by transferring the vertical dimension and the centric relation of the provisional restoration with stable occlusion using digital technology. We report a simple protocol of implant treatment in edentulous patients by using digital techniques to preserve the patient's vertical dimension and occlusion.
Aged ; Centric Relation ; Dentistry ; Denture, Complete ; Diagnosis ; Hand ; Humans ; Printing, Three-Dimensional ; Prostheses and Implants ; Vertical Dimension

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