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Morphological analysis of anatomical structure of nasopharynx in cone-beam computed tomography in Korean population

2026-01-01T00:00:00Z

Title: Morphological analysis of anatomical structure of nasopharynx in cone-beam computed tomography in Korean population Authors: Lee, Chena; Lee, Ji Yun; MacDonald, David Abstract: Purpose: This study evaluated the nasopharyngeal anatomy, particularly the fossa of Rosenm & uuml;ller (FoR), on cone-beam computed tomography (CBCT) in a Korean population to establish normative reference data by sex and age. Materials and Methods: In CBCT images, FoR was classified into three types (A-C) for image analysis. Measurements of nasopharyngeal dimensions were performed in Types B and C. Sex-and age-related differences were evaluated using chi-square and independent t-tests, and reliability was assessed using the intraclass correlation coefficient. Results: In total, 492 CBCTs (244 males, 248 females; 20-69 years) were included. Type C was the most frequent morphology and increased with age. Types A and B were more prevalent among males than among females, whereas Type C was predominant among females (57.3%) compared with males (34.4%). Asymmetry was more frequent in males (13.9%) than in females (10.1%). Significant sex differences due to the larger males were found in the distance of the torus levatorius, the distance between the sphenopalatine notch and the right torus levatorius, and the horizontal and vertical dimensions of the FoR. No significant side-to-side differences were observed. Reliability was excellent (ICC = 0.97). Conclusion: Type C was the most frequent morphology in both sexes, whereas Types A and B were more frequently observed in males than in females. These differences may indirectly contribute to sex-related disparities in nasopharyngeal carcinoma (NPC) incidence. The normative reference values may aid early detection in dental imaging, and further prospective studies including NPC patients are needed to clarify the role of nasopharyngeal morphology.

Multimodal deep learning with anatomically constrained attention for screening MRI-detectable TMJ abnormalities from panoramic images

2026-01-01T00:00:00Z

Title: Multimodal deep learning with anatomically constrained attention for screening MRI-detectable TMJ abnormalities from panoramic images Authors: Jung, Hyo-Jung; Ju, Dayun; Kim, Chanyoung; Hwang, Seong Jae; Lee, Chena; Park, Younjung Abstract: Early diagnosis of temporomandibular disorders is challenging. Particularly, intra-articular temporomandibular joint (TMJ) abnormalities can only be confirmed using magnetic resonance imaging (MRI). This study aimed to develop a comprehensive screening method for MRI-detectable TMJ pathologies. We developed an interpretable deep learning framework that leveraged paired open- and closed-mouth TMJ panoramic radiographs and structured clinical metadata. The architecture integrated anatomically guided attention, multimodal clinical features, and ensemble learning for enhanced diagnostic accuracy and interpretability. Across 1355 patients (2710 joints), the best-performing ensemble framework achieved an area under the curve of 0.86, with a balanced classification of MRI-negative and -positive cases. Gradient-weighted Class Activation Mapping visualizations confirmed a consistent focus on the condylar regions, and ablation studies demonstrated the added value of clinical metadata and spatial attention. In conclusion, our prototype workflow can be useful to triage TMJ patients for MRI referral, thus supporting early detection of TMJ abnormalities and timely interventions.

Palatal bone healing after removal of miniscrew-assisted rapid palatal expansion devices

2025-12-01T00:00:00Z

Title: Palatal bone healing after removal of miniscrew-assisted rapid palatal expansion devices Authors: Nguyen, Hieu; Lee, Kee-Joon; Lee, Hyeonjong; Lee, Chena; Kim, Dongjae; Choi, Yoon Jeong Abstract: Introduction: Miniscrew-assisted rapid palatal expansion (MARPE) is an effective approach for correcting maxillary constriction in adults. This study aimed to evaluate palatal bone healing after miniscrew removal in MARPE-treated patients and to identify key factors influencing the healing process. Methods: This retrospective study included 38 patients (18 men, 20 women; mean age at >= 6 months postremoval [T2], 24.7 +/- 4.2 years) and analyzed 152 removal sites (76 anterior and 76 posterior). The average number of MARPE screw turns and expansion width were 29.5 +/- 6.1 mm and 5.9 +/- 1.2 mm, respectively. At the end of the consolidation phase (T1) and T2, miniscrew inclination, distance to the midpalatal suture, palatal bone thickness, and removal site dimensions (width, depth, volume, and total surface area) were measured. The average T1-T2 interval was 12.0 +/- 3.7 months. Volume and total surface area healing ratios-representing percentage of bone recovery- were separately compared between anterior and posterior sites, and between monocortical and bicortical sites. Correlation analyses (point-biserial, Spearman, or Kendall's tau) assessed relationships between healing and patient-related and miniscrew-related factors. Results: All removal site dimensions decreased significantly at T2. Anterior and monocortical sites showed significantly greater healing. Posterior site healing ratios were significantly correlated with age at T2, healing duration, MARPE width, distance to midpalatal suture, palatal bone thickness, and anchorage type. Conclusions: Substantial palatal bone healing occurred after miniscrew removal. Healing was greater at anterior and monocortical sites, whereas posterior site healing was influenced by patient/miniscrew-related factors. This study addresses concerns regarding healing at the miniscrew removal site after MARPE; however, long-term follow-up is recommended for comprehensive insights. (Am J Orthod Dentofacial Orthop 2025;168:739-52)

Leveraging multimodal large language model chatbots in oral radiology: a comprehensive evaluation using questions from a Korean dental university

2025-12-01T00:00:00Z

Title: Leveraging multimodal large language model chatbots in oral radiology: a comprehensive evaluation using questions from a Korean dental university Authors: Jeong, Hui; Jeon, Kug Jin; Lee, Chena; Choi, Yoon Joo; Jo, Gyu-Dong; Han, Sang-Sun Abstract: Objectives This study aimed to conduct a comprehensive evaluation of general-purpose multimodal large language model (LLM) chatbots in oral radiology. Methods Ninety text- and image-based oral radiology questions from a Korean dental university were extracted and categorized into six educational contents and two question types. ChatGPT-4o and Gemini 2.0 Flash were evaluated with following items: accuracy with group differences across six contents (using Fisher's exact test with Bonferroni correction, P < .0167), answer consistency across ten repeated outputs (evaluated as the mean agreement and Fleiss' kappa coefficient), and hallucination (evaluated as the mean of the 5-point Global Quality Score assigned by two oral radiologists). Results Multimodal LLM chatbots (ChatGPT-4o and Gemini 2.0 Flash) achieved excellent performance on text-based questions with over 80% accuracy but showed limited performance on image-based tasks, with accuracy under 30%. Additionally, image-based tasks exhibited high response variability, and hallucinations were frequently observed, providing incorrect information. These findings suggest that AI chatbots are not yet suitable for reliable use in oral radiology. Conclusions This study provided timely insights into the capabilities and limitations of general-purpose multimodal LLM chatbots in the oral radiology, and will serve as a foundation for more safe and effective applications of AI chatbots in the oral radiology field in the future. Advances in knowledge This is the first study to comprehensively assess multimodal LLM chatbots in oral radiology. It provides key insights into the performance benchmarks for AI chatbots in oral radiology, promoting the responsible and transparent integration of AI into dental education.