RESUMO
BACKGROUND: Complicated crown-root fracture is considered a severe dental trauma and is unlikely to heal without treatment. Usually, dentists have to remove the loose coronal fragment of the fractured tooth and treat the remaining part with multidisciplinary approaches. However, we observed spontaneous healing of fracture in two pediatric cases with a history of complicated crown-root fractures over 4 years ago. CASE SUMMARY: In case 1, a 12-year-old boy complained of pain at tooth 11 following an accidental fall 1 d ago. Clinical examination showed a crack line on the crown of tooth 11. Cone beam computed tomography (CBCT) images of tooth 11 showed signs of hard tissue deposition between the fractured fragments. The patient recalled that tooth 11 had struck the floor 1 year ago without seeking any other treatment. In case 2, a 10-year-old girl fell down 1 d ago and wanted to have her teeth examined. Clinical examination showed a fracture line on the crown of tooth 21. CBCT images of tooth 21 also showed signs of hard tissue deposition between the fractured fragments. She also had a history of dental trauma 1 year ago and her tooth 11 received dental treatment by another dentist. According to her periapical radiograph at that time, tooth 21 was fractured 1 year ago and the fracture was overlooked by her dentist. Both of these two cases showed spontaneous healing of complicated crown-root fractures. After over 4 years of follow-up, both fractured teeth showed no signs of abnormality. CONCLUSION: These findings may provide new insights and perspectives on the management and treatment of crown-root fractures in children.
RESUMO
PURPOSE: Sprague-Dawley rat models of tooth movement were established to investigate the expression of transient receptor potential vanilloid 1 (TRPV1) and calcitonin gene related peptide (CGRP) in rat trigeminal ganglion during orthodontic tooth movement, and to explore the roles of TRPV1 and CGRP in orthodontic pain. METHODS: Sixty-six Sprague-Dawley rats were randomly divided into control group (n=6), sham operation group (n=6), and experimental group (n=54). Tooth movement models were established, orthodontic force (50 g) was applied on the maxillary first molar in the rats of experimental group, and then the trigeminal ganglia were collected at 4, 8 h, 1 d (3 subgroups were set up according to the force: 1 d-30 g, 1 d-50 g, 1 d-80 g), 3, 5, 7, 14 d after tooth movement. The changes of TRPV1 and CGRP expression were detected by immunofluorescence staining. SPSS16.0 software package was used for statistical analysis. RESULTS: According to immunofluorescence staining, the TRPV1-IR and CGRP-IR neurons were mostly small to medium sized. The percentages of TRPV1-IR and CGRP-IR neurons in trigeminal ganglion increased after applying force, and reached the peak at 1-3 d and then fell to the initial level gradually. In addition, the application of greater force during experimental tooth movement induced higher percentages of TRPV1-IR and CGRP-IR neurons in trigeminal ganglion. CONCLUSIONS: Experimental tooth movement leads to the regular changes of TRPV1-IR and CGRP-IR neurons in trigeminal ganglion, indicating that TRPV1 and CGRP may play important roles in orthodontic pain.
