Purpose: This study was conducted to identify the typical sites and patterns of peri-implant bone defects on conebeam computed tomography (CBCT) images, as well as to evaluate the detectability of the identified bone defects on panoramic images. Materials and Methods: The study population included 114 patients with a total of 367 implant fixtures. CBCT images were used to assess the presence or absence of bone defects around each implant fixture at the mesial, distal, buccal, and lingual sites. Based on the number of defect sites, the presentations of the peri-implant bone defects were categorized into 3 patterns: 1 site, 2 or 3 sites, and circumferential bone defects. Two observers independently evaluated the presence or absence of bone defects on panoramic images. The bone defect detection rate on these images was evaluated using receiver operating characteristic analysis. Results: Of the 367 implants studied, 167 (45.5%) had at least 1 site with a confirmed bone defect. The most common type of defect was circumferential, affecting 107 of the 167 implants (64.1%). Implants were most frequently placed in the mandibular molar region. The prevalence of bone defects was greatest in the maxillary premolar and mandibular molar regions. The highest kappa value was associated with the mandibular premolar region. Conclusion The typical bone defect pattern observed was a circumferential defect surrounding the implant. The detection rate was generally higher in the molar region than in the anterior region. However, the capacity to detect partial bone defects using panoramic imaging was determined to be poor.

Background/Aims: Hybrid endoscopic submucosal dissection (ESD), in which an incision is made around a lesion and snaring is performed after submucosal dissection, has some advantages in colorectal surgery, including shorter procedure time and preventing perforation. However, its value for rescue resection in difficult colorectal ESD cases remains unclear. This study evaluated the utility of rescue hybrid ESD (RH-ESD). Methods: We divided 364 colorectal ESD procedures into the conventional ESD group (C-ESD, n=260), scheduled hybrid ESD group (SH-ESD, n=69), and RH-ESD group (n=35) and compared their clinical outcomes. Results: Resection time was significantly shorter in the following order: RH-ESD (149 [90–197] minutes) >C-ESD (90 [60–140] minutes) >SH-ESD (52 [29–80] minutes). The en bloc resection rate increased significantly in the following order: RH-ESD (48.6%), SH-ESD (78.3%), and C-ESD (97.7%). An analysis of factors related to piecemeal resection of RH-ESD revealed that the submucosal dissection rate was significantly lower in the piecemeal resection group (25% [20%–30%]) than in the en bloc resection group (40% [20%–60%]). Conclusions RH-ESD was ineffective in terms of curative resection because of the low en bloc resection rate, but was useful for avoiding surgery.