Infections of the hand are encountered across emergency medicine, primary care, and surgical practice, and their outcomes depend heavily on early recognition. The complex anatomy of the hand, with its multiple fascial planes, tendon sheaths, and confined spaces, allows infection to spread rapidly and produce lasting functional impairment when treatment is delayed. This pictorial review presents a series of clinically important hand infections drawn from the archive of a board-certified hand surgeon, spanning common superficial conditions to uncommon but limb-threatening deep-space, articular, and osseous disease. For each entity, we summarize characteristic clinical features, useful diagnostic and imaging findings, likely causative organisms, and initial management, illustrated with representative clinical photographs and imaging. By organizing these conditions across tissue planes, the review offers a practical, pattern-based reference that clinicians can use at the point of care to triage urgency, select empiric therapy, and identify patients who require early referral or operative intervention.

Skeletal Class II malocclusion with facial asymmetry, occlusal cant, and multiple impacted canines presents a significant clinical challenge requiring coordinated interdisciplinary care. This report describes the management of a 20-year-old female who presented with a retruded mandible, right-sided chin deviation, soft-tissue lip cant, and a Class II Division 1 malocclusion with deep bite, increased overjet, and missing permanent canines. Radiographic evaluation revealed right condylar hypoplasia, 9% condylar asymmetry, a difficult palatal impaction of tooth 23 according to the KPG difficulty index, and mid-alveolar impactions of teeth 33 and 43. Skeletal assessment confirmed mandibular retrognathia, a hyperdivergent pattern, and a 3-mm occlusal cant. Treatment involved the extraction of over-retained deciduous canines and third molars, orthodontic alignment, and space creation, followed by surgical exposure and traction of the impacted canines. After successful eruption, pre-surgical orthodontic decompensation was performed to optimize incisor inclinations. Bimaxillary orthognathic surgery, including left maxillary impaction and asymmetric mandibular advancement, was undertaken to correct the skeletal discrepancies and facial asymmetry. Post-surgical orthodontic finishing refined occlusal relationships, and implant-supported prostheses were placed to replace missing mandibular molars. The interdisciplinary approach achieved successful canine alignment, correction of skeletal discrepancies, normalization of the occlusal plane, and improved facial symmetry. At a 36-month follow-up, the results remained stable with satisfactory function and aesthetics. This case highlights the value of coordinated orthodontic, surgical, and prosthetic care in managing complex dentofacial deformities.

Delayed eruption of multiple teeth in systemically healthy, non-syndromic adolescents represents a diagnostic and therapeutic challenge. When combined with impacted maxillary canines and vertical discrepancies, management becomes more complex. A 14-year-old healthy male presented with delayed eruption (DE) of multiple permanent teeth. Clinical and radiographic examination revealed bilateral DE of mandibular canines and both premolars, a unilateral impacted maxillary canine, and a severe deep bite. The patient had no relevant medical history and showed normal physical development. Orthodontic treatment included space creation for mandibular teeth, closed surgical exposure of maxillary canines, and traction of the impacted maxillary canines, piggyback arch mechanics for canine alignment, and occlusal plane levelling using auxiliary intrusion mechanics supported by a mini-implant for skeletal anchorage. During treatment, the patient sustained a traumatic mandibular fracture, which required management and temporarily interrupted orthodontic therapy, prolonging overall treatment time. Following fracture stabilization, orthodontic treatment was resumed and completed, resulting in satisfactory functional and aesthetic outcomes. This case highlights the complexity of managing non-syndromic delayed tooth eruption combined with impacted canines and a deep bite, particularly when complicated by traumatic injury. Careful biomechanical planning and multidisciplinary coordination are essential for achieving stable outcomes.

Malocclusion is a common oral health problem with a strong hereditary component. Previous genetic studies were limited by small sample sizes and low genomic coverage. To address these limitations, we conducted a genome-wide association study (GWAS) using array-based genotype data in 5 large, multiancestral cohorts. The study included 3,405 participants from the United States and its territories, the Philippines, Colombia, and Nigeria. Class II malocclusion was defined as an Angle's class II molar relationship with an overjet >3.5 mm, class III malocclusion as an Angle's class III molar relationship with a negative overjet, and class I malocclusion (controls) as an Angle's class I molar relationship with an overjet of 0 to 3.5 mm. In the vertical plane, an anterior open bite of any magnitude was classified as "open bite," while an overbite >3.5 mm was classified as "deep bite," with controls having an overbite of 0 to 3.5 mm. Multiplanar malocclusion included cases with both sagittal and vertical discrepancies, with controls having an Angle's class I molar relationship, an overjet of 0 to 3.5 mm, and an overbite of 0 to 3.5 mm. GWAS for each phenotype was conducted within individual cohorts before meta-analysis. We identified genome-wide significant associations (P ≤ 5E-08) at 11q22.3 (rs372564249, odds ratio [OR] = 3.12) and 3p24.3 (rs13060317, OR = 2.4) for class II and multiplanar malocclusion, respectively. Additionally, we observed a near-significant signal at 12q15 (rs1261646, OR = 1.9, P = 6.2 × 10[-8]) for class II malocclusion and a suggestive association at 1p21.3 (rs7541224, OR = 2.0, P = 1.7 × 10[-7]) for class III malocclusion. The 11q22.3 and 3p24.3 loci were QTLs for the PDGFD and SGO1-AS1 genes, and transcriptomic data showed consistent expression of these genes during facial development. These findings provide valuable insights into malocclusion etiology and lay the groundwork for genetic risk score development.

Objectives: This study aimed to evaluate the influence of panoramic radiograph quality on the performance of an artificial intelligence (AI)-based tooth detection system and to identify specific image quality criteria associated with detection accuracy. Methods: A total of 424 panoramic radiographs were retrospectively selected from a clinical database. Radiographic quality was assessed using a modified Clinical Image Evaluation Chart, including criteria related to bite block presence, anteroposterior positioning, occlusal plane curvature, patient movement, anatomical coverage, overlapping contact points, air gap, contrast, cervical spine overlap, symmetry of the ascending mandibular ramus, and the number of visible teeth. Automated tooth detection was performed using a convolutional neural network based on the Mask R-CNN architecture (SynbrAIn, Italy). AI detection outputs were validated against expert human evaluation. Spearman's rank correlation analyses were conducted to assess associations between individual image quality criteria and the number of AI detection errors per radiograph. Results: Significant negative associations were observed between AI detection errors and the number of visible teeth (ρ = -0.311, p < 0.001), presence of a bite block (ρ = -0.248, p < 0.001), reduced patient movement (ρ = -0.204, p < 0.001), correct anteroposterior positioning (ρ = -0.165, p < 0.001), and overall image quality score (ρ = -0.120, p = 0.010). In contrast, the presence of an air gap above the anterior teeth (ρ = 0.099, p = 0.042) and overlapping contact points (ρ = 0.122, p = 0.012) were positively associated with increased detection errors. No significant associations were identified for occlusal plane curvature, contrast, cervical spine overlap, anatomical coverage, or mandibular ramus symmetry. Overall, the AI system was more sensitive to indicators of anatomical completeness and patient positioning than to minor radiographic imperfections. Conclusions: Panoramic radiograph quality, particularly indicators of anatomical completeness and patient positioning, is associated with the performance of AI-based tooth detection. While the AI system demonstrated robustness to common image quality variations, adherence to standardized acquisition protocols remains important to minimize detection errors.

Background: Skeletal deep bite malocclusion (Angle Class II division 2) represents a common vertical skeletal discrepancy characterized by excessive anterior overbite and a hypodivergent craniofacial growth pattern. The contribution of cranial base morphology to mandibular growth direction during early development remains incompletely understood. Objective: To evaluate the relationship between cranial base morphology and maxillofacial growth patterns in children with skeletal deep bite, using a longitudinal cephalometric approach. Materials and Methods: This retrospective longitudinal cohort study included 96 prepubertal patients aged 7-10 years (54 with skeletal deep bite, 42 Angle Class I dentoalveolar controls). Skeletal deep bite was defined by overbite > 4 mm and mandibular plane angle (FMA) < 22°. A total of 298 standardized lateral cephalometric radiographs (2-4 per subject; mean follow-up 24 ± 4 months) were analyzed. Twenty-two cephalometric parameters were assessed. Longitudinal changes were evaluated using repeated-measures analysis, and predictors of deep bite severity were identified using multiple linear regression. Results: Compared with controls, the deep bite group exhibited significantly reduced mandibular plane angle (18.5° vs. 24.0°), smaller gonial angle (104.3° vs. 111.0°), and decreased lower anterior facial height (86.3 mm vs. 92.0 mm; all p < 0.001). Differences in cranial base morphology were modest, including reduced anterior cranial base length (58.6 mm vs. 60.0 mm; p = 0.031). Regression analysis identified gonial angle and lower anterior facial height as significant predictors (R[2] = 0.58). Longitudinal analysis suggested early tendencies toward forward mandibular rotation and reduced vertical growth rate over the observation period. Conclusions: In prepubertal children, skeletal deep bite is associated with early tendencies toward reduced vertical facial development and forward mandibular rotation. Cranial base morphology appears to be associated with mandibular growth direction as a secondary modulatory factor rather than a primary determinant. Early identification of hypodivergent growth indicators may facilitate timely interceptive orthodontic strategies.

Two pairs of enantiopure mononuclear Co(II) complexes with a CoO4 coordination motif, (S/R-F2BINOL)2Co[TMG-H+]2 (S/R-Co-F, where F2BINOL refers to 3,3'-difluoro-BINOL, TMG = 1,1,3,3-tetramethylguanidine) and (S/R-N2BINOL)2Co[TMG-H+]2 (S/R-Co-N, where N2BINOL refers to 3,3'-dinaphthyl-BINOL), were constructed from BINOLate ligands. The introduction of TMG-H+ cations into the second coordination sphere induces intramolecular N-H···O hydrogen-bonding interactions, which enhance the air stability of the complexes. The different substituents at the 3,3'-positions of the BINOLate ligands modulate the molecular geometries of these two pairs of compounds. Compared with S/R-Co-F, which exhibits a distorted tetrahedral coordination geometry, the bulkier naphthyl substituents in S/R-Co-N give rise to a distorted seesaw geometry accompanied by smaller dihedral (δ) and bite angles (θ). Such structural differences result in their distinct magnetic anisotropies with S/R-Co-F and S/R-Co-N being easy-plane and easy-axis, respectively, as supported by the opposite signs of the zero-field splitting (ZFS) parameter D from CASSCF/RASSI-SO calculations and the experimental fitting. Additionally, both S/R-Co-F and S/R-Co-N behave as single-molecule magnets (SMMs) under a 1 kOe dc field, with effective barriers of 46(1)/41(1) K and 63(6)/48(2) K, respectively. These findings provide new insights into the design of air-stable four-coordinate Co(II) SMMs.