The loss of occlusal vertical dimension due to multiple tooth loss and wear can lead to a collapsed occlusion, resulting in both functional and aesthetic problems.This case report describes a patient exhibiting mandibular prognathism as a result of vertical dimension loss. A comprehensive oral rehabilitation involving an increase in vertical dimension was required. A minimal number of implants were placed, and implant-supported surveyed crowns were fabricated, allowing for the design of a stable and retentive implant-assisted removable partial denture. The treatment resulted in both functional and aesthetic improvements. The anterior rotational pattern of the mandible was alleviated, and the implant-assisted partial denture provided clinically high levels of patient satisfaction. This case report details the diagnostic and therapeutic processes involved in this treatment.

Crossbite refers to a condition where there are remaining teeth, but none of the teeth are in occlusal contact, resulting in the loss of vertical support. When posterior vertical stop is lost, it is important to appropriately restore this support and create a harmonious occlusal plane. In this case, the patient had lost posterior support but declined surgical intervention due to a history of osteoporosis and the associated risk of medication-related osteonecrosis of the jaw (MRONJ). To restore the vertical space required for prosthetic rehabilitation, the vertical dimension was increased. The missing posterior teeth were replaced using removable partial dentures. Cross-mounting was performed, and the metal copings of the surveyed crowns and the framework of the final removable partial denture were 3D printed. After the treatment was completed, the patient expressed satisfaction with both functions and aesthetics. Regular follow-ups were conducted to monitor oral hygiene and occlusal stability.

Objective: Using finite element method (FEM) analysis of a clear aligner (CA), this study aimed to investigate the effects of varying the edentulous space on canine distal bodily movement during space closure following maxillary first premolar extraction. Methods: FEM analysis was used to simulate distal canine bodily movement following maxillary first premolar extraction using CAs. Four CA designs for edentulous spaces were compared: no-pontic, full-pontic, halfpontic, and beam. Three-dimensional models of the tooth components and CA were created. The target was set at a 0.25-mm distal canine movement. Long-term tooth movement was simulated using an iterative calculation method. Results: All the groups initially showed crown displacement, distal tipping, and distal rotation.Over time, the movement patterns differed in relation to the design. The no-pontic design exhibited the greatest displacement and tipping. The beam design exhibited the largest initial displacement but showed the lowest displacement and tipping thereafter. Full- and half-pontic designs yielded intermediate results. Significant force reduction was observed immediately after CA application, and was followed by a gradual decrease. The mean tooth-movement achievement rate was approximately 76.7%. Conclusions The edentulous space design of the CA substantially affected tooth-movement behavior. An iterative simulation is necessary to evaluate longterm tooth-movement patterns. The beam design demonstrated optimal suitability for bodily movement with minimal tipping. For optimal results, additional setup or overcorrection may be necessary.

Objective: To quantitatively analyze and compare the forces and moments generated by thermoformed polyethylene terephthalate glycol (PETG) and direct-printed TC-85 clear aligners (CAs), with various margin designs, during premolar rotation. Methods: In total, 132 CAs were fabricated and divided into four groups (n = 33 per group). Group C consisted of thermoformed PETG aligners with a 2 mm gingival margin. Group E comprised direct-printed TC-85 aligners with equi-gingival margin, whereas Group G utilized direct-printed TC-85 aligners with 2 mm gingival margins.Finally, Group T featured direct-printed TC-85 aligners with an additional 1 mm thickness at the mesial embrasure. The forces and moments were measured using a 6-axis force/moment transducer at 2°, 3°, and 4° of rotation. All measurements were conducted at 37°C to simulate intraoral conditions. Forces were measured in the buccolingual, anteroposterior, and vertical directions, while moments were measured in the mesiodistal, buccolingual, and rotational planes. Results: The PETG aligners (Group C) showed significantly increased buccal and posterior force across the rotation angles (P < 0.05), whereas the intrusive force remained consistent. In contrast, the TC-85 aligners maintained consistent forces across all rotation angles.Direct-printed aligners demonstrated significantly lower intrusive forces than PETG aligners (P < 0.001). Group T exhibited reduced unwanted forces while maintaining effective rotational moments. Furthermore, all direct-printed aligners showed more predictable force delivery patterns than thermoformed aligners. Conclusions Direct-printed TC-85 aligners demonstrated superior force consistency and reduced unwanted side effects compared with traditional PETG aligners. Although marginal design modifications did not significantly improve rotational efficiency, they effectively reduced unwanted intrusive forces.

Purpose: To compare the perioperative and postoperative outcomes between traditional trans-vesical robot-assisted simple prostatectomy (TV-RASP) and the newly introduced urethral-sparing (US) RASP. Materials and Methods: We retrospectively reviewed 42 patients who underwent TV-RASP (n=22) or US-RASP (n=20) performed by two experienced surgeons at two tertiary centers. Perioperative outcomes including operation time, estimated blood loss, length of hospital stay, and catheterization time were assessed. Postoperative outcomes were evaluated using the International Prostate Symptom Score (IPSS), quality of life (QoL), uroflowmetry parameters, Male Sexual Health Questionnaire-Ejaculation Dysfunction-Short Form (MSHQ-EjD-SF) scores, and maintenance of anterograde ejaculation. Results: This study analyzed 22 and 20 patients who underwent TV-RASP and US-RASP, respectively. Except for the TV-RASP group being older (70.0 years) than the US-RASP group (64.5 years) (p=0.028), no differences among other baseline characteristics existed. Perioperative outcomes indicated that hospital stay and catheterization time were significantly shorter in the US-RASP group than in the TV-RASP group (p<0.001). At postoperative month 1, the median IPSS and QoL scores were significantly better in the US-RASP group than in the TV-RASP group (p=0.001 and p=0.002, respectively). However, at months 6 and 12, no significant differences were noted in IPSS, QoL, maximum flow rate, and postvoid residual urine between the two groups. Sexually active patients in the US-RASP group maintained postoperative MSHQ-EjD functional and bother scores, whereas the TV-RASP group experienced a decline. Notably, 75.0% of patients in the US-RASP group preserved antegrade ejaculation, compared to only 20.0% in the TV-RASP group (p<0.001). Conclusions US-RASP is not inferior to TV-RASP in terms of functional outcomes. In addition, US-RASP yielded more rapid symptom improvements and preserved antegrade ejaculation than TV-RASP. However, larger prospective studies are required to confirm these findings and to further investigate the long-term efficacy and safety of US-RASP.

Purpose: In this study, we investigated the effect of bisphenol-A (BPA) and its major analogs, bisphenol-F (BPF), and bisphenol-S (BPS), on spermatogonial stem cells (SSCs) populations using in vitro SSC culture and in vivo transplantation models. Materials and Methods: SSCs enriched from 6- to 8-day-old C57BL/6-eGFP+ male mice testes were treated with varying concentrations of bisphenols for 7 days to examine bisphenol-derived cytotoxicity and changes in SSC characteristics. We utilized flow cytometry, immunocytochemistry, real-time quantitative reverse transcription-PCR, and western blot analysis. The functional alteration of SSCs was further investigated by examining donor SSC-derived spermatogenesis evaluation through in vivo transplantation and subsequent testis analysis. Results: BPF exhibited a similar inhibitory effect on SSCs as BPA, demonstrating a significant decrease in SSC survival, inhibition of proliferation, and induction of apoptosis. On the other hand, while BPS was comparatively weaker than BPA and BPF, it still showed significant SSC cytotoxicity. Importantly, SSCs exposed to BPA, BPF, and BPS exhibited a significant reduction in donor SSC-derived germ cell colonies per total number of cultured cells, indicating that, like BPA, BPF, and BPS can induce a comparable reduction in functional SSCs in the recipient animals. However, the progress of spermatogenesis, as evidenced by histochemistry and the expressions of PCNA and SSC specific markers, collectively indicates that BPA, BPF, and BPS may not adversely affect the spermatogenesis. Conclusions Our findings indicate that the major BPA substitutes, BPF and BPS, have significant cytotoxic effects on SSCs, similar to BPA. These effects may lead to a reduction in the functional self-renewal stem cell population and potential impacts on male fertility.

Purpose: The immunological response and adverse effects of antineutrophil cytoplasmic antibody-associated vasculitis (AAV) in patients receiving coronavirus disease-2019 (COVID-19) vaccines remain unclear. We aimed to evaluate the effects of these vaccines on AAV disease activity. Materials and Methods: We reviewed the medical records of 52 patients with AAV who had received at least second doses of the COVID-19 vaccine and evaluated their immunogenicity by measuring the anti-spike (S) antibody (Ab) titer levels using the Roche Elecsys® immunoassay. Responses to the Birmingham Vasculitis Activity Score (BVAS) tool and 36-Item Short Form Survey before and after vaccination were obtained to assess AAV disease activity. Vaccine reactivity was measured using a standardized questionnaire. Results: We enrolled 52 patients with AAV. No differences were found between those who received second and third doses of vaccination in terms of AAV type, disease activity, vaccine type, or the use of immunosuppressive agents, including steroids. The median anti-S Ab titer was 3967.0 after third doses compared to 419.0 after second doses (p=0.001). Except for mycophenolate mofetil (MMF), when immunosuppressants were administered in conjunction with steroids, the Ab titer was higher after the third vaccination than that after the second dose. The BVAS remained unchanged before and after second and third doses. No life-threatening adverse events were reported. Conclusion Although COVID-19 vaccine may not produce sufficient antibodies in patients taking MMF, the vaccine did not exacerbate disease activity or cause severe side effects. Therefore, COVID-19 vaccines should be considered in patients with AAV.

Purpose: While colonoscopy is the standard surveillance tool for stage I colorectal cancer according to National Comprehensive Cancer Network guidelines, its effectiveness in detecting recurrence is debated. This study evaluates recurrence risk factors and patterns in stage I colorectal cancer to inform comprehensive surveillance strategies. Materials and Methods: A retrospective analysis of 2,248 stage I colorectal cancer patients who underwent radical surgery at Samsung Medical Center (2007-2018) was conducted. Exclusions were based on familial history, prior recurrences, preoperative treatments, and inadequate data. Surveillance included colonoscopy, laboratory tests, and computed tomography (CT) scans. Results: Stage I colorectal cancer patients showed favorable 5-year disease-free survival (98.3% colon, 94.6% rectum). Among a total of 1,467 colon cancer patients, 26 (1.76%) experienced recurrence. Of the 781 rectal cancer patients, 47 (6.02%) experienced recurrence. Elevated preoperative carcinoembryonic antigen levels and perineural invasion were significant recurrence risk factors in colon cancer, while tumor budding was significant in rectal cancer. Distant metastasis was the main recurrence pattern in colon cancer (92.3%), while rectal cancer showed predominantly local recurrence (50%). Colonoscopy alone detected recurrences in a small fraction of cases (3.7% in colon, 14.9% in rectum). Conclusion Although recurrence in stage I colorectal cancer is rare, relying solely on colonoscopy for surveillance may miss distant metastases or locoregional recurrence outside the colorectum. For high-risk patients, we recommend considering regular CT scans alongside colonoscopy. This targeted approach may enable earlier recurrence detection and improve outcomes in this subset while avoiding unnecessary scans for the low-risk majority.