Morphology and classification of the second mesiobuccal canal in maxillary first molars: a cone-beam computed tomography analysis in a Chinese population.

BACKGROUND: Understanding the tooth anatomy is crucial for ensuring effective endodontic treatment. This study investigated the root canal morphology of the second mesiobuccal (MB2) canal in maxillary first molars (MFMs) in a Chinese population using cone-beam computed tomography (CBCT). METHODS: This study evaluated 486 MFMs with MB2 canals from 285 participants undergoing CBCT examination and determined the Vertucci's classification and position of the MB2 canal orifice. The prevalence of the MB2 canal was correlated with the sex, age, and tooth side. The correlations between the prevalence of the MB2 canal and sex and tooth side were assessed using the Fisher's exact test. The chi-square test was used for evaluating the correlation between the prevalence of the MB2 canal and age. RESULTS: The number of type II, III, IV, V, VI, VII, and other root canals in the MFMs was 30.9%, 0.6%, 65.0%, 1.2%, 1.2%, 0.4%, and 0.6%, respectively. Among the 201 cases with bilateral inclusion, 87.6% showed consistent canal configuration. Results of the first clear apparent position (FCAP) of the MB2 canals showed that 434, 44, and 3 teeth had FCAP at the upper, middle, and bottom one-third of the root, respectively. The FCAPs of the MB2 canal in the MFMs with types II, IV, and VI, as well as types III and V canals showed significant differences (p<0.05). The horizontal distance between the MB1 and MB2 canal orifices in the type II canals of MFMs was significantly lesser than those in the type IV canals of MFMs (p < 0.01). The longitudinal distance between the pulp chamber floor plane and MB2 canal orifice significantly correlated with age (p < 0.05). CONCLUSIONS: The morphology of the mesiobuccal root canal in the MFMs is complex. Complete understanding of the anatomical morphology of the root canal combined with the CBCT and dental operating microscope is necessary for the accurate detection of the MB2 canal and consequently improved success rate of root canal treatment. Our study findings can help endodontists improve endodontic treatment outcomes.

Clinical observation of autologous platelet rich fibrin assisted revascularization of mature permanent teeth.

OBJECTIVE: To investigate the clinical observation of autologous platelet-rich fibrin (PRF) assisting the revascularization of mature permanent teeth. METHODS: Twenty patients with mature permanent teeth were divided into experimental group and control group. The control group was treated with classic revascularization, and the experimental group was treated with PRF-assisted mature permanent tooth revascularization. RESULTS: After treatment, the total effective rate of the experimental group (100.00%) was higher than that of the control group (50.00%); the thickness of the root canal wall of the experimental group was higher than that of the control group, and the crown root length was lower than that of the control group; The bite degree, chewing function, color, overall aesthetic score, and satisfaction rate of the patients were higher, and the difference was statistically significant (P < 0.05). CONCLUSION: Autologous PRF assists in revascularization of mature permanent teeth, which can achieve ideal results, and promote pulp regeneration.

The phenotypic characteristics of patients with athelia and tooth agenesis.

BACKGROUND: Although athelia, which is a congenital aplastic deformity of the nipple, is seldom reported in tooth agenesis patients, we observed athelia in 2 hypodontia patients. This study aimed to summarize the phenotypic characteristics of patients with athelia and tooth agenesis. METHODS: A database search was conducted for publications reporting on patients with athelia and tooth agenesis, and the phenotypes of such patients were recorded. Athelia-related syndromes were identified in the Online Mendelian Inheritance in Man (OMIM) database. The common symptoms and the causative genes were documented. Potential interactions between athelia-related genes and tooth agenesis-related genes were analyzed in the Database for Annotation, Visualization, and Integrated Discovery (DAVID) Bioinformatics Resources and the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database. RESULTS: We summarized the phenotypic characteristics of 8 previously reported patients. Deformities in hair, skin, and sweat glands were common in these patients. There were 23 nipple deformity-related syndromes reported. The most common symptoms included abnormalities of the head and neck, cardiovascular, genitourinary, and skeletal systems, and the skin, nails, and hair. Hypodontia was noted in association with 10 syndromes. A total of 16 genes were related to them, including TP63, KCTD1, and IKBKG. The interaction found in the study suggests that nipple deformity-related genes potentially interact with tooth agenesis-related genes. CONCLUSIONS: These results indicated that athelia might be related to hypodontia. Additional molecular genetics research is needed to fully elucidate the underlying relationship between athelia and tooth agenesis.