ABSTRACT Objectives To quantify the occlusal adjustment required for two‐unit, implant‐supported polymethyl‐methacrylate (PMMA) crowns with either digital or conventional impression techniques, using full‐arch and half‐arch workflows. Material and Methods An acrylic maxillary–mandibular model carrying two bone‐level implant analogs (sites 46–47) was mounted on a semi‐adjustable articulator. Twenty impressions were made (n = 5 per group): digital full‐arch, digital half‐arch, conventional full‐arch, and conventional half‐arch. PMMA crowns were designed using computer‐aided design (CAD) software, milled, and surface‐scanned before adjustment. Occlusal contacts were refined on the articulator with 21 µm film while recording adjustment time. Pre‐ and post‐adjustment scans were superimposed and analyzed using three‐dimensional surface analysis software to quantify mean material reduction (µm). Data were analyzed with one‐way ANOVA and independent‐samples t‐tests (α = 0.05). Results Digital workflows required significantly less occlusal reduction (146 ± 35 µm vs. 226 ± 35 µm; p = 0.035) and shorter adjustment times (144 ± 36 s vs. 385 ± 36 s; p < 0.001) than conventional, with no effect of arch span (full vs. half; p > 0.05). Within protocols, the digital half‐arch group showed the smallest adjustment (127 ± 37 µm) and fastest finishing (98 ± 33 s), whereas the conventional half‐arch group required the longest time (456 ± 21 s). Conclusion Fully digital impressions reduce both the amount of occlusal adjustment and the chairside time needed to seat implant‐supported crowns compared with conventional silicone impressions. Reducing the scan to a half‐arch does not compromise occlusal precision, making the digital half‐arch workflow an efficient alternative for posterior, free‐end implant restorations. Clinical Relevance In implant posterior PMMA crowns, the impact of impression/workflow choice on occlusal adjustment is unclear. This in‐vitro study measured occlusal reduction and chairside time across digital versus conventional and full‐ versus half‐arch workflows. Digital, especially half‐arch, required less adjustment and shorter time. Clinically, a digital half‐arch approach may streamline delivery and reduce unnecessary material removal, pending confirmation in patient‐based settings.
ABSTRACT Objective Osteoporosis is a silent systemic skeletal disease characterized by microarchitectural deterioration and increased fracture risk; thus, early case‐finding is essential. Although dual‐energy X‐ray absorptiometry (DEXA) is the reference standard for bone mineral density (BMD) assessment, limited accessibility and cost restrict its use for large‐scale screening. Given that cone‐beam computed tomography (CBCT) is routinely obtained in dental practice, image‐derived parameters—gray value (GV) and fractal dimension (FD)—may provide insight into their association with systemic bone mineral density measured by DEXA in postmenopausal women, without additional radiation exposure. Materials and Methods This cross‐sectional study included 63 postmenopausal women aged 50–70 years undergoing dental CBCT (NewTom 3G; standardized acquisition). Six trabecular regions of interest (ROIs) were evaluated: mandibular retromolar, mandibular premolar, mandibular anterior (central), maxillary premolar, maxillary anterior (central), and maxillary tuberosity. GV values were extracted using OnDemand3D‐Dental from standardized 25 × 25‐pixel ROIs positioned to exclude cortical bone and dental structures. FD was calculated in ImageJ using a box‐counting method following Gaussian blur subtraction, binarization, and skeletonization. Lumbar spine and hip BMD were measured by DEXA and categorized according to WHO criteria. Statistical analyses included t‐tests/ANOVA, Pearson correlation (α = 0.05). Intra‐observer reliability was assessed with intraclass correlation coefficients (ICC). Results DEXA classified 49.2% as normal, 34.9% as osteopenic, and 15.9% as osteoporotic. Lumbar assessment identified more non‐normal cases than the hip evaluation. Reliability was good (ICC > 0.70). Although mean GV and FD did not differ significantly between groups, site‐specific GV–FD correlations were observed. Notably, FD at the maxillary premolar correlated with lumbar T‐scores in the non‐normal group (p = 0.030). Conclusion While GV and FD did not discriminate BMD categories overall, region‐dependent associations between CBCT‐derived parameters and systemic BMD were observed, suggesting potential clinical relevance in dental imaging. These exploratory findings should not be interpreted as diagnostic or screening indicators and require confirmation in larger studies.
ABSTRACT Objectives This study investigated the association between Single Nucleotide Polymorphisms (SNPs) in calcium and vitamin D maintenance genes and mesiodistal tooth size (MTS) of permanent teeth. Materials and Methods A total of 108 patients undergoing orthodontic treatment were recruited. Pretreatment orthodontic diagnostic casts were used to obtain the MTS. One single calibrated evaluator assessed the maximum crown dimensions in the mesiodistal direction of mandibular and maxillary permanent teeth with a digital caliper. Salivary genomic DNA was isolated from buccal cells, and six SNPs of the VDR, CYP24A1, CYP27B1, and PTH genes were selected. Real‐Time PCR was performed for the genotyping analysis. For statistics analysis, uni‐ and multivariate tests accounting for multiple observations per‐subject and adjusted by gender were performed (α = 5%). Results In multivariate analysis, the rs694 and rs6256 (PTH) SNPs were associated (p < 0.05) with smaller MTS of the maxillary first molar. The rs7975232 (VDR) and rs307247 (PTH) were associated with a smaller mesiodistal size of the mandibular first molar. The rs7975232 (VDR) was also associated with a smaller mesiodistal size of the maxillary central incisor and a greater mesiodistal size of the maxillary first premolar. The rs4646536 (CYP27B1) was also associated with greater mesiodistal size of the first premolar. Conclusion SNPs in the PTH and vitamin D‐related genes (VDR and CYP27B1) might be related to MTS variations of permanent teeth.
ABSTRACT Objectives Because mandibular ramus fractures represent a rare entity among the various fracture patterns of the mandible, the present study evaluated the prevalence, morphology, and risk factors associated with mandibular ramus fractures. Material and Methods The prevalence of mandibular ramus fractures was evaluated in patients diagnosed with mandibular fractures over 5 years. Along with epidemiologic data, fracture morphology, treatment modalities, and patient‐related risk factors, such as gonial angle and third molar impaction, were assessed for the ramus fractures and compared with angle fractures. Results Out of 547 patients diagnosed with mandibular fractures, 15 (2.7%; 10 m/5 f) presented with ramus fractures. Patients with mandibular ramus fractures demonstrated a significantly higher rate of female patients (33.3% vs. 9.6%, p = 0.021) and multiple fracture patterns (66% vs. 40.9%, p = 0.042; OR 2.91) compared to those with angle fractures (115/547; 21%; 104 m/11 f). Regarding fracture morphology, 12/15 (80%) ramus fractures exhibited a vertical/oblique fracture line, while comminuted fractures were observed only in 3/15 (20%) patients. Road traffic accidents (RTAs) were the predominant etiology for ramus fractures (46.6%, p < 0.025) and served as a potent predictor for complex multiple fractures (OR = 6.48, p < 0.001). Although deeply impacted third molars were significantly less frequent in ramus fractures than in angle fractures (13.3% vs. 38.3%; p = 0.049), the mean gonial angle was wider in the ramus group (130.3° ± 7.2° vs. 127.4° ± 6.2°, p = 0.098). In contrast to maxilla–mandibular fixation (13.3%), open reduction and internal fixation (ORIF) was the primary treatment modality (86.4%, p < 0.01); both yielded a high success rate without severe complications. Conclusion A high gonial angle and the absence of deep third molar impaction structurally predispose the mandibular ramus to injury, particularly acting as predictors for complex fracture patterns during road traffic accidents (RTAs).
ABSTRACT Introduction Single‐tooth replacement in the aesthetic zone remains clinically challenging. Implant‐supported single crowns (ISSCs) provide predictable long‐term outcomes, yet complications such as infraposition, along with time‐dependent aesthetic changes, may still occur over time. Objectives To evaluate early infraposition of ISSCs in the anterior maxilla of adult patients and assess aesthetic outcomes. Materials and Methods Twenty‐five patients (median age 23 years) with ISSCs were followed for a median of 1.2 years. Positional changes were measured using TRIOS 3 intraoral scanner and TRIOS Patient Monitoring software (3Shape A/S, Copenhagen, Denmark). Aesthetic outcomes were assessed through Patient‐Reported Outcomes and Clinician‐Rated Outcomes, focusing on pink and white aesthetics via visual analogue scales. Overall satisfaction was recorded using a four‐level ordinal scale. Results Median vertical movement of 0.16 mm (IQR = 0.19 mm; range = 0–1 mm; Z = −4.29; p < 0.001) while a median bucco‐palatal movement of 0.04 mm (IQR = 0.15 mm; range = −0.10–0.68 mm; Z = −2.44; p = 0.015) was found. Patients consistently rated aesthetic outcomes higher than clinicians, with statistically significant differences across all parameters and time points. Conclusions ISSCs in the anterior maxilla exhibited small but statistically significant positional changes within 1 year after crown delivery. Patients rated the aesthetic outcome more favorably than clinicians. The clinical significance of these early changes remains uncertain and warrants further longitudinal investigation. Trial Registration Not applicable due to observational study design.
