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*

There is a high incidence of chronic periapical periodontitis of deciduous teeth, however, there is a low incidence of the apical cyst. This paper reports a 7-year-old child with deciduous periodontitis caused by chronic periapical periodontitis of deciduous teeth. Through literature review, the etiology, imaging characteristics, diagnosis, differential diagnosis, and treatment methods were discussed to provide the basis for clinical diagnosis and treatment.
Child ; Humans ; Cysts ; Diagnosis, Differential ; Periapical Periodontitis/therapy* ; Tooth, Deciduous

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

Early orthodontic treatment refers to the orthodontic treatment of dental-maxillofacial deformities in the early deciduous or mixed dentition. More and more attentions has been paid to early orthodontic treatment. Many kinds of orthodontic appliances are emerging on the market with the rapid development of the orthodontic technology. At the same time, problems and increased risks have followed in early orthodontic treatment. The contents of the article include the establishment of deciduous occlusion and the characteristics of the deciduous dentition, the orthodontic principles of different stages of deciduous dentition, the oral bad habits during the deciduous dentition and the risk control of early orthodontic treatment.
Dental Occlusion ; Dentition, Mixed ; Humans ; Malocclusion/therapy* ; Orthodontic Appliances ; Tooth, Deciduous

OBJECTIVE: To evaluate the efficacy of iRoot BP Plus, a novel bioceramic material, and mineral trioxide aggregate (MTA) by comparing the clinical and radiographic results of pulpotomy in human primary molars, and to find out the influence factor. METHODS: Children who had at least one primary molar diagnosed as pulpitis, and received pulpotomy in the Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology from January, 2017 to December, 2018 were searched by the selection criteria in the Electronic Medical Record Database of Peking University School and Hospital of Stomatology. The molars with the pulp capping agents were iRoot BP Plus or MTA were included, and the molars with other pulp capping agents were excluded. Molars using iRoot BP Plus were selected into the experimental group (iRoot BP Plus group). Molars using MTA were selected into the control group (MTA group) using propensity score matching model (1 ∶ 1), considering the gender, age, tooth position, the title of clinician, pulp status, restoration and length of follow-up as the potential influence factor. Basic information, the relevant medical records including symptoms, clinical and radiographic examination before and after operation, intraoperative information and follow up examination records were collected. The success rates were compared and the influence factors were analyzed respectively. RESULTS: The study included 132 children, 178 molars (89 molars from each group) and the mean follow-up time was (462±99) days by December, 2019. In the iRoot BP Plus group, 9 molars failed whilst 6 molars failed in MTA group. The success rate was 89.9% and 93.3%, respectively, showing no significant difference between the two groups. Through Cox proportional risk model analysis, the success rate of iRoot BP Plus was significantly lower when the pulp status was poor, while other factors including age, tooth position, title of clinician and restoration were not found to be associated with the clinical outcome. CONCLUSION Pulpotomy of human primary molars with iRoot BP Plus has the same effectiveness with MTA. The pulp status is the main factor that influences the outcome of iRoot BP Plus. Further studies with larger sample sizes and longer follow-up terms are needed.
Child ; Humans ; Pulpotomy/methods* ; Pulp Capping and Pulpectomy Agents ; Pemetrexed ; Silicates/therapeutic use* ; Aluminum Compounds/therapeutic use* ; Calcium Compounds ; Oxides ; Molar/surgery* ; Drug Combinations ; Treatment Outcome ; Tooth, Deciduous

OBJECTIVE: To explore the construction process of the digital reference crown models, and to initially establish the digital reference crown models of the primary teeth to lay the foundation for the establishment of the standardized crown models and the future related applications of computer-aided design/computer-aided manufacture (CAD/CAM) technology to pediatric dentistry. METHODS: This study randomly selected children who were caries free, aged from 4 to 5 years in several kindergartens of Haidian District of Beijing.Plaster dental models were made for the children after taking complete impressions.The digital dental models were reconstructed by using the three-dimensional (3D) dental model scanner.And then, Geomagic Studio, a 3D reverse engineering software, was employed to extract the single dental crown data, the mesiodistal and buccolingual diameters and the height of the crowns were measured.The object was reduced or enlarged by a numerical factor, and then the size of each dental crown was standardized.A total of 3-5 points features on the crown were created, and all the objects were aligned through the functions of feature-based alignment.Finally, through average-based object creation and smoothing, the digital models of reference crowns of the primary teeth were established. RESULTS: A total of 40 plaster dental models from 16 boys and 26 girls were selected out for our further study.The digital dental models were reconstructed, and the mesiodistal and buccolingual diameters and the height of the crowns were measured by using reverse engineering technology.Comparing the results of using mesiodistal diameter, buccolingual diameter and height as the standards, we chose the mesiodistal diameters of crowns to do the standardization, and successfully established the digital reference models of 20 primary teeth crowns with detailed surface characteristics. CONCLUSION In this study, the digital reference crown models of the primary teeth were established by reverse engineering technology, providing reference value for the standardized crown models and application for clinical practice, scientific research and teaching.Furthermore, this study also contributes to the extensive application of CAD/CAM technology in pediatric dentistry and the development of CAD/CAM dental systems with independent intellectual property rights.
Child ; Computer-Aided Design ; Crowns ; Dental Prosthesis Design ; Female ; Humans ; Male ; Software ; Tooth Crown ; Tooth, Deciduous

Devitalization has been widely used in the root canal therapy of primary and permanent teeth in China more than ten years ago. With the development of local anesthetic drugs and injection technologies, this treatment method with high potential risks has been gradually abandoned. However, a questionnaire survey targeted all the participants at the 2018 China Pediatric Dentistry Conference showed that the devitalizer utilization proportion was still as high as 38.1% (383/1 005), even though the ratio was much lower than 75.5% (105/139) in 2003. These doctors had pay more attention to tissue burn caused by devitalizer marginal leakage or direct leakage, and know how to identify and handle with devitalizer burn. Devitalizers were usually made of arsenic trioxide, metal arsenic or paraformaldehyde, which have cytotoxicity, allergenicity, mutagenicity, carcinogenicity, and teratogenic effects on animals. Marginal leakage of devitalizers have high risks of causing soft and hard tissue necrosis. Most of the dentists have an understanding of the potential damages of arsenic containing devitalizers, so they will choose parafor maldehyde with relatively less toxicity. Paraformaldehyde has a certain self limitation, and there are few cases reported, so some dentists lack of vigilance. Paraformaldehyde can also causes tissue necrosis if leakage happens, and the treatment methods are similar to that of arsenic containing devitalizers. When handling with devitalizers burn, the necrosed soft and hard tissue, for example gingiva, alveolar bone or teeth that cannot keep, must be completely removed until fresh blood appears, then rinse with large amount of saline and seal with iodoform gauze. This paper described two cases of devitalizer burn during the root canal treatment of primary molars, both of the doctors failed to identify the devitalizer burn symptoms in the early stage, thus didn't do proper treatments immediately after burning. Resulting in the necrosis of large area of gingiva and alveolar bone, loss of primary molars and permanent tooth germs 1-2 months after devitalizer burn. This paper reported these two cases in detail in order to warn dentists the high risks of using any kind of devitalizers, help them learn how to identify and treat devitalizer burn, and remind them to stop using devitalizers as soon as possible.
Arsenic/toxicity* ; China ; Dental Pulp Devitalization ; Humans ; Necrosis ; Root Canal Therapy ; Tooth Germ ; Tooth Loss/chemically induced* ; Tooth, Deciduous

Infraocclusion is a phenomenon that the relative occlusal growth of a tooth stops after the period of active eruption and then the tooth becomes depressed below the occlusal plane. Infraocclusion occurred more commonly in children and the mostly affected teeth were the primary mandibular second molars. The occlusal problem caused by infraocclusion may progressively worsen with age. This review summarizes the etiology, diagnosis and treatment of infraoccluded second primary molars, so as to provide reference for the dental clinicians.
Child ; Humans ; Malocclusion/therapy* ; Molar ; Tooth Abnormalities ; Tooth Eruption ; Tooth, Deciduous

Lateral luxation injuries are common during childhood and in young adolescence. These injuries involve the surrounding tissues that could lead to extensive clinical treatment problems with a risk of pulpal complications such as pulp necrosis. A case of a healthy 4-year old Malay boy visiting the paediatric dental clinic after seven months of laterally luxated injury on the lower right lateral incisor (tooth 82) was reported. The traumatic tooth was splinted by a private practitioner three days after the trauma, however, the splint dislodged less than 24-hour after placement. In view of the mother’s fear of bringing her child to the dentist due to the COVID-19, no follow-up and further treatment were carried out. This has resulted in the development of discolouration and pulpal necrosis to the injured tooth. Lesion sterilization and tissue repair technique (LSTR) was performed. This report highlights the rare occurrence of lateral luxation injury on tooth 82 and the management of pulp necrosis as a complication via lesion sterilization and tissue repair technique due to the uncooperative behaviour of the child.
Tooth, Deciduous

This validation study aimed to provide a validated Malay language version of the Ages and Stages Questionnaire: Social Emotional-2 (ASQ:SE-2) as a developmental screening tool for the social emotional development of Malaysian toddlers. In this study, content validity determination, translation, cultural and lingual modifications, and construct validity were made to the original English version of ASQ:SE-2. A pilot study was conducted to determine the internal consistency and construct validity of ASQ:SE-2 18-Month and 36-Month Questionnaires, with 100 respondents for each instrument, respectively. Test-retest reliability was conducted on 60 respondents for each instrument, respectively. Acceptable internal consistency was obtained based on Cronbach’s alpha of 0.731 and 0.686 for ASQ:SE-2 18-Month and 36-Month Questionnaires, respectively. Reproducibility of both sets of instruments are excellent, with Intraclass Coefficient of 0.922 and 0.970 for 18-Month and 36-Month Questionnaires, respectively. The Malay Language version of the ASQ:SE-2 has appropriate validity and reliability for screening social emotional developmental of Malaysian toddlers.
Tooth, Deciduous