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*

Objective: To summarize the clinical characteristics of patients with cleidocranial dysplasia (CCD) and analyze their treatment methods. Methods: From January 2000 to December 2020, patients with CCD who completed comprehensive treatment in the Department of Orthodontics and the First Dental Clinic, School and Hospital of Stomatology, China Medical University were retrospectively analyzed. A total of 14 CCD patients [7 males and 7 females, aged (16.1±4.5) years] were collected. There were 153 impacted permanent teeth in this study. In addition to the teeth that needed to be extracted due to special conditions, 147 impacted teeth were pulled into the dentition using closed traction. Patients were divided into adolescent group (≥12 years and<18 years, 10 patients) and adult group (≥18 years, 4 patients). Failure rate of traction was compared between the two groups. Factors affecting the success rate of closed traction such as vertical position of teeth (high, middle and low) and horizontal position of the teeth (palatal, median and buccal) were analyzed. Results: The incidence of maxillary impacted teeth [69.3% (97/140)] was higher than that of mandibular impacted teeth [40% (56/140)]. The difference was statistically significant (χ²=24.22, P<0.001). The supernumerary teeth were mainly located in the premolar area 61.4% (21/44), and most of them were in the palatal region of the permanent teeth 95.5% (42/44). They were generally located at the same height or the occlusal side of the corresponding permanent teeth. The success rate of closed traction was 93.9% (138/147). The success rate in the adolescent group [98.2% (108/110)] was higher than that in the adult group [81.1% (30/37)], and the difference was significant (χ²=14.09, P<0.05). Failure after closed traction of 9 teeth was found totally, including 7 second premolars. The success rate of traction in impacted second premolars at different vertical (χ²=11.44, P<0.05) and horizontal (χ²=9.71, P<0.05) positions in alveolar bone was different significantlly. The success rates of the second premolars were high (15/16), middle (12/13), low (2/7), and lingual palatine (10/17), median (19/19), lip-buccal (0/0), respectively. Conclusions: The closed traction of impacted teeth in patients with CCD was effective, and the age was the main variable affecting the outcome. The success rate of traction in impacted second premolars located in low position vertically or in palatal position was low, which required close observation during treatment.
Adolescent ; Adult ; Bicuspid ; Child ; Cleidocranial Dysplasia/therapy* ; Female ; Humans ; Male ; Mandible ; Retrospective Studies ; Tooth, Supernumerary/surgery* ; Young Adult

OBJECTIVE: To explore the application of digital positioning guide plate in extraction of impacted supernumerary teeth and evaluate its clinical efficacy. METHODS: From March to August, 2019, 30 patients with labial impacted supernumerary teeth treated in the Department of Oral and Maxillofacial Surgery, Stomatological Hospital, Southern Medical University were enrolled in this study. Fifteen of the patients were treated with digital positioning guide plate to remove the impacted supernumerary teeth (test group). According to the CBCT data and the dentition model of the patients, the positioning guide plate was positioned by avoiding the important anatomical structure with the tooth-bone surface as the support to design the soft tissue incision line and bone tissue exposure range. The other 15 patients who were treated without the use of the guide plate for operation served as the control group. The design time, tooth searching time, operation time and complications were compared between the two groups. RESULTS: The positioning guide plate was well attached during the operation and allowed quick location of the supernumerary teeth while helping to expose the supernumerary teeth and avoid the damage of the adjacent important anatomical structures. The pre-operative design time was 50 ± 5 min in the test group and 0 min in the control group. The average time of tooth finding in the test group was 5±2 min, as compared with 10±3 min in the control group (=15.40, < 0.01); the average time of operation was significantly shorter in the test group than in the control group (25±4 min 45±6 min; =35.50, < 0.01). No intraoperative complications occurred in the test group, and slight deviation occurred in one case in the control group. CONCLUSIONS The application of digital positioning guide plate in extraction of embedded supernumerary teeth can significantly shorten the time of tooth finding, reduce the difficulty of operation, and improve the quality of operation.
Bone Plates ; Bone and Bones ; Humans ; Operative Time ; Tooth Extraction ; Tooth, Impacted ; Tooth, Supernumerary

PURPOSE: The prevalence of supernumerary teeth has been reported to be between 0.1% and 3.8%. The aim of this study was to determine the prevalence, clinical significance, and associated pathologies of fourth molars based on a retrospective study and a literature review. MATERIALS AND METHODS: A 5-year retrospective prevalence study was conducted at the Department of Oral Diagnosis and Dentomaxillofacial Radiology of Okayama University Hospital, Okayama, Japan. The study involved extracting data from the digital records of patients from January 1, 2013 through December 31, 2017. The sampling frame included all patients who had panoramic radiographs, cone-beam computed tomography (CT), and multislice CT images during the period under review. RESULTS: A total of 26,721 cases were reviewed and 87 fourth molars were identified. The prevalence of fourth molars in the 5-year study at Okayama was calculated as 0.32%. The mean age of patients with a fourth molar was 30.43 years, and the male-to-female ratio was 1:0.98. The vast majority of cases were in the maxilla (92%) and had normal shapes (89.7%); furthermore, 82.8% of cases were unerupted. CONCLUSION: The prevalence of fourth molars in the study population was found to be 0.32%, and fourth molars occurred with approximately equal frequency in males and females. Fourth molars were more common in the maxilla and were predominantly unerupted and small.
Cone-Beam Computed Tomography ; Cross-Sectional Studies ; Diagnosis, Oral ; Female ; Humans ; Japan ; Male ; Maxilla ; Odontogenic Cysts ; Odontoma ; Pathology ; Prevalence ; Retrospective Studies ; Tooth, Supernumerary

OBJECTIVE: To study the application of surgical locating guides based on cone beam computed tomography (CBCT) and computer-aided design/computer-aided manufacturing (CAD/CAM) technique on extraction of impacted supernumerary teeth. METHODS: This study included 15 patients with impacted supernumerary teeth in anterior maxillary. Surgical approach was determined by CBCT. Surgical locating guides of labial approach or palatal approach were designed and fabricated by CAD/CAM technique. Impacted supernumerary teeth were extracted under the location of surgical locating guides. RESULTS: Surgical locating guides were well attached in the operation. The impacted supernumerary teeth were located and exposed rapidly, and the adjacent important anatomical structures were avoided. CONCLUSIONS Surgical locating guides benefit the accurate detection and reduction of trauma in extraction of impacted supernumerary teeth.
Cone-Beam Computed Tomography ; Humans ; Maxilla ; Tooth Extraction ; Tooth, Impacted ; Tooth, Supernumerary

The aim of this study was to analyze cells from human dental pulp tissue of impacted supernumerary teeth as stem cells with flow cytometry. Human dental pulp cells from 15 supernumerary teeth were identified their characteristics as stem cells by expression of mesenchymal stem cell markers through flow cytometry analysis at passage 3 and passage 10. Cluster of differentiation (CD) 73, CD 90, CD 34, CD 45 and STRO-1 cell surface markers were used to figure out characteristics of dental pulp stem cells from supernumerary teeth. At passage 3, the cell population showed positive expression of CD 73, CD90 and STRO-1, lacked expression of CD 34 and CD 45. At passage 10, CD 73, CD 90 and STRO-1 showed positive expression while CD 34 and CD 45 showed negative expression. This study indicated that dental pulp stem cells of supernumerary teeth had the properties of mesenchymal stem cells at both early and late passage. Impacted supernumerary teeth could be considered as a noble source of stem cells because of rapid growth and maintaining characteristics of stem cells until late passage.
Dental Pulp ; Flow Cytometry ; Humans ; Mesenchymal Stromal Cells ; Stem Cells ; Tooth, Supernumerary

Cleidocranial dysplasia (CCD) is an autosomal-dominant disease characterized by the delayed closure of cranial sutures, defects in clavicle formation, supernumerary teeth, and delayed tooth eruption. Defects in the Runt-related transcription factor 2 (RUNX2), a master regulator of bone formation, have been identified in CCD patients. The aim of this study was to identify the molecular genetic causes in a CCD family with delayed tooth eruption.The 23-year-old female proband and her mother underwent clinical and radiographic examinations, and all coding exons of the RUNX2 were sequenced. Mutational analysis revealed a single nucleotide deletion mutation (NM_001024630.4 : c.357delC) in exon 3 in the proband and her mother. The single C deletion would result in a frameshift in translation and introduce a premature stop codon [p.(Asn120Thrfs*24)]. This would result in the impaired function of RUNX2 protein, which may be the cause of delayed eruption of permanent teeth in the family.
Clavicle ; Cleidocranial Dysplasia ; Clinical Coding ; Codon, Nonsense ; Core Binding Factor Alpha 1 Subunit ; Cranial Sutures ; Exons ; Female ; Humans ; Molecular Biology ; Mothers ; Osteogenesis ; Sequence Deletion ; Tooth ; Tooth Eruption ; Tooth, Supernumerary ; Transcription Factors ; Young Adult

This report describes 3 cases of cleidocranial dysplasia (CCD) and presents relevant findings on long-term follow-up radiographic images of impacted permanent teeth with delayed eruption. Radiographic images of 3 CCD patients were reviewed retrospectively. These images were mainly composed of panoramic and skull radiographs, and the follow-up periods were 3, 13, and 13 years, respectively. The distinct features revealed by the images were described, and the eruption state of impacted permanent teeth was evaluated. The features common to the 3 cases were multiple supernumerary teeth, the presence of Wormian bone, underdevelopment of the maxilla and the maxillary sinus, and clavicular hypoplasia. The eruption of impacted permanent teeth was not observed without proper dental treatment in adult CCD cases, even after long time periods had elapsed. When proper orthodontic force was applied, tooth movement was observed in a manner not significantly different from the general population.
Adult ; Cleidocranial Dysplasia ; Follow-Up Studies ; Humans ; Jaw ; Maxilla ; Maxillary Sinus ; Radiography ; Retrospective Studies ; Skull ; Tooth Movement ; Tooth ; Tooth, Supernumerary

The purpose of this study is to compare the properties of dental pulp and periodontal ligament stem cells from extracted supernumerary teeth by quantitative real-time PCR.Impacted supernumerary teeth in the maxillary anterior region were extracted. Dental pulp and periodontal ligament cells were collected from extracted supernumerary teeth on the same day. After isolation and culture of cells, compare characterization of them by using qRT-PCR. Primer sequences for odontoblasts are ONT, ALP, OCN, DMP-1 and DSPP.On dental pulp group, ONT has the largest quantity of gene expression, followed by OCN, ALP, DMP-1 and DSPP. On periodontal ligament group, ONT has the largest quantity of gene expression, followed by OCN, ALP, DSPP and DMP-1. Analysis of quantitative gene expression data using relative quantification showed that the expression of all genes decreased in periodontal ligament cells.Dental pulp and periodontal ligament stem cells from supernumerary teeth have the properties of odontoblasts. Considering that properties, supernumerary teeth were considered a useful donor site of dental pulp and periodontal ligament stem cells.
Dental Pulp ; Gene Expression ; Humans ; Odontoblasts ; Periodontal Ligament ; Real-Time Polymerase Chain Reaction ; Stem Cells ; Tissue Donors ; Tooth, Supernumerary

This study was conducted to investigate the characteristics of subculture times in the early, middle, and late passages by measuring the time under subculture until it was judged that the supernumerary tooth-derived pulp stem cells (sDPSCS) were no longer proliferating. Three supernumerary teeth from two healthy six-years old boys were extracted and stem cells were obtained from the pulp tissue. This was called SNT1 (supernumerary tooth 1), SNT2, and the supernumerary tooth from another child was named SNT3. SNT1 and 2 were subcultured at the same time and SNT3 was subcultured a little faster. The mean time of complete subculture was 3.6 ± 1.1 days. Total passages were cultured up to 23.3 ± 0.6 and took 83 days. These were divided into three groups based on the passage. The increase rate of time taken in subculture between group I and group II was 11.9%, but the rate between group II and group III was 28.6%, which was 2.4 times increased. The time taken between passages during long-term subculture up to 22 passages shows a regressive pattern y = 0.1169x + 2.25 and y = 0.1169x + 2.0. In conclusion, the passage time of SPSCs increased in late passages, and it shows a similar pattern.
Child ; Humans ; Stem Cells ; Tooth ; Tooth, Supernumerary