Epidemiological and Clinical Features of Regional Odontodysplasia in South Korean Pediatric Patients: A Multicenter Case Series Study

Abstract

Background: Regional odontodysplasia (RO) is a rare developmental dental anomaly with unknown prevalence. Current knowledge is largely limited to individual case reports.

Aim: This study aims to present epidemiological data, clinical features, and radiographic characteristics of pediatric and adolescent patients with RO in South Korea.

Design: In this multicenter cohort study, we prospectively and retrospectively recruited participants from 11 university dental hospitals. Patients aged < 19 years diagnosed with RO were included in this study. In prospective cases, epidemiological information, family history, and clinical and radiographic data were collected after obtaining parental consent. All data were anonymized and stored using a study-specific data management system.

Results: Age at diagnosis ranged from 2 to 12 years, with a higher incidence in males. RO was more commonly observed in the maxilla, and all patients exhibited delayed eruption and development. The treatment approaches vary widely and include observation, extraction, pulp therapy, crown restoration, prosthetic rehabilitation, and orthodontic treatment.

Conclusion: This multicenter study provides the first comprehensive dataset on RO in Korean children and adolescents. These findings will contribute to the development of clinical guidelines and inform future healthcare policies for the management of rare dental anomalies.

Keywords: cohort; dental rare disease; multicentered; regional odontodysplasia.

FIGURE 1

Locations of the 11 university dental hospitals in South Korea participating in the multicenter study on rare dental developmental disorders.

FIGURE 2

Case 1 (Patient 5). Intraoral photograph and panoramic radiograph at first visit. (A) Intraoral photo showing affected teeth in the right mandibular quadrant. Tooth #81 was congenitally missing, and #84 had been extracted. Teeth #82, #83, and #85 appeared smaller and exhibited enamel hypoplasia. Other quadrants showed normal development. (B) Panoramic radiograph showing ghost‐like appearances in teeth #41, #43 (tentative numbering), #82, #83, #85, and #46. Delayed development was observed in #41, #43 and #46. No abnormalities were observed in the remaining quadrants.

FIGURE 3

Case 1 (Patient 5). Intraoral photos and radiographic views around age 9 years. (A) Periapical view at 8Y4M showing periapical lesions in #82 and #83 and an enlarged dental follicle in #41. (B) Panoramic radiograph showing extraction of #41, #82, and #83. (C) Intraoral photo without flexible denture. (D) Intraoral photo with flexible denture in place.

FIGURE 4

Case 1 (Patient 5). Intraoral photo and panoramic view at age 12Y3M. (A) Intraoral photo during orthodontic treatment showing gingival abscess on #46. Endodontic treatment was performed on #46 due to caries and a periapical lesion. (B) Panoramic view at 12Y3M, showing initiation of orthodontic treatment for intrusion of #16 and alignment of the maxillary dentition.

FIGURE 5

Case 2 (Patient 9). Intraoral photographs and radiographic images. (A) Intraoral photographs (frontal, lateral, and occlusal views). A gumboil is visible on the buccal gingiva of #45. Enamel hypoplasia with yellow discoloration and a chalky surface is present on #41 and #42. Teeth #44 and #45 are partially erupted, with enamel hypoplasia also seen on #46. Teeth #41 and #42 show smaller crown size compared to #31 and #32. (B) Panoramic view taken at the first visit showing congenitally missing #43 and a ghost‐like appearance of #42, #44, and #45, in contrast to the normal appearance of the contralateral lower teeth. Short roots are observed in #41 and #42 compared to #31 and #32, with delayed development noted in #41, #42, #44, and #45. (C) CBCT sagittal view showing a periapical lesion on #45, with a large pulp chamber and incomplete root formation. The boundary between enamel and dentin is indistinct in #44 and #45.

FIGURE 6

Case 2 (Patient 9). Follow‐up intraoral photos and radiographs. (A) Intraoral photograph, and periapical view following regenerative endodontic treatment of #45. (B) Intraoral photograph and periapical view after SS crown restorations on #45 and #46. Apex closure is observed in #45. (C) Panoramic radiograph taken 2 years and 7 months after the initial visit, at the age of 15.

FIGURE 7

Case 3 (Patient 3). Gross anatomical findings. At age 5Y4M, tooth #84 was extracted. (A) Comparison of an RO‐affected primary first molar with a normal counterpart. The affected tooth appears markedly smaller and has an underdeveloped root. (B) The crown is reduced in size, with yellow‐brown discoloration associated with enamel hypocalcification and hypoplasia. Surface irregularities include grooves and pitting. The root is defective and underdeveloped, appearing short, thin, and disrupted.

FIGURE 8

Case 3 (Patient 3). Histological features of the extracted RO‐affected tooth stained with hematoxylin and eosin. All dental tissues show pathological alterations. (A) Pulp: The pulp chamber is markedly enlarged with pulpal calcifications (middle blue arrow) and (B) Dentin: Numerous interglobular areas, globular masses, dentinal clefts, and structural discontinuities are present. (C) Root area: (Right) Widened predentin zone with relatively less abnormal cementum; (Left) the presence of extensive inflammatory tissue in the apical region suggests a periapical abscess.

FIGURE 9

Flowchart for managing regional odontodysplasia.