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Oral Surgery, Oral Medicine, Oral... Oct 2022To analyze the biomechanical properties of a novel temporomandibular joint (TMJ) prosthesis with an attachment area for the lateral pterygoid muscle (LPM).
OBJECTIVE
To analyze the biomechanical properties of a novel temporomandibular joint (TMJ) prosthesis with an attachment area for the lateral pterygoid muscle (LPM).
STUDY DESIGN
Three prosthesis models were created and compared using finite element analysis for the displacement, stress, and strain when simulating the maximum bite force loading. A verification experiment and a compression test were conducted.
RESULTS
The displacement, stress, and strain of the novel TMJ prosthesis were larger than the solid condylar neck prosthesis and similar to the slotted condylar neck prosthesis, but the values were far less than the yield strength of titanium alloy. The maximum stress and strain in the novel TMJ prosthesis was concentrated in the inner and boundary areas of the LPM reattachment region beside the thinnest part of the prosthesis neck. The difference in the strain values measured using the verification test and those using finite element analysis was <20%. Compression testing of the novel TMJ prosthesis revealed that the mandible fractured when the force reached 588.97 N, whereas the prosthesis itself did not break or deform.
CONCLUSIONS
The mechanical distribution of the novel prosthesis was feasible under maximum bite force for potential clinical application.
Topics: Alloys; Biomechanical Phenomena; Finite Element Analysis; Humans; Joint Prosthesis; Mandibular Condyle; Pterygoid Muscles; Temporomandibular Joint; Titanium
PubMed: 35484032
DOI: 10.1016/j.oooo.2022.03.004 -
International Journal of Oral and... Jan 2023The aim of this study was to perform a systematic review of the literature on the temporomandibular joint (TMJ) prosthesis as a treatment option after mandibular condyle... (Meta-Analysis)
Meta-Analysis Review
The aim of this study was to perform a systematic review of the literature on the temporomandibular joint (TMJ) prosthesis as a treatment option after mandibular condyle fracture. Three databases were searched (PubMed, Embase, Cochrane Library) and 2670 unique papers were identified. A total of 337 studies were included (121 case reports, 89 case series, and 127 cohort/clinical studies). In total 14,396 patients and 21,560 prostheses were described. Of the 127 cohort or clinical studies, 100 (79%) reported inclusion criteria, 54 (43%) reported exclusion criteria, and 96 (76%) reported the inclusion period. The base population from which patients were recruited was reported in 57 studies (45%). The reason for TMJ prosthesis implantation was reported for 4177 patients (29.0%). A history of condylar fracture was present in 83 patients (2.0%); a history of mandibular trauma was present in 580 patients (13.9%). The meta-analysis showed a pooled prevalence of condylar fracture of 1.6% (95% confidence interval 0.9-2.4%) and a pooled prevalence of trauma or condylar fracture of 11.3% (95% confidence interval 7.1-16.0%). Heterogeneity was highly significant (P < 0.001). The TMJ prosthesis appears to be reserved for patients with persistent pain, bony or fibrous ankylosis, or osteomyelitis after primary closed or open treatment of fractures of the mandibular condyle.
Topics: Humans; Mandibular Condyle; Temporomandibular Joint Disorders; Tooth Ankylosis; Mandibular Fractures; Temporomandibular Joint; Ankylosis
PubMed: 35752530
DOI: 10.1016/j.ijom.2022.05.014 -
Journal of Oral and Maxillofacial... Oct 2020The Jaw in a Day (JIAD) procedure allows for complete primary reconstruction of bone and teeth during the same operation as tumor resection. We reviewed 12 cases, the...
PURPOSE
The Jaw in a Day (JIAD) procedure allows for complete primary reconstruction of bone and teeth during the same operation as tumor resection. We reviewed 12 cases, the largest published case series of the JIAD procedure, and discussed both the prosthodontic and surgical considerations.
MATERIALS AND METHODS
A multi-institutional retrospective chart review was completed to identify patients undergoing the JIAD procedure. Patients with a minimum of 6 months' follow-up were included. Variables included skeletal relationship, dental Angle classification changes, postoperative diet, prosthesis complications, flap failure, osseointegration of dental implants, hardware complications, infection, intelligible speech, and patients' subjective satisfaction with facial and dental esthetics.
RESULTS
The sample included 12 patients (8 male and 4 female patients) with a mean age of 38 years (range, 15 to 75 years) and an average follow-up period of 19 months (range, 7 to 42 months). Patients underwent the JIAD procedure at the same time as resection of an ameloblastoma (mandibular in 9 and maxillary in 1) or odontogenic myxoma (mandibular in 1 and maxillary in 1). Nine patients' Angle classification remained unchanged after the procedure, with 3 patients showing correction from dental Class III to Class I. On average, 4 implants (range, 2 to 6 implants) were placed. Hybrid or splinted crown prostheses replaced, on average, 8 teeth (range, 3 to 12 teeth) with no prosthetic fractures. All patients had viable fibular flaps, absence of infection, and completely intelligible speech. All but 1 patient had subjective satisfaction with facial and dental esthetics. Complications included plate fracture with fibrous union (1), premature contacts requiring occlusal equilibration (2), implant loss (1), delayed wound healing (1), heterotopic bone formation along the pedicle (1), and dissatisfaction with chin symmetry (1).
CONCLUSIONS
The JIAD technique predictably reconstructs bone and teeth in a single operation. The tools and services streamlining this protocol are now widely available. However, there are still several challenges with this protocol that surgeons and patients must overcome. Further study and refinements are necessary to address these.
Topics: Child; Child, Preschool; Dental Implantation, Endosseous; Dental Implants; Dental Prosthesis, Implant-Supported; Dental Restoration Failure; Female; Follow-Up Studies; Humans; Infant; Jaw; Male; Mandible; Osseointegration; Retrospective Studies; Surgical Flaps; Treatment Outcome
PubMed: 32707040
DOI: 10.1016/j.joms.2020.06.007 -
The British Journal of Oral &... Jan 2023Porcine mandibular defect models are commonly used for the preclinical evaluation of reconstruction techniques. Existing studies vary in technique, complexity, and...
Porcine mandibular defect models are commonly used for the preclinical evaluation of reconstruction techniques. Existing studies vary in technique, complexity, and postoperative outcomes. The procedures are complex and often described without sufficient detail. We describe in detail a simple and reproducible method for creating a critical-size mandibular defect in a porcine model. Seven hemimandibular critical size defects were created in five male Yorkshire-Landrace pigs, three with unilateral defects and two with bilateral defects. A transverse incision was made over the mandibular body. Periosteum was incised and elevated to expose the mandibular body and a critical-size defect of 30 × 20 mm created using an oscillating saw. The implant was inserted and fixed with a titanium reconstruction plate and bicortical locking screws, and the wound closed in layers with resorbable sutures. Intraoral contamination was avoided. Dentition was retained and the mental nerve and its branches preserved. The marginal mandibular nerve was not encountered during dissection. All pigs retained normal masticatory function, and there were no cases of infection, wound breakdown, haematoma, salivary leak, or implant-related complications. The procedure can be performed bilaterally on both hemimandibles without affecting load-bearing function. All pigs survived until the end point of three months. Postoperative computed tomographic scans and histology showed new bone formation, and a three-point bend test showed the restoration of biomechanical strength. Straight-segment mandibulectomy is a simple and reproducible method for the creation of critical-size mandibular defects in a porcine model, simulating a load-bearing situation.
Topics: Animals; Male; Mandible; Mandibular Osteotomy; Mandibular Reconstruction; Periosteum; Swine; Tomography, X-Ray Computed; Models, Animal; Bone-Anchored Prosthesis; Titanium
PubMed: 36470696
DOI: 10.1016/j.bjoms.2022.11.003 -
Technology and Health Care : Official... 2022Customized prosthetic joint replacements have crucial applications in severe temporomandibular joint problems, and the combined use of porous titanium scaffold is a...
BACKGROUND
Customized prosthetic joint replacements have crucial applications in severe temporomandibular joint problems, and the combined use of porous titanium scaffold is a potential method to rehabilitate the patients.
OBJECTIVE
The objective of the study was to develop a design method to obtain a titanium alloy porous condylar prosthesis with good function and esthetic outcomes for mandibular reconstruction.
METHODS
A 3D virtual mandibular model was created from CBCT data. A condylar defect model was subsequently created by virtual condylectomy on the initial mandibular model. The segmented condylar defect model was reconstructed by either solid or porous condyle with a fixation plate. The porous condyle was created by a density-driven modeling scheme with an inhomogeneous tetrahedral lattice structure. The porous condyle, supporting fixation plate, and screw locations were topologically optimized. Biomechanical behaviors of porous and solid condylar prostheses made of Ti-6Al-4V alloy were compared. Finite element analysis (FEA) was used to evaluate maximum stress distribution on both prostheses and the remaining mandibular ramus.
RESULTS
The FEA results showed levels of maximum stresses were 6.6%, 36.4% and 47.8% less for the porous model compared to the solid model for LCI, LRM, and LBM loading conditions. Compared to the solid prosthesis, the porous prosthesis had a weight reduction of 57.7% and the volume of porosity of the porous condyle was 65% after the topological optimization process.
CONCLUSIONS
A custom-made porous condylar prosthesis with fixation plate was designed in this study. The 3D printed Ti-6Al-4V porous condylar prosthesis had reduced weight and effective modulus of elasticity close to that of cortical bone. The.
Topics: Finite Element Analysis; Humans; Joint Prosthesis; Mandible; Porosity; Printing, Three-Dimensional; Prosthesis Design; Temporomandibular Joint; Titanium
PubMed: 35275582
DOI: 10.3233/THC-213534 -
Frontiers in Bioengineering and... 2023Mandibular flexure, characterized by unique biomechanical behaviors such as elastic bending and torsion under functional loading, has emerged as a crucial factor in oral... (Review)
Review
Mandibular flexure, characterized by unique biomechanical behaviors such as elastic bending and torsion under functional loading, has emerged as a crucial factor in oral clinical diagnosis and treatment. This paper presents a comprehensive review of the current research status on mandibular flexure, drawing insights from relevant studies retrieved from the PubMed database (www.ncbi.nlm.nih.gov/pubmed), including research conclusions, literature reviews, case reports, and authoritative reference books. This paper thoroughly explores the physiological mechanisms underlying mandibular flexure, discussing different concurrent deformation types and the essential factors influencing this process. Moreover, it explores the profound implications of mandibular flexure on clinical aspects such as bone absorption around dental implants, the precision of prosthesis fabrication, and the selection and design of superstructure materials. Based on the empirical findings, this review provides crucial clinical recommendations. Specifically, it is recommended to exert precise control over the patients mouth opening during impression-taking. Those with a high elastic modulus or bone-tissue-like properties should be prioritized when selecting superstructure materials. Moreover, this review underscores the significance of customizing framework design to accommodate individual variations in facial morphology and occlusal habits. Future research endeavors in this field have the potential to advance clinical diagnosis and treatment approaches, providing opportunities for improvement.
PubMed: 37744259
DOI: 10.3389/fbioe.2023.1238181 -
Clinical Oral Investigations Feb 2022The aim of this study was to evaluate the factors influencing edentulous patients' willingness about mandibular implant-supported complete denture.
OBJECTIVE
The aim of this study was to evaluate the factors influencing edentulous patients' willingness about mandibular implant-supported complete denture.
MATERIALS AND METHODS
A cross-sectional study was carried out with 117 bimaxillary edentulous patients wearing removable complete dentures (CDs). Patients were assessed concerning denture-related items (number of previous mandibular CDs, previous denture wearing period, dentures maker professional, and regular wearing of previous mandibular dentures) and individual-related aspects, such as mandibular edentulousness period, mandibular bone height, and willingness to the use of mandibular implant-supported complete denture. Masticatory performance was evaluated by the median particle diameter. Mandibular bone height and satisfaction were assessed using a validated method. The Chi-square test was used for data analysis and prevalence ratios were adjusted by using multivariate Poisson regression, both with 95% confidence interval.
RESULTS
A total of 78 participants (66.7%) were interested in mandibular implant-supported overdenture (mean age 65.33 ± 9.49). Masticatory performance was not influenced by choosing mandibular implant-supported complete denture. The preference about mandibular implant-supported complete denture was correlated with longer mandibular complete denture experience (p = 0.021) and it was significantly associated with dissatisfaction about retention (p = 0.005).
CONCLUSION
Previous experience with mandibular complete dentures and dissatisfaction about retention influence the willingness about mandibular implant-supported overdenture.
CLINICAL RELEVANCE
Many factors are associated with rehabilitation preferences for edentulous patients and mandibular implant-supported complete denture is one of the available alternatives. Therefore, this study has demonstrated the factors influencing the decision to replace a mandibular conventional complete denture by dental implant treatment based on patient's outcomes. Such finding may be considered as a relevant aspect towards shared decision-making for prosthodontic rehabilitation of edentulous patients.
Topics: Aged; Cross-Sectional Studies; Dental Implants; Dental Prosthesis, Implant-Supported; Denture Retention; Denture, Complete; Denture, Overlay; Humans; Jaw, Edentulous; Mandible; Mastication; Middle Aged; Multivariate Analysis; Patient Satisfaction
PubMed: 34491447
DOI: 10.1007/s00784-021-04158-2 -
The Journal of Prosthetic Dentistry Sep 2022Although mandibular implant-supported overdentures have been highly recommended as a treatment option, a consensus on the type of attachment systems that can be used to... (Review)
Review
STATEMENT OF PROBLEM
Although mandibular implant-supported overdentures have been highly recommended as a treatment option, a consensus on the type of attachment systems that can be used to increase implant and prostheses survivability is lacking.
PURPOSE
The purpose of this systematic review and meta-analysis was to compare different types of attachments for retention by investigating outcome measures such as implant and prosthesis survival rates and biological and prosthesis complications in participants with a mandibular implant-supported overdenture.
MATERIAL AND METHODS
The search was performed in the PubMed, Cochrane, Embase, and Scopus databases by following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria and registered with the International Prospective Register of Systematic Reviews (CRD42021253566). An analysis of association was conducted between different attachment systems and implant and overdenture survival rates in randomized controlled clinical trials.
RESULTS
The initial search indicated 477 studies, of which 25 randomized controlled trials (RCTs) were included for analysis. A total of 2154 implants and 737 overdentures were analyzed in the meta-analysis. The main results indicated the failure rate for dental implants to be 2.0% (95% confidence interval [CI], 1.3 to 3.2) and overdentures 4.2% (95% CI, 1.6 to 10.5), respectively. With regard to different attachment systems, a similar failure rate was identified with bar-type retention (7.7% to 95% CI, 3.0 to 18.1), magnetic retention systems (7.6% to 95% CI, 2.2 to 22.7), and ball-type retention (6.8% to 95% CI, 3.0 to 14.3). No significant difference was found in biological complications for splinted and unsplinted implant overdentures (P=.902). Regarding prosthetic complications, the most favorable groups were LOCATOR attachments followed by telescopic and Conus, bar, and ball attachments. Magnet attachments had higher prosthetic complications (7.4 times) than the other attachments.
CONCLUSIONS
Implants and implant-supported mandibular overdentures showed a high survival rate irrespective of the attachment system used. Splinting implants did not significantly affect the rate of biological complications. Prosthetic complications were most common for magnet and least common for LOCATOR attachments.
PubMed: 36115712
DOI: 10.1016/j.prosdent.2022.08.004 -
The Journal of Craniofacial Surgery Sep 2021Temporomandibular joint (TMJ) reconstruction with alloplastic prosthesis is a commonly performed procedure, which can be used as a treatment for improving pathologic...
Temporomandibular joint (TMJ) reconstruction with alloplastic prosthesis is a commonly performed procedure, which can be used as a treatment for improving pathologic conditions affecting the TMJ. Depending of the severity of the condition, the patient's ability to eat can be impaired, which in turn can affect their quality of life. Several syndromes can affect the patient's facial features, and some of those also affect TMJ's. Use of alloplastic prosthesis in TMJ's affecting syndromes, by means of correcting TMJ conditions and mandibular deformities, is still rather uncommon. Purpose of our study is to review the use TMJ total prosthesis as a treatment modality for correcting TMJ conditions and the reconstruction of mandibular deformities in congenital syndromes affecting the facial features. This study consists of a retrospective cohort of patients treated with TMJ reconstruction with alloplastic prosthesis at the Helsinki University Hospital during the past decade. All subjects with congenital syndrome who underwent TMJ reconstruction were included the study. The cohort consisted of seven patients and ten joints treated. Temporomandibular joints affecting syndromes were Goldenhar syndrome, hemifacial macrosomia, Nager syndrome, and Treacher-Collins syndrome. The majority of the patients have had several previous operative treatments on the facial skeleton during their childhood, which in turn probably affected and compromised the TMJ surgery outcome. Mouth opening was sufficiently achieved as average maximal opening was 34 mm (range 24-42 mm) postoperatively. Temporomandibular joint reconstruction with alloplastic prosthesis can offer new tools and approaches for treatment of facial deformities in syndromes with craniofacial abnormalities. Impaired jaw functions and asymmetry can be addressed with the use of alloplastic prostheses, achieving sufficient mouth opening and restoring the symmetry of the lower facial skeleton.
Topics: Child; Humans; Joint Prosthesis; Quality of Life; Retrospective Studies; Temporomandibular Joint; Temporomandibular Joint Disorders; Treatment Outcome
PubMed: 34081423
DOI: 10.1097/SCS.0000000000007533 -
The Journal of Prosthetic Dentistry Nov 2022Previous studies on single-implant mandibular overdentures have reported favorable results for clinical and patient-reported outcomes. However, information from longer...
STATEMENT OF PROBLEM
Previous studies on single-implant mandibular overdentures have reported favorable results for clinical and patient-reported outcomes. However, information from longer term clinical studies is lacking.
PURPOSE
The purpose of this clinical study was to assess clinical, radiographic, and patient-reported outcomes of edentulous individuals rehabilitated with single-implant mandibular overdentures after a 5-year follow-up.
MATERIAL AND METHODS
A prospective clinical study was performed including completely edentulous individuals who received new conventional complete dentures and then an external hexagon implant in the mandibular midline region, followed by the incorporation of a retention system (O-ring/ball attachment; Neodent). Data collection occurred at baseline and 3, 6, 12, 24, and 60 months after implant loading. Assessed outcomes included implant stability, peri-implant soft tissue condition, peri-implant marginal bone level, satisfaction with the prostheses, and oral health-related quality of life (OHRQoL). Clinical maintenance events were also recorded. Descriptive statistics, incidence rates, Wilcoxon Signed Ranks test, and Generalized Estimating Equation regression were used for data analysis (α=.05).
RESULTS
Thirty of 34 eligible participants attended the 5-year follow-up visit, mean ±standard deviation age was 68.1 ±7.8 years, and 70% were women. The overall implant survival rate was 88.9%. After 5 years, the OHRQoL showed statistically significant improvement for all evaluation periods compared with baseline (P<.001). Regarding satisfaction with the mandibular denture, a significant increase was found between all evaluation periods compared with baseline in terms of comfort, stability, and ability to masticate (P<.001). Implant stability significantly increased (P=.003), and a mean bone loss of 1.46 mm was observed compared with baseline measures. The most frequent maintenance event was replacement of the O-ring matrix (n=80). Twenty-one midline fractures of the overdenture occurred in 14 study participants. No significant changes in peri-implant soft tissue conditions were observed.
CONCLUSIONS
A single-implant mandibular overdenture effectively maintained the positive effect of the intervention on oral health-related quality of life and patient satisfaction, stable peri-implant condition, and acceptable rates of prosthetic events.
Topics: Humans; Female; Middle Aged; Aged; Male; Denture, Overlay; Quality of Life; Prospective Studies; Follow-Up Studies; Dental Prosthesis, Implant-Supported; Dental Implants; Mandible; Patient Reported Outcome Measures; Patient Satisfaction; Denture Retention
PubMed: 33640091
DOI: 10.1016/j.prosdent.2021.01.007