Jaw Relation Record Research Articles

Jaw relation recording and transferring: Using digital technology to augment its instruction in predoctoral prosthodontics

AbstractObjectivesThe study compared the learning effectiveness and teaching satisfaction of dental students from three teaching methods (traditional, digital, and combined pedagogy) for instructing jaw relation recording and transferring (JRRT).MethodsNote that, 276 fourth‐year undergraduate students from three classes were randomly divided into three groups to study JRRT in complete dentures using different teaching methods: traditional pedagogy group, digital pedagogy group, and combined digital and traditional pedagogy group. After the course, the learning effectiveness of basic knowledge and satisfaction questionnaire was administered to the three groups of participants using a quick response code for online answering. The questionnaire was customized by the teacher based on the content delivered to each group.ResultsThe data were analyzed using the Chi‐square test with Fisher's exact test. Both the digital and combined pedagogy groups showed a significant increase in basic knowledge test scores and higher satisfaction, compared to the traditional pedagogy group (p < 0.01). Particularly, the participants from combined pedagogy showed better teaching satisfaction than the digital pedagogy group (p < 0.001).ConclusionsThe use of digital technology in JRRT significantly enhanced students' learning effectiveness and teaching satisfaction.Clinical significanceThis educational innovation emphasizes digital technology to visualize vital concepts and operational intricacies related to JRRT. The findings have major implications for improving teaching methods in the field of prosthodontic dentistry.

Digital jaw relation recording to evaluate a new vertical dimension of occlusion using CAD/CAM-fabricated tooth-colored splints: a case report.

Pronounced defects of the dental hard tissue can be caused by different etiologic factors. Most frequently, they are associated with changes in the vertical dimension of occlusion (VDO), which may also influence the condylar positions. These defects can lead to irreversible loss of tooth structure and have dramatic functional and esthetic consequences, often requiring complex rehabilitation. In this situation, CAD/CAM-fabricated occlusal splints made of tooth-colored polycarbonate are a proven and safe pretreatment approach in terms of esthetics and function. Rebuilding lost dental hard tissue to restore the occlusion and VDO to an adequate condylar position is a prerequisite for any sustainable and functional rehabilitation. In the future, digital systems will support this complex process, customizing it and making it simpler and more precise. The DMD-System (Ignident) provides patient-specific jaw movement data to optimize the CAD/CAM workflow. This system allows real movement patterns to be digitized and analyzed for functional and potential therapeutic purposes, integrating them into the dental and laboratory workflow. In the present case, the familiar tooth-colored CAD/CAM-fabricated occlusal splint is supplemented by digital centric jaw relation recording and individual movement data.

Key points to ensure successful jaw relation record in complete dentures

Key points to ensure successful jaw relation record in complete dentures

A study comparing patient satisfaction and retention of CAD/CAM milled complete dentures and 3D printed CAD/CAM complete dentures versus conventional complete dentures: a randomized clinical trial

Objective: To compare the three different methods of complete denture fabrication assessing patient satisfactionand retention after insertion for six months’ follow-up period. Material and Methods: The study was conductedin the Prosthodontic Department where a total of forty-eight patients were recruited from the outpatient clinicsfulfilling the inclusion criteria. This study was designed as a randomized controlled clinical trial. All patientsfollowed the steps of complete denture construction till jaw relation record. Then, all eligible patients wererandomized to intervention and control groups. For intervention groups digital scanning, designing, manufacturingof complete dentures was done; 3D printing for first and milling for second intervention. For the comparatorgroup, complete dentures were manufactured the conventional way. After 2 weeks of delivery of the dentures,patients received a patient satisfaction questionnaire, retention was measured by retention force gauge. Bothreadings were also recorded after 3 months and at 6 months. The mean and standard deviation values werecalculated for each group in each test. The significance level was set at P < 0.05. Results: No statistical differencewas found in terms of patient satisfaction and retention between the three groups at different time intervals.Conclusion: The manufacturing technique seemed to have no influence on patient satisfaction and retentionwith milled showing the least results.KEYWORDSComputer-aided design; Denture, Complete; Denture retention; Patient satisfaction; Printing, Three-dimensional

Comparison of Techniques for Obtaining Centric Relation Based on the Reproducibility of the Condylar Positions in Centric Relation-A Systematic Review.

The objective of this systematic review was to compare centric relation (CR) techniques that belong to the same method of obtaining CR (guided, graphical, or physiological method), to verify which CR technique within each method of obtaining CR generates the greatest reproducibility of the condylar positions (or mandibular position) in CR. The PubMed, Cochrane Library, SciELO, Scopus, and Web of Science databases were searched for articles published up to May 5, 2021. The search terms were combinations of “dental centric relation” (MeSH), with each of the following terms (individually): “reproducibility of findings” (MeSH); “jaw relation record” (MeSH); “chin point”; “gothic arch”; “bimanual manipulation”; “swallowing” (MeSH); and “jig.” Inclusion criteria: clinical studies in English; individuals without temporomandibular dysfunction and with complete or almost complete dentition or complete edentulous; and comparison between CR techniques belonging to the same method of obtaining CR based on the reproducibility of condylar positions in CR. For each method of obtaining the CR, the following CR techniques were considered: guided method (chin point guidance and bimanual manipulation); graphic method (intraoral and extraoral gothic arch tracing); and physiologic method (swallowing and tongue retrusion along the palate). A total of 1692 articles were screened. After the inclusion and exclusion criteria were applied, six articles were included in this review. None of the included studies evaluated edentulous individuals. All included articles compared CR techniques of the guided method. Three articles concluded that the bimanual technique showed greater reproducibility of the condylar positions in CR than the chin point guidance technique, two articles showed equivalence between these techniques, and 1 article concluded that the chin point guidance technique showed greater reproducibility of the condylar positions in CR than the bimanual technique. Thus, in this systematic review, the bimanual technique was often superior (generated greater reproducibility of the CR) or at least equivalent to the chin point guidance technique. Therefore, for individuals with complete dentition and without temporomandibular disorders, the bimanual technique is more recommended.

Retention of Rapid Prototyped Complete Dentures Using Two Retention of Rapid Prototyped Complete Dentures Using Two different types Liquid Resin

Objectives: Comparing the retention of upper complete denture manufactured using two different denture base materials, both of them were manufactured using rapid prototyping method. Methods: Nineteen patients were selected. For both groups, the dentures were manufactured using Rapid prototyping method following the next steps, a preliminary impression was made & trial denture bases were constructed on the primary casts for the upper & lower arches for a jaw relation record. A facebow record was used to mount the upper cast, while the lower cast was mounted using a centric relation record. Setting of artificial teeth was performed, then the denture was tried in patient`s mouth. Functional impression was taken during the try in stage. CBCT scanning of the try in with the functional impression was done to obtain STL file then denture manufacturing was done by 3D printing. Results: results showed that there is no significant difference between the two groups. Conclusion: Complete denture retention is not significantly affected by the material used for denture construction. Clinical significance: This in-vivo cross over study introduces a novel approach for digital construction of upper complete denture using recent materials and gives an idea about their retentive value

Diagnostic Testing Using Pterygomaxillary Notches and Retromolar Pads on Casts to Check Horizontal Jaw Relation.

To verify horizontal jaw relations using anatomical marks on a cast and evaluate the efficiency and accuracy of the test on checking the horizontal relation. A total of 200 patients with a loss of posterior occlusion were recruited. After casts were made and the horizontal jaw relation was recorded, the pterygomaxillary notch and retromolar pad were identified bilaterally on the maxillary and mandibular casts. On each cast, a vertical line was drawn to bisect the anatomical landmarks and the distance between the two vertical lines was measured. Using the result of the wax try-in appointment and the corresponding measurements, a diagnostic test was conducted. A receiver operating curve was created and the maximum horizontal distance between bisecting points that still obtained correct jaw relations was determined to be a criterion. The accuracy of the test to verify horizontal jaw relations was evaluated. The area under the curve of the receiver operating curve was 0.833 (P < 0.05). With a maximum Youden index, the d value threshold was 1.0 mm. Using 1.0 mm as a criterion to check the horizontal relation, the sensitivity of the test was 0.76 and the specificity was 0.93. The kappa value for different researchers was calculated to be 0.79 (P < 0.05). The intraexaminer 1 reliability gave a kappa value of 0.76 (P < 0.05), and intraexaminer 2 gave a value of 0.81 (P < 0.05). The test for verifying the accuracy of horizontal jaw relations is reliable. If horizontal distance is measured as greater than 1.0 mm at the jaw relation record appointment, the recorded horizontal jaw relationship may be wrong and need to be reexamined.

Centric relation registration with intraoral central bearing on curved vs. flat plates with rim trays in edentulous patients.

The aim of this study was to compare jaw relation record in the completely edentulous patient using acrylic rim trays with curved or flat registration plates or using the manual guidance technique. The study included 17 patients - 11 female and 6 male, average age 70 years. Three jaw relation records were taken during one session, in the same vertical dimension, using acrylic rim trays: (1) with manual guidance (IM), (2) with self-guided recording system with acrylic rim tray and central support using a curved plate (BYC) and (3) with self-guided recording system with acrylic rim tray and central support using a flat plate (BYR). The models were mounted on a Whip Mix 2240 articulator to which a condyle position device (Orthodent) was added to register, at the level of the condyle box and incisal table, the differences among the positions recorded with the different setups (IM, BYC and BYR). The distances were measured on millimeter paper provided by the recording system manufacturer. For statistical analysis, confidence intervals (95%) were calculated for the mean differences and Student's t-test for paired data (significance level: alpha<0.05). On both the mesiodistal plane and the vertical plane at the level of each condyle box and the incisal table, there were statistically significant differences among the three systems (p<0.001). At the level of incisal table, BYC and BYR provided more retrusive records than IM [arithmetic means (standard deviations) in millimeters: 3.82 (2.10) and 4.53 (2.18), respectively). The records obtained with BYR were significantly more retrusive with BYC [arithmetic mean (standard deviation) in millimeters: 1.41 (1.00)]. We reject the null hypothesis that proposes that all three registration systems described are clinically equivalent for establishing a jaw relation record in completely edentulous patients.

Revisiting a Funding Model for University-led Dental Clinics: The Case of Complete Denture Fabrication Case of Complete Denture Fabrication

Objectives: University-led dental clinics are rarely seen as core to the national healthcare system. Thus, when publicly funded universities experience a decline in government support, dental clinic services operated by students are confronted by a potentially inadequate operating budget. Prompted by the need for strategic resource allocation, this study seeks to quantify the resources consumed in the construction of complete dentures by undergraduate students in an effort to identify opportunities for cost-cutting measures. Methods: Clinical cases were retrieved from the logbooks of graduating students of Class 2015, and patient records were reviewed to identify and quantify all clinical and laboratory procedures involved in constructing a set of complete dentures. Cost estimation was carried out using the activity-based method on the basis of direct medical costs. Results: A total of 83 patient records were reviewed. The average number of visits required to fabricate a set of complete dentures was 10 (range, 6–20 visits) with an average total cost of MYR2131±538 (€450±114). The number of visits contributed substantially to the total cost, and procedures requiring multiple visits included secondary impression and jaw relation recording. The major cost components were dental equipment (44%), laboratory costs (28%), dental consumables (17%), salaries (7%), and dental instruments (3%). Conclusion: The operating cost for training students in denture fabrication is substantial. Schools should formulate strategies to reduce the number of patient visits by ensuring that students optimize the time spent per visit. A financially sustainable model to fund dental training is necessary to ensure that quality of care is not compromised in university-led clinics.

Rehabilitation for a scleroderma patient with severe microstomia using digital and conventional methods

BackgroundMicrostomia is a principal clinical symptom in patients with scleroderma. It is characterized by an abnormally small mouth opening, which makes traditional prosthetic rehabilitation difficult. MethodsFirst, the primary impression and jaw relation record were acquired using an intraoral scanning technique and the primary diagnostic dentures were fabricated using 3-dimensional printing (3DP). The definitive impression and jaw relation were obtained and digitally scanned. The second diagnostic denture was also made to confirm the esthetic and occlusal effects. Next, the adjusted dentition parts were scanned and milled from a cross-linked polymethyl methacrylate disk. In addition, the titanium alloy frameworks were also fabricated using 3DP. With flasking, the milled dentition parts were inserted and the definitive dentures were finally fabricated and delivered to the patient. ResultsThe authors constructed the definitive removable partial dentures successfully using the digital methods of intraoral scanning, computer-aided design, and 3DP. Conclusions and Practical ImplicationsThese digital methods provide an alternative option for prosthetic rehabilitation in scleroderma patients with severe microstomia.

Digital Jaw Relation Record of Edentulous Patients in the CAD-CAM Workflow of the Implant-Supported Full-Arch Prosthesis.

No abstract is required for research letters.

Patient satisfaction, clinical outcomes and oral health-related quality of life after treatment with traditional and modified protocols for complete dentures

Background/purposeConventional complete denture treatment course requires six appointments, but modified protocol only takes four appointments. This study compared the conventional and modified protocol for complete denture fabrication regarding patient satisfaction and clinical outcomes. Materials and methodsA total of 24 patients accepted complete denture treatment. According to complete denture treatment protocol, these patients were divided into the conventional group (group C, n = 12) and the modified group (group M, n = 12). Group C used the conventional protocol and required six appointments. Group M used the one-appointment master impression and jaw relation record technique, and it took four appointments. Data of oral health impact profile-14 (OHIP-14), satisfaction scale and the number of recalls in the first year were collected for the statistical analysis. ResultsThe mean OHIP-14 scores in group C and group M were 13.79 ± 3.81 and 15.33 ± 5.25, respectively. In terms of satisfaction, the mean scores in group C and group M were 8.33 ± 0.61 points and 8.66 ± 1.13 points, respectively. There were no statistically significant differences between the group C and M in terms of participant ratings for satisfaction and OHIP-14. At the same time, the results indicated that group M significantly reduced the number of postinsertion visits (P < 0.05). ConclusionIn terms of OHIP-14 and patients’ satisfaction, the modified treatment protocol is comparable to the conventional protocol. Based on the number of recalls in the first year, the modified treatment protocol has a better clinical outcome.

Accuracy of three intraoral scans for primary impressions of edentulous jaws

OBJECTIVE To provide a reference for using intraoral scanners for making clinical diagnostic dentures of edentulous jaws by comparing the accuracy of three intraoral scanners for primary impression and jaw relation record of edentulous jaws. METHODS This study contained 6 primary impressions of the edentulous patients. Each of the impressions consisted of the maxillary primary impression, the mandibular primary impression and the jaw relation record. For each of them, a dental cast scanner (Dentscan Y500) was used to obtain stereolithography (STL) data as reference scan, and then three intraoral scanners including i500, Trios 3 and CEREC Primescan were used for three times to obtain STL data as experiment groups. In Geomagic Studio 2013 software, trueness was obtained by comparing experiment groups with the reference scan, and the precision was obtained from intragroup comparisons. Registered maxillary data of the intraoral scan with reference scan, the morphological error of jaw relation record was obtained by comparing jaw relation record of the intraoral scan with the reference scan. Registered mandibular data with jaw relation record of intraoral scan and the displacement of the jaw position were evaluated. Independent samples t test and Mann-Whitney U test in the SPSS 20.0 statistical software were used to statistically analyze the trueness, precision and morphological error of jaw relation record of three intraoral scanners. The Bland-Altman diagram was used to evaluate the consistency of the jaw relationship measured by the three intraoral scanners. RESULTS The trueness of i500, Trios 3 and CEREC Primescan scanners was (182.34±101.21) μm, (145.21±71.73) μm, and (78.34±34.79) μm for maxilla; (106.42±21.63) μm, and 95.08 (63.08) μm, (78.45±42.77) μm for mandible. There was no significant difference in trueness of the three scanners when scanning the maxilla and mandible(P>0.05). The precision of the three scanners was 147.65 (156.30) μm, (147.54±83.33) μm, and 40.30 (32.80) μm for maxilla; (90.96±30.77) μm, (53.73±23.56) μm, and 37.60 (93.93) μm for mandible. The precision of CEREC Primescan scanner was significantly better than that of the other two scanners for maxilla (P<0.05). Trios 3 and CEREC Primescan scanners were significantly better than i500 scanner for mandible (P<0.05). The precision of the i500 and Trios 3 scanners for mandible was superior to maxilla (P<0.05). The upper limit of 95% confidence intervals of trueness and precision of three scanners for both maxilla and mandible were within ±300 μm which was clinically accepted. The morphological error of jaw relation record of the three scanners was (337.68±128.54) μm, (342.89±195.41) μm, and (168.62±88.35) μm. The 95% confidence intervals of i500 and Trios 3 scanners were over 300 μm. CEREC Primescan scanner was significantly superior to i500 scanner(P<0.05).The displacement of the jaw position of the three scanners was (0.83±0.56) mm, (0.80±0.45) mm, and (0.91±0.75) mm for vertical dimension; (0.79±0.58) mm, (0.62±0.18) mm, and (0.53±0.53) mm for anterior and posterior directions; (0.95±0.59) mm, (0.69±0.45) mm, and (0.60±0.22) mm for left and right directions. The displacement of the jaw position of the three scanners in vertical dimension, anterior and posterior directions and the left and right directions were within the 95% consistency limit. CONCLUSION Three intraoral scanners showed good trueness and precision. The i500 and Trios 3 scanners had more errors in jaw relation record, but they were used as primary jaw relation record. It is suggested that three intraoral scanners can be used for obtaining digital data to make diagnostic dentures and individual trays, reducing possible deforming or crack when sending impressions from clinic to laboratory.

Relationship Between Oral Health-Related Quality of Life and Usage Period of Complete Dentures.

To investigate the relationship between oral health-related quality of life (OHRQoL) and usage period of complete dentures. Data were obtained from 432 edentulous patients who required complete dentures as part of an investigation registered in the University Hospital Medical Information Network (UMIN) Center (UMINCTR clinical trial, unique trial number: 000028711). Mandibular ridge form, denture quality, and usage period of the dentures were recorded and incorporated into a multiple linear regression analysis. Multiple linear regression analysis in the 267 participants who completed the study demonstrated significant effects on OHRQoL of mandibular ridge form, mandibular denture stability and retention, accuracy of jaw relation recording, and usage period of dentures. A significant relationship between the usage period of dentures and OHRQoL in complete denture wearers was noted when the effects of mandibular ridge form and denture quality were controlled for.

A single procedure for the registration of maxillo-mandibular relationships and alignment of intraoral scans of edentulous maxillary and mandibular arches

PurposeThe presented technique describes the intraoral scanning workflow to capture scans of edentulous arches and occlusion rims, align them as per maxillo-mandibular relationships registered in the occlusion rims, and incorporate data for tooth arrangement. MethodsOn preliminary intraoral scans of the edentulous arches, design the baseplates for the occlusion rims, make a 3D print of them and finalize by adding wax. Use occlusion rims to make jaw relation record and definitive intraoral scans. Use the “Pre-preparation scan” function to link scans of occlusion rims to scans of edentulous arches and align each other. ConclusionsMaking and aligning, in a single procedure, intraoral scans of the edentulous arches and occlusion rims incorporating maxillo-mandibular relationships and information for tooth arrangement, allow to proceed directly with the denture design, thus, being sensible from the treatment time efficiency point of view. The technique is applicable to both partial and complete edentulous maxillary and mandibular arches. Nonetheless, care should be taken in stabilizing occlusion rims, whose shape is characterized by a reduction in size of the baseplates. In addition, its accuracy in comparison with the current clinical best practice based on conventional procedure requires to be addressed by further research.

Structural equation modeling of the impact of mandibular ridge form and denture quality on oral health-related quality of life in complete denture wearers

PurposeTo examine the effect of mandibular ridge form and denture quality on oral health-related quality of life (OHRQoL) in complete denture wearers by using structural equation modeling (SEM) analysis of data before and after new complete denture insertion. MethodsFour hundred thirty-two edentulous patients who visited the Dental Hospital of Tokyo Medical and Dental University for new complete dentures were recruited. An intervention study design was conducted, including complete denture fabrication with SEM analysis. Mandibular ridge form, mandibular denture stability, accuracy of jaw relation record, and the Oral Health Impact Profile for edentulous subjects (OHIP-EDENT-J) total score before and after new complete denture insertion were used in the hypothesized model. ResultsTwo hundred and thirty-seven participants completed the research. SEM analysis demonstrated adequate model fit. Path coefficients of mandibular ridge form to OHIP-EDENT-J before and after insertion, and mandibular denture stability to OHIP-EDENT-J before insertion, were significant. ConclusionsThis study demonstrated that mandibular denture stability and mandibular ridge form are important to ensure successful complete denture therapy.

Digital impression and jaw relation record for the fabrication of CAD/CAM custom tray

PurposeThis article describes the protocol of a digital impression technique to make an impression and recording of the jaw relationship of edentulous patients for the fabrication of CAD/CAM custom tray using computer-aided design and manufacturing (CAD/CAM) technology. MethodsScan the maxillary and mandibular edentulous jaws using an intraoral scanner. Scan the silicone jig with the maxillary and mandibular jaws while keeping the jig between the jaws. Import the standard tessellation language data of the maxillary and mandibular jaws and jig to make a jaw relation record and fabricate custom trays (CAD/CAM trays) using a rapid prototyping system. Make a definitive impression of the maxillary and mandibular jaws using the CAD/CAM trays. ConclusionsDigitalization of the complete denture fabrication process can simplify the complicated treatment and laboratory process of conventional methods In addition, the proposed method enables quality control regardless of the operator’s experience and technique.

Research and development of digital design and fabrication of complete denture

Removable complete denture are still the primary prosthetic solution for edentulous patients. Functional pressure impression obtaining, jaw relation recording, personalized balance occlusion and highly precise fabrication of denture are difficult. The digital restoration technique represented by intraoral three-dimensional scanning and three-dimensional (3D) printing compensates for the shortages of the manual techniques, but there are still many limitations in the application of complete dentures. At present, a few computer aided design and computer aided manufacture (CAD/CAM) complete denture systems have been developed both domestically and abroad, and these system are mainly focused on the digital design and manufacture of denture, and are seldom used for the recording of impression and jaw relation. This review is based on the main clinical procedures of the traditional complete denture restoration, elaborating the research and application status of digital technique in each steps, in order to provide reference for clinical application.

Triad treatment option to restore full mouth

The primary consideration for continued denture success with a single conventional complete denture is the preservation of that which remains in the oral cavity. The single denture is a complex prosthesis that requires a complete understanding of the basics of denture occlusion. The problems involved in providing comfort, function, proper esthetics, and retention for the maxillary complete denture patient with natural opposing dentition may be challenging. The damage to the edentulous ridge and inability to wear the denture may be avoided by good prosthetic treatment which includes adequate denture base, correct jaw relation record, and proper occlusion. In this case report, a female patient reported with generalized attrition of the remaining maxillary dentition. After clinical evaluation, taking into consideration the patient's expectations, treatment plan was decided. Using fixed, removable, and complete denture prosthesis, patients functional and esthetic requirements were fulfilled, which gave her comfort and satisfaction.

Face‐bow transfer in prosthodontics: a systematic review of the literature

An extensive search for randomised controlled clinical trials was accomplished to compare dental prostheses and occlusal splints constructed with or without face-bow transfer, and question whether face-bow transfer may present better clinical results than simpler approaches. Studies were identified by searching electronic databases (PubMed/MEDLINE, Latin American and Caribbean Literature on the Health Science, and Brazilian Bibliography of Dentistry). The keywords 'dental articulator', 'semi-adjustable articulator', 'face-bow', 'jaw relation record' and 'occlusal splint therapy' were used. The minimum inclusion requirements were (i) randomised controlled trials with patients of any age, (ii) comparison between dental prostheses or occlusal splints constructed with or without face-bow transfer and (iii) assessment of clinician's time, number of occlusal contacts, patient satisfaction or masticatory function. The search resulted in the identification of 8779 articles. Subsequently, 8763 articles were excluded on the basis of title and abstract. By the end of the search phase, eight randomised controlled trials were considered eligible. Current scientific evidence suggests that face-bow transfer is not imperative to achieve better clinical results in prosthodontics. Randomised clinical trials suggest that simpler approaches for the construction of complete dentures and occlusal splints may present acceptable results, while no clinical study has investigated its use in fixed and removable partial dentures.