Search Results (82)

Background/Objectives: Temporomandibular disorders (TMDs) are a group of musculoskeletal and neuromuscular conditions involving the temporomandibular joint (TMJ), masticatory muscles, and related anatomical structures. Although magnetic resonance imaging (MRI) is considered a noninvasive and highly informative imaging modality for assessing TMJ soft tissues, few studies have examined how TMJ structural features observed on MRI findings relate to oral function and craniofacial morphology in female patients with malocclusion. To investigate the associations among TMJ structural features, oral function, and craniofacial morphology in female patients with malocclusion, using MRI findings interpreted in conjunction with a preliminary assessment based on selected components of the DC/TMDs Axis I protocol. Methods: A total of 120 female patients (mean age: 27.3 ± 10.9 years) underwent clinical examination based on DC/TMDs Axis I and MRI-based structural characterization of the TMJ. Based on the structural features identified by MRI, patients were classified into four groups for comparison: osteoarthritis (OA), bilateral disk displacement (BDD), unilateral disk displacement (UDD), and a group with Osseous Change/Disk Displacement negative (OC/DD (−)). Occlusal contact area, occlusal force, masticatory efficiency, tongue pressure, and lip pressure were measured. Lateral cephalometric analysis assessed skeletal and dental patterns. Results: OA group exhibited significantly reduced occlusal contact area (p < 0.0083, η² = 0.12) and occlusal force (p < 0.0083, η² = 0.14) compared to the OC/DD (−) group. Cephalometric analysis revealed that both OA and BDD groups had significantly larger ANB angles (OA: 5.7°, BDD: 5.2°, OC/DD (−): 3.7°; p < 0.0083, η² = 0.21) and FMA angles (OA: 32.4°, BDD: 31.8°, OC/DD (−): 29.0°; p < 0.0083, η² = 0.17) compared to the OC/DD (−) group. No significant differences were observed in masticatory efficiency, tongue pressure, or lip pressure. Conclusions: TMJ structural abnormalities detected via MRI, especially osteoarthritis, are associated with diminished oral function and skeletal Class II and high-angle features in female patients with malocclusion. Although orthodontic treatment is not intended to manage TMDs, MRI-based structural characterization—when clinically appropriate—may aid in treatment planning by identifying underlying joint conditions. Full article

Background/Objectives: This systematic review analyzed the epidemiologic and macro/microscopic features of manifestations of hypersensitivity reactions with oral and extra-oral involvement in orthodontic patients with fixed (FAs) or removable (RAs) appliances or clear aligners (CAs), and evaluated them based on patient and treatment characteristics to provide clinical recommendations. Methods: The study protocol followed the PRISMA guidelines and was registered on PROSPERO (CRD42024517942). Results: Thirty-one studies were qualitatively assessed and synthetized, involving 858 subjects (114 males and 714 females, 9–49 years old), of whom there were 86 with a history of allergy, and 743 wearing recorded appliances (FAs = 656, FAs and RAs = 81, intra- and extra-oral RAs = 3, CAs = 3), with a mean treatment duration of 21.5 months (6 weeks–40 months). Among 75 reports, 29 (38.67%), describing burning, gingival hyperplasia, erythema, and vesicles, had oral involvement, while 46 (61.33%) had skin, eye, and systemic involvement, with erythema, papules, conjunctival hyperemia, and vertigo. Positive allergy tests concomitant with the manifestations identified nickel 451 times, cobalt 6 times, titanium 5 times, and chromium 4 times. Management included antihistamines or corticosteroids and removing the offending materials, with treatment discontinuation/appliance substitution. Conclusions: Pre-treatment evaluations, including patient histories and allergy testing, are essential to identify potential allergens and select hypoallergenic materials like titanium or ceramic brackets; regular monitoring and early intervention during treatment are crucial to prevent severe outcomes. Full article

Background/Objectives: This study evaluates the diagnostic and referral skills of final-year dental students at Al-Iraqia University using a questionnaire based on malocclusion cases ranging from mild to severe. Methods: The questionnaire, featuring photos and radiographs of five selected treated cases from two textbooks, was answered by 165 students who were asked to assess each case and determine whether orthodontic or surgical treatment was necessary, as well as to identify factors contributing to an unesthetic profile, such as irregular teeth. Frequency distribution and the Chi-square test were used for statistical analysis. Results: The results indicated good overall clinical competence. The unesthetic profile and irregular teeth were the main reasons for referring both Class II and III cases for surgery, with mandibular retrusion being the most common factor in aesthetic concerns. Maxillary protrusion was less frequently selected as a key factor in Class II malocclusion cases. Conclusions: The findings suggest that students demonstrated a high level of diagnostic accuracy in identifying treatment needs for various malocclusion cases. Full article

Objectives: This study investigated the use of artificial intelligence (AI) in the design of lingual bracket indirect bonding trays and its association with bracket transfer accuracy using three-dimensional (3D) printing. Methods: Digital impressions of patient’s dental arches were captured using an intraoral scanner, and orthodontic setups were virtually constructed. Brackets were virtually positioned in their ideal locations using the digital setups guided by virtual archwire templates. Indirect bonding trays were automatically generated using the AI-powered Auto Creation function of the Medit Splints application, which analyzes anatomical features to streamline design. Bracket transfer accuracy was evaluated in vivo by comparing planned and actual bracket positions across grouped and individual tray configurations. Linear and angular deviations were measured using conventional 3D inspection software. Results: Most bracket transfer errors were within clinically acceptable thresholds, although torque accuracy remained suboptimal. Grouped trays generally exhibited greater precision than individual trays in several dimensions. Conclusions: These findings support the application of AI-assisted design tools to enhance digital workflows and improve consistency in appliance fabrication. Full article

Tooth agenesis is among the most prevalent congenital anomalies affecting human dentition, characterized by the developmental absence of one or more teeth. This condition may be present in either syndromic or non-syndromic forms, with significant implications for oral function, aesthetics, and craniofacial development. This narrative review aims to provide a comprehensive overview of tooth agenesis, defining its classification, genetic underpinnings, epidemiological aspects, phenotypic features, and therapeutic approaches. Recent advances in genetic research have identified numerous causative genes, notably EDA, MSX1, WNT10A, and PAX9, each associated with specific patterns of missing teeth and involved in isolated and/or syndromic forms. Additionally, genes such as TSPEAR, LRP6, PITX2, and GREM2 contribute to varying degrees of severity and tooth distribution, often blurring the lines between syndromic and isolated cases. The genotype-phenotype correlations underscore the complexity of the underlying molecular pathways involved in odontogenesis. From a therapeutic perspective, the management of tooth agenesis requires a multidisciplinary approach, often involving orthodontic, prosthetic, and surgical interventions tailored to the severity of tooth loss and patient age. Early diagnosis represents a crucial role in treatment planning, facilitating timely intervention during growth and enhancing long-term outcomes. In conclusion, tooth agenesis remains a complex clinical condition with a strong genetic basis. A patient-centered and interdisciplinary strategy is essential to address both functional and psychosocial needs. Full article

Objective: Intraoral scanners (IOS) provide high-precision 3D data of teeth and gingiva, critical for personalized orthodontic diagnosis and treatment planning. However, traditional segmentation methods exhibit reduced performance with complex dental structures, such as crowded, missing, or irregular teeth, constraining their clinical applicability. This study aims to develop an advanced 3D point cloud segmentation model to enhance the automated processing of IOS data in intricate orthodontic scenarios. Methods: A 3D point cloud segmentation model was developed, incorporating relative coordinate encoding, Transformer-based self-attention, and attention pooling mechanisms. This design optimizes the extraction of local geometric features and long-range dependencies while maintaining a balance between segmentation accuracy and computational efficiency. Training and evaluation were conducted using internal and external orthodontic datasets. Results: The model achieved a mean Intersection over Union (IoU) of 92.14% on the internal dataset and 91.73% on the external dataset, with Dice coefficients consistently surpassing those of established models, including PointNet++, TSGCN, and PointTransformer, demonstrating superior segmentation accuracy and robust generalization. Conclusions: The model significantly enhances tooth segmentation accuracy in complex orthodontic scenarios, such as crowded or irregular dentitions, enabling orthodontists to formulate treatment plans and simulate outcomes with greater precision—for example, optimizing clear aligner design or improving tooth arrangement efficiency. Its computational efficiency supports clinical applicability without excessive resource consumption. However, due to the limited sample size and potential influences from advancements in IOS technology, the model’s generalizability requires further clinical testing and optimization in real-world orthodontic settings. Full article

Mechanical force regulates tissue remodeling during orthodontic tooth movement (OTM) by inducing macrophage-mediated sterile inflammatory responses. Pyroptosis, as an inflammatory form of programmed cell death, triggers a robust inflammatory cascade by activating the inflammasome. Although recent reports have demonstrated that pyroptosis can be activated by mechanical force, it remains unclear whether and how orthodontic force induces macrophage pyroptosis and sterile inflammation. In this study, by establishing a rat OTM model and a force-loaded macrophage model, we found that force induces Caspase1-dependent pyroptosis in macrophages and activates sterile inflammation both in vivo and in vitro. Mechanistically, we uncovered that mechanical force disrupts macrophage energy metabolism, characterized by an imbalance between lactate dehydrogenase A (LDHA) and pyruvate dehydrogenase (PDH), as well as mitochondrial dysfunction. Notably, inhibiting pyruvate dehydrogenase kinase 1 (PDK1) effectively restored this metabolic balance, thereby alleviating pyroptosis and sterile inflammation in force-stimulated macrophages. Overall, this study elucidates that force induces macrophage pyroptosis and sterile inflammation, and further identifies imbalances in the LDHA/PDH ratio and mitochondrial dysfunction as pivotal mechanistic features. These insights offer novel perspectives and potential therapeutic targets for the precise and effective modulation of OTM. Full article

Background: Condylar hyperplasia (CH) leads to mandibular overgrowth with anatomical, aesthetic, and functional consequences, particularly affecting facial harmony. It is characterized by severe mandibular prognathism (MP) in bilateral cases. This study aims to propose a therapeutic algorithm for diagnosing and treating bilateral condylar hyperplasia (BCH) based on demographic, clinical, craniofacial growth, and clivus ratio uptake conditions. Methods: Ten patients with severe skeletal Class III by MP, whose alteration was clinically associated with BCH, were consecutively evaluated in a specialized dentofacial deformity center between the period of 2019 and 2024. A detailed protocol was followed to gather clinical history, assess anatomical features, evaluate malocclusion, and identify potential BCH. When suspicion arose, a nuclear medicine test measured condylar scintigraphy uptake. If the result was positive, patients underwent bilateral condylectomy, following one of three treatment protocols. Results: Severe PM, pronounced Class III with excessive negative overjet, elongated condyles of normal anatomy, absence of family history, and accelerated growth since preadolescence and adolescence were common characteristics in these patients. Regarding the treatment protocol chosen according to the characteristics of the patients, five cases followed treatment protocol A: condylectomy and surgical correction of the alteration in two surgical stages. Two cases followed protocol B: bilateral condylectomy and orthognathic surgery in the same surgical time, and three cases followed protocol C: condylectomy and later post-surgical orthopedics and/or orthodontics without a second surgical intervention. Histopathological results confirmed bilateral hyperplastic growth and stability in mandibular size, and occlusion was observed during follow-up. Conclusions: Specialists need to recognize the clinical signs of BCH and use scintigraphy tests to measure condylar metabolic activity when suspected. Early detection of BCH is crucial, as it influences treatment decisions and helps prevent relapses in orthodontic or surgical interventions aimed solely at correcting or compensating for Class III malocclusion caused by MP. Full article

Background/Objectives: Surgical guides have been used in a variety of dental procedures, such as implant placement to improve clinical accuracy and reduce post-operative complications. This report presents a novel and versatile workflow for the design and fabrication of a “multi-purpose” fully-guided tooth- and bone-supported one-piece surgical guide. Methods: Briefly, intraoral and perioral anatomical features were captured by an intraoral scan and a cone-beam computed tomography scan. The data were segmented and aligned with analysis software to enable the digital design of surgical guides. The versatility of this method was demonstrated through its application in the two cases presented: the first involved a lateral sinus lift with simultaneous implant placement, and the second involved the removal of a foreign object from the alveolar bone prior to implant placement. Results: Positive clinical outcomes were confirmed at follow-up visits for up to 12 months. Conclusions: This method may be applied to a range of challenging clinical scenarios, such as apicectomy, the extraction of supernumerary or unerupted teeth, corticotomy to facilitate orthodontic movement, the precise reduction of bony spurs or exostoses, and the conservative surgical removal of pathologies. Full article

Background/Objectives: The stabilization disc (SD) for orthodontic mini-implants is a novel device designed to enhance anchorage stability and minimize the risk of mini-implant mobility. The disc features a flat structure with four prongs and is crafted from biocompatible materials such as titanium or stainless steel. It provides additional support to mini-implants by improving force distribution and reducing stress concentration around the insertion site. This study aims to evaluate the biomechanical performance of mini-implants with an SD compared to without-SD mini-implants, with a specific focus on their ability to maintain anchorage under orthodontic loading conditions. Methods: A finite element analysis (FEA) model was created for a commercially available mini-implant (2.0 mm in diameter and 12 mm in length). The mandible’s anatomical structure was reconstructed in 3D from computed tomography (CT) scans using SpaceClaim software 2023.1. To simulate real-world orthodontic conditions, forces of 10 N were applied at an angle of 30°. This retrospective study explores the role of SDs in enhancing mini-implant stability by reducing displacement and optimizing stress distribution. The evaluation included analyzing von Mises stress, cortical bone deformation, and mini-implant movement under simulated orthodontic loading. Results: The results demonstrate that the SD significantly reduces maximum total displacements by over 41% and redistributes von Mises stresses more evenly across the mini-implant and surrounding bone. Cortical bone stress and deformation were reduced in cases utilizing the SD, indicating enhanced implant stability and durability. Conclusions: The stabilization disc enhances mini-implant stability by improving stress distribution and reducing deformation without requiring permanent implant modifications. Its adaptability makes it a valuable solution for managing variable bone density and high orthodontic forces, offering a promising advancement in orthodontic anchorage. Full article

Accurate identification of growth and development stages is critical for orthodontic diagnosis, treatment planning, and post-treatment retention. While hand–wrist radiographs are the traditional gold standard, the associated radiation exposure necessitates alternative imaging methods. Lateral cephalometric radiographs, particularly the maturation stages of the second, third, and fourth cervical vertebrae (C2, C3, and C4), have emerged as a promising alternative. However, the nonlinear dynamics of these images pose significant challenges for reliable detection. This study presents a novel approach that integrates chaotic functional connectivity (FC) matrices and fractal dimension analysis to address these challenges. The fractal dimensions of C2, C3, and C4 vertebrae were calculated from 945 lateral cephalometric radiographs using three methods: fast Fourier transform (FFT), box counting, and a pre-processed FFT variant. These results were used to construct chaotic FC matrices based on correlations between the calculated fractal dimensions. To effectively model the nonlinear dynamics, chaotic maps were generated, representing a significant advance over traditional methods. Feature selection was performed using a wrapper-based approach combining k-nearest neighbors (kNN) and the Puma optimization algorithm, which efficiently handles the chaotic and computationally complex nature of cervical vertebrae images. This selection minimized the number of features while maintaining high classification performance. The resulting AI-driven model was validated with 10-fold cross-validation and demonstrated high accuracy in identifying growth stages. Our results highlight the effectiveness of integrating chaotic FC matrices and AI in orthodontic practice. The proposed model, with its low computational complexity, successfully handles the nonlinear dynamics in C2, C3, and C4 vertebral images, enabling accurate detection of growth and developmental stages. This work represents a significant step in the detection of growth and development stages and provides a practical and effective solution for future orthodontic diagnosis. Full article

Background: The characterization of facial sexual dimorphic patterns in healthy populations serves as valuable normative data to tailor functionally effective surgical treatments and predict their aesthetic outcomes and to identify dysmorphic facial traits related to hormonal disorders and genetic syndromes. Although the analysis of facial sexual differences in juveniles of different ages has already been investigated, few studies have approached this topic with three-dimensional (3D) geometric morphometric (GMM) analysis, whose interpretation may add important clinical insight to the current understanding. This study aims to investigate the location and extent of facial sexual variations in juveniles through a spatially dense GMM analysis. Methods: We investigated 3D stereophotogrammetric facial scans of 304 healthy Italians aged 3 to 18 years old (149 males, 155 females) and categorized into four different age groups: early childhood (3–6 years), late childhood (7–12 years), puberty (13–15 years), and adolescence (16–18 years). Geometric morphometric analyses of facial shape (allometry, general Procrustes analysis, Principal Component Analysis, Procrustes distance, and Partial Least Square Regression) were conducted to detail sexually dimorphic traits in each age group. Results: The findings confirmed that males have larger faces than females of the same age, and significant differences in facial shape between the two sexes exist in all age groups. Juveniles start to express sexual dimorphism from 3 years, even though biological sex becomes a predictor of facial soft tissue morphology from the 7th year of life, with males displaying more protrusive medial facial features and females showing more outwardly placed cheeks and eyes. Conclusions: We provided a detailed characterization of facial change trajectories in the two sexes along four age classes, and the provided data can be valuable for several clinical disciplines dealing with the craniofacial region. Our results may serve as comparative data in the early diagnosis of craniofacial abnormalities and alterations, as a reference in the planning of personalized surgical and orthodontic treatments and their outcomes evaluation, as well as in several forensic applications such as the prediction of the face of missing juveniles. Full article

Background/Objectives: The nature, diameter, and cross-section of orthodontic archwires affect tooth movement and the surrounding alveolar bone. Researchers have explored different features of archwires to optimize treatment outcomes. In this context, this study aimed to evaluate the properties of the I-arch for its effects on alveolar bone height, dehiscence, fenestration, and treatment duration. Methods: Forty patients (eight males, and thirty-two females; mean age: 20.97 ± 2.41 years) with dental crowding ≤ 6 mm and Class I malocclusion were treated without extractions. They were randomly divided into two groups: the experimental group (EG, n = 20), treated with the I-arch, and the control group (CG, n = 20), treated with traditional archwires of the MBT technique. Two CBCT scans were taken for each patient, one before treatment (T0) and one after leveling (T2). The studied teeth were upper and lower centrals, canines, and second premolars. The treatment duration was measured across three periods: T0–T1, T1–T2, and T0–T2. Results: Alveolar bone resorption, dehiscence, and fenestration were lower in the EG. Total treatment duration (T0–T2) was similar between groups, but the first period (T0–T1) was significantly shorter in the EG (p < 0.05). Conclusions: The I-arch resulted in fewer side effects on alveolar bone height during leveling and alignment. Full article

Primary failure of tooth eruption (PFE) is a rare genetic disorder characterized by the failure of teeth to erupt in the absence of obvious physical obstructions, often resulting in a progressive open bite that is resistant to orthodontic treatment. While PFE can be caused by genetic or systemic factors (such as cysts, tumors, and endocrine imbalances), the non-syndromic causes are primarily genetic, with an autosomal dominant inheritance pattern with variable expressivity. Several genes have been closely associated with the non-syndromic PFE form. The PTH1R (parathyroid hormone 1 receptor) is the most commonly PFE-associated gene. Additional genes associated with minor frequency are Transmembrane protein 119 (TMEM119), which reduces the glycolytic efficiency of bone cells, limiting their mineralization capacity and causing bone fragility; Periostin (POSTN), which regulates the extracellular matrix and the bone’s response to mechanical stress; and Lysine (K)-specific methyltransferase 2C (KMT2C), which establishes histone methylation near the Wnt Family Member 5A (WNT5A) gene involved in dental development (odontogenesis). Syndromic forms of PFE are typically associated with complex multisystem disorders, where dental eruption failure is one of the clinical features of the spectrum. These syndromes are often linked to genetic variants that affect ectodermal development, craniofacial patterning, and skeletal growth, leading to abnormal tooth development and eruption patterns. Notable syndromes include GAPO syndrome, ectodermal dysplasia, and cleidocranial dysplasia, each contributing to PFE through distinct molecular mechanisms, such as disruptions in dental structure development, cranial abnormalities, or systemic developmental delays. The main aim of this review is to provide a comprehensive overview of the genetic basis underlying both syndromic and non-syndromic forms of PFE to facilitate precision diagnosis, foster the development of personalized therapeutic strategies, and offer new insights into managing this complex dental anomaly. Full article

Oxidative stress (OS) is a common feature of many inflammatory diseases, oral pathologies, and aging processes. The impact of OS on periodontal ligament cells (PDLCs) in relation to oral pathologies, including periodontal diseases, has been investigated in different studies. However, its impact on orthodontic tooth movement (OTM) remains poorly understood. This study used an in vitro model with human PDLCs previously exposed to H₂O₂ to investigate the effects of OS under a static compressive force which simulated the conditions of OTM. Human PDLCs were treated with varying concentrations of H₂O₂ to identify sub-lethal doses that affected viability minimally. To mimic compromised conditions resembling OTM under OS, the cells were pretreated with the selected H₂O₂ concentrations for 24 h. Using an in vitro loading model, a static compressive force (2 g/cm²) was applied for an additional 24 h. The cell viability, proliferation, and cytotoxicity were evaluated using live/dead and resazurin assays. Apoptosis induction was assessed based on caspase-3/7 activity. The gene expression related to bone remodeling (RUNX2, TNFRSF11B/OPG, BGLAP), inflammation (IL6, CXCL8/IL8, PTGS2/COX2), apoptosis (CASP3, CASP8), and autophagy (MAP1LC3A/LC3, BECN1) was analyzed using RT-qPCR. This study suggests an altering effect of previous OS exposure on static-compression-related mechanosensing. Further research is needed to fully elucidate these mechanisms. Full article