Root canal treatment of a three-rooted maxillary second premolar.

Successful root canal treatment relies on correct access cavity preparation, sufficient cleaning, adequate shaping, and complete obturation. Prior to these, location of all existing canals in the tooth plays an important part in the initial treatment procedures. While most teeth have a normal morphology, we should recognize that variations do exist. Normal maxillary second premolars have one or two root canals. Maxillary second premolars are less likely to have three canals. To date, only a few cases of maxillary second premolars with three roots (and three canals) have been reported in the literature. This case presentation reports a 20-year-old female who had three root canals in a maxillary second premolar, which underwent endodontic treatment at a teaching hospital in Taiwan.

A case-control study of dental development in Hypodontic and Hyperdontic children.

PURPOSE: The purpose of this study was to investigate the rate of dental development in children with nonsyndromic hypodontia and nonsyndromic hyperdontia compared to age- and gender-matched controls. METHODS: Dental age assessment was performed using orthopantomograms on 115 children (63 girls, 52 boys) with hypodontia and 61 children (22 girls, 39 boys) with hyperdontia and compared with 176 normal controls, case-matched for gender and age. RESULTS: Both girls and boys with hypodontia showed a significant delay in dental development compared to case controls. The mean differences between dental age and chronological age in hypodontia girls and boys were -0.1+/-1.5 years and -0.1+/-1.2 years, respectively, compared to 1.0+/-1.0 years and 0.8+/-0.8 years in the case controls, respectively (P<.001 for both boys and girls). The delay in dental development was accentuated during puberty. By contrast, no significant differences were observed between hyperdontic children and case controls. CONCLUSIONS: Nonsyndromic hypodontia children experience delayed dental development, whereas nonsyndromic hyperdontia children have similar rotes of dental development compared to normal children. These findings have implications for management of dental growth and development in children with agenesis of the teeth and supernumerary teeth.

Taurodontism in children with hypodontia and supernumerary teeth: a case control study.

PURPOSE: The aim of the present investigation was to compare the prevalence of taurodontism in the permanent mandibular first molars of nonsyndromic children with hypodontia and supernumerary teeth with age- and gender-matched controls. METHODS: The crown-body root ratios of the permanent first molars were determined from orthopantomograms of 83 children with hypodontia (> or =1 missing teeth) and 37 children with supernumerary teeth (> or =1 extra teeth) compared with normal case controls. RESULTS: In children with hypodontia, only girls showed a significantly higher tendency for taurodontism compared to case controls (P=.003), while boys with hypodontia showed a similar prevalence of taurodontism as controls (P=.83). Children with multiple missing teeth were significantly more susceptible to taurodontism than children with a single missing tooth (P=.004). By contrast, the prevalence of taurodontism in children with supernumerary teeth was not significantly different from that of controls. CONCLUSIONS: Compared to normal case controls, children with nonsyndromic hypodontia are more likely to show taurodontism of the permanent first molar teeth whereas children with nonsyndromic supernumerary teeth are not.

Phorbol ester-induced podosomes in normal human bronchial epithelial cells.

Spreading and migration of the basal cells neighboring a wound is essential for airway epithelial repair. To gain insight into the molecular mechanisms that govern these cellular processes, we asked whether normal human airway epithelial cells can form podosomes, a cellular structure discovered from cancer and mesenchymal cells that controls migration and invasion. Herein, we report that phorbol-12, 13-dibutyrate (PDBu), a protein kinase C activator, induced reorganization of cytoskeletal structure in primary normal human bronchial epithelial cells, and in normal human airway epithelial BEAS2B cells. Z-stack scanning confocal microscopy showed that PDBu-induced podosome-like structures contain actin-rich columns that arise from the ventral surface of the cell, and also revealed the presence of circular ruffles/waves at the dorsal cell surface. The molecular components of these cytoskeletal structures were determined with immunofluorescent staining. Using in situ zymography, we demonstrated that PDBu-induced podosomes were capable of degrading fibronectin-gelatin-sucrose matrix. PDBu also increased epithelial cell invasion across Transwell chamber. Podosomes and circular dorsal ruffles may be important for epithelial cell migration and invasion, thus contributing to respiratory epithelial repair and regeneration.