OBJECTIVES: This study aimed to investigate the clinical characteristics of congenital deciduous teeth absence and its permanent teeth performance type by using panoramic radiographs. METHODS: A total of 15 749 panora-mic radiographs of 3-6-year-old children with deciduous dentition were collected from January 2020 to December 2021. The incidence of congenital deciduous teeth absence was observed, and the abnormality of permanent teeth was recor-ded. SPSS 24.0 software was used for statistical analysis. RESULTS: The incidence of congenital deciduous teeth absence was 2.54% (400/15 749), which was found in 217 girls and 183 boys, and the difference between the genders was statistically significant (P=0.003). The absence of one and two deciduous teeth accounted for 99.75% (399/400) of the subjects. In addition, 92.63% (490/529) of mandibular deciduous lateral incisor was congenitally absent, 44.80% (237/529) of deciduous teeth was absent in the left jaw, and less than 55.20% (292/529) was absent in the right; the difference between them was statistically significant (P=0.017). The absence of 96.41% (510/529) deciduous teeth in the mandibular was significantly more than that of 3.59% (19/529) in the maxillary, and the difference between was statistically significant (P=0.000). Furthermore, 68.00% (272/400) and 32.00% (128/400) of deciduous teeth were absent in unilateral and bilateral, respectively, and the difference was statistically significant (P=0.000). Four types of congenital deciduous teeth absence with permanent teeth were observed as follows: 1) 73.91% (391/529) of permanent teeth was absent; 2) 20.60% (109/529) of permanent teeth was not absent; 3) the number of fused permanent teeth accounted for 4.91% (26/529); 4) the number of supernumerary teeth was 0.57% (3/529). CONCLUSIONS Although the absence of congenital deciduous teeth is less common than that of permanent teeth, it affects deciduous and permanent teeth to some extent. Dentists should pay attention to trace and observe whether abnormalities are present in the permanent teeth and take timely measures to maintain children's oral health.
Male ; Female ; Humans ; Tooth, Deciduous ; Dentition, Permanent ; Tooth, Supernumerary/epidemiology* ; Anodontia/etiology* ; Tooth Abnormalities/complications* ; Fused Teeth/epidemiology*

Dens invaginatus is a rare developmental anomaly of the teeth that is caused by the infolding of enamel organs or the penetration of their proliferations into dental papillae before calcification has occurred. The presence of double dens invaginatus is extremely rare. This paper describes the use of cone beam computed tomography in the evaluation of a maxillary lateral incisor with double dens invaginatus and periapical periodontitis. The tooth was treated through microscopic root canal therapy. The tooth was free of clinical symptoms, and the periradicular lesion narrowed during the follow-up period of 1 year.
Humans ; Dental Pulp Cavity/abnormalities* ; Dens in Dente/pathology* ; Incisor/pathology* ; Root Canal Therapy ; Periapical Periodontitis/pathology*

Objective: To analyze the clinical and genetic characteristics of pediatric patients with dual genetic diagnoses (DGD). Methods: Clinical and genetic data of pediatric patients with DGD from January 2021 to February 2022 in Peking University First Hospital were collected and analyzed retrospectively. Results: Among the 9 children, 6 were boys and 3 were girls. The age of last visit or follow-up was 5.0 (2.7,6.8) years. The main clinical manifestations included motor retardation, mental retardation, multiple malformations, and skeletal deformity. Cases 1-4 were all all boys, showed myopathic gait, poor running and jumping, and significantly increased level of serum creatine kinase. Disease-causing variations in Duchenne muscular dystrophy (DMD) gene were confirmed by genetic testing. The 4 children were diagnosed with DMD or Becker muscular dystrophy combined with a second genetic disease, including hypertrophic osteoarthropathy, spinal muscular atrophy, fragile X syndrome, and cerebral cavernous malformations type 3, respectively. Cases 5-9 were clinically and genetically diagnosed as COL9A1 gene-related multiple epiphyseal dysplasia type 6 combined with NF1 gene-related neurofibromatosis type 1, COL6A3 gene-related Bethlem myopathy with WNT1 gene-related osteogenesis imperfecta type XV, Turner syndrome (45, X0/46, XX chimera) with TH gene-related Segawa syndrome, Chromosome 22q11.2 microduplication syndrome with DYNC1H1 gene-related autosomal dominant lower extremity-predominant spinal muscular atrophy-1, and ANKRD11 gene-related KBG syndrome combined with IRF2BPL gene-related neurodevelopmental disorder with regression, abnormal movement, language loss and epilepsy. DMD was the most common, and there were 6 autosomal dominant diseases caused by de novo heterozygous pathogenic variations. Conclusions: Pediatric patients with coexistence of double genetic diagnoses show complex phenotypes. When the clinical manifestations and progression are not fully consistent with the diagnosed rare genetic disease, a second rare genetic disease should be considered, and autosomal dominant diseases caused by de novo heterozygous pathogenic variation should be paid attention to. Trio-based whole-exome sequencing combining a variety of molecular genetic tests would be helpful for precise diagnosis.
Humans ; Abnormalities, Multiple ; Retrospective Studies ; Intellectual Disability/genetics* ; Bone Diseases, Developmental/complications* ; Tooth Abnormalities/complications* ; Facies ; Muscular Dystrophy, Duchenne/complications* ; Muscular Atrophy, Spinal/complications* ; Carrier Proteins ; Nuclear Proteins

OBJECTIVE: To explore the clinical and genetic characteristics of three children with KBG syndrome. METHODS: Clinical data of the three children from two families who have presented at the First Affiliated Hospital of Zhengzhou University between October 2019 and September 2020 and their family members were collected. Trio-whole exome sequencing (trio-WES) and Sanger sequencing were carried out. RESULTS: All children had feeding difficulties, congenital heart defects and facial dysmorphism. The sib- pair from family 1 was found to harbor a novel de novo heterozygous c.6270delT (p.Q2091Rfs*84) variant of the ANKRD11 gene, whilst the child from family 2 was found to harbor a novel heterozygous c.6858delC (p.D2286Efs*51) variant of the ANKRD11 gene, which was inherited from his mother who had a mild clinical phenotype. CONCLUSION The heterozygous frameshift variants of the ANKRD11 gene probably underlay the disease in the three children. Above findings have enriched the spectrum of the ANKRD11 gene variants.
Female ; Child ; Humans ; Abnormalities, Multiple/genetics* ; Intellectual Disability/genetics* ; Bone Diseases, Developmental/genetics* ; Tooth Abnormalities/genetics* ; Facies ; Repressor Proteins/genetics* ; Mothers ; Mutation

Palatal radicular groove is a developmental malformation of maxillary incisors, lateral incisors in particular, which often causes periodontal destruction. This paper reports a case of combined periodontal-endodontic lesions induced by palatal radicular groove, which was initially misdiagnosed as a simple periapical cyst. After root canal therapy and periapical cyst curettage, the course of disease was prolonged, resulting in the absence of buccal and maxillary bone plates in the affected tooth area. After the etiology was determined, the affected tooth was extracted and guide bone tissue regeneration was performed at the same time, followed by implantation and restoration at the later stage, leading to clinical cure. The palatal radicular groove is highly occult, and the clinical symptoms are not typical. If the abscess of the maxillary lateral incisor occurs repeatedly, and the abscess of the maxillary lateral incisor has not been cured after periodontal and root canal treatment, cone-beam computed tomographic and periodontal flap surgery should be considered.
Humans ; Incisor ; Radicular Cyst ; Abscess ; Tooth Root/abnormalities* ; Root Canal Therapy ; Maxilla ; Cysts

Epithelial root sheath plays a key role in guiding the development of tooth root. Any problems during its growth can lead to various forms of defects or abnormalities in the development of tooth root. Radicular invaginatus may occur when the epithelial root sheath excessively proliferates and infolds into the dental papilla. In terms of tissue origin and occurrence mechanism, the radicular dens invaginatus is similar to the coronal invaginatus which is led by the proliferation and infolding of enamel organ. However, there had been no consensus on the term and classification of this type of developmental abnormality as well as the relationships among the dens invaginatus, the radicular invaginatus and the palatogingival groove. From the role of epithelial root sheath during root development, the manifestations of root developmental defects and abnormalities will be analyzed. The pathogeny, classification, clinical characteristics of the radicular invaginatus, the relationship with the dens invaginatus and the impact on treatment were specially focused on.
Humans ; Root Canal Therapy ; Dens in Dente/therapy*

The classification as well as the clinical manifestations of hereditary malformations of dentin are of great concern and have been deeply elucidated. The understanding of its genetic basis also increases progressively. Dentin sialophosphoprotein (DSPP) is the pathogenic gene of dentinogenesis imperfecta type Ⅱ, dentinogenesis imperfecta type Ⅲ and dentin dysplasia type Ⅱ. In this article, the classification of DSPP mutations as well as the resultant dysfunction of the mutant DSPP are summarized respectively and the corresponding clinical manifestations are analyzed. This work will provide a reference for the diagnosis and treatment of hereditary malformations of dentin.
Humans ; Dentinogenesis Imperfecta/pathology* ; Mutation ; Extracellular Matrix Proteins/genetics* ; Phosphoproteins/genetics* ; Sialoglycoproteins/genetics* ; Dentin/pathology*

Fused teeth were a phenomena of teeth anomalies in shape, which can affect the dental teeth both in primary and permanent dentition. Fused teeth do not only cause problems on crowding of dentition, abnormal occlusion and aesthetic, but also increase risks of dental caries, endodontics diseases, periapical diseases and periodontal diseases. Fusion of deciduous teeth may lead to abnormality of subsequent permanent teeth. Treatment of fused teeth may require multidisciplinary approach in endodontics, periodontics, oral and maxillofacial surgery, prosthodontics and orthodontics. The aim of the present article is to review the etiology, classification, clinical manifestations and treatment of fused teeth in order to provide dental clinicians with a reference of clinical management for fused teeth.
Humans ; Fused Teeth/therapy* ; Anodontia ; Tooth, Deciduous ; Dental Caries/therapy* ; Esthetics, Dental

Humans ; Anodontia/genetics* ; Tooth Abnormalities/genetics* ; Mutation ; Malocclusion/genetics* ; Wnt Proteins/genetics*

Dens invaginatus (DI) is a developmental anomaly as a result of a deepening or invagination of the enamel organ into the dental papilla during tooth development. In addition, DI is a malformation with varying anatomical features, which poses numerous challenges to treatment. Endodontic treatment of dens in dente is one of the most complica-ted cases of DI. Herein, an immature lateral incisor that employed regenerative endodontic treatment was presented. The mentioned tooth was diagnosed with DI, pulp necrosis, and chronic apical periodontitis. Hence, a favorable prognosis has been shown by a 2-year review with cone beam computed tomography. The tooth was functional with normal periodontal parameters and exhibited a normal response to the electric pulp sensibility test. Thus, regenerative endodontic treatment can also be recommended to endodontists for teeth with DI.
Humans ; Regenerative Endodontics ; Incisor/diagnostic imaging* ; Dens in Dente ; Dental Pulp Necrosis/therapy* ; Odontogenesis