Development and validation of an AI-driven tool to evaluate chewing function: a proof of concept

BACKGROUND

Masticatory function is an important determinant of oral health and a contributing factor in the maintenance of general health. Currently, objective assessment of chewing function is a clinical challenge. Previously, several methods have been developed and proposed, but implementing these methods in clinics may not be feasible. Therefore, more efforts are needed for accurate assessment of chewing function and clinical use.

AIM

The study aimed to establish a proof of concept for development and validation of an automated tool for evaluating masticatory function.

METHODS

YOLOv8, a deep neural network, was fine-tuned and trained to detect and segment food fragments. The model's performance was assessed using bounding box recall metrics, segmentation metrics, confusion matrix, and sensitivity values. Additionally, a separate conversion test set evaluated the model's segmentation performance using physical units, demonstrated with Bland-Altman diagrams.

RESULTS

The YOLOv8-model achieved recall and sensitivity rates exceeding 90 %, effectively detecting and classifying food fragments. Out of 316 ground truth fragments, 301 were correctly classified, with 15 missed and 5 false positives. The Bland-Altman diagram indicated general agreement but suggested a systematic overestimation in measuring the size of post-masticated food fragments.

CONCLUSION

Artificial intelligence presents a reliable approach for automated analysis of masticatory performance. The developed application proves to be a valuable tool for future clinical assessment of masticatory function.

CLINICAL SIGNIFICANCE

The current study provides a proof of concept for development of an automated tool for clinical assessment of masticatory function.

Are patient-reported outcomes improved by implant-assisted maxillary prostheses compared to conventional maxillary dentures? A systematic review

OBJECTIVES

Edentulism can be treated with conventional complete dentures or implant-assisted prostheses. While two-implant assisted overdentures are superior to conventional mandibular dentures, the effectiveness of maxillary options remains unclear. This systematic review aims to assess whether conventional or implant-assisted maxillary prostheses provide better satisfaction and quality of life for patients with edentulous maxilla.

DATA AND SOURCES

An electronic search was conducted across Medline (PubMed), Scopus, Embase, and the Cochrane Library up to May 23, 2024, to find studies comparing satisfaction and oral health-related quality of life in patients using conventional maxillary dentures versus implant-assisted maxillary prostheses.

STUDY SELECTION

Out of 1119 retrieved articles, 1085 were deemed irrelevant after screening, and 34 studies were evaluated for inclusion. Only six studies met the criteria, with the main reason for exclusion being the lack of comparison between new implant prostheses and new conventional dentures, as opposed to old unsatisfactory conventional maxillary dentures. Due to limited sample sizes and high heterogeneity, a meta-analysis was not feasible. The literature did not show significant differences in quality of life or satisfaction between conventional and implant-assisted complete maxillary prostheses, except for patients with pre-treatment preference toward implants.

CONCLUSIONS

There is no evidence supporting the superiority of either conventional or implant-assisted prosthetic options for restoring the edentulous maxilla. Further well-designed clinical studies are needed to compare new conventional and new implant-assisted complete maxillary prostheses with different designs.

CLINICAL SIGNIFICANCE

Conventional and implant-assisted complete maxillary prostheses appear equally successful in restoring the quality of life and satisfaction of patients with an edentulous maxilla. The cost and morbidity associated with implant-assisted prostheses may be greater. A properly made conventional denture can serve as a diagnostic tool to assist treatment planning.

Maxillary and mandibular overdentures retained by two unsplinted narrow-diameter titanium-zirconium implants - A clinical pilot study

OBJECTIVES

To evaluate the survival rates and marginal bone loss of narrow-diameter titanium-zirconium implants supporting complete maxillary and mandibular overdentures up to 3 years after loading.

MATERIALS AND METHODS

Ten completely edentulous patients who were dissatisfied with their complete dentures were enrolled. Two narrow-diameter implants were placed in the canine region of the maxilla and mandible. After second-stage surgery, implant-supported overdentures (palatal-free) attached by parallel alignable stud-attachments were placed. Patients were followed periodically for up to 36 months. Standardized radiographs were taken at baseline, 12 and 36 months to analyze mean marginal bone level changes around the implants.

RESULTS

The Kaplan-Meier survival rates were 100% for mandibular and 68.0% (SE ± 10.9%) for maxillary implants at 36 months (p = .008). Six maxillary implants failed after loading; no mandibular implants were lost. Five implants failed due to loss of osseointegration. One implant fractured. The mean marginal bone level changes around the analyzed implants (n = 28, 9 patients) were -0.71 ± 0.82 mm in the mandible and -2.08 ± 1.52 mm in the maxilla at the 36-month follow-up. The difference in marginal bone level changes between the maxilla and mandible was significant (p = .019) at the 12- and 36-month follow-ups.

CONCLUSION

Two narrow-diameter titanium-zirconium implants with stud-attachments showed a highly satisfactory outcome in the mandible. The maxillary implants showed a high failure rate and significantly more bone loss over time than the mandibular implants. The minimal concept of two implants and an overdenture should be limited to the edentulous mandible.

Maxillary implant overdenture retained by four unsplinted attachments and opposed by a natural or fixed dentition: Five-year clinical outcomes. A prospective case series

OBJECTIVES

The objective of this study was to assess, over a period of 5 years, implant prosthesis and patient-reported outcomes of complete dentures retained by four implant-supported attachments in the edentulous maxilla facing either natural teeth or fixed rehabilitation in the lower jaw.

MATERIALS AND METHODS

Implant, prosthodontic and patient-related outcomes were assessed in 30 patients at 1, 3 and 5 years. Prosthodontic survival, complications or maintenance events as well as implant survival were recorded. Patient-reported outcome measures (PROMs) were evaluated with the Oral Health Impact Profile (OHIP-20) questionnaire and a visual analogue scale (VAS) before implant placement (baseline) and during the follow-up period.

RESULTS

After 5 years, three patients dropped out, 21 implants failed, and four overdentures were replaced leading to a prosthesis survival rate of 85.2% (95% CI: 71.8%-98.6%) and an implant survival rate of 80.6% (95% CI: 73.1%-88.0%). Prosthodontic success rate decreased from 86.2% to 74% between the 1st and the 3rd year and reached 63% after 5 years. OHIP results improved significantly from baseline to 1 year (p < .0001) and to 3 years (p = .036), but, at 5 years, the improvement was no longer significant when compared to baseline (p = .12). The overall VAS score remained significantly higher up to 5 years (p < .001).

CONCLUSION

A substantial number of prosthetic complications and replacements occurred over the 5-year follow-up. After 5 years, the OHIP-20 deteriorated and reached again the baseline level. Nonetheless, the VAS results suggest significantly increased patient satisfaction after implant-supported retention was provided for the removable prostheses.

Prosthetic failures in dental implant therapy

Both fixed and removable implant-supported prostheses are well-established methods for replacing missing teeth in partially or fully edentulous patients. Numerous systematic reviews have been performed in recent years to evaluate the survival and complication rates of implant-retained fixed dental prostheses and implant-retained overdentures, displaying high 5-year survival rates ranging from 97.1% for fixed dental prostheses to 95%-100% for implant-retained overdentures. However, the survival rates only represent the prostheses remaining in use for a defined follow-up time, and do not account for the potential prosthetic complications that may have arisen and influence the general success of the implant treatment. The most common technical complications of fixed implant-retained single crowns are crown fracture, fractures of ceramic implant abutments, and esthetic problems. The predominant technical complication at multiple-unit, implant-retained fixed dental prostheses is fracture/chipping of the veneering ceramic. Reported technical complications for implant-retained overdentures are overdenture fracture or chipping of the veneer materials, whereas mechanical complications include implant fracture, attachment failure, and attachment housing or insert complications. To reduce the risk of such failures, a comprehensive pretreatment diagnostic work-up is essential, including defining the prosthetic goal with the aid of a wax-up or set-up and the associated ideal, prosthetically oriented three-dimensional implant position. Furthermore, selection of the ideal type of prosthesis, including the respective implant components and materials, is important for clinical long-term treatment success.

Clinical study of the biofilm of implant-supported complete dentures in healthy patients

OBJECTIVE

The purpose of this study was to quantify the area covered by biofilm and identify bacteria and yeasts present in mandibular acrylic resin full-arch implant-supported fixed prostheses.

BACKGROUND

Biofilm control of implant-supported fixed prosthesis is hampered by their design, and it can cause oral and systemic problems, mainly in immunocompromised patients like the elder. Knowledge about microbiota reinforces the awareness about the need for periodic professional cleaning maintenance.

MATERIALS AND METHODS

Twenty prostheses were unscrewed, washed in 0.89% sodium chloride, stained with eosin 1% and photographed. The area covered by biofilm was digitally delimited and quantified. Biofilm samples were collected, diluted up to 1:10⁷ , seeded in chromogenic agar media and incubated for 48 hours, at 37°C, for counting of colony-forming units (CFU/mL). DNA hybridization was performed to complement the identification and quantification of microorganisms. Data were analyzed using Mann-Whitney test, Spearman correlation and Fisher's exact test (α = .05).

RESULTS

An average of 62% of the gingival surface of the prostheses was covered by biofilm. Enterococcus spp. (5.82 ± 1.38 log₁₀ CFU/mL) and Staphylococcus aureus (5.75 ± 2.02 log₁₀ CFU/mL) showed higher prevalence in cultures. Patients with five implants had less biofilm compared to those with four implants (P = .031) but had higher Escherichia coli counts (P = .039). In DNA hybridization, Streptococcus pneumoniae, Veillonella parvula and Fusobacterium nucleatum presented higher quantification and were present in all the samples; patients over 65 years old contained more Candida tropicalis (P = .049); prostheses on five implants presented lower quantification for several species.

CONCLUSION

Biofilm was present on all prostheses, containing potentially pathogenic microorganisms. The number of implants may play a role in quantification of biofilm and in microorganism counts.

Evaluation of the intaglio surface shape of implant-supported complete-arch maxillary prostheses and its association with biological complications: An analytical cross-sectional study

STATEMENT OF PROBLEM

Whether the shape of the intaglio surface of fixed implant-supported maxillary prostheses is associated with the occurrence of biological is unclear.

PURPOSE

The purpose of this cross-sectional study was to evaluate the shape (convex or concave) of the intaglio surface of complete-arch implant-supported maxillary fixed prostheses and to assess the association with biofilm accumulation, hyperemia, bone loss, and patient satisfaction.

MATERIAL AND METHODS

Study participants consisted of 56 individuals with fixed complete implant-supported maxillary prosthesis attending follow-up appointments. The 56 prostheses supported by 388 implants had been in place for an average of 5.5 years (range 1-14 years). The intaglio surface was divided into areas corresponding to the cantilever regions and between implants (n=442) and was assessed for shape (concave or convex) and biofilm index (0 to 3). Tissue hyperemia (redness) was assessed as absent or present. Bone loss (mm) was measured from digital periapical radiographs by 2 calibrated evaluators (kappa=94.9%). Study participant satisfaction was investigated by using a visual analog scale. Association assessments (α=.05) between the shape of each area and all these parameters were performed with the Friedman, linear regression, and logistic regression tests.

RESULTS

Of the analyzed areas, 58 (13.1%) were concave, and 384 (86.9%) were convex. Biofilm was absent on 3.5% of the concave and 5.5% of the convex areas. Biofilm was detectable with a probe on 12% of the concave and 22.4% of the convex areas and clinically visible in 58.6% of the concave and 57.8% of the convex areas. Abundant biofilm was seen in 25.9% of the concave and 14.3% of the convex areas and was associated with hyperemia (P=.003). A statistically significant association was found between the shape and biofilm accumulation (P=.009). Hyperemia was present in 199 (45%) areas. The association analysis between the shape of the area and the presence of hyperemia was not significant (P>.05). The mean bone loss was 0.71 mm (0.91 mm). Implants placed near concave areas underwent greater bone loss (P=.001). Study participants reported a high level of satisfaction with the esthetics, mastication, speech, and smile provided by the prosthesis, with satisfaction scores ranging between 8.46 and 8.77. However, in relation to ease of cleaning, only 19.6% were fully satisfied.

CONCLUSIONS

The shape of the intaglio surface of prostheses influenced the occurrence of biofilm accumulation and bone loss, and concave areas showed greater biofilm accumulation and bone resorption. High rates of satisfaction with treatment were identified.

How many implants are necessary to stabilise an implant-supported maxillary overdenture?

Data sources Pubmed and EMBASE databases were searched from 2000 to 2017 and complemented by manual searching of the references of reviews and the full-text articles assessed for inclusion.Study selection The inclusion criteria were: (i) Randomised clinical trials (RCT), prospective or retrospective studies, and case series or case reports including at least ten totally edentulous patients rehabilitated with maxillary implant-supported overdenture; (ii) analysed one of the following outcomes: survival rate of the implants, survival rate of the overdenture and patient-reported results; (iii) had at least two years of follow-up; (iv) and were written in English language.Data extraction and synthesis The data extraction was performed by two independent reviewers. The comparison of the analysed outcomes was performed by nonparametric Fisher Test for unpaired data according to the number of implants and to the splinting technique. A meta-analysis was performed for the odds ratio (OR) for implant failure between four splinted implants and more than four splinted implants.Results Twenty-eight studies were included in the systematic review. The survival rate of implants appeared to be higher when at least four implants were placed to support the overdenture, compared to less than four implants. The survival rate of overdentures and the patient satisfaction were not influenced by the number of implants.The metanalysis could only be performed to compare the implant survival rate of a four splinted implants group and more than 4 splinted implants group, without significant differences between both groups (OR = 0.39; 95 % CI: 0.14, 1.14; p = 0.09).Conclusions Although the placement of at least four implants to support a maxillary overdenture seems to report higher implant survival rates, further studies are needed to confirm this conclusion. No differences were found for overdenture survival rates or patient satisfaction according to the number of implants.

Maxillary implant overdenture retained by four unsplinted attachments and opposed by a natural or fixed dentition: One-year clinical outcomes

OBJECTIVES

The aim of this prospective study was to evaluate the implant, prosthesis, and patient-reported outcomes of maxillary removable prostheses retained by 4 implant-supported study abutments after a follow-up period of 1 year in patients with natural teeth or a fixed rehabilitation in the mandible.

MATERIALS AND METHODS

A total of 30 patients were included, and all received 4 implants in the upper maxilla. After 12 weeks, the prostheses were connected to the implant with unsplinted attachments. The implant and prosthodontics outcomes were assessed over a follow-up period of 1 year. Patient-reported outcome measures (PROMs) were evaluated with the Oral Health Impact Profile (OHIP-20) questionnaire and an adaptation of the McGill Denture Satisfaction Instrument using a visual analogue scale (VAS).

RESULTS

A single patient dropped out. At the post-operative 12-week follow-up, 79.3% (95% CI: 64.6%-94.1%) of the patients displayed peri-implant mucosa hyperplasia and 69.0% (95% CI: 52.1%-85.8%) showed pain. After 1 year, 16 implants failed in 10 patients, leading to an implant survival rate of 86.2% (95% CI: 79.0%-92.5%), and the mean peri-implant bone loss was 1.01 ± 0.77 mm (95% CI: 0.85-1.16 mm). The prosthesis survival rate was 96.6% (95% CI: 82.2%-99.9%). The OHIP-20 and VAS scores both improved significantly from baseline to 1 year (p < .001).

CONCLUSION

The implant survival rate was lower compared to the literature for the upper maxilla. Despite the encountered problems, PROMs showed significant improvement with the implant overdenture retained by 4 unsplinted implants compared to conventional dentures.

Impact of immediately loaded implant-supported maxillary full-arch dental prostheses: a systematic review

OBJECTIVE

The immediate loading of implant-assisted fixed prostheses in edentulous maxillae may achieve favorable success rates with reduced treatment time. An evidence summary of clinical trials is key to recommend loading protocols in these cases.

OBJECTIVES

To compare immediately loaded, fully implant-supported complete dentures to early and conventional/delayed loading in the edentulous maxillae of adult patients by a systematic review of controlled clinical trials (CCT).

METHODOLOGY

CCTs reports were identified up to January 17, 2019 from Cochrane Oral Health Group's Trial register, Cochrane Central Register of controlled trials (CENTRAL), MEDLINE (Ovid), BIOSIS, EMBASE, CINAHL, Web of Science, and DARE. Two independent reviewers screened titles/abstracts and confirmed inclusion using full texts. Data were extracted and quality assessed (Cochrane Risk of Bias tool) independently and in duplicate. Study heterogeneity prevented pooling by meta-analysis.

RESULTS

Out of 1,052 candidate studies, four CCTs were included. Two trials had patient satisfaction as an outcome: (1) A randomized trial compared immediately and early loaded fixed dentures and found more satisfaction with the first after 12 months; (2) A non-randomized study found better satisfaction with immediate fixed dentures compared to conventional loading after 3 months (no more at 12 months). Regarding implant success and prosthetic complications, three trials did not report significant differences comparing immediate loading to other protocols.

CONCLUSIONS

This review found weak evidence of differences between immediate load and other loading regimens, regarding patient satisfaction and maintenance events/adversities. The potential of immediate loading for favorable results in edentulous maxillae reinforces the need for well-designed RCTs, for solid clinical guidelines. Registration number CRD42018071316 (PROSPERO database).

Patient Eligibility for Standardized Treatment of the Edentulous Mandible: A Retrospective CBCT-Based Assessment of Mandibular Morphology

The aim of the study was to evaluate the proportion of patients recommended for full-arch mandibular restoration that would be eligible for treatment with a recently developed premanufactured full-arch prosthesis (Trefoil™, Nobel Biocare) based on the morphology of their lower jaw. Anonymized cone beam computed tomography (CBCT) data from 100 partially and fully edentulous patients referred for full-arch mandibular restoration were retrospectively collected from an imaging center database. Using custom-built software, CBCTs of mandibles were registered to a reference CBCT of a patient treated previously with a premanufactured full-arch prosthesis to determine if patients had adequate horizontal width and vertical height for implant placement. Bone height and thickness around simulated implants and distances to the incisive canal were evaluated. Mandibular arch width and semi-automated volume calculations were also performed. Using the system-specific 5.0 mm diameter implants with lengths of 13 and 11.5 mm, 85% and 86% of patients, respectively, were eligible for treatment with the standardized prosthesis. Eligibility was higher for men than women (odds ratio = 3.9, p = 0.045) due to increased bone volume. Based on mandibular morphology, our results suggest that the standardized treatment concept could serve a large percentage of patients with edentulous mandibles or failing dentition in the mandible.

A within-subject clinical trial on the conversion of mandibular two-implant to three-implant overdenture: Patient-centered outcomes and willingness to pay

OBJECTIVES

To examine the impact of adding a third midline implant with stud attachment to a mandibular two-implant overdenture on patient-oriented outcomes.

METHODS

In this pre-post design clinical trial, following the standard procedures, mandibular two-implant overdentures of 17 edentulous individuals (61.9 ± 6.6 years) were converted to three-implant overdentures by adding a stud attachment to an unloaded midline implant. Patient-oriented outcomes included patient expectations and satisfaction with implant overdenture as well as willingness to pay the cost of conversion. Data were collected at baseline and at the 6-week follow-up using visual analog and binary scales as well as open-ended questions. Statistical analysis included descriptive statistics, Spearman's correlation, Fisher exact test, Mann-Whitney U test, and the exact sign test.

RESULTS

After connecting the third midline implant to the mandibular two-implant overdenture, there was a statistically significant decrease in the anteroposterior movement (p = 0.005) as evaluated by clinicians. Moreover, study participants reported an increase in perceived stability of the overdenture (95% CI; 0.68-1.00, p = 0.002) and in their ability to speak (95% CI; 0.63-1.00, p = 0.008). The addition of a third implant met the expectations of 94% of patients in regard to lower denture stability, 100% for retention, and 82.4% for comfort. The mandibular three-implant overdenture increased patient general satisfaction over a short period of time, but this improvement was not statistically significant. About 80% of patients would recommend this type of prosthesis to their peers but only 47% of them would agree to pay a large increase in the cost of treatment compared to a two-implant overdenture.

CONCLUSIONS

The addition of a midline third implant to an existing mandibular two-implant overdenture resulted in several improved patient-reported outcomes.

Implant retention systems for implant-retained overdentures

Implant retained overdentures are being increasingly utilised in both general and specialist practice to rehabilitate patients with missing teeth, particularly those that are edentate. This article aims to inform the reader of a variety of retention systems that are available to retain an implant overdenture and to understand how these systems work, their advantages and disadvantages and to outline some of the clinical and treatment planning considerations involved in selecting the most appropriate retention system for patients.

Efficacy of Mandibular 2-implant Overdenture: An Updated Meta-analysis on Patient-based Outcomes

The extent of heterogeneity regarding the efficacy of the mandibular 2-implant overdenture is still in question. The aim of this meta-analysis is to provide an update on the existing evidence from randomized controlled trials assessing the efficacy of the mandibular 2-implant overdenture in regard to patient-based outcomes. Electronic searches were carried out to September 2015 through MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, and the Cochrane Systematic Reviews. Only randomized controlled trials that compared conventional dentures with mandibular 2-implant overdentures were included. Patient-based outcomes were assessed, including patient satisfaction and oral health- and general health-related quality of life. Random effects models were used to pool the effect sizes of all included studies. Further stratified analyses and heterogeneity analyses were tested, as was publication bias. In addition to the 7 randomized controlled trials that were included in the previous meta-analysis, 4 new trials were identified and included in this update. A random effects model showed that, when compared with conventional dentures, mandibular 2-implant overdentures significantly improved patient satisfaction (pooled effect size = 0.87, z = 5.31, 95% confidence interval: 0.55 to 1.19, P < 0.0001, χ² = 41.82, df = 8, P < 0.0001, I² = 81%) and oral health-related quality of life (pooled effect size = -0.66, z = 2.72, 95% confidence interval: -1.13 to -0.18, P = 0.007, χ² = 21.26, df = 4, P = 0.0003, I² = 81%). The differences in participant recruitment and their pretreatment condition were important sources of heterogeneity among the studies. Only 1 study investigated the impact of mandibular implant overdentures on perceived general health, and it revealed no between-treatment differences. The 2-implant mandibular overdenture improves patient satisfaction and quality of life for the general edentate population. Health status, poor oral condition, and patient characteristics may effect patient-based outcomes and should be considered by clinicians in treatment planning. Knowledge Transfer Statement: This meta-analysis shows that mandibular 2-implant overdentures are significantly more satisfactory to the general edentate populations than new conventional dentures. The results also show that mandibular 2-implant overdentures provide significantly better oral health-related quality of life than do new conventional dentures. These results should be shared with edentate patients in planning their treatment.