Atypical presentation of lateral periodontal cyst associated with impacted teeth: two case reports

Odontogenic keratocystic can be misdiagnosed for a lateral periodontal cyst when the clinical and radiographical findings are similar

Lateral periodontal cyst (LPC) and odontogenic keratocystic (OK) are two osteolytic lesions of the jaw with different local invasiveness and percentage of recurrence. The aim of this study was to highlight the attention on the differential diagnosis of these lesions that sometimes can have unexpected location and can lead doubts on diagnosis, therapy, and follow-up. A 34-year-old man presented to our department with a complaint of soft pain in the vestibular aspect of left mandibular second premolar and left mandibular first molar. Vital teeth in the left mandible, no mucosal swelling, and no drainage were observed. The CBCT showed a well circumscribed hypodensity area, extending between 3.5 and the apex of mesial root of 3.6. No displacement and no resorption of the roots were notified. Upon clinical and radiographical examination, a provisional diagnosis of LPC was made and enucleation of the lesion and histological examination were planned. Histologically, a cystic wall partially lined by a keratinizing squamous epithelium was observed. Surrounding and within the lesion, there was a chronic inflammatory infiltrate also of granulomatous type and with cholesterol clefts. Based on these findings, the diagnosis of odontogenic keratocystic was done. Radiolucent lesions in the premolar and canine region are frequently clinically and radiographically misdiagnosed. The identification of keratocyst in a location preoperatively favoring a lateral periodontal cyst should be suspected and biopsy must be considered in all cases to establish the nature of the lesion, the best surgical treatment, and the follow-up appointments.

Usage of Guided Bone Regeneration in the Case of Lateral Periodontal Cyst in the Maxilla with Buccal Cortical Expansion

A lateral periodontal cyst (LPC) is a rare finding. Patients diagnosed with LPC younger than 40 years of age are not that common. Mostly asymptomatic LPCs can be discovered on routine radiographs as an oval radiolucency between two mandibular premolar teeth roots and can vary in shape and size. Most cases are treated with enucleation, bone curettage, or a combination of both, greatly depending on the surgeon’s preference. Because most LPCs are quite small, lesions do not require any regenerative procedures. In the presented case, because of cortical expansion of the lesion and loss of vital bone bridge surrounding two adjacent maxillary teeth, a guided bone regenerative procedure (GBR) with xenograft bone substitute was used. Despite that small lesions can heal on their own, nowadays the approach of full-mouth therapy (FMT), including direct soft or hard tissue reconstruction in the oral cavity, seems to be a wise treatment. The presented paper presents and describes an unusual LPC case with cortical bone expansion in a very rare maxillary canine–premolar region.

Odontogenic Keratocyst is frequently misdiagnosed for a Lateral Periodontal Cyst in premolar and anterior tooth-bearing areas

INTRODUCTION

Radiolucent lesions with gingival swelling found in the premolar and intercanine region can elicit a different clinical diagnosis than one confirmed by histologic findings. The purpose of the study is to identify and present the frequency of the unexpected microscopic diagnosis of Odontogenic Keratocyst (OKC) in a location preoperatively favoring a Lateral Periodontal Cyst (LPC) with similar clinical and radiographic appearance.

METHODS

A retrospective analysis of biopsies received from 2011 and 2019 was performed and the number of LPC and OKC cases were assessed. The alignment of clinical and radiographic diagnosis to histologic findings and anatomic location was analyzed and the number of OKC cases preoperatively misdiagnosed as LPCs was identified.

RESULTS

A total of 79257 biopsies were received. Of those, 184 were diagnosed as LPCs and 742 as OKCs. For all preoperatively diagnosed LPCs, the clinical and histological diagnosis aligned; however, 182 of 742 OKCs were submitted with a clinical misdiagnosis of LPCs. The location of these lesions with the unanticipated diagnosis overlapped with those for LPCs, specifically the maxillary and mandibular anterior and premolar regions.

CONCLUSION

Radiolucent lesions with gingival swelling in the premolar and intercanine region are frequently clinically and radiographically misdiagnosed. A biopsy should be considered in all cases to establish the correct pathologic diagnosis and treatment course.