Ⅰ. INTRODUCTION
Paradental cysts (PCs) are cystic lesions that develop near the cervical margin on the lateral aspect of a tooth root, mostly originating from inflammatory processes within the periodontal pocket1. Several authors believe that the reduced enamel epithelium and epithelial rests of Malassez are keys to the formation of PCs2. These epithelial remnants may proliferate in response to inflammatory stimuli, thus giving rise to PCs. The major clinical features of the PC are recurring inflammatory periodontal symptoms, including discomfort, tenderness, moderate pain, and suppuration3. These cysts frequently manifest on the buccal aspects of partially or fully erupted vital teeth and are commonly associated with mandibular third molars, though they may also affect the mandibular first and second molars4.
For mandibular third molars, the recommended treatment approach involves enucleation of the PC while extracting the affected tooth. Enucleation of the cyst while preserving the tooth is typically preferred for first and second molars5. Recurrence is infrequent if the cystic lesion is entirely removed 6. However, enucleation of cysts in anatomically complex areas, such as the lingual aspect of the tooth, can be challenging. Therefore, intentional replantation (IR) is a viable alternative to achieve complete cyst removal while conserving the associated tooth.
Intentional replantation (IR), used predominantly for endodontic lesions, has been practiced for over a millennium. This procedure involves tooth extraction, endodontic treatment, apical repair, and immediate replantation7. IR is indicated for teeth with anatomic limitations, accessibility issues, or persistent chronic pain and patients who have cooperation issues or refuse to undergo periapical surgery. The success of IR depends upon maintaining strict aseptic conditions throughout the procedure8. Reported retention rates for intentionally replanted teeth range between 52% and 95%9. Despite its relative simplicity, IR may be accompanied by complications such as replacement resorption, which can adversely impact the long-term survival of the replanted tooth10.
This study presents the case of a 13-year-old female patient with delayed eruption of the mandibular left second molar, attributed to a cystic lesion located on the lingual aspect of the crown.
Ⅱ. CASE REPORT
A 13-year-old female presented to the oral and maxillofacial department of Kyungpook National University Dental Hospital, Korea, with a chief complaint of delayed eruption of the mandibular left second molar (Fig.1 A). Given her age, a decision was made to monitor the progress of eruption. After six months, panoramic X-ray and cone-beam computed tomography (CBCT) revealed a cystic lesion on the lingual-coronal aspect of the mandibular left second molar, identified as the likely cause of delayed eruption (Fig.1 B & C). Due to the patient’s young age and the location of the cyst, enucleation of the lesion and replantation of the mandibular left second molar were planned under local anesthesia. The mandibular left second molar was extracted along with the cystic lesion (Fig.2 A). Subsequently, the cystic lesion was carefully removed from the tooth (Fig.2 B), followed by replantation. The tooth was splinted with wire to ensure stability (Fig.2 C).
Postoperatively, histopathological analysis confirmed the lesion to be a paradental cyst. The cystic lining consisted of non-keratinized stratified squamous epithelium with fibrous connective tissue containing blood vessels and variable inflammatory cell infiltrates (Fig.3 A & B). The patient was subsequently referred to the Conservative Dentistry department for evaluation and further management of the affected tooth (Fig.4 A). The resin-wired splint was removed three weeks postoperatively, and root canal therapy (RCT) was initiated. At the six-month follow-up, RCT was successfully completed without any observed complications (Fig.4 B).
The patient is receiving regular follow-ups at the outpatient department and the Conservative Dentistry department. The replanted tooth shows satisfactory stability with no detectable mobility.
Ⅲ. DISCUSSION
The term PC was initially introduced by Craig in 1976 to describe a cystic lesion associated with a partially erupted vital tooth that underwent recurrent episodes of pericoronitis 11. A study by Craig analyzed 49 cases from 48 patients and identified a consistent association with mandibular third molars. Later, Stoneman and Worth elaborated on its clinical and radiographic features and characterized the lesion as a mandibular infected buccal cyst or mandibular infected buccal bone cyst12. Their observations highlighted distinctive features, including swelling, radiolucency on the buccal aspect overlying the root, an intact periodontal ligament space, and a periosteal reaction on the buccal surface. These cysts were frequently linked to partially erupt permanent mandibular first molars. However, this case report presents a rare variant where the cyst was associated with the mandibular second molar and located on the lingual aspect of the tooth, differing from the commonly documented presentations.
The origin of PCs remains unclear as the epithelial source is still debatable13. Many researchers have hypothesized that the epithelium may be derived from reduced enamel epithelium; however, some researchers suggest alternative origins, including the junctional epithelium and epithelial remnants of Malassez2. PCs are attached to the cervical-enamel junction (CEJ), which generally has a cervical enamel projection— a feature more commonly observed in molars and predominantly on the buccal surface. This study reports an atypical presentation of the cyst occurring in the lingual-coronal region of a mandibular second molar, a finding that contrasts with the usual occurrences described in the literature.
PCs are typically managed through thorough enucleation while preserving the affected tooth. However, the lingual position of the cyst posed significant access challenges in this case. Consequently, the authors used a combined approach of IR and enucleation. This operative technique successfully saved the involved teeth and guaranteed further stability. IR involves tooth extraction, cyst enucleation, and tooth replantation into its original alveolar socket14. A critical component of IR is the completion of RCT, ideally conducted by an endodontist before or during the procedure. The principal risk of failure in IR is external inflammatory resorption, primarily due to prolonged extra oral exposure time15. Therefore, it is crucial to complete endodontic treatment before surgery.
This case report describes the management of a 13-year-old female patient presenting with delayed eruption of the mandibular left second molar, attributed to a cystic lesion on the lingual-coronal aspect of the tooth. Due to the challenges presented by the location of the lesion, standard enucleation alone was considered inadequate. Therefore, the authors used a combined treatment approach involving IR followed by enucleation to ensure comprehensive cyst removal while preserving the affected tooth. The patient remains under regular follow-up at the outpatient clinic and shows favorable progress. Continued monitoring of tooth eruption and ongoing maintenance is recommended for future treatment planning.
