Symphyseal Region Research Articles

Prevalence of Asymptomatic Changes in the Groin Region Among Adult Professional Soccer Players and Their Association With Limb Dominance.

To investigate the prevalence of asymptomatic radiologic groin region findings in adult professional soccer players using magnetic resonance imaging (MRI) and examine the influence of age and limb dominance on their occurrences. Cross-sectional trial. Soccer club medical service, private practice. Forty-seven male professional soccer players. Players underwent a groin presigning MRI scan with a magnetic field induction of 1.5 Tesla. Image analysis of their pubic bones was performed according to The Copenhagen Standardized MRI protocol to assess the pubic symphysis and adductor regions of players. The prevalence of various changes in the symphysis, pubic bone, and adjacent areas. Fifty images of pubic bones and adjacent regions (53.2%) highlighted 1 to 4 changes, while another 44 images (46.8%) demonstrated 5 or more changes. The most frequent changes observed in the pubic bone were joint surface irregularities (100%), symphyseal sclerosis (93.6%), pubic bone swelling (56.3%), parasymphyseal high-intensity line (55.3%), fatty infiltration in bone marrow (38.3%), and adductor tendinopathy (34%). When comparing the prevalence of different changes in the dominant and nondominant limbs, no statistically significant differences were found. In adult professional soccer players with no prior groin pain complaints in recent history (12 months), asymptomatic changes are extremely common in the pubic joint and adjacent areas, including those that are very likely to be considered the main cause of pain when investigated in soccer players with groin pain. None of these changes were associated with limb dominance.

Light and scanning electron microscope characterization of mandibular symphysis tissue as a functional adaptation in the mandible development of human fetuses.

When developing, the mandible presents great plasticity and contains condensed mesenchymal cells that develops into Meckel's cartilage, of which the anterior part forms the mandibular symphysis. Mandible human development studies focus on investigating whether the beginning of mandibular fusion in fetal period is related to symphysis ossification and the tensions imposed on it, considering that tongue movements, mouth opening, and closing can be seen in fetuses. This research analyses tissue modifications during human mandibular symphysis growth using light and scanning electron microscopy to relate them to its functional structure. The study sample consisted of 12 human fetuses distributed into two groups: Group I (GI) of 10-14 weeks old and Group II (GII) of 20-24 weeks old. Fragments of mandibular symphysis were removed en bloc together with the surrounding tissues to preserve the relation with adjacent structures. Decalcified specimens were prepared in semi-serial coronal sections 5-μm-thick and stained with hematoxylin and eosin, Masson՚s trichrome, Verhoeff, and Sirius red for histological analysis with light microscopy. Collagen fibers Type I or III and elastic fibers were quantified by volume fraction (Vv). Coronal sections of the GI and GII symphyseal region were submitted to scanning electron microscopy. Comparison between groups used independent t-test. Our study presents the different endochondral ossification stages in the anterior part of Meckel's cartilage in GI. Both groups showed abundantly vascularized mesenchymal tissue with intense cellular activity forming the mandibular symphysis, such as a source of new osteoblasts adjacent to the newly deposited bone matrix. Scanning electron microscopy analysis revealed an invasion of the bony trabecula in the transverse direction from the hemimandible, rectilinear in GI and sinuous in GII due to interdigitating bone process, promoting its ossification. In collagen Vv analysis was verified a prevalence of type I in GII and type III in GI, indicating a proportional relation between maturation and tissue arrangement. Functionally, the collagen and elastic fibers in the mandibular symphysis were arranged in a pantographic network, and the fibrillar interconnectivity clearly contributes to resilience capacity and efficiency of the force transfer. This study inferred the functional significance of the knowledge about the tissue composition of mandibular symphysis, and the importance of this tissue for surrounding structures. The mesenchymal tissue of mandibular symphysis participates in bone growth process, revealing an adaptation mechanism of mandibular symphysis in the fetal period investigated.

A Case Study of Pan-Facial Trauma with Subsequent Chronic Hyponatremia

Pan-facial trauma represents a complex pattern of injuries requiring meticulous surgical planning and comprehensive post-operative care. We present a case of a 51-year-old male smoker who sustained severe pan-facial trauma. Initial evaluation revealed multiple facial fractures, including the zygomatic maxillary complex, coronoid, condylar, and symphysis regions. Computed tomography demonstrated additional linear undisplaced fractures of the left temporal and parietal bones, with associated hemorrhagic contusion in the right temporal region. The patient exhibited circumorbital edema, ecchymosis, and multiple lacerations over the scalp and face. Laboratory investigations revealed anemia with hemoglobin of 8.7 g/dL. Following initial stabilization, the patient underwent open reduction and internal fixation under general anesthesia. During the post-operative period, the patient developed significant hyponatremia with serum sodium levels dropping to 117 mEq/L, manifesting as altered sensorium and drowsiness. The electrolyte imbalance was managed using a combination therapy of normal saline infusion (500mL at 20mL/hr), 3% hypertonic saline (10mL/hr), and oral tolvaptan (15mg twice daily). This intervention successfully normalized serum sodium levels to 135 mEq/L within three days. This case highlights the importance of vigilant post-operative monitoring in pan-facial trauma patients, particularly for electrolyte disturbances, and demonstrates the effectiveness of prompt, targeted intervention in managing complications. The successful outcome emphasizes the value of a multidisciplinary approach in treating complex maxillofacial injuries

Template for positioning miniplates (PUNPLAPOT-M) on mandibular symphysis: Novel innovation

Purpose: This study was conducted to check the efficacy of PUNPLAPOT-innovative Template for positioning of the bone miniplate for fracture fixation. Material and Methods: Twenty dried mandible specimens were used in this study. The specimens were then divided into two groups using random sampling. Each group consisted of ten mandibles each. The mandibles were fractured in mandibular symphysis region. Study group mandibles were subjected to fixation using 2.5 mm titanium miniplate using PUNPLAPOT plate positioning template. Control group specimens were subjected to fracture fixation without the use of template. All the 20 specimens were then subjected to dial gauge test of parallelism. Plate orientation with respect to lower border of mandible was checked for both the groups. PUNPLAPOT 2.0 is developed to be used in extremely oblique fractures. Results: Significant difference was noted in review parameters -plate parallelism and distance of screws from fracture line within study and control group. Results obtained with this template were statistically significant. Conclusion: PUNPLAPOT definitely provides the maxillofacial surgeons a reliable template to position the miniplate at an optimum position. The template has few limitations like comminuted lower border fractures and severely oblique fractures. Further device development is aimed towards overcoming these.

Management of Multiple Fractures of the Parasymphysis and Angle of the Mandible

Introduction: Mandibular fracture is a fracture that often occurs in maxillofacial trauma. Fracture locations most often occur in the parasymphysis region and combined angle- parasymphysis fractures. Multiple mandibular fractures usually cause facial asymmetry and are challenging to reduce. Fracture treatment must be carried out immediately to restore function and aesthetics. This case report aims to discuss managing multiple mandibular fractures in the angulus and parasymphysis regions of the mandible. Case report: A 13-year-old male patient came to the emergency room at Hasan Sadikin Hospital with bleeding from the mouth caused by a two-wheeled traffic accident. Clinical and radiographic examination results revealed a fracture of the right para symphysis and left mandibular angle. The procedure carried out is Open Reduction Internal Fixation (ORIF). Discussion: Mandibular fractures often occur, and the leading cause is usually caused by driving accidents. Clinical examination and radiographs are needed so appropriate treatment can be carried out. In this case, treatment involves open reduction internal fixation (ORIF) extra and intra-oral approaches. Installation of 2 mini plates each in the symphysis region and angle of the mandible. Conclusion: Treatment for multiple fractures that occurred in the maxillofacial area, in this case, was internal fixation with open reduction (ORIF). The results of the treatment showed facial symmetry and normal chewing function. Keywords: Trauma, mandibular fracture, angulus, para symphysis, ORIF

Arterial vascularization of the mandible and soft tissues. Anatomic study.

The literature has for too long described the arterial supply of the mandible as coming from a single artery, the inferior alveolar artery, and being of the terminal type. Rather, it appears to come from an extensive and complex arterial network dependent on the lingual, facial, and maxillary arteries and their collateral branches. Our study aims to confirm and demonstrate the arterial vascular richness of the mandible and to establish arterial mapping. The arterial vascularization of the mandible was revealed in six anatomic specimens after performing selective injections of the lingual, facial, and maxillary arteries with different dyes. A specimen was injected intra-arterially with colored latex at the level of the maxillary artery for a morphometric study. Eighteen selective arterial injections were performed on six anatomic specimens. The mucocutaneous, musculoperiosteal, and intramedullary vascularizations were analyzed. Each of the arteries has a defined and delimited cutaneo-mucous vascular territory. The facial and maxillary arteries supply the musculoperiosteal vascularization of the mandible from the condyle to the symphysis. The lingual artery supplies only the inner cortex of the parasymphyseal and symphyseal regions. The facial and maxillary arteries provide intramedullary vascularization from the angle of the mandible to the parasymphysis. The vascularization of the symphysis depends on the facial artery. No staining was found in the condyle region. Neoprene latex injection was performed on an anatomic specimen, revealing a permeable anastomosis between the inferior alveolar and facial arteries. The arterial vascularization of the mandible is dependent on the maxillary, facial, and lingual arteries. This is a network vasculature. This study makes it possible to establish an arterial map of the mandible. The presence of an anastomosis between the inferior alveolar artery and the facial artery confirms the existence of dynamic and borrowed vascularization. Knowledge of this arterial system makes it possible to adapt maxillofacial surgical care and to anticipate possible intraoperative complications.

Isotropic and orthotropic mechanical properties of in vivo mandible model: Assessment of computational modelling

This study assesses the various methodologies utilized in the literature for computational mandible modeling and their implications on research findings. Previous studies have explored diverse material properties for the mandible, whether modeled as a single entity, in pairs, or as multiple sub-regions. Within this framework, a finite element model of an intact mandible was created using sliced tomographic images to examine the dispersion of stress fields resulting from different sets of bone material properties sourced from specialized literature. This research introduces the methodology employed in mandible model development, strategies for achieving high precision, and the influence of mechanical properties. Through an evaluation of models proposed by different authors, significant dispersion was observed, leading to disparities ranging from 4.4% to 67.4% in stress field outcomes at the symphysis region. RMSE served as an estimator to assess the similarity between these models. The findings suggest that the Caraveo (2008) and Palka (2020) models exhibit notable convergence in predicting stress fields in the symphysis regions. By incorporating good modeling practices in the intact mandible model, a more reliable representation is ensured, laying the groundwork for future investigations involving nonlinear contact phenomena and topology optimization.

Finite Element Analysis of New Modified Three-dimensional Strut Miniplate versus Conventional Plating in Mandibular Symphysis and Angle Fractures - An In vitro Study.

Mandibular fractures are common injuries during maxillofacial trauma, and currently, open reduction and internal fixation are considered gold-standard treatments. There is a wide discussion about which plates give the best outcomes. Hence, we are conducting a biomechanical comparison of two plates for mandibular symphysis and angle fracture with finite element analysis (FEA). The aim of this study was to do a comparative study of FEA between the conventional and our new modified three-dimensional (3D) strut miniplate in mandibular fractures at symphysis and angle regions. Finite element models of symphyseal and angle fractures of the mandible were developed. Each fracture model was then realigned and fixed by the conventional method 2.0 mm system, and our modified 3D strut plating method 2.0 mm system followed by the analysis of various stresses developed in plates and mandibular fracture area after application of load was observed in the study. The modified 3D strut plating system with 2.0 mm miniplates is significantly better in preventing displacement of fracture segments by better distribution of forces compared to the conventional plating system. Rest of the parameters were within the permitted limits. Modified 3D strut plating method was reasonably effective and superior in managing force-displacement compared to the conventional method of fixation for comminuted and unfavourable mandibular symphyseal fracture and angle fracture.

Three-dimensional assessment of upper airway changes associated with mandibular positional deviations following fibula free flap reconstruction

ObjectivesFibula free flaps (FFF) are the standard approach to mandibular reconstruction after partial resection, with the goal of restoring aesthetics and masticatory function. The graft position affects both and must be carefully selected. Correlations between sagittal positioning and upper airway anatomy are known from orthognathic surgery. This study aims to evaluate changes in mandibular position and upper airway anatomy after reconstructive surgery with FFF and corresponding correlations.Materials and methodsMandibular position after reconstruction was evaluated using three-dimensional datasets of pre- and postoperative computed tomography scans of patients treated between 2020 and 2022. Three-dimensional measurements were performed on both condyles and the symphyseal region. Changes in upper airway volume and minimum cross-sectional area (minCSA) were analysed. Intra-rater reliability was assessed. Correlations between changes in upper airway anatomy and sagittal mandibular position were tested.ResultsThe analysis included 35 patients. Intra-rater reliability was good to excellent. Condylar deviations and rotations were mostly rated as small. Changes in symphyseal position were considerably greater. Median airway volume decreased in the oropharynx and hypopharynx. Posterior deviation of the symphysis was associated with a decreasing minCSA in the hypopharynx and vice versa.ConclusionsThe overall accuracy of mandibular reconstructions with FFF is high, but there is room for optimization. The focus of research should be extended from masticatory to respiratory rehabilitation.Clinical relevanceEffects on respiratory function should be considered prior to graft positioning. The clinical relevance of upper airway changes within the complex rehabilitation of reconstructive surgery patients needs to be further investigated.

An Innovative Technique for Assessment of Bone Change, Bite Force, and Retention of the Single-Implant-Supported Mandibular Overdenture: A Clinical Study

ABSTRACT This study is the first study to incorporate a novel approach to single-implant-retained mandibular overdenture with a bar attachment on a single implant in the symphysis region. The use of a single-implant-retained bar overdenture significantly improved patients’ chewing efficiency, indicating enhanced overdenture retention and stability Materials and Methods: Ten maxillary and mandibular completely edentulous patients were enrolled in the study. A complete denture was fabricated for them. On completion, bite force, retention force, and bone change were recorded. Bite force was recorded with the strain gauge, retention force with the force measurement gauge, and bone changes with radiographs Conclusion: Single-implant-supported bar mandibular overdenture (SISBOD) can be a suitable standard economic option for edentulous mandible and can greatly improve the quality of life of patients.

Comparison of Man Hours Utilized for Mandibluar Overdenture Treatment Retained by Single Implant with Bar Fabricated by CAD-CAM Process and Conventional Casting Processs – An Vivo Study

ABSTRACT Introduction: Both the population’s average life expectancy and the number of patients without teeth are rising. A 2012 epidemiological survey in India found that 30% of the population is edentulous. The rehabilitation process with a set of removable maxillary and mandibular complete dentures is the standard treatment for patients who are edentulous. This study is the first to incorporate and compare a novel approach to a single implant-retained mandibular overdenture with a bar attachment fabricated by CAD-CAM and a casting process on a single implant in the symphysis region. Method: Five maxillary and mandibular completely edentulous patients were enrolled in the study. Results: Significant difference was seen in the conventional laboratory time and CAD-CAM time as P < 0.05 Conclusion: Compared to the conventional casting process, the single implant-supported bar mandibular overdenture (SISBOD) with a novel bar required fewer man hours and was more convenient.

The effect of frontal trauma on the edentulous mandible with four different interforaminal implant-prosthodontic anchoring configurations. A 3D finite element analysis

PurposeThe present three-dimensional (3D) finite element analysis (FEA) was aimed to assess the biomechanical effects and fracture risks of four different interforaminal implant-prosthodontic anchoring configurations exposed to frontal trauma.Material and methodsA symphyseal frontal trauma of 1 MPa was applied to four dental implant models with different configurations (two unsplinted interforaminal implants [2IF-U], two splinted interforaminal implants [2IF-S], four unsplinted interforaminal implants[ 4IF-U], four splinted interforaminal implants [4IF-S]. By using a 3D-FEA analysis the effective cortical bone stress values were evaluated in four defined regions of interest (ROI) (ROI 1: symphyseal area; ROI 2: preforaminal area; ROI 3: mental foraminal area; and ROI 4: condylar neck) followed by a subsequent intermodel comparison.ResultsIn all models the frontal traumatic force application revealed the highest stress values in the condylar neck region. In both models with a four-implant configuration (4IF-U, 4IF-S), the stress values in the median mandibular body (ROI 1) and in the condylar neck region (ROI 4) were significantly reduced (P <0.01) compared with the two-implant models (2IF-U, 2IF-S). However, in ROI 1, the model with four splinted implants (4IF-S) showed significantly (P < 0.01) reduced stress values compared to the unsplinted model (4IF-U). In addition, all models showed increased stress patterns in the area adjacent to the posterior implants, which is represented by increased stress values for both 2IF-U and 2IF-S in the preforaminal area (ROI 3) and for the four implant-based models (4IF-U, 4IF-S) in the mental foraminal area.ConclusionThe configuration of four splinted interforaminal implants showed the most beneficial distribution of stress pattern representing reduced stress distribution and associated reduced fracture risk in anterior symphysis, condylar neck and preforaminal region.

Optimised return to play: high treatment success rate in core muscle injury with surgical release of the anterior tendon of the rectus abdominis muscle and proximal tenotomy of the adductor longus muscle

ObjectivesCore muscle injury is a debilitating condition that causes chronic groin pain in athletes, particularly common in soccer players. The condition is characterised by pain in the inguinal region and can lead to a significant number of absences from high-intensity physical activity. It is caused by repetitive overload without proper counterbalance from the abdominal muscles, hip flexors, and adductors in susceptible athletes. Surgical indications for core muscle injury consider cases where non-surgical treatments have not provided sufficient relief. The aim of this study was to assess the results of surgical intervention for core muscle injury using the technique employed by the Sports Medicine Group of (Institute of Orthopedics and Traumatology of Hospital das Clínicas – Universidade de São Paulo). The procedure involves releasing the anterior portion of the tendon of the rectus abdominis muscle near the pubic symphysis, along with proximal tenotomy of the adductor longus muscle tendon. MethodsThis study utilised a consecutive historical cohort analysis of the medical records of 45 male athletes, of which, 75.6% were professional soccer players, who underwent surgical treatment between January 1, 2002, and December 31, 2021. The participants included active athletes aged between 18 and 40 years, with a mean age of 23.9 years, and were diagnosed with myotendinous core muscle injury. These athletes experienced pain in the pubic symphysis and adductor tendon region and had previously undergone medical treatment and physical therapy for a duration of three to six months without significant improvement. ResultsThe average time for athletes to return to sport after surgery was 135 days, with a majority of participants being soccer and futsal players. The surgical intervention yielded promising results, with a positive correlation between unilateral injuries and the time taken to return to sport. The complication rate was low, at 6.7%. Notably, the rate of symptom resolution was high, at 93.3%. Furthermore, the analysis indicated that the player's position on the field significantly influenced the discharge period, suggesting that the game position plays a role in the recovery process. ConclusionThe combined surgical procedure involving the release of the rectus abdominis tendon and adductor longus muscle tenotomy demonstrates favourable outcomes for athletes with core muscle injury. This study provides strong support for the effectiveness of this surgical approach in managing the condition and offers a potential path to recovery and return to sports activities. Level of evidence4. Study designCross-sectional study.

Development and validation of a digital twin of the human lower jaw under impact loading by using non-linear finite element analyses

Mandibular fractures are one of the most frequently observed injuries within craniofacial region mostly due to tumor-related problems and traumatic events, often related to non-linear effects like impact loading. Therefore, a validated digital twin of the mandible is required to develop the best possible patient-specific treatment. However, there is a need to obtain a fully compatible numerical model that can reflect the patients’ characteristics, be available and accessible quickly, require an acceptable level of modeling efforts and knowledge to provide accurate, robust and fast results at the same time under highly non-linear effects. In this study, a validated simulation methodology is suggested to develop a digital twin of mandible, capable of predicting the non-linear response of the biomechanical system under impact loading, which then can be utilized to design treatment strategies even for multiple fractures of the mandibular system.Using Computed Tomography data containing cranial (skull) images of a patient, a 3-dimensional mandibular model, which consists cortical and cancellous bones, disks and fossa is obtained with high accuracy that is compatible with anatomical boundaries. A Finite Element Model (FEM) of the biomechanical system is then developed for a three-level validation procedure including (A) modal analysis, (B) dynamic loading and (C) impact loading. For the modal analysis stage: Free-free vibration modes and frequencies of the system are validated against cadaver test results. For the dynamic loading stage: Two different regions of the mandible are loaded, and maximum stress levels of the system are validated against finite element analyses (FEA) results, where the first loading condition (i) transfers a 2000 N force acting on the symphysis region and, the second loading condition (ii) transfers a 2000 N force acting on the left body region. In both cases, equivalent muscle forces dependent on time are applied. For the impact loading stage: Thirteen different human mandibular models with various tooth deficiencies are used under the effects of traumatic impact forces that are generated by using an impact hammer with different initial velocities to transfer the impulse and momentum, where contact forces and fracture patterns are validated against cadaver tests. Five different anatomical regions are selected as the impact site.The results of the analyzes (modal, dynamic and impact) performed to validate the digital twin model are compared with the similar FEA and cadaver test results published in the literature and the results are found to be compatible. It has been evaluated that the digital twin model and numerical models are quite realistic and perform well in terms of predicting the biomechanical behavior of the mandible.The three-level validation methodology that is suggested in this research by utilizing non-linear FEA has provided a reliable road map to develop a digital twin of a biomechanical system with enough confidence that it can be utilized for similar structures to offer patient-specific treatments and can help develop custom or tailor-made implants or prosthesis for best compliance with the patient even considering the most catastrophic effects of impact related trauma.

Biomechanical behavior of carbon fiber-reinforced polyetheretherketone as a dental implant material in implant-supported overdenture under mandibular trauma: A finite element analysis study.

Implant-supported overdentures are well-known and widely accepted treatment modality to increase retention which is a crucial factor for determining patient satisfaction. The placement of two implants in the anterior region can be selected as a first-line treatment in patients with the atrophic mandibular ridge. The purpose of this research was to assess the biomechanical effects of carbon fiber-reinforced polyetheretherketone (CFR-PEEK) implant-supported overdenture in the event of 2,000 N forefront trauma to an atrophic edentulous mandible by using the finite element analysis method. Three types of mandible models were simulated; the first one was an edentulous atrophic mandible model; in the second model, 3.5 × 11.5 mm CFR-PEEK implants; and in the third model, 4.3 × 11.5 mm CFR-PEEK implants were positioned in the region of the lateral incisor of the identical edentulous atrophic mandible. Maximum Von Misses stresses 979.261 MPa, 1,454.69 MPa, and 1,940.71 MPa and maximum principal stresses 1,112.74 MPa, 1,249.88 MPa, and 1,251.33 MPa have been detected at the condylar neck area and minimum principal stresses - 1,203.38 MPa, -1,503.21 MPa, and - 1,990.34 MPa have been recorded at the symphysis and corpus regions from M1 to M3, respectively. In addition, the M2 and M3 models showed low-stress distributions around the implant-bone interface, particularly where the implants were in contact with cancellous bone. The results showed that the insertion of different diameters of CFR-PEEK implants led to low and homogenous stress distribution all around the implant-bone interface and stresses transferred directly to the condylar neck areas. Therefore, it was observed that CRF-PEEK implants did not change the basic behavior of the mandibula in response to frontal stresses.

Comparison of linear and angular measurements in mandibular symphyseal region using lateral cephalometric and cone beam CT images

AbstractAimTo compare the linear and angular measurements of the mandibular symphyseal region using lateral cephalometric (LC) and cone beam computed tomography (CBCT) images.Materials and MethodsOne hundred patients justifying both LC and CBCT exposures were included. Both lateral cephalometric and CBCT images of the patients were used for angular and linear measurements. Angular measurements included vestibular concavity and lingual and tooth inclination angles. Vestibular and lingual cortical bone and total bone thickness measurements were obtained for the comparison of linear measurements. Three radiologists performed the measurements on 200 images. Comparison of the measurements and the imaging methods were done using paired‐ and Wilcoxon t‐tests. Inter‐observer reliability was evaluated with the intra‐class correlation coefficient (ICC).ResultsA significant difference was observed between measurements of two imaging methods for tooth inclination and vestibular concavity angles; however, no difference was found between LC and CBCT measurements for lingual inclination angle (p &gt; 0.05). Vestibular cortical bone and total bone thickness measurements showed a significant difference (p &lt; 0.05), whereas no difference was obtained in lingual bone thickness measurements of two imaging methods (p &gt; 0.05).ConclusionCBCT imaging is recommended in selected patients where recipient bone or bone augmentation site(s) reveal suspect in clinical examination and lateral cephalometric imaging may not reveal the true anatomic structure and relationships.

Clinical and Radiographic Evaluation of Marginal Bone Level (BL) in Two Implant-Retained Mandibular Overdenture With Lingualized Occlusion (LO): A Six-Year Clinical Trial.

The objective of this research was to assess the marginal bone loss and stability in a lingualized occlusal scheme with implant-supportedmandibular overdenturesas a viable solution for individuals experiencing difficulties with the retention of conventional mandibular dentures. The study assessed the marginal bone level (BL) using radiographic evaluation and clinically by evaluating periodontal health using probing depth indexvalues over a period of 6 years. Ten completely edentulous male patients with a bone height (BH) of 15-25 mm at the mandibular symphyseal region and dissatisfaction with their mandibular conventional complete denture were included in the study. Patients were willing to accept the conditions of the study and provide informed consent. Bleeding index, plaque index (PI), probing depth, and crestal BL were accessed during the follow-up period. Marginal BLs using Wical and Swoop Analysis method were evaluated at baseline (BL) (during loading), 3 yearsand 6 years post-loading. During the observation period, there was no incidence of implant loss, and all patients expressed contentment with the retention, stability, chewing functionality, and esthetic appeal of their dentures.Marginal BLs through clinical and radiographic evaluation, periodontal health using bleeding on probing (BOP), and probing depth were assessed during the follow-up period. Throughout the entire period of observation, no instances of implant displacement were detected. The study found that the use of a lingualized occlusal scheme with two implant-retained mandibular complete overdenture effectively transmitted horizontal loads, reduced stress on individual implants leading to decreased bone loss, and increased stability.

Evaluation of stresses and displacement in the craniofacial region as a reaction to bone-anchored maxillary protraction in conjugation with posterior bite plane and rapid maxillary expansion in patients with Class III malocclusion: A finite element analysis study

Treating a Class III malocclusion is often challenging for orthodontists. Bone-anchored maxillary protraction (BAMP) is known for achieving a significant maxillary protraction. The study aimed to evaluate the stress distribution and displacement of craniofacial bones as a reaction to the forces of BAMP, along with rapid maxillary expander and the posterior bite plane, in growing patients with skeletal Class III malocclusion using a finite element method. An finite element model was constructed from the spiral computed tomographic images of a skull from an 11-year-old growing patient with skeletal Class III malocclusion along with BAMP, rapid maxillary expander, and the posterior bite plane. The created model had 105,189 nodes and 481,066 elements. After assigning the appropriate material properties and the boundary condition, 800 g of transverse force per side and a Class III intraoral elastic 250 g of force per side were applied to the model, and after the postprocessing, the results were obtained in the form of color bands. The maxilla and the attached structures were displaced and expanded transversely. The maxilla was displaced anteriorly by 0.692 mm, and the mandible was displaced backward by 0.204 mm in the sagittal direction. The anterior region of the maxilla and mandible, dentition, and nasal bone were rotated counterclockwise. Displacement in an upward direction was greatest at the symphysis region of the mandible. The stresses experienced by most of the bones were tensile, with the maxilla and maxillary dentition experiencing the maximum. Favorable changes were appreciated with maxillary forward and mandibular backward displacement, with appreciable tensile stresses in all the bones.

An automated landmark method to describe geometric changes in the human mandible during growth

ObjectiveThe principal aim of this study was to assess an automatic landmarking approach to human mandibles based on the atlas method. The secondary aim was to identify the areas of greatest variation in the mandibles of middle-aged to older adults. DesignOur sample consisted of 160 mandibles from computed tomography scans of 80 men and 80 women aged between 40 and 79 years. Eleven anatomical landmarks were placed manually on mandibles. The automated landmarking through point cloud alignment and correspondence (ALPACA) method implemented in 3D Slicer was used to automatically place landmarks to all meshes. Euclidean distances, normalized centroid size, and Procrustes ANOVA were calculated for both methods. A pseudo-landmarks approach was followed using ALPACA to identify areas of changes among our sample. ResultsThe ALPACA method showed significant differences in Euclidean distances for all landmarks compared to the manual method. A mean Euclidean distance of 1.7 mm was found for the ALPACA method and 0.99 mm for the manual method. Both methods found that sex, age, and size had a significant effect on mandibular shape. The greatest variations were observed in the condyle, ramus, and symphysis regions. ConclusionThe results obtained using the ALPACA method are acceptable and promising. This approach can automatically place landmarks with an average accuracy of less than 2 mm, which may be sufficient in most anthropometric analyses. In the light of our results, however, odontological application such as occlusal analysis is not recommended.

Evaluation of the pattern of fracture formation from trauma to the human mandible with finite element analysis. Part 1: Symphysis region.

The mandible is the largest, strongest bone in the maxillofacial region. When a fracture occurs in the mandible, its location depends on several factors: the direction of the trauma, the angle of the trauma, masticatory muscles and the quality of the bone. The aim of this study was to evaluate the stresses caused by trauma to the symphysis region from different angles. Computer-based mandible models were created, and a 2000 N force was applied to the symphysis at three different angles using finite element analysis. Six trauma situations were simulated with the mouth open or closed. Forces were applied to the symphysis at 90° (Model 1) in the anteroposterior direction, 45° (Model 2) in the anteroposterior-inferosuperior direction and 90° (Model 3) in the inferosuperior direction, when the mouth was open or closed. The resulting stress intensity was assessed using finite element analysis. As a result of trauma applied to the symphysis region, maximum stresses were found where the impact originated and at the condyle region (Model 2, open mouth: condyle 1 [1172 MPa]). The open mouth position caused higher stress values than the closed mouth position (Model 2, open mouth: condyle 1 [1172 MPa]; closed mouth: symphysis 4 [82 MPa]). The Model 2, open-mouth state (Model 2, open mouth: condyle 1 [1172 MPa]) sustained higher stresses than all the other models. The stress values in the mandible were affected by the force applied to the symphysis region, the angle of impact arrival and the open or closed state of the mouth. Keeping the mouth closed at the time of trauma reduced the stress value. A closed mouth during trauma directed at the symphysis reduced the possibility of mandible fractures.