Odontogenic keratocyst (OKC) shows a high rate of recurrence, so aggressive treatment has been recommended. However, if the patient is a child and still has unerupted permanent teeth in the region of the OKC, aggressive treatment may not be the best option. We report herein a case of multiple OKCs in a pediatric patient treated using marsupialization five times and enucleation twice. Recurrence was not observed after surgical treatments in 7 years of follow-up. We suggest that treatment with marsupialization should be considered as the first-line treatment strategy for young patients with OKC.
The term odontogenic keratocyst (OKC) was first used by Philisen in 1956 and the histological criteria and features of OKC were first described by Pindborg and Hansen in 1963 . However, the World Health Organization (WHO) reclassified and renamed OKC as keratocystic odontogenic tumor (KCOT) due to its aggressive behavior, high recurrence rates and specific histological characteristics. The WHO defined KCOT as “a benign uni- or multi-cystic, intraosseous tumor of odontogenic origin, with a characteristic lining of parakeratinized stratified squamous epithelium and potential for aggressive, infiltrative behavior . However, in 2017 the new WHO classification of head and neck pathologies reclassified KCOT back into the cystic category and returned to the term “odontogenic keratocyst” .
The OKC occurs with a peak incidence in the second to third decade of life, and is rare in children under 10 years old . The recurrence rate of OKC has been reported as 2.5%–62.5% . Recurrence has been attributed to incomplete removal or the presence of epithelial remnants or satellite cysts in the osseous margin . Aggressive treatment of this lesion has thus been recommended to prevent recurrence. However, if the patient is a child and still has unerupted permanent teeth in the region affected by OKC, the decision to perform aggressive treatment may be difficult.
In this study, we report a case of OKC in a pediatric patient treated using marsupialization five times and enucleation twice due to multiple OKCs, with follow-up continued for approximately 10 years. The patient and her guardians provided informed consent for publication of this paper.
An 8-year-old girl was referred to the Department of Pediatric Dentistry at Osaka Dental University Hospital, Osaka, Japan, with a chief complaint of pressure pain and swelling in the right anterior region of the mandible. No relevant medical history was elicited and there was no family history of dental anomalies.
No abnormalities were evident on clinical extraoral examination. Intraoral examination showed slight buccal swelling around the mandibular right primary lateral incisor and primary canine ( Fig. 1 a).
Panoramic radiography revealed congenital absence of seven permanent premolars (all permanent premolars except for the maxillary left premolar) and a round radiolucency with well-demarcated sclerotic margins. The lesion had displaced the roots of the mandibular right permanent central incisor and primary lateral incisor, and also the crowns of the unerupted mandibular right permanent lateral incisor and canine ( Fig. 1 b).
Computed tomography revealed a round, well-defined, expansive, hypodense lesion involving the mandibular right lateral incisor and canine ( Fig. 1 c).
First surgical treatment (right side of mandible)
Under local anesthesia, the mandibular right primary lateral incisor and primary canine were extracted, and marsupialization was performed.
Histological examination of the excised lesion revealed the characteristics of OKC. The cyst wall consisted of fibrous connective tissue and continuous thin stratified squamous epithelium that appeared parakeratinized.
The luminal surface of the cyst presented with corrugated epithelial cells. The cyst was diagnosed as OKC. Infiltration of lymphocytes and plasmacytes into the cyst wall was observed ( Fig. 2 ).
After surgical treatment, a lingual arch was used to maintain the spacing of the permanent teeth.
Five months after the first treatment (when the patient was 8 years 8 months old), panoramic examination showed that the lesion had become smaller and the impacted teeth had resumed a normal eruption path. However, another radiolucency was identified around the maxillary left canine ( Fig. 3 ).
Second surgical treatment (left side of maxilla)
Ten months after the first treatment (when the patient was 9 years old), the maxillary left primary canine was extracted, and marsupialization was performed under local anesthesia. Histological examination of the excised lesion revealed the characteristics of OKC.
Seven months after the second surgery (when the patient was 9 years 7 months old), another radiolucent, well-defined lesion was found around the unerupted maxillary right canine ( Fig. 4 ).
Third surgical treatment (right side of maxilla)
Eight months after the second treatment (when the patient was 9 years 8 months old), the maxillary right primary canine was extracted, and marsupialization was performed under local anesthesia. Histological examination of the excised lesion revealed the characteristics of OKC.
Three months after the third surgical treatment (when the patient was 9 years 11 months old), panoramic examination revealed continuous eruption of the permanent mandibular lateral incisor and canine. However, another well-defined radiolucency was observed around the unerupted mandibular left canine ( Fig. 5 ).