Determination of occlusal vertical dimension for complete dentures patients: an updated review

Stereophotometric facial changes in edentulous older adults after rehabilitation with complete dentures

OBJECTIVES

To evaluate the facial characteristics of edentulous older adults who underwent rehabilitation using complete dentures, and to compare them with dentate individuals.

BACKGROUND

Edentulism rehabilitation with complete dentures aims to restore occlusion and facial aesthetics.

MATERIALS AND METHODS

The study included 102 edentulous participants needing prosthodontic rehabilitation with complete dentures and 30 with a natural dentition (aged >65). The 3D facial scans were performed using an Artec optical scanner. Superficial facial landmarks were identified, and 16 parameters were calculated. Regional analysis with the superimposition of two scans was used to calculate the average distances and percentage of non-matching surfaces in the 11 regions. Paired and independent t-tests (α = .05) were used to test for group differences, as appropriate.

RESULTS

After rehabilitation with complete dentures, facial changes were most noticeable in the perioral region: wider rima oris, longer upper lip, wider upper vermilion, and more protruded profile. The comparison of facial regions without and with dentures showed fuller and curvier cheeks, with no direct influence of dentures. The edentulous faces with dentures appeared shorter and more retruded than those of dentate individuals. A narrower lower vermilion, retruded upper lip, and more flattened facial profile were observed in females with dentures than in their dentate peers.

CONCLUSION

Besides the expected positive influence of rehabilitation with complete dentures on facial appearance in the perioral region, there are some unexpected changes, such as fuller cheeks, but there is still deficiency in vertical facial dimensions and a more flattened facial profile.

A Literature Review of Vertical Dimension in Prosthodontics Theory and Practice - Part 1: Theoretical Foundations

Vertical dimension (VD) is a critical factor in prosthodontics, playing a pivotal role in the functional and aesthetic outcomes of dental treatments. This literature review explores theoretical foundations and the various aspects of VD, including its definition, measurement, and clinical significance in prosthodontics. The relationship between VD and temporomandibular disorders (TMDs) is examined. Additionally, the impact of VD on facial proportions and aesthetics is significant, as it affects the lower third of the face and influences the patient's overall appearance and self-esteem. In conclusion, understanding the intricate relationship between VD, TMDs, facial aesthetics, and psychological well-being is essential for effective prosthodontic treatment. This comprehensive review provides valuable insights into the multifaceted role of VD in enhancing both functional and aesthetic outcomes, ultimately improving patient satisfaction and quality of life.

Increasing Vertical Dimension of Occlusion (VDO): Review

The need to increase the Vertical Dimension of Occlusion (VDO) to restore lost dental function or optimise specific dental treatments is a common occurrence in daily dental practice. The common belief that the Vertical Dimension at Rest (VDR) is fixed hinders the development of restorations with a VDO that encroaches on or surpasses the interocclusal rest space (IRS), thereby preventing potential tissue damage to the masticatory apparatus. Recent studies have shown that the mandible rest position falls within a range termed as the "comfort zone". The range of this zone may vary from one person to another and within the same person over time due to factors such as age or health status. In this review, we have concluded that a permanent increase in the VDO, once indicated, is a safe procedure for dentulous patients. However, it is important to minimise the extent of the increase to simplify the prosthodontics treatment process. An inter-incisal increase exceeding 5 mm is seldom needed. Moreover, it is important to consider the functional, aesthetic, and biological elements associated with VDO. The biological and functional environment closely related to the VDO had great adaptive capacities, which have for a historically been underestimated. Patient adaptation has been observed in dentate patients, edentulous patients, and even cases involving implant-supported prostheses. Muscle relaxation and changes in muscle length are likely the primary adaptation mechanisms, rather than the restoration of the original VDO through dentoalveolar maturation. Intervention with a fixed restoration is more predictable and results in a higher and more rapid level of adaptation. Finally, the increase should include the entire arch to prevent relapse of the VDO to its previous value, and changes in VDO should be assessed by utilising temporary diagnostic restorations for a period before implementing definitive prostheses, in order to evaluate the adaptive muscle response.

Maxillomandibular relationship record methods for computer-engineered complete dentures: a scoping review

OBJECTIVES

The purpose of this scoping review was to identify different methods employed for recording the maxillomandibular relationship (MMR) for computer-aided designed and manufactured (CAD-CAM) complete dentures (CDs).

MATERIALS AND METHODS

This scoping review followed the PRISMA-ScR guidelines and was developed according to Arksey and O'Malley and The Joanna Briggs Institute protocol. The methods were registered on the Open Science Framework (< osf.io/rf4xm> ). The focus question was: "What are the different techniques for recording the maxillomandibular relationship in the digital workflow used in CECDs?" Two investigators searched 3 online databases [MEDLINE (PubMed), Scopus, and Science Direct] independently. The inclusion criteria were clinical studies and reviews that assessed techniques for recording MMR using digital workflow for manufacturing of CECDs. A descriptive analysis was performed considering the study design, manufacturing system, clinical steps, and tools for the determination of MMR, and the difficulty level of procedures.

RESULTS

4779 articles were identified in the electronic search and 10 studies were included for data analysis. The review identified 4 commercially available CAD-CAM denture systems and 3 innovative methods suitable for abbreviating the number of appointments (2 to 4 visits). The trial denture is inherent to the procedure for the Baltic System and 3 innovative techniques. Three techniques (2 innovative and WholeYouNexteeth) demonstrated lower difficulty levels for performing the clinical procedures, regardless of the professional skills.

CONCLUSIONS

The commercially available and innovative techniques for the recording of MMR may provide predictability of the treatment. The techniques are effective, however, rely on the learning curve and the patient's clinical condition.

CLINICAL RELEVANCE

Recording of the maxillomandibular relationship is paramount for the manufacturing and functionality of complete dentures. Clinicians should be aware of the different tools and techniques described for registering the jaw relationship.

Fabrication of digital complete dentures guided by facial scanning with a device for recording the maxillomandibular relation: A dental technique

This article describes a technique for the fabrication of digital complete dentures guided by facial scanning using an innovative device for maxillomandibular relation records. For this, a device was designed and 3-dimensionally (3D) printed to assist in the maxillomandibular record stage. Digital files of the diagnostic casts, jaw relation record, and facial images were superimposed, and the complete denture was virtually planned. Subsequently, trial complete dentures were 3D printed, and a functional and esthetic clinical tooth evaluation was conducted. Then, definitive impressions were made, and definitive complete dentures were obtained. The method of recording the maxillomandibular relation associated with facial scanning in a digital workflow for manufacturing the dentures in a 3-appointment protocol provided better predictability of patient care and reduced clinical and laboratory time than with the conventional denture technique.

Double-crown-retained removable dentures: Types and clinical application

A 55-year-old man wearing maxillary and mandibular clasp-retained removable partial dentures (RPDs) sought improvement in retention, support, mastication efficiency, and esthetics. Three prosthodontic treatment options were provided to the patient, who selected maxillary and mandibular conical crown-retained removable partial dentures (CCRPDs) without strategic implants. Oral health-related quality of life (OHRQoL) and satisfaction of the patient were evaluated before treatment and 2 weeks and 1 year after inserting the CCRPDs. The patient reported better retention, support, stability, mastication efficiency, esthetics, and an improved OHRQoL after CCRPD placement than before treatment. These improvements were maintained after 1 year.

Development of craniometry-based predictive model to determine occlusal vertical dimension by using the eye-ear distance in a French population

STATEMENT OF PROBLEM

Techniques for determining occlusal vertical dimension (OVD) have limitations, including the lack of reproducibility or invasiveness. Recently, a craniometry-based predictive model comparing OVD with eye-ear distance (EED) was developed in Chile. However, this study included a specific population and excluded patients with a history of orthodontics. For verification, studies on other populations are required.

PURPOSE

The purpose of this clinical study was to follow the previously described protocol to obtain an equation for determining OVD in a French cohort (mostly White with an orthodontic history).

MATERIAL AND METHODS

Dentate adults with a stable occlusion and no known maxillofacial, otolaryngeal, or temporomandibular problems were included in this study. Demographic information, including participant age, sex, and history of orthodontic treatment, was collected. Facial height and width were measured with digital calipers, and the left EED and OVD were recorded with a craniometer. The facial index was calculated to classify participants into euryprosopic, mesoprosopic, or leptoprosopic types.

RESULTS

Of the 300 included participants (28 ±11 years), 60% were women, and 67% reported a history of orthodontic treatment. Euryprosopic represented 17% of participants, mesoprosopic 48%, and leptoposopic 35%. A positive correlation was found between the left EED and OVD in all facial types, but it was more important in women. The following equation was obtained: OVD=44.58+(0.45×left EED)+sex (women=-4.57; men=0)+facial type (leptoprosopic=0; mesoprosopic=-3.35; euryprosopic=-7.27).

CONCLUSIONS

The occlusal vertical dimension is correlated with sex, left EED, and facial type. This straightforward method can be applied in conjunction with other techniques to determine the OVD in the French population.

A fully digital workflow to register maxillomandibular relation using a jaw motion tracer for fixed prosthetic rehabilitation: A technical report

OBJECTIVE

This technique aimed to describe a fully digital workflow to register maxillomandibular relation for fixed prosthetic rehabilitation.

CLINICAL CONSIDERATIONS

Mandibular kinematics could be reproduced in a four-dimensional (4D) virtual patient based on the intraoral scan, facial scan, cone beam computed tomography, and jaw motion trajectory, which helped record centric relation and determine a proper occlusal vertical dimension in a virtual environment. The therapeutic position could be exported directly to the dental computer-aided design software for digital waxing design with a facial scan. The 4D virtual patient was also used to verify the functional and esthetic outcomes of provisional restorations.

CONCLUSIONS

This novel approach digitized the process of determination, delivery, and double-check of maxillomandibular relation, thus contributing to the establishment of a completely digital workflow for fixed prosthetic rehabilitation.

CLINICAL SIGNIFICANCE

Registration of maxillomandibular relation, including centric relation and occlusal vertical dimension is critical to the success of prosthetic rehabilitation. Traditional procedures are complex and time-consuming, and heavily rely on the clinical experience of dentists. A fully digital approach to creating a 4D virtual patient and registering the maxillomandibular relation is established, which guides to determine a proper occlusal vertical dimension in centric relation. Digital delivery and double-check can simplify the conventional procedure and ensure that the determined maxillomandibular relation is reliable.

Evaluation of automated detection of head position on lateral cephalometric radiographs based on deep learning techniques

BACKGROUND

Lateral cephalometric radiograph (LCR) is crucial to diagnosis and treatment planning of maxillofacial diseases, but inappropriate head position, which reduces the accuracy of cephalometric measurements, can be challenging to detect for clinicians. This non-interventional retrospective study aims to develop two deep learning (DL) systems to efficiently, accurately, and instantly detect the head position on LCRs.

METHODS

LCRs from 13 centers were reviewed and a total of 3000 radiographs were collected and divided into 2400 cases (80.0 %) in the training set and 600 cases (20.0 %) in the validation set. Another 300 cases were selected independently as the test set. All the images were evaluated and landmarked by two board-certified orthodontists as references. The head position of the LCR was classified by the angle between the Frankfort Horizontal (FH) plane and the true horizontal (HOR) plane, and a value within - 3°- 3° was considered normal. The YOLOv3 model based on the traditional fixed-point method and the modified ResNet50 model featuring a non-linear mapping residual network were constructed and evaluated. Heatmap was generated to visualize the performances.

RESULTS

The modified ResNet50 model showed a superior classification accuracy of 96.0 %, higher than 93.5 % of the YOLOv3 model. The sensitivity&recall and specificity of the modified ResNet50 model were 0.959, 0.969, and those of the YOLOv3 model were 0.846, 0.916. The area under the curve (AUC) values of the modified ResNet50 and the YOLOv3 model were 0.985 ± 0.04 and 0.942 ± 0.042, respectively. Saliency maps demonstrated that the modified ResNet50 model considered the alignment of cervical vertebras, not just the periorbital and perinasal areas, as the YOLOv3 model did.

CONCLUSIONS

The modified ResNet50 model outperformed the YOLOv3 model in classifying head position on LCRs and showed promising potential in facilitating making accurate diagnoses and optimal treatment plans.

Workflow for complete dentures fabrication in three appointments: A dental technique

This technical report describes a novel workflow for complete denture fabrication designed to abbreviate the necessary steps for dental prostheses delivery by using a 3-appointment protocol in which preliminary impressions are made in the first session together with the registration of maxillary lip support, occlusal plane, and reference lines for tooth arrangement. A trial denture is fabricated with conventional or computer-aided design and computer-aided manufacturing procedures and is evaluated in the second appointment for esthetics, the definitive impression, and the maxillomandibular relationship record to provide precise references for definitive denture fabrication.

Determination of Mandibular Position and Mouth Opening in Healthy Patients and Patients with Articular and/or Muscular Pathology: A Pilot Study with 3D Electromagnetic Articulography and Surface Electromyography

Temporomandibular disorders (TMDs) are a group of pathologies that affect the temporomandibular joint and its related structures, producing intracapsular and muscular pathologies. The aim of this study is to describe, by electromagnetic articulography (EMA) and simultaneous electromyography (sEMG), the mandibular postural position and mouth opening in healthy patients and with articular and/or muscular pathology.

MATERIALS AND METHODS

A pilot study was conducted with a sample of sixteen participants aged 18 years or older who attended the TMDs and Orofacial Pain Polyclinic of the University of La Frontera due to TMDs. The physiological inoculation space was evaluated from the mandibular postural position (MPP) with swallowing command and without command, in both healthy patients and patients with articular, muscular, and mixed TMDs, measured simultaneously with EMA and sEMG. An angular measurement of the oral opening was also performed with the data obtained.

RESULTS

The physiological inoculation space was obtained from the determination of the MPP through the procedures with swallowing command and without command, and different mouth opening degrees were evaluated.

CONCLUSIONS

Simultaneous position and sEMG records can be produced from EMA, and different characterization variables such as the vertical distance, Euclidean distance, and angle can be obtained.

Marginal Mandibulectomy and Oral Rehabilitation of Xeroderma Pigmentosum Patient

Xeroderma pigmentosum (XP) may cause tissue deformation in patients who have undergone oral cancer surgery requiring resection of any part of the mandible. Oral rehabilitation is a pivotal factor in the restoration of function and esthetics. The aim of this study was to report a clinical case of successful prosthetic rehabilitation of a 57-year-old woman who presented with marginal mandibulectomy and a significant reduction in maximal mouth opening after treatment for XP. With her reduced opening and considerable loss of structure and tissue, she had difficulty speaking, swallowing, and altered esthetics. The oral rehabilitation was performed with complete maxilla denture and mandible overdenture retained by 2 implants. This case demonstrates that the rehabilitation with mandible overdentures and complete maxilla dentures provide function and esthetic improvement in the mutilated area for XP patients with marginal mandibulectomies.

The Effect of Bite Raise on AHI Values in Adult Patients Affected by OSA: A Systematic Review with Meta-Regression

Obstructive sleep apnea (OSA) is a highly prevalent sleep breathing disorder characterized by the collapse of the pharyngeal walls that entails recurrent episodes of cessation of breathing or decrease in airflow while sleeping. This results in sleep fragmentation, decreased oxygen saturation and an increase in the partial pressure of carbon dioxide, causing excessive daytime sleepiness, hypertension and increased prevalence of cardiovascular morbidity and mortality. Mandibular advancement devices (MAD) represent a valid alternative therapy to Continuous Positive Airway Pressure, thrusting the mandible forward, increasing the lateral diameter of the pharynx and reducing the collapsibility of the airway. Several investigations have focused on the detection of the best mandibular advancement amount in terms of effectiveness and tolerance, but few and contrasting data are available on the role of occlusal bite raise in reducing the apnea/hypopnea index (AHI). The aim of this systematic review with meta-regression analysis was to investigate the effect of the bite raise of MAD on AHI values in adult patients affected by OSA. An electronic search was performed in MEDLINE, the Cochrane Database, Scopus, Web of Science and LILACS. Randomized controlled trials (RCT) investigating the effectiveness of MAD in OSA patients were included. The quality of evidence was evaluated with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) and the risk of bias with the Cochrane risk-of-bias tool for randomized trials (RoB2). Six RCT were included. The success rate of each study was computed: (mean baseline AHI - mean post treatment AHI)/mean baseline AHI. The GRADE scores indicated that the quality of evidence was very low. The meta-regression analysis showed that there was no correlation between the occlusal bite raise and the AHI improvement.

Full-Arch Guided Restoration and Bone Regeneration: A Complete Digital Workflow Case Report

OBJECTIVE

complex rehabilitations present multiple difficulties, regarding both the planification of the surgery and the design of the prothesis. A digital approach can support the workflow, as well as the degree of intraoperative precision, and improve the long-term prognosis.

METHODS

A surgical guide was designed for implant placement. An extensive regeneration of the upper jaw was performed with contextual implant insertion, and a delayed load rehabilitation was chosen. After four months, a second surgery and a simultaneous soft tissue augmentation was performed, and a 3D-printed temporary restoration was placed. After another two months, new dental and facial scans, smile design, and facial bite registrations were obtained. Upper and lower dentures were built using an exclusively digital workflow. Both metal substructures were passivated and cemented in one session; in the following appointment, the aesthetic and occlusal checks were carried out. During the third visit, both prostheses were delivered.

RESULTS

Careful case planning and the surgical guide made it possible to achieve primary stability and acceptable emergence profiles in an extremely reabsorbed upper jaw. Leukocyte-Platelet Rich Fibrin (L-PRF) made the extensive bone regeneration more approachable and lowered the post-operative pain and swelling, while speeding up the soft tissue healing process. During the re-entry surgery, the volumes of soft tissues were increased to improve aesthetics, and the amount of keratinized gingiva around the six implants was also increased. Smile design and facial scans have provided the means to create acceptable aesthetics and function in a few sessions with minimal patient discomfort.

CONCLUSIONS

Computer-assisted implantology is a safe and precise method of performing dental implant surgery. Preliminary studies have a high degree of accuracy, but further studies are needed to arrive at a fully digital clinical protocol at all stages.

Full-Digital Workflow for TMDs Management: A Case Series

Temporomandibular joint disorders (TMDs) have always been the subject of studies due to the difficult management of symptoms and the complex stabilization of the so-called therapeutic position. In this effort, digital technologies open new opportunities for such planning, allowing the clinician to digitally assess the situation and verify the stability of the new position from a functional point of view. The present case series shows examples of preliminary full-digital planning of treatment in TMDs patients made with the preliminary evaluation of the kinematic activity of the mandible through a digital device (Tech in motion™, ModJaw, Villeurbanne, France). Three TMD clinical cases are analyzed with full-digital techniques and workflow. A personalized treatment for each case was digitally planned on the base of proper kinematic tracings recorded for each patient, and intraoral appliances were digitally customized through a full-digital or semi-digital workflow. The digitalization of mandibular kinematic gave us the possibility of making a more “aware” diagnosis, especially in a dynamic key, and then it allowed a faster realization and execution of the intraoral appliance through a digital workflow, memorizing the therapeutic position and early checking the device, before its realization, on the real kinematics of the patient.

Clinician evaluation of removable complete denture quality: A systematic review of the criteria and their measurement properties

STATEMENT OF PROBLEM

Different criteria have been developed and used for the clinician evaluation of removable complete denture (CD) quality. However, the optimal criteria under a specific clinical or research purpose are unclear.

PURPOSE

The purpose of this systematic review was to identify the development and clinical parameters of criteria for the clinician evaluation of CD quality and to evaluate the measurement properties of each criterion.

MATERIAL AND METHODS

An electronic search was conducted through PubMed, Scopus, and Cochrane Database of Systematic Reviews from database inception to April 2022. A hand search was conducted based on the references in the included studies. The measurement properties of the included CD quality criteria were assessed based on the consensus-based standards for the selection of health measurement instruments (COSMIN) checklist and a previous study. The articles that supported the measurement properties of the original CD quality criteria were also included.

RESULTS

Of the 282 abstracts reviewed, 22 clinical studies were included; 17 original articles that developed a new CD quality criterion and 5 articles that additionally supported measurement properties of the original criterion. There were 18 CD quality criteria with 2 to 11 clinical parameters in each criterion, predominantly denture retention and stability, followed by denture occlusion and articulation, and vertical dimension. Sixteen criteria possessed criterion validity shown by its associations with patient performance or patient-reported outcomes. Responsiveness was reported when a CD quality change was detected after delivery of a new CD, denture adhesive use, or during postinsertion follow-up.

CONCLUSIONS

Eighteen criteria have been developed for clinician evaluation of CD quality with various clinical parameters, predominantly retention and stability. None of the included criteria met all measurement properties in the 6 assessed domains, but more than half of them had relatively high-quality assessment scores.

A digital, custom gothic arch tracing technique for vertical dimension of occlusion and centric relation recording

A method for identifying the vertical dimension of occlusion and centric relation in patients requiring dental rehabilitation is described. The technique relies on designing and fabricating a custom variant of the gothic arch tracer based on intraoral scans and its application following the principles of neuromuscular balance of the stomatognathic system.

The Impact of Increase in the Vertical Dimension of Occlusion on Nociception in Rats - A Preliminary Report

Since the change in vertical dimension of occlusion (VDO) is extremely important in prosthetic dentistry, the aim of the study was to examine the effect of VDO increase on nociception parameters in rodent experimental model. The study was performed on seven experimental groups (6 animals per group) on male Wistaralbino rats: sham; 0.6/3, 0.9/3, and 1.2/3 groups where VDO was increased by 0.6, 0.9, and 1.2 mm (respectively), for three days; 0.6/20, 0.9/20, and 1.2/20 groups where VDO was increased by 0.6, 0.9, and 1.2 mm (respectively), for twenty days. The VDO raising protocols were performed as follows: on a day 1, following anaesthesia, a two-phase impression was taken with addition silicones; on a day 3, the cementing process for both maxillary incisors and inside crowns preparation was performed, and cementing zirconium crowns, manufactured using CAD-CAM technology, were applied. The behavioural testing (the tail flick and hot plate test) was performed on day 3 and 20. The results obtained in the tail flick test suggest that the raise in VDO in the early phase induced increased sensitivity to pain in a stepwise manner, while this hyperalgesic effect was diminished in a timedependent manner. The stepwise increase in VDO also resulted in significant decline in the pain tolerance with the higher VDO (0.9 and 1.2 mm) in the hot plate test that persisted after twenty days in 1.2/20 group. It seems that VDO elevation is sufficient to produce hyperalgesic effect in this experimental model, which may be attenuated in time-dependent manner.

Prosthodontic Treatment in Patients with Temporomandibular Disorders and Orofacial Pain and/or Bruxism: A Review of the Literature

Temporomandibular disorders are a group of conditions affecting the temporomandibular joints, the jaw muscles, and related structures. Patients with temporomandibular signs and/or symptoms frequently present with indications for prosthetic treatment. The management of these patients aims to achieve patient comfort, occlusal stability, and the complex restoration of the teeth. The goal of this review is to provide an overview of the relationship between prosthodontics and temporomandibular disorders and/or bruxism with a focus on the cause-and-effect implications and the strategies for planning prosthetic treatments in patients with temporomandibular disorders and/or bruxism.

Adaptation to New Dentures and 5 Years of Clinical Use: A Comparison between Complete Denture and Mini-implant Mandibular Overdenture Patients based on Oral Health-Related Quality of Life (OHRQoL) and Orofacial Esthetics

Objective of work

It is unclear how long patients need to adapt to new dentures. This study assessed adaptation and five years of clinical use, comparing complete denture wearers (CDs) and mini-implant mandibular overdenture wearers opposing a maxillary CD (MDI-OD), based on oral health reported quality of life (OHRQoL) and orofacial esthetics (OES).

Material and Methods

A total of 36 subjects in the CD group (25 females) and 30 subjects in the MDI group (20 females) completed the 5-year study. All patients received new CDs, but in the MDI-OD group, four mini-implants were inserted interforaminally in the mandible before denture manufacture. Participants filled in the OHIP-EDENT and OES questionnaires one day after dentures’ delivery, on the 3^rd, 8^th, 15^th, 30^th day, and at the 1-, 3- and 5-year follow-up examinations. Statistical analysis comprised descriptive methods, X² test, independent t-test, Friedman, and Mann-Whitney test.

Results and Conclusions

Both groups' adaptation to new dentures was completed within a month. The MDI-OD group had significantly better OHRQoL in all follow-ups except for the 3^rd and 8^th day, probably due to soreness and pain, the reason why the MDI-OD group had limitation in functioning in the first days after new dentures’ delivery. Already after the third year and at the fifth year, OHRQoL worsened (p<0.01) in both groups. However it was significantly more pronounced in the conventional CD wearers (p<0.01) than in the MDI-OD group. Orofacial esthetics was highly scored in both groups. The scores dropped down only after three years, equally in both groups.

Keywords

OHRQoL, OES, prospective study, complete dentures, mini-implants, adaptation

MeSH Terms

Complete Dentures; Dental Implants; Quality of Life; Dental Esthetics

Digital Determination and Recording of Edentulous Maxillomandibular Relationship Using A Jaw Movement Tracking System

PURPOSE

To establish a direct digital method for determining and recording edentulous maxillomandibular relationship using a custom-made jaw movement tracking system and evaluate its accuracy.

MATERIALS AND METHODS

A novel jaw tracking system was used to record the trajectory of habitual opening-closing jaw movement, and mandibular rest position (MRP) in 10 edentulous patients. 3D surface scanning was performed on the conventional maxillomandibular impressions and facial structures of patients in MRP. The multi-source data were registered using a custom-made recording tool. A plane parallel to the ala-tragus and horizontal lines was constructed 2 mm above the MRP, and its vertical position was used to determine the vertical relationship. The intersections of the trajectory passing through the plane were located, and their density distributions were analyzed. The coordinates of highest density, which presented the highest repeatability of jaw movement, were used to construct the digital maxillomandibular relationship (test group). The maxillomandibular relationship of the new complete dentures with artificial teeth in the intercuspal position was defined as the control group. The displacements of the anterior reference point and 3D deviations of the entire mandibular arch were measured and compared between the test and control groups using a Wilcoxon signed-ranks test and a one-sample t-test, respectively.

RESULTS

With reference to the centric relationship position, the maximum displacements of the anterior reference points were in the horizontal anteroposterior direction for both groups, and there were no significant differences. Compared to the control group, the 3D deviations of the entire mandibular arch in the test group were significant (95% confidence interval: 0.76 mm to 1.35 mm, P < 0.001).

CONCLUSIONS

By analyzing the individual trajectory features obtained by the in-house developed jaw tracking system, a digital method for determining and recording edentulous maxillomandibular relationships was established; however, the accuracy needs to be further improved. This article is protected by copyright. All rights reserved.

Comparison of patient satisfaction between complete dentures fabricated using "conventional" and "cephalometric angular reconstruction" vertical dimension procedures: A multicenter randomized clinical trial

Aim

In Prosthodontics, during complete denture fabrication, conventional methods employed to determine occlusal vertical dimension require patient co-operation. Hence, the aim of the present study is to evaluate the clinical effectiveness of the 'cephalometric angular reconstruction' procedure in the calculation of these lost dimensions.

Settings and Design

Multicentric randomised clinical trial conducted in four dental hospitals.

Materials and Methods

Fully edentulous people who came to the hospitals for complete denture treatment were recruited into the study. Those who fulfilled the inclusion criteria were randomly assigned to two groups; Group 1: Dentures fabricated using a 'conventional' procedure and Group 2: Dentures fabricated using 'cephalometric angular reconstruction'. The patient's level of satisfaction was assessed on a scale of 1 to 5; 1-dissatisfaction to 5-excellent. The confounding factors that can influence the satisfaction were also recorded.

Statistical Analysis Used

The distribution of patient's satisfaction was assessed using Chi-square test, whereas the difference between the two groups was evaluated using Mann-Whitney test.

Results

There was no significant difference either in the vertical dimension determined (P = 0.465) or the patient's level of satisfaction (P = 0.943) between the two groups. There was no influence of confounding factors considered in the present study on the satisfaction levels. There was no difference in the distribution of satisfaction levels based on the dentist's quality assessment (P = 0.243).

Conclusion

Complete dentures fabricated using cephalometric angular reconstruction procedure of vertical dimension determination were equivalent with respect to patient satisfaction, compared to those made using a conventional method. Hence, the new method can be clinically recommended during denture fabrication.

Accuracy between Functional Swallowing and Knebelman Craniometric Method to Measure Occlusal Vertical Dimension in Total Denture Wearers: A Quasi-experimental Study

Objective:

The objective was to determine the accuracy between functional swallowing (FS) and the Knebelman craniometric method (KCM) to measure occlusal vertical dimension (OVD) in total denture wearers.

Materials and Methods:

A quasi-experimental, prospective study was conducted considering the KCM diagnostic method as the gold standard compared to FS. All the totally edentulous patients attended at the School of Dentistry of the Universidad Nacional Mayor de San Marcos (n = 32) in 2018–2019 were evaluated. Previous informed consent was obtained from all patients. A Knebelman’s Craniometer was used to obtain longitudinal measurements measured in millimeters. The measurement was made with the Knebelman Craniometer by placing the tip into the external auditory canal inside the right meatus. On the other hand, for the FS method, the patients were seated comfortably with their back supported and their head in a natural position. Both upper and lower rollers were inserted into the mouth and the patient was instructed to swallow saliva for a period of 5min.

Results:

When comparing the measurement of the OVD of KCM versus FS according to sex, men presented an OVD of 68.1 ± 3.9 mm, being 64.1 ± 3.8 mm in women. Accuracy was evaluated with an analysis of concordance between FS and the KCM in the determination of OVD in totally edentulous patients with a value of 0.97 (confidence interval = 0.31–0.99) (P = 0.013).

Conclusions:

There is a good concordance between the FS method and the KCM at the time of determining the OVD of edentulous patients using total prostheses.

Effects of rehabilitation with complete dentures on bite force and electromyography of jaw and neck muscles and the correlation with occlusal vertical dimension

OBJECTIVES

The purpose of this study was to assess the effects of oral rehabilitation with complete dentures on bite force and electromyography of the suprahyoid and sternocleidomastoid muscles, and their correlation with occlusal vertical dimension (OVD). The research questions were "What are the effects of rehabilitation with complete dentures on bite force and electromyography of suprahyoid and sternocleidomastoid muscles, and how are they correlated with OVD?"

MATERIALS AND METHODS

Patients who are wearers of unsatisfactory removable complete dentures were attended in three sessions (T0, T1, and T2). At T0, while the patients still wore the old dentures, they were submitted to bite force and surface electromyographic exams of the suprahyoid and sternocleidomastoid muscles. These exams were repeated, and the OVD was measured while the patients wore their old and new prostheses, 30 days after insertion of the new prosthesis (T1). The exams were repeated 100 days after the insertion of the new prosthesis (T2). The data were submitted to the Shapiro-Wilk normality test, analysis of variance (ANOVA), and Pearson correlation and linear regression, all with 5% significance.

RESULTS

Fifteen patients participated in the study. No statistically significant difference was observed for bite force or electromyography in T0, T1, or T2. However, the correlation and regression tests showed important interactions between the OVD and maximum voluntary occlusal bite force, as well as the OVD and electromyography during deglutition for the suprahyoid muscles.

CONCLUSION

Rehabilitation did not impact bite force nor the activity of the assessed muscles (electromyography). On the other hand, OVD was shown to be an important factor for bite force, and deglutition of water after rehabilitation.

CLINICAL RELEVANCE

This study shows what are the influences of rehabilitation on oral functions and reinforces the importance of corrected reestablishment of OVD because it has been found to be an important factor for bite force and electromyography during deglutition.

Visible Portion of Anterior Teeth at Rest and Analysis of Different Smile Characteristics in the Saudi Population of the Jeddah Region

This cross-sectional study aimed to determine the degree of visibility of maxillary and mandibular anterior teeth at rest in different age groups and to evaluate the smile line, smile arc, and number of maxillary teeth displayed during smiling among the Saudi population visiting King Abdulaziz University Dental Hospital, Jeddah, Saudi Arabia. A total of 157 participants (77 males and 80 females) were included in this study with an age range of 19 to 69 years. All participants had maxillary and mandibular anterior teeth without restorations. Crown length and visible portions of anterior teeth at rest were measured using a Fowler Electronic Digital Caliper. Three measurements of each variable were recorded by two independent dental interns and calibrating their measurements was performed. Smile line, smile arc, and number of teeth displayed during smiling were examined. The collected data were statistically analyzed using SPSS software. It was found that the average clinical crown lengths in the maxillary lateral incisor, mandibular central incisor, and canine were significantly higher in males than females. At rest position, females displayed more maxillary central and lateral incisors. The displayed length of maxillary teeth at rest is inversely proportional to increasing age; the reverse occurs in mandibular teeth. The common visibility of maxillary teeth during smiling was from the second bicuspid to its counterpart. Average smile line and consonant smile arc were the most common characteristics. It was concluded that both age and gender affect the characteristics of tooth display at rest and in smiling. These effects should be considered during treatment planning and restoration of anterior teeth to obtain a more predictable esthetic outcome.

Predictive Model for Occlusal Vertical Dimension Determination and Digital Preservation with Three-Dimensional Facial Scanning

(1) Background: Occlusal vertical dimension (OVD) in the optimal maxillo–mandibular relationship is an important parameter to establish when complex dental rehabilitation has to be done. The optimal method to measure OVD is still a challenge in everyday practice. The aim of the present study was to test the reliability of the correlation between OVD and some anthropometric and cephalometric methods described in the literature. The validity of OVD registration using a facial scanner was also assessed. (2) Materials and Methods: 150 dentate participants, aged 20–25 years, were randomly selected using sealed envelopes. Anthropometric measurements between specific standard points were performed: Subnasion–Prementon (Sn–PM) and Subnasion–Gnation (Sn–Gn) in maximum intercuspation and in the rest mandibular position, right and left pupil to the corresponding chelion. The cephalometric measurements registered were the lower facial angle and the angle between mandibular and Frankfurt planes. The distance Sn–Gn in maximum intercuspation was compared to all other parameters. Facial scanning, with a mobile phone and installed dedicated application, was performed on ten subjects, randomly selected using the same method among the participants, and the obtained 3D files were analyzed. The digital measurements were compared, for validity, to the clinical measurements. Pearson’s correlation coefficient was used, for comparing clinical Sn–Gn in maximum intercuspation position to the other parameters. (3) Results: A strong agreement between all measured anthropometric parameters of the facial scan and clinical contact measurement method was registered. None of the measured parameters could predict the exact OVD. (4) Conclusions: In the limits of our study, the facial scanning could be used for predictable registration of OVD and the stored digital information could be preserved through life and use for oral rehabilitation. However, if OVD needs to be determined, several measurement methods, including cephalometric measurements, need to be used simultaneously to reach a final decision.

Evaluation of Masticatory Muscle Function Using Digital versus Traditional Techniques for Mockup Fabrication: A Controlled Prospective Study

Background: the aim of this longitudinal prospective study was to analyze the effect of digital and traditional mockup on masticatory muscle activity in patients with teeth wear, rehabilitated with an increase of occlusal vertical dimension. Subjects and Methods: a sample of 22 adult patients who were about to receive a prosthetic rehabilitation was divided into a study group (3M; 9F; mean age 42 ± 0.8 years), treated using the digital mockup; and a control group (2M; 8F; mean age 37 ± 0.5 years), treated using the conventional technique (traditional) mockup. Electromyographic activity of anterior temporalis and masseter muscles were evaluated before the beginning of the treatment (T0), at mockup insertion (T1), after treatment (T2) and each lapse of time lasted 2–5 months. Results: the comparison between the two groups at different time gaps revealed that at ∆1 (T1–T0) only the impact index (IMP) showed significant difference and no other significant variation was observed between the two groups at ∆2 (T2–T1) and ∆3 (T2–T0). It concludes that traditional and digital methods generally have nonsignificant differences. Conclusions: both methods seem to be effective in prosthetic rehabilitation and give comparable effects on masticatory muscles.

A craniometry-based predictive model to determine occlusal vertical dimension

STATEMENT OF PROBLEM

Craniometry is a method of determining the occlusal vertical dimension (OVD); the current prediction models do not consider factors such as facial type and sex or normalizing the OVD by using 1 main variable.

PURPOSE

The purpose of this clinical study was to determine whether sex, facial type, and age can influence the creation of a predictive model by using the right or left eye-to-ear distance to determine the OVD in dentate and edentate individuals.

MATERIAL AND METHODS

Healthy individuals (N=385) (238 women, 147 men) aged between 18 and 50 years were classified according to sex, age, and facial type. A single operator recorded all distances in millimeters between the anatomic landmarks proposed by Knebleman (nose-to-chin and right and left eye-to-ear distances) by using a computer numerical control (CNC) machined aluminum anatomic gauge. Measurements were converted into z-scores to determine abnormal values (±3 standard deviations criteria). The Pearson correlation coefficient was calculated for each facial type and for the entire sample between nose-to-chin and the right and left eye-to-ear distances. Multiple regression analysis was performed to establish the dependence of the measured variables on the OVD and the development of a further predictive model (α=.05).

RESULTS

According to the z-scores of the measured distances, 4 participants were discarded, leaving a final sample of 381 participants (237 women, 144 men; 115 leptoprosopic, 164 mesoprosopic, 102 euryprosopic). The left eye-to-ear distance showed a better correlation with the nose-to-chin distance (leptoprosopic r=0.54, mesoprosopic r=0.60, euryprosopic r=0.55, total sample=0.56) than the right eye-to-ear distance (leptoprosopic r=0.48, mesoprosopic r=0.56, euryprosopic r=0.54, total sample=0.51). Multiple regression analysis revealed that age was not a predictive variable (P=.57), that OVD depended on sex (P<.001) and facial type (P<.01), and that women had shorter OVD than men, as well as more euryprosopic faces than leptoprosopic faces. Using these relationships, the following equation to determine OVD was constructed as a model: OVD=42.17+(0.46×left eye-to-ear distance)+sex (women=-3.38, men=0)+facial type (leptoprosopic=0, mesoprosopic=-1.19, euryprosopic=-2.19).

CONCLUSIONS

OVD depends on facial type and sex, both of which are craniometric variables. This study proposed a baseline method of determining OVD by using the left eye-to-ear distance as an initial reference that involves a straightforward mathematical calculation.

[Cone-beam computed tomography-synthesized cephalograms for evaluating the vertical dimension of occlusions]

OBJECTIVE

The accuracy of the occlusion vertical dimensions of edentulous Han patients from Yunnan province was compared and analyzed on the basis of cone-beam computed tomography (CBCT)-synthesized cephalograms, closest speaking space method, and interocclusal distance.

METHODS

A database correlating the CBCT head lateral images of Han patients from Yunnan province with normal occlusal conditions was first constructed. Then, five edentulous Han patients aged 63-78 years old from Yunnan Province were selected. NNT.View software was used to measure and analyze hard tissue cephalometric radiographs that had been transformed by the CBCT marker. The radiographs were then combined with the normal population database for the assessment of occlusion vertical dimensions. The occlusion vertical dimensions determined on the basis of CBCT-synthesized cephalograms, the closest speaking space method, and the free-way space were analyzed.

RESULTS

The closest speaking space method was used as the standard control group, the differences between seven methods and the closest speaking space method were analyzed. The seven methods include free-way space method and six CBCT-synthesized cephalograms methods (N-ANS/ANS-Me, S-Go/N-Me, ANS-Gn/N-ANS, ANS-FH/Me-FH, ANS-Xi-Pm, and CA/LA). The seven methods were highly consistent with the closest speaking space method (intraclass correlation coefficient>0.986). The absolute values of the differences between the methods of free-way space, N-ANS/ANS-Me, S-Go/N-Me and the closest speaking space method were lower than those of the other four groups (P<0.05), while the differences between ANS-FH/Me-FH and the closest speaking space method was higher than those other groups (P<0.05).

CONCLUSIONS

CBCT-synthesized cephalograms, with the exception of ANS-FH/Me-FH, can provide references for the clinical evaluation of the occlusion vertical dimensions of patients with edentulous jaws.

Highly producible method for determination of occlusal vertical dimension: relationship between measurement of lip contact position with the closed mouth and area of upper prolabium

PURPOSE

A new method inducing the physiologic rest position of the mandible using the lip contact position with the closed mouth have compared with those obtained using conventional methods of placing the mandible in the physiologic rest position.

METHODS

The lip contact position with the closed mouth as a method was investigated whether the technique was useful for determining the occlusal vertical dimension. The relationship between the space between the maxillary and mandibular front teeth in the lip contact position with the closed mouth and the areas of the prolabia was also investigated.

RESULTS

Median space between the maxillary and mandibular front teeth in the lip contact position with the closed mouth was 1.53mm, a value intermediate between the value of 2.16mm in the resting mandibular position obtained by the conventional technique and that of 1.33mm in the swallowing position. The coefficient of variation of the space in the lip contact position with the closed mouth was significantly lower than those in the resting mandibular position and in the swallowing position. A significant positive correlation was recognized between the space in the lip contact position with the closed mouth and the area of the prolabium of the upper lip.

CONCLUSIONS

These results clarified that the lip contact position with the closed mouth obtained the excellent reproducibility comparing to the conventional methods. These findings suggested that the area of the prolabium of the upper lip might offer an effective index for individual determination of the correct free-way space.

An Anthropometric Study of Cranio-Facial Measurements and Their Correlation with Vertical Dimension of Occlusion among Saudi Arabian Subpopulations

BACKGROUND

Determining and restoring physiological vertical dimension of occlusion (VDO) is the critical step during complete mouth rehabilitation. The improper VDO compromises the aesthetics, phonetics and functional efficiency of the prosthesis. Various methods are suggested to determine the accurate VDO, including the facial measurements in the clinical situations with no pre-extraction records. The generalisation of correlation between the facial measurements to VDO is criticised due to gender dimorphism and racial differences. Hence, it is prudent to verify the hypothesis of facial proportion and correlation of lower third of the face to remaining craniofacial measurements in different ethnic groups. The objective of the study was to evaluate the correlation of craniofacial measurements and OVD in the Saudi-Arabian ethnic group.

METHODOLOGY

Total of 228 participants from Saudi-Arabian Ethnic group were randomly recruited in this cross-sectional study. Fifteen craniofacial measurements were recorded with modified digital Vernier callipers, and OVD was recorded at centric occlusion. The obtained data were analysed by using the Spearman's correlation and linear regression analysis.

RESULTS

The Mean OVD in male participants was higher (69.25 ± 5.54) in comparison to female participants (57.41 ± 5.32). The craniofacial measurement of Exocanthion-right labial commissure and the Mesial wall of the right external auditory canal-orbitale lateral had a strong positive correlation with VDO. The strong correlation was recorded with a trichion-upper border of right eyebrow line and trichion-Nasion only in males. Meanwhile, the length of an auricle recorded the positive correlation in female participants.

CONCLUSIONS

Being simple and non-invasive technique, craniofacial measurements and linear equations could be routinely utilised to determine VDO.