ABSTRACT Background Impaction most commonly affects the third molars, followed by the maxillary canines, whereas impaction of the mandibular central incisor is extremely rare. Case Presentation An 18‐year‐old woman presented with an impacted tooth in the mandibular anterior region surrounded by a pericoronal radiolucency. The lesion and impacted tooth were surgically removed, and histopathological examination established the diagnosis of hyperplastic dental follicle (HDF). The impacted tooth was subsequently identified as the right mandibular central incisor based on morphological findings. Conclusion Impaction of the mandibular central incisor is a rare condition, particularly in adults. This case indicates the importance of careful clinical and radiographic evaluation for the identification of impacted mandibular central incisors.
ABSTRACT Aim Dental pulp‐derived cells have attracted attention as an accessible source of mesenchymal stem cell‐like cells for bone regeneration. However, donor‐to‐donor variability in osteogenic potential remains a challenge for their clinical application. This study aimed to characterize human dental pulp‐derived cells from permanent teeth and to identify candidate surface markers associated with in vitro mineralization capacity. Methods Dental pulp cells were isolated from extracted human third molars ( n = 6 donors) and expanded to Passage 3. Cell surface antigen expression was analyzed by flow cytometry, and osteogenic potential was evaluated by Alizarin Red S staining and absorbance measurement after osteogenic induction. Results The expanded adherent cells exhibited a mesenchymal stem cell‐like surface antigen profile, with high expression of CD73, CD90, and CD105 and low expression of hematopoietic and endothelial markers. Under osteogenic induction conditions, the cells formed Alizarin Red S‐positive mineralized deposits, although the extent of mineralization varied among donor‐derived cell lines. Correlation analysis between the positivity of 20 cell surface markers associated with mesenchymal and progenitor cell populations and in vitro mineralization, assessed by Alizarin Red S absorbance, showed that CD49e, CD106, and CD140a were identified as candidate markers positively associated with mineralization capacity. Conclusion These findings suggest that CD49e, CD106, and CD140a may represent candidate markers reflecting the osteogenic potential of dental pulp‐derived cells and may be useful for the selection and quality assessment of cell populations for future bone regeneration applications.
ABSTRACT Aim Tongue movement is essential for oral functions, including mastication, swallowing, and speech articulation; however, objective methods for evaluating lateral tongue movement remain limited. This study aimed to develop an ultrasonography‐based method for quantitatively assessing lateral tongue movement in healthy adults and school‐aged children and to examine its association with tongue pressure. Methods Twenty‐five healthy children and 16 healthy adults participated in the study. Coronal ultrasonographic images were acquired at rest and during maximum lateral tongue movement. The angle between the tongue axis at rest and during maximum lateral movement was measured using ImageJ and defined as the maximum lateral tongue movement angle. Sex differences, right–left differences, and associations with tongue pressure were analyzed. Tongue pressure was measured only in adults. Results The mean right and left lateral tongue movement angles were 9.12° ± 3.49° and 8.32° ± 2.61°, respectively, in adults, and 11.48° ± 3.75° and 9.03° ± 2.92°, respectively, in children. A significant right–left difference was observed only in children, with no significant differences between age groups. Tongue pressure was not significantly correlated with lateral tongue movement angle. Conclusion Ultrasonography enabled quantitative assessment of lateral tongue movement in healthy adults and school‐aged children. The lateral tongue movement angle did not differ significantly between age groups and was not associated with tongue pressure, suggesting that these measures reflect distinct aspects of tongue function. Ultrasonography may provide a simple, noninvasive method for multidimensional assessment of oral function.
ABSTRACT Introduction Impacted mandibular third molars are often removed, but proximity between mandibular third molar roots and the mandibular canal is clinically important because it may influence surgical planning and the assessment of anatomical relationships before extraction. Cone beam computed tomography (CBCT) enables three‐dimensional assessment of the mandibular canal–root relationship for surgical planning. Methods This retrospective cross‐sectional study was approved by the Ethics Committee of Islamic Azad University, Isfahan (approval no. IR.IAU.KHUISF.REC.1399.0113). Included mandibular third molars were impacted/semi‐impacted with complete root development and radiographic proximity to the canal; inadequate images and cases with anomalies, lesions, fractures, tumors, infection, or other pathology were excluded. Canal position relative to roots (apical, buccal, lingual, inter‐radicular), impaction angulation (vertical, horizontal, mesioangular, distoangular), and canal–root relationship (no contact, cortical contact, penetration) were recorded. Associations were tested using chi‐square/Fisher's exact tests ( α = 0.05). Results In 164 teeth, mesioangular impaction was most common (44.5%), followed by vertical (33.5%), horizontal (20.7%), and distoangular (1.2%). Canal position was most often apical (43.3%), then buccal (27.4%), lingual (23.8%), and between roots (5.5%). Impaction type was not significantly associated with canal position ( p = 0.153) or contact variables (contact type p = 0.328). Among 162 teeth with available contact classification, contact type differed by canal position ( p < 0.001): Penetration was highest with lingual (66.7%) and apical (54.9%) canals, while no contact predominated with buccal canals (48.9%). Conclusion CBCT indicated that apical canal positioning and mesioangular impaction predominated. Canal position, rather than impaction type, showed the strongest association with radiographic penetration and should be considered during preoperative evaluation of mandibular canal–root relationships and surgical planning.
ABSTRACT Background A fractured injection needle does not necessarily remain at its initial location. Case Presentation An 18‐year‐old man was referred 4 days after fracture of a 31‐gauge, 16‐mm injection needle that had been bent during infiltration anesthesia, straightened, and reused for inferior alveolar nerve block anesthesia. CT revealed the fractured needle in the submandibular space, medial to the submandibular gland. The needle was removed under general anesthesia through an extraoral submandibular approach using a metal detector. Conclusion After needle fracture, the dental procedure should be stopped immediately, and rest, mouth‐opening restriction, and prompt referral are essential.
