-
Journal of Clinical Medicine Jun 2023The aim of this study was to assess intra-arch mandibular dimensional changes that may occur during mouth opening using cone beam-computed tomography (CBCT). Fifteen...
The aim of this study was to assess intra-arch mandibular dimensional changes that may occur during mouth opening using cone beam-computed tomography (CBCT). Fifteen patients in need of any type of treatment whose execution considered a pre- and post-CBCT assessment consented and were enrolled. CBCTs were taken with the following settings: 90 kV, 8 mA, field of view (FOV) 140 by 100 mm (height and diameter), Voxel size 0.25 mm (high resolution). The pre-CBCT was executed in the maximum mandibular opening (MO), while the post-CBCT was in the maximum intercuspation (MI). A thermoplastic stent with radiopaque fiducial markers (steel ball bearings) was fabricated for each patient. Measurements were made using radiographic markers between contralateral canines and contralateral first molars and between ipsilateral canines and first molars on both sides. Paired -tests were performed to evaluate the difference between open and closed positions on these four measurements. In the MO position were registered a significative tightening of the mandible at the canine (-0.49 mm, SD 0.54 mm; < 0.001) and molar points (-0.81 mm, SD 0.63 mm; < 0.001) and a significative shortening of the mandible on the right (-0.84 mm, SD 0.80 mm; < 0.001) and left sides (-0.87 mm, SD 0.49 mm; < 0.001). Within the study limitations, mandibular flexure determined a significant shortening and tightening between maximum intercuspation to maximum opening positions. Mandibular dimensional changes should be considered in light of other patient factors in the treatment planning of implant positioning and long-span complete arch implant-supported fixed prostheses in order to avoid technical complications.
PubMed: 37373841
DOI: 10.3390/jcm12124149 -
Clinical Oral Implants Research Aug 2023To report the 1-year implant survival/success and peri-implant outcomes of mandibular overdentures retained by four titanium-zirconium mini implants (Straumann® Mini... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVE
To report the 1-year implant survival/success and peri-implant outcomes of mandibular overdentures retained by four titanium-zirconium mini implants (Straumann® Mini Implant System), and to assess how surgery and loading protocols influence these outcomes.
MATERIALS AND METHODS
A 2 × 2 factorial randomized clinical trial (RCT) tested the combined effects of two loading protocols (immediate or delayed) and two surgical approaches (flapless or flapped) on the success/survival of the mini implants, and peri-implant parameters (plaque, bleeding, sulcus depth, gingival position, and marginal bone loss). Outcomes were assessed up to 1-year after loading, and generalized estimating equations (GEEs) were used to analyze longitudinal and within-patient clustered data.
RESULTS
Two hundred and ninety-six implants were placed in 74 patients. The implant survival/success rates after 1 year were 100%, and no major biological complications were observed. After 1-year, descriptive data suggest no noticeable changes in plaque scores, whilst a reduction in bleeding scores at the 6-month and 1-year follow-ups compared to baseline. Good longitudinal stability was observed for the probing depth and gingival margin height measures. Overall mean marginal bone loss was 0.68 (±0.68) mm after 3 months and 0.89 (±0.75) mm after 1-year. The flapless protocol showed better results on soft tissue stability and health but a slightly higher risk for marginal bone loss.
CONCLUSION
The results of this RCT suggest that mandibular overdentures retained by this novel mini implant system represent a safe and predictable treatment option as confirmed by implant survival/success and peri-implant outcomes, even when flapless surgery and immediate loading protocols are adopted.
Topics: Humans; Dental Implants; Titanium; Zirconium; Denture, Overlay; Dental Implantation, Endosseous; Immediate Dental Implant Loading; Mandible; Dental Prosthesis, Implant-Supported; Treatment Outcome; Follow-Up Studies; Alveolar Bone Loss
PubMed: 37254798
DOI: 10.1111/clr.14102 -
Indian Journal of Dental Research :... 2016There are very few studies concerning the role of denture status in temporomandibular disorders (TMDs) and those show conflicting results.
CONTEXT
There are very few studies concerning the role of denture status in temporomandibular disorders (TMDs) and those show conflicting results.
AIM
To evaluate the association of edentulousness and removable prosthesis rehabilitation with severity of TMD signs and symptoms.
SETTINGS AND DESIGN
Data were collected from 2000 subjects reporting for dental treatment, above 30 years of age.
SUBJECTS AND METHODS
The subjects were interviewed with a questionnaire and clinically examined for TMD on basis of Helkimo's index. The number of existing teeth, wearing of removable dentures, need for denture repair, and age of dentures was recorded.
STATISTICAL ANALYSIS
The association between the TMD findings and recorded variable outcomes was analyzed by means of Chi-square test.
RESULTS
Completely edentulous individuals associated more with TMD related findings in incidence and intensity than partially/fully dentate subjects. Complete denture wearers were more associated with TMD symptoms, limited mandibular mobility, muscle tenderness, and pain on mandibular movement. Partial denture wearers were more associated with severely impaired temporomandibular joint function and joint pain. Signs and symptoms of TMD were more prevalent and severe in patients who needed to get their dentures repaired, those wearing dentures more than 5-year-old, and in patients who had not got their dentures repaired during the past 5 years.
CONCLUSIONS
Edentulousness, complete/partial denture wearing and poor condition of the dentures associate with greater incidence and intensity of TMD associated signs and symptoms.
Topics: Aged; Dentures; Female; Humans; Incidence; India; Male; Middle Aged; Mouth, Edentulous; Severity of Illness Index; Surveys and Questionnaires; Temporomandibular Joint Disorders
PubMed: 27237201
DOI: 10.4103/0970-9290.183129 -
Frontiers in Bioengineering and... 2023This study presents an innovative articular fossa prosthesis generated by the envelope surface of condyle movement, and compares its mandible movements, muscle...
This study presents an innovative articular fossa prosthesis generated by the envelope surface of condyle movement, and compares its mandible movements, muscle activities, and joint reaction forces with two temporomandibular joint (TMJ) prostheses using multibody musculoskeletal simulation. A healthy 23-year-old female was recruited for this study. Cone-beam computed tomographic (CBCT) was performed to reconstruct the mandibular bone geometry. A customized TMJ fossa prosthesis was designed based on the subject-specific envelope surface of condyle movement (ESCM). Mandibular kinematics and jaw-closing muscle electromyography (EMG) were simultaneously recorded during maximum jaw opening-closing movements. To validate our prosthesis design, a mandibular musculoskeletal model was established using flexible multibody dynamics and the obtained kinematics and EMG data. The Biomet fossa prosthesis and the ellipsoidal fossa prosthesis designed by imitating the lower limb prostheses were used for comparison. Simulations were performed to analyze the effects of different fossa prostheses on jaw opening-closing motions, mandibular muscle activation, and contact forces. The maximum opening displacement for the envelope-based fossa prosthesis was greater than those for Biomet and ellipsoidal prostheses (36 mm, 35 mm, and 33 mm, respectively). The mandibular musculoskeletal model with ellipsoidal prosthesis led to dislocation near maximal jaw opening. Compared to Biomet, the envelope-based fossa reduced the digastric and lateral pterygoid activation at maximal jaw opening. It also reduced the maximal resistance to condylar sliding on the intact side by 63.2 N. A customized TMJ fossa prosthesis was successfully developed using the ESCM concept. Our study of musculoskeletal multibody modeling has highlighted its advantages and potential. The artificial fossa design successfully achieved a wider condylar range of motion. It also reduced the activation of jaw opening muscles on the affected side and resistance on the intact side. This study showed that an ESCM-based approach may be useful for optimizing TMJ fossa prostheses design.
PubMed: 38026896
DOI: 10.3389/fbioe.2023.1273263 -
Journal of Prosthodontic Research Oct 2021Purpose This study aimed to determine the influence of mandibular free-end partial edentulism and use of conventional or implant-supported removable dental prostheses in...
Purpose This study aimed to determine the influence of mandibular free-end partial edentulism and use of conventional or implant-supported removable dental prostheses in the partially edentulous area on the load exerted on the maxillary anterior teeth.Methods A jaw model with mandibular free-end missing teeth was used, and a distal extension, removable partial dental prosthesis was fabricated to replace the missing posterior teeth. Four experimental conditions were set up: 1) without prosthesis, 2) with a conventional removable partial dental prosthesis, 3) with an implant-supported removable partial dental prosthesis, and 4) with a complete dental arch. Strain gauges were attached to the root surface of the maxillary left central incisor, canine, first premolar, and first molar. The load exerted on them was calculated based on the calibration coefficient. An occlusal load of 49 N was applied, and the forces were compared using a Kruskal-Wallis test (P < 0.05). Results The load exerted on the maxillary anterior teeth increased significantly with no prosthesis, decreased significantly with a conventional removable partial dental prosthesis, and decreased even more significantly with an implant-supported removable partial dental prosthesis. Conclusions The burden on the maxillary anterior teeth decreased with the use of a removable partial dental prosthesis and decreased even further with the use of an implant-supported dental prosthesis. The use of an implant to support a distal extension removable partial dental prosthesis is potentially effective in preserving the remaining teeth and tissues by reducing excessive stress in patients with mandibular free-end partial edentulism.
Topics: Dental Implants; Dental Prosthesis, Implant-Supported; Denture, Partial, Removable; Humans; Mandible
PubMed: 33896889
DOI: 10.2186/jpr.JPR_D_20_00077 -
International Journal of Surgery Case... Jun 2022Mandibular prognathism manifests as elongation of the mandible in the anteroposterior direction, resulting in a sunken appearance of the middle third of the face and sad...
Orthognathic correction and corticobasal implant-supported prostheses as a treatment modality for partial edentulism with mandibular prognathism: A case report and review of literature.
INTRODUCTION
Mandibular prognathism manifests as elongation of the mandible in the anteroposterior direction, resulting in a sunken appearance of the middle third of the face and sad look of the eyes. It adversely affects esthetics, function, and oral health, reducing the patients' self-esteem. It therefore presents a significant challenge.
PRESENTATION OF CASE
A 23-year-old woman presented with prognathic features characterized by mandibular protrusion, maxillary retrusion, a prominent chin, and reduce self-esteem. Intraoral examination revealed multiple extracted teeth, severe fracture of the crown at 23, mobility of the fixed prosthesis on 13, 14, 15, and 16, a root stump of 18, and periodontally compromised teeth (31, 32, 33, 41, and 42). A multidisciplinary team formulated the following treatment plan: stage 1, orthognathic osteotomy to retrude the mandible at 34 and 44; stage II, fabrication of transitional acrylic partial dentures; and stage III: fabrication of definitive corticobasal implant-supported prostheses. The patient was delighted with the treatment and complied with the oral hygiene instructions and follow-up program. After 7 years of function, the patient presented without complaints and exhibited significant improvement in oral health, self-esteem, and quality of life.
DISCUSSION
The management of mandibular prognathism requires a multidisciplinary approach. The treatment implemented was considered the optimal option that aligned with the recommendations of several researchers to reduce facial disfigurement and rehabilitate the edentulous state.
CONCLUSION
The use of corticobasal implant-supported prostheses for the rehabilitation of patients with partial edentulism can significantly improve the treatment outcome following orthognathic surgery in cases with mandibular prognathism.
PubMed: 35623120
DOI: 10.1016/j.ijscr.2022.107219 -
Plastic and Reconstructive Surgery.... Jun 2021The deep circumflex iliac artery (DCIA) flap is one of the most commonly used vascularized free flaps for jaw reconstruction; however, its clinical application is...
The deep circumflex iliac artery (DCIA) flap is one of the most commonly used vascularized free flaps for jaw reconstruction; however, its clinical application is limited by donor site complications. We aimed to describe a new technique of using 3-dimensionally (3D) printed patient-specific devices for mandibular reconstruction with DCIA flap and simultaneous dental implants, and for donor site restoration after harvesting the DCIA flap. One patient with mandible ameloblastoma underwent mandibular reconstruction using a DCIA flap with the "jaw-in-a-day" approach. The 3D-printed patient-specific devices included mandibular cutting guides, DCIA harvesting and dental implant guide, surgical plate, and iliac prosthesis. The postoperative 1-month accuracy measurement showed the mean distance deviations of the mandible, transferred bone grafts, dental implants and iliac prosthesis were 1.8 mm, 2.1 mm, 0.9 mm, and 1.2 mm, respectively. Three-dimensionally printed iliac prosthesis satisfactorily restored the contour of the iliac crest after DCIA flap harvesting. No complication of donor site was recorded during the follow-up of 12 months. We successfully used 3D-printed patient-specific implants in both donor and recipient sites for DCIA flap jaw reconstruction. Further studies with a larger sample size and long-term follow-up are needed.
PubMed: 34123686
DOI: 10.1097/GOX.0000000000003618 -
Quantitative Imaging in Medicine and... Jul 2023To analyze and compare the trajectory of condylar motion during mouth opening in normal volunteers and patients after total joint replacement (TJR) of the...
BACKGROUND
To analyze and compare the trajectory of condylar motion during mouth opening in normal volunteers and patients after total joint replacement (TJR) of the temporomandibular joint (TMJ).
METHODS
Condylar movement during mouth opening was recorded by dynamic magnetic resonance imaging (MRI) for volunteers with normal TMJs and dynamic computed tomography (CT) for patients after TMJ TJR. Trajectories of the points selected every 5 mm from the superior point of the condyle (P) along its axis to the mandibular angle (P) were recorded. The arc length and curvature radius of average trajectories for each point were calculated and compared between the normal joints and TJRs, especially P which is the corresponding point of the prosthesis apex without lateral pterygoid muscle (LPM) attachment at the normal joint with LPM attachment. The location of the point with the most similar trajectory was identified in the normal joints and compared with the condylar prosthesis.
RESULTS
A total of 9 volunteers with 18 normal TMJs, and 5 patients with 6 prostheses were included in this study. For normal TMJs, the average condylar trajectories during mouth opening were a concave upward curve. Meanwhile, the trajectories of contralateral normal joints in patients with unilateral TJR and all condylar prostheses were significantly decreased. The arc length and curvature radius of average trajectories gradually decreased from P. In the normal joints, P had the most similar trajectories with the average arc lengths and a curvature radius of 13.0/4.2 mm. In P, the average arc lengths and curvature radius of the normal cases, natural TMJ of the unilateral replacement patients, prosthetic TMJ of the unilateral replacement patients, and prosthetic TMJ of the bilateral replacement patient, were 15.6/6.6 mm, 13.1/4.9 mm, 4.7/4.4 mm, and 6.4/5.8 mm, respectively.
CONCLUSIONS
P in the normal joint exhibited the most similar trajectory among individuals. The trajectory difference between the prosthesis apex without LPM attachment and the corresponding point at the normal joint with LPM attachment provides a reference for fossa prosthesis functional surface design.
PubMed: 37456288
DOI: 10.21037/qims-22-1239 -
Cells, Tissues, Organs 2011This study was undertaken to determine whether periosteum from different bone sources in a donor results in the same formation of bone and cartilage. In this case,...
This study was undertaken to determine whether periosteum from different bone sources in a donor results in the same formation of bone and cartilage. In this case, periosteum obtained from the cranium and mandible (examples of tissue supporting intramembranous ossification) and the radius and ilium (examples of tissues supporting endochondral ossification) of individual calves was used to produce tissue-engineered constructs that were implanted in nude mice and then retrieved after 10 and 20 weeks. Specimens were compared in terms of their osteogenic and chondrogenic potential by radiography, histology, and gene expression levels. By 10 weeks of implantation and more so by 20 weeks, constructs with cranial periosteum had developed to the greatest extent, followed in order by ilium, radius, and mandible periosteum. All constructs, particularly with cranial tissue although minimally with mandibular periosteum, had mineralized by 10 weeks on radiography and stained for proteoglycans with safranin-O red (cranial tissue most intensely and mandibular tissue least intensely). Gene expression of type I collagen, type II collagen, runx2, and bone sialoprotein (BSP) was detectable on QRT-PCR for all specimens at 10 and 20 weeks. By 20 weeks, the relative gene levels were: type I collagen, ilium >> radial ≥ cranial ≥ mandibular; type II collagen, radial > ilium > cranial ≥ mandibular; runx2, cranial >>> radial > mandibular ≥ ilium; and BSP, ilium ≥ radial > cranial > mandibular. These data demonstrate that the osteogenic and chondrogenic capacity of the various constructs is not identical and depends on the periosteal source regardless of intramembranous or endochondral ossification. Based on these results, cranial and mandibular periosteal tissues appear to enhance bone formation most and least prominently, respectively. The appropriate periosteal choice for bone and cartilage tissue engineering and regeneration should be a function of its immediate application as well as other factors besides growth rate.
Topics: Animals; Bone Regeneration; Cartilage; Cattle; Collagen Type I; Collagen Type II; Core Binding Factor Alpha 1 Subunit; Gene Expression Regulation; Integrin-Binding Sialoprotein; Mice; Mice, Nude; Periosteum; Prosthesis Implantation; Radiography; Tissue Engineering; Tissue Scaffolds
PubMed: 21597269
DOI: 10.1159/000324642 -
National Journal of Maxillofacial... 2021Guide flange is given to patients who have undergone surgical hemi/segmental/subtotal mandibulectomy due to various reasons (leading cause being squamous cell...
Guide flange is given to patients who have undergone surgical hemi/segmental/subtotal mandibulectomy due to various reasons (leading cause being squamous cell carcinoma), with resultant mandibular deviation. If procedures such as secondary osseous grafting are planned, the clinician has to wait for healing of the graft, lesion, or radiotherapeutic effects to abate. Only after the healing of the graft, a definitive prosthesis can be planned. During this time lag, prosthesis must be given to the patient to correct mandibular deviation on account of unilateral muscle pull. Furthermore, in certain cases, a definitive prosthesis has to be put on hold due to failure of bone grafting or when the patient is not willing for a second surgery. This report describes the fabrication of such a mandibular guide flange prosthesis.
PubMed: 34483593
DOI: 10.4103/njms.NJMS_36_19