Ⅰ. INTRODUCTION

Localized juvenile spongiotic gingival hyperplasia (LJSGH) is a rare gingival condition that predominantly affects individuals aged <20 years, with an average onset between 11.8 and 13 years. Clinically, LJSGH is characterized by distinct red, granular, or papillary lesions that bleed easily. These lesions are predominantly sessile, with occasional pedunculated extensions to adjacent gingival areas. LJSGH typically involves the facial maxillary gingiva, particularly the roots of anterior teeth.^1-3 Lesions generally range in size from 2 mm to 10 mm, with a median diameter of 6 mm, and are often solitary.² Differential diagnoses often include puberty gingivitis, as gingival erythema in adolescents is commonly attributed to local inflammatory processes. However, LJSGH differs in that it does not respond to periodontal treatment. Additionally, it may be misdiagnosed as pyogenic granuloma, peripheral giant cell granulomas, or HPV-related lesions, particularly in cases of gingival overgrowth. In instances of diagnostic uncertainty, a biopsy is recommended to establish a definitive diagnosis.^3-5

Despite being a benign condition, surgical excision remains the primary treatment modality for LJSGH.⁶ However, this approach has limitations, including recurrence and aesthetic concerns. Although spontaneous regression has been proposed, documented cases of natural resolution are limited.⁴ In particular, few cases have been reported in Korea. This report highlights a case of LJSGH demonstrating complete self-limiting regression of a mandibular lesion.

Ⅱ. CASE REPORT

A 7-year-old boy presented to Wonkwang University Daejeon Dental Hospital with persistent gingival swelling following the exfoliation of his lower anterior primary teeth. According to his parents, a red lesion appeared approximately 1 month after exfoliation of the mandibular primary incisors. Clinical examination revealed a red, sessile lesion in the facial gingiva of the newly erupted lower incisors (Fig.1 A). An anterior deep bite was observed between the maxillary primary and mandibular incisors; however, there was no contact between the upper anterior teeth and the lower anterior gingiva.

Over the next 5 months, despite exfoliation of the maxillary primary incisors, which could have been a potential source of irritation, the lesion in the mandibular anterior region continued to enlarge, exhibiting increased swelling (Fig.1 B). With parental consent, an incisional biopsy was performed under nitrous oxide sedation to facilitate patient cooperation. Histopathological analysis confirmed a diagnosis of LJSGH (Fig.2 A & B). The lesion remained unchanged until the exfoliation of the lower right primary lateral incisor, at which point a new lesion appeared on the facial gingiva as its permanent successor erupted (Fig.1 C). After 16 months, the anterior mandibular lesion resolved completely without any intervention (Fig.1 D). The total time from the initial appearance of the lesion to complete resolution was 32 months.

Ⅲ. DISCUSSION

Histopathologically, LJSGH is characterized by a non-keratinized epithelium with intracellular edema (spongiosis) and neutrophil exocytosis, closely resembling the epithelial structure of the junctional or sulcular areas.^1-3 The etiology of LJSGH remains unclear, but it is hypothesized to originate from junctional epithelial remnants associated with primary teeth. These remnants may persist in the gingiva during the eruption of permanent teeth and, when exposed to external factors such as trauma or inflammation, lead to the development of LJSGH.^2,7-9 In this case, lesions appeared around the mandibular incisors after primary tooth exfoliation and permanent tooth eruption, supporting the hypothesis that LJSGH originate from junctional epithelial remnants exposed to external stimuli may trigger an inflammatory response.

Management of LJSGH includes various approaches, such as surgical excision, periodontal treatment, and observation. Among these, surgical excision is the most commonly performed treatment, with studies reporting it as the treatment of choice in 93.75% of LJSGH cases.⁶ However, the potential for natural regression, as indicated by LJSGH’s low prevalence in adults, warrants consideration of non-invasive approaches.¹ Despite this possibility, documented cases of natural resolution confirmed by biopsy remain rare, making it challenging for clinicians to confidently counsel patients about its likelihood.⁴ This case presents an instance of spontaneous regression, supporting conservative management options. Initially, the lesions appeared on the facial gingiva of the central mandibular incisors and later involved the region around the lateral mandibular incisors. Over a period of 32 months, the lesions regressed spontaneously without periodontal treatment or surgical intervention. These findings support the hypothesis that LJSGH lesions originating from odontogenic epithelial remnants may undergo keratinization and integrate into the gingival epithelium over time. This process of epithelial adaptation and maturation may explain the eventual resolution of LJSGH without active intervention, consistent with the natural history suggested in earlier studies.^2,9

From a clinical perspective, several factors should be considered when managing LJSGH. Surgical removal, while commonly performed, has been associated with recurrence rates ranging from 6% to 25% depending on the study.^1-3 Additionally, LJSGH predominantly affects the anterior gingiva in approximately 93% of cases, where surgical intervention poses a significant risk of compromising gingival aesthetics.⁶ Another important consideration is the potential for natural regression, as highlighted in this study, where lesions resolved spontaneously without surgical treatment.^4,10 Finally, in pediatric patients, limited cooperation can pose a significant challenge for surgical approaches, further emphasizing the value of observation as a viable management strategy.

In conclusion, although surgical excision remains a widely used approach, observation represents a reasonable alternative, particularly in cases where recurrence risks, aesthetic concerns, and patient cooperation are significant considerations. By presenting these cases, this study emphasizes the importance of reducing unnecessary surgical interventions and highlights observation as a viable management strategy for LJSGH.

One limitation of this case report is the lack of long-term follow-up after spontaneous resolution. Although studies have investigated recurrence rates following surgical excision, little is known about the recurrence of LJSGH after natural regression.^1-3 Further long-term studies are needed to better understand the prognosis of spontaneously resolving lesions.