Abstract
Background
Tooth anomalies may occur during the various developmental stages.
Case presentation
A 2Y3M-old Japanese girl came to our clinic. At 1Y8M, the mandibular left primary central incisor had erupted with little or no crown formation, and also showed dysplasia and pulp exposure. Root canal treatment was performed at the first visit, with crown restoration performed with composite resin. The permanent tooth germ showed the same development as the contralateral one.
Conclusion
Symptoms observed in the affected tooth were somewhat similar to those in regional odontodysplasia cases. Careful follow-up examinations until permanent tooth replacement will be necessary.
1
Introduction
Various tooth anomalies, related to number, structure, size, and shape, can occur when the developmental stage is affected [ ]. Although the etiology of such abnormalities remains largely unknown, local factors, such as space restriction during development, local trauma, excessive occlusal force, or local infection after development, and also systemic factors, including anomalies associated with pregnancy, nutritional deficiency, endocrine influence, infectious or inflammatory processes, excessive ingestion of medication, or hereditary or congenital diseases, may be responsible for related developmental disturbances [ , ].
The classification “Structural developmental anomalies of teeth and periodontal tissues” is noted in the World Health Organization (WHO) International Classification of Disease-11 (ICD-11) [ ]. Additionally, anomalies related to tooth size and form are listed in ICD-11, including fusion, dens evaginatus, dens in dente, macrodontia, microdontia, taurodontism, talon cusp, shovel teeth, conical teeth, and globodontia. Among disorders related to tooth development, amelogenesis imperfecta is also noted, which includes hypocalcified amelogenesis imperfecta and hypomaturation amelogenesis imperfecta, as well as dentine dysplasia, dentinogenesis imperfecta, and odontogenesis imperfecta [ ].
Teeth with enamel hypomineralization are easily affected by dental caries [ , ]. In addition, abscess formation is often observed in teeth with abnormal dentin, even in those without caries [ ]. A tooth development abnormality leads to malocclusion, resulting in poor oral hygiene and increased dental caries risk [ ]. Therefore, it is important to consider management of affected patients for dental caries prevention and/or treatment, as well as crown restoration and dental occlusion.
Herein, details of a child patient who underwent treatment for a mandibular left primary incisor with abnormal crown formation, and hypoplasia of enamel and dentin are reported. Informed consent was obtained from the parents for publication of this case report and the accompanying images.
2
Case report
A 2-year-3-month (2Y3M)-old Japanese girl was referred to the Pediatric Dentistry Clinic of Osaka University Dental Hospital for diagnosis and treatment of dental hard tissue that had erupted in the mandibular left primary central incisor area. Eruption of the left mandibular primary central incisor did not occur until 1Y8M, after which hard tissue with an abnormal morphology began to erupt. Her mother had no abnormalities during pregnancy, and delivery occurred after a gestation period of 39 weeks, with the newborn having a length of 49.5 cm and weight of 3200 g. Development was normal, with no findings of systemic disease. Primary tooth eruption began with the maxillary central incisor at around 0Y8M. As for related family history, a cousin had a tooth number deficiency.
Intraoral examination findings obtained at the first visit showed eruption of dental hard tissue in the area of the mandibular left primary central incisor, considered to be a primary tooth, with little or no crown formation, enamel hypoplasia and pulp exposure with scant bleeding observed ( Fig. 1 ). There was no pain noted in the affected tooth area, while a small amount of bleeding from the root canal was observed, with no gingival abscess or fistula. Other primary teeth extending to the first molar had erupted, with no morphological abnormalities or hypoplasia. Dental radiograph results indicated that the hard tissue likely corresponded to a mandibular primary central incisor, while root formation was normal and complete without a periapical lesion ( Fig. 2 ). The pulp chamber was narrowed as compared to that of the other teeth, and the dentin-enamel junction showed a blurred demarcation. No abnormalities were observed in the tooth germ of the succedaneous tooth.
Although the option of waiting was considered, due to the patient being unable to cooperate with dental care because of age, immediate treatment was determined necessary because of the exposed pulp. Root canal treatment for the mandibular left primary central incisor was started at the first visit, and a calcium hydroxide preparation (Vitapex®︎) was applied. At 2Y4M, no inflammatory symptoms such as pain or gingival abscess were observed, and dental radiography showed no abnormal findings such as root apex transparency ( Fig. 3 ). Thus, the root canal orifice was sealed with use of composite resin.
Regular checkups were continued at three-month interval. At 3Y4M of age, the crown was restored with a composite resin crown, as the patient had become accustomed to dental treatment ( Fig. 4 ). At the time of writing, no abnormal findings, such as dehiscence of the composite resin crown, reduction in Vitapex amount, or root apex lesions, have been observed. Furthermore, the permanent tooth germ is at the same level of development as the contralateral tooth, indicating good progress.
