TMEM119 (c.G143A, p.S48L) Mutation Is Involved in Primary Failure of Eruption by Attenuating Glycolysis-Mediated Osteogenesis.

Primary failure of eruption (PFE) is a rare oral disease with an incidence rate of 0.06%. It is characterized by abnormal eruption mechanisms that disrupt tooth eruption. The underlying pathogenic genetic variant and mechanism of PFE remain largely unknown. The purpose of this study was to explore the role of a novel transmembrane protein 119 (TMEM119) mutation in two PFE patients in a Chinese family. Information collection was performed on the family with a diagnosis of PFE, and blood samples from patients and healthy family members were extracted. Whole-exome sequencing was performed. Bioinformatics analysis revealed that a heterozygous variant in the TMEM119 gene (c.G143A, p.S48L) was a disease-associated mutation in this family. Recombinant pcDNA3.1 plasmid-containing wild-type and mutant TMEM119 expression cassettes were successfully constructed and transfected into MC3T3-E1 cells, respectively. The results of in vitro analysis suggested that the subcellular distribution of the TMEM119 protein was transferred from the cell cytoplasm to the nucleus, and the ability of cells to proliferate and migrate as well as glycolytic and mineralized capacities were reduced after mutation. Furthermore, rescue assays showed that activating transcription factor 4 (ATF4) overexpression rescued the attenuated glycolysis and mineralization ability of cells. Results of in vivo analysis demonstrated that TMEM119 was mainly expressed in the alveolar bone around the mouse molar germs, and the expression level increased with tooth eruption, demonstrated using immunohistochemistry and immunofluorescence. Collectively, the novel TMEM119 mutation is potentially pathogenic in the PFE family by affecting the glucose metabolism and mineralized function of osteoblasts, including interaction with ATF4. Our findings broaden the gene mutation spectrum of PFE and further elucidate the pathogenic mechanism of PFE.

Third molar mineralization in relation to chronologic age estimation of the Han in central southern China.

The purpose of this study is to provide a forensic reference data about estimating chronologic age by evaluating the third molar mineralization of Han in central southern China. The mineralization degree of third molars was assessed by Demirjian's classification with modification for 2519 digital orthopantomograms (1190 males, 1329 females; age 8-23 years). The mean ages of the initial mineralization and the crown completion of third molars were around 9.66 and 13.88 years old in males and 9.52 and 14.09 years old in females. The minimum ages of apical closure were around 16 years in both sexes. Twenty-eight at stage C and stage G and 38 and 48 at stage F occurred earlier in males than in females. There was no significant difference between maxillary and mandibular teeth in males and females except that stage C in males. Two formulas were devised to estimate age based on mineralization stages and sexes. In Hunan Province, the person will probably be over age 14, when a third molar reaches the stage G. The results of the study could provide reference for age estimation in forensic cases and clinical dentistry.

A retrospective study on the long-term outcomes of pulpectomy and influencing factors in primary teeth.

Background/purpose: Pulpectomy is the last means to preserve primary teeth with pulpitis or pulp necrosis. The aim of the study was to investigate the survival rate of primary teeth after pulpectomies and to explore the factors influencing the prognosis of pulpectomy. Materials and methods: This retrospective study was performed on patients who received primary tooth pulpectomy in the Department of Pediatric Dentistry at Peking University Hospital of Stomatology between January 2014 and February 2019. The demographic characteristics of children and the information of teeth treated were collected, and the clinical and radiographic examination after treatment were evaluated. Survival analysis was performed to determine the influencing factor of pulpectomy failure. Results: A total of 592 primary anterior teeth and 583 primary molars were included. The 30-month survival rate of primary anterior teeth was 58.5% and that of primary molars was 37.0%. The survival rate of postoperative primary molars was lower than that of primary anterior teeth (P < 0.05). Primary anterior tooth interventions with preoperative periapical lesions, Vitapex® filling, or nongeneral anesthesia treatment had a higher failure risk (P < 0.05). Treatment at an older age and glass ionomer cement filling indicated a higher failure risk for primary molar pulpectomies. Conclusion: Primary anterior teeth after pulpectomies had a higher survival rate than primary molars. Periapical lesions, treatment methods, and root filling materials had significant impacts on the prognosis of primary anterior pulpectomies, and children's age significantly affected the prognosis of primary molar pulpectomies, which has not been reported before.