A 16-year-old male patient presented to the central out-patient department (OPD), Department of Dental surgery, Armed Forces Medical College, Pune with a chief complaint of a swelling in the gum on the left side of the upper jaw from the past five to six months in Nov 2009. The patient was apparently normal before this. He could not recall any recent trauma, pain, or discharge from the swelling or an increase in size of the lesion. His medical history was non-significant, and he was not on any medication at that time. Prior to this visit, the patient had not received dental care for more than 10 years.
During intraoral examination, a smooth round pink colored nodule approximately 5 mm in diameter was noted. It was located on the attached gingiva in relation to the upper left canine and first premolar extending superiorly up to the mucogingival junction . The nodule was non tender, soft, and cystic in consistency, fluctuant and non compressible. Probing of the adjacent teeth yielded pocket depths of 2-3 mm with all sites exhibiting bleeding on probing, without any communication between the sulci of the adjacent teeth and the lesion. Pulp testing of the canine and first premolar indicated that both were vital. Radiographically, there was no finding suggestive of osseous involvement . Based on the clinical and radiographic findings, the provisional diagnosis of cystic lesion of the gingiva was made. The differential diagnosis included a lateral periodontal cyst, peripheral fibroma, parulis, and odontogenic keratocyst. Lateral periodontal cyst was ruled out because there was no radiographical finding suggesting of osseous involvement, peripheral fibroma was ruled since the lesion was soft and cystic consistency, parulis was ruled out since the lesion was not associated with periodontal pocket or pus discharge on probing and odontogenic keratocyst was ruled out since the lesion was not associated with pain or localized expansion of bone, and radiographically there was no osseous involvement.
Clinical presentation of the lesion
IOPA radiograph 23,24 showing no radiographic involvement
The periodontal treatment plan included scaling, root planing, re-evaluation, and excisional biopsy of the lesion. Two weeks after scaling and root planing, a re-evaluation and excisional biopsy were performed in Dec 2009. Anesthesia was obtained with local infiltration. An incision was placed on the mucosa overlying the lesion  and the lesion was separated from the adjacent tissues through blunt dissection and the lesion was removed . The surgical specimen measuring 6 × 6 mm was placed in 10% neutral buffered formalin.
After the lesion was removed and the area irrigated with sterile saline, it was apparent that a well defined, 2-3 mm deep, saucer-like defect was present in the alveolar process in relation to 23 and 24 . Hydroxyapatite bone substitute hydrated with sterile saline was placed in the defect , the edges of the soft tissue were undermined and approximated to facilitate primary closure and was secured with a 3-0 black silk suture. Gentle pressure was applied with wet gauze to achieve hemostasis and the wound was covered with a periodontal dressing. The patient was given postoperative instructions and was dismissed with prescription for an analgesic (tab Ibuprofen-400 mg tds every four to six hours as needed for pain), antibiotic (capAmoxicillin-500 mg tds for three days) and antimicrobial rinse (0.2% chlorhexidine gluconate twice a day for one week).
Hydroxyapatite bone substitute filled in the defect
The biopsy specimen microscopically consisted of a fibrovascular connective tissue associated with a cystic lining of stratified squamous epithelium. The histopathologic diagnosis was gingival cyst of adult .
Histopathological slide showing a thin stratified squamous epithelium lining the lumen
At one week postoperative visit, the patient reported minimal discomfort. The sutures were removed. At one month post-surgery, the wound had completely reepithelialized . The patient is on regular follow-up with a satisfactory healing at six months post-surgery .