Narrow band imaging (NBI) magnification endoscopy for the diagnosis of early-stage oral cavity-related cancer and precancerous lesions can recognize oral lesions as brownish areas, and can observe intraepithelial papillary capillary loops (IPCLs) in the mucosa and submucosa to make a qualitative diagnosis of the lesion and highlight the mucosal surface microstructure to facilitate appropriate diagnosis and early treatment. IPCLs are classified from Type 0 to IV: Type 0 is normal mucosa or no blood vessels observed, e.g., in keratinization; Type I is mainly normal mucosa; Type II is mainly inflammatory sites or non-malignant lesions; Type III is mainly precancerous or suspected malignant lesions; and Type IV is cancerous or malignant lesions. NBI magnification endoscopy is a useful noninvasive method for identifying the malignant transformation of oral potentially malignant disorders (OPMDs). Oral lesions classified as IPCL Type II or higher are atypical epithelial or oral squamous cell carcinoma (OSCC); oral biopsy is recommended for early and accurate diagnosis, and is an indicator of the appropriate biopsy site in the follow-up for OPMDs. In the future, the accuracy of NBI magnification endoscopy for malignant transformation of OPMDs and OSCC will be further confirmed.

BACKGROUND:If a tooth fragment is displaced into the floor of the mouth during mandibular third molar extraction, surgical retrieval can be challenging because the fragment cannot be directly visualized in the operative field. Several studies have described the use of navigation systems or endoscopic techniques individually. However, to the best of our knowledge, no reports have described their combined use for this condition. CASE REPORT:A 37-year-old man underwent extraction of a left mandibular third molar at a dental clinic in May 2021, during which a root fragment was displaced into the floor of the mouth. An attempt to retrieve the fragment under general anesthesia at another hospital was unsuccessful, and the patient was subsequently referred to our department. Because direct retrieval was considered technically difficult, surgical retrieval was performed by using a combination of electromagnetic navigation and endoscopic guidance. The fragment was successfully removed via an intraoral approach with minimal surgical invasion. Postoperatively, the wound healed uneventfully and no lingual nerve injury was observed. CONCLUSIONS:Electromagnetic navigation systems provide real-time spatial localization based on preoperative imaging, and are particularly useful when the target is difficult to palpate or directly visualize. Endoscopic guidance provides enhanced illumination and direct visualization within confined anatomical spaces, thereby facilitating minimally invasive surgery. In the present case, the combined use of electromagnetic navigation and endoscopic guidance can facilitate accurate intraoperative localization and minimally invasive retrieval of a displaced mandibular root fragment on the floor of the mouth.

Narrow band imaging (NBI) magnification endoscopy for the diagnosis of early-stage oral cavity-related cancer and precancerous lesions can recognize oral lesions as brownish areas, and can observe intraepithelial papillary capillary loops (IPCL) in the mucosa and submucosa to make a qualitative diagnosis of the lesion and highlighting of the mucosal surface microstructure to facilitate appropriate diagnosis and early treatment. IPCL is classified from Type 0 to IV, Type 0 being normal mucosa or no blood vessels are observed e.g. in keratinisation, Type I being mainly normal mucosa, Type II being mainly inflammatory sites or non-neoplastic lesions, Type III being mainly neoplastic lesions, and Type IV being neoplastic lesions. NBI magnification endoscopy is a useful noninvasive method for identifying malignant transformation of oral potentially malignant disorders (OPMDs), and oral lesions classified as IPCL Type II or higher would be atypical epithelial or oral squamous cell carcinoma (OSCC), oral biopsy is recommended for early and accurate diagnosis, and is an indicator of the appropriate biopsy site in the follow-up of OPMDs. In the future, the accuracy of NBI magnification endoscopy for malignant transformation of OPMDs and OSCC will be further confirmed. It is then expected that NBI magnification endoscopy will be widely used by dentists in hospitals and general dental clinics.

Alveolar bone defects can result from trauma, resection of benign or malignant tumors, congenital anomalies, or periodontitis. These defects require bone augmentation to restore normal occlusal function and improve esthetics. This case report describes a 26-year-old man referred to our hospital with a diagnosis of jaw deformity. A deficiency of alveolar bone and teeth in the maxillary anterior region, caused by childhood trauma, was confirmed. Sagittal split ramus osteotomy was performed, accompanied by bone augmentation of the maxillary anterior region using a custom-made titanium mesh and autogenous iliac particulate cancellous bone and marrow, guided by three-dimensional simulation. Dental implants were placed in the augmented region 4 months later, followed by prosthetic treatment. This case demonstrates successful esthetic and functional reconstruction of a maxillary anterior bone defect and jaw deformity using preoperative three-dimensional simulation.