Recent advancements in artificial intelligence have led to increased interest in predictive modeling across various domains, including medicine. Although numerous metrics have been established for binary classification, the growing adoption of multi-class systems necessitates robust evaluation measures. However, comprehensive simulation studies comparing the performance of existing multi-class metrics under diverse data conditions remain limited. In this study, we first provide a concise overview of commonly used accuracy metrics for multi-class classification. Then, we report a simulation study that systematically evaluates several diagnostic accuracy measures under a wide range of scenarios, including three- and five-class settings, balanced and imbalanced sample sizes, and different distributional assumptions for predictors. We assessed each metric’s performance in terms of bias and 95% confidence interval coverage. Under balanced conditions, most metrics demonstrated stable and unbiased performance, closely approximating the true values. However, under imbalanced conditions, greater bias was observed, with the M-index and polytomous discrimination index exhibiting comparatively more stable performance across various scenarios. The micro-averaged receiver operating characteristic curve area consistently showed higher bias under class imbalance. Finally, we applied these metrics to a glioma tumor grading task using external datasets. This study provides a systematic comparison of commonly used metrics and offers practical guidance for selecting appropriate measures in multi-class classification tasks.

Purpose: This study aimed to evaluate the clinical outcomes of a single type of narrowdiameter implant (NDI) by investigating its survival rate and peri-implant marginal bone loss (MBL). In addition, variables possibly related to implant survival and MBL were investigated to identify potential risk factors. Methods: The study was conducted as a retrospective study involving 49 patients who had received 3.0-mm diameter TSIII implants (Osstem Implant Co.) at Seoul National University Dental Hospital. In total, 64 implants were included, and dental records and radiographic data were collected from 2017 to 2022. Kaplan-Meier survival curves and a Cox proportional hazard model were used to estimate the implant survival rate and to investigate the effects of age, sex, jaw, implant location, implant length, the stage of surgery, guided bone regeneration, type of implant placement, and the surgeon’s proficiency (resident or professor) on implant survival. The MBL of the NDIs was measured, and the factors influencing MBL were evaluated. Results: The mean observation period was 30.5 months (interquartile range, 26.75–45 months), and 6 out of 64 implants failed. The survival rate of the NDIs was 90.6%, and the multivariate Cox regression analysis showed that age was associated with implant failure (hazard ratio, 1.17; 95% confidence interval, 1.04–1.31, P=0.01). The mean MBL was 0.44±0.75 mm, and no factors showed statistically significant associations with greater MBL. Conclusions NDIs can be considered a primary alternative when standard-diameter implants are unsuitable. However, further studies are required to confirm their long-term stability.

Noonan syndrome is characterized by distinctive facial features, short stature, and congenital heart disease. It is a congenital genetic disorder with a prevalence of between 1/1,000 and 1/2,500 in both genders.An 11-year-old boy with Noonan syndrome visited the hospital with an ectopically positioned tooth. A pulmonary stenosis was diagnosed and his growth and development were delayed. In many cases of this diseases there is obvious hemostasis, which he was not experiencing. His facial appearance showed characteristic features of Noonan syndrome. The patient showed a dental class II relationship, labioversion of the upper anterior teeth, and a shallow overbite. Radiographic examination revealed that the upper right canine was ectopically positioned, which led to root resorption of the upper right lateral incisor. A lateral cephalometric radiograph revealed a craniofacial pattern that was within normal limits. Surgical opening and button attachment on the impacted upper right canine were performed and traction was applied on the impacted tooth using a removable appliance.This patient was mildly affected by Noonan syndrome and showed some dental problems. However, few studies have reported the oral characteristics of Noonan syndrome despite its high incidence. Thus, this case report describes the oral features and management of Noonan syndrome.
Child ; Growth and Development ; Heart Defects, Congenital ; Hemostasis ; Humans ; Incidence ; Incisor ; Male ; Noonan Syndrome ; Overbite ; Prevalence ; Pulmonary Valve Stenosis ; Root Resorption ; Tooth ; Tooth, Impacted ; Traction

Children need regularly dental check-ups after dental treatment because there are a lot of changes of oral conditions such as tooth exfoliation and eruption, occlusion, and recurrence of dental caries. The purpose of this study is to determine the factors that affect the follow-up pattern after dental treatment under conscious sedation.Patients who were treated under sedation at the department of pediatric dentistry of Ewha Womans University Mokdong Hospital from 2009 to 2013 were included in this study. The final samples comprised of 562 patients that were classified into 4 groups according to the number of visits during 3 years. The chi-square test was used to determine the factors affecting regular follow-up.There were statistically significant differences between each treatment groups and factors such as the change of doctor, overall treatment time, the number of treated teeth under sedation, restorative treatment, minor operation, and preventive treatment (p < 0.05).This study identified factors that affect regular follow-up after dental treatment under conscious sedation. It is recommended to educate the importance of regular check-ups to parents who are less likely to return.
Child ; Conscious Sedation ; Dental Caries ; Female ; Follow-Up Studies ; Humans ; Parents ; Pediatric Dentistry ; Recurrence ; Tooth ; Tooth Exfoliation