e35 Inflamed Odontogenic Cyst with Actinomyces Colonization: Management of an Atypical Case in a 16-Year-Old Patient Ahmad Soolari, DMD, MS1 Odontogenic cysts arise from pro- Amin Soolari, BS, CRT2 liferation of remnants of the epi- Christopher Fielding, DDS3 thelial rests of Malassez, stimulated by inflammation that results from pulpal necrosis of an associated tooth that expanded by hydrostatic Inflammatory odontogenic cysts, if not treated, may lead to progression pressure/osmotic gradient, lead- of osteolytic activity, potential paresthesia, and loss of teeth. A 16-year-old ing to fluid transport.1 Interleukin-1, female patient was referred by a pediatric dentist for asymptomatic abnormal interleukin-6, and tumor necrosis radiolucency found interproximally to the mandibular left first and second factor alpha are important proin- premolars. Radiographic, clinical, and pathologic analyses led to a diagnosis of an inflamed odontogenic cyst (type K09.0) with Actinomyces colonization. The flammatory cytokines released by cyst was treated by periodontal regenerative therapy and resulted in successful macrophages,2 and this inflamma- osseous regeneration. This was a rare case because of the patient’s age, the tory response induces proliferation location of the lesion, its association with vital teeth, and its presentation. of fibroblasts that stimulate pros- Int J Periodontics Restorative Dent 2020;40:e35–e41. doi: 10.11607/prd.4452 taglandins, causing the bone re- sorption seen in a cyst.3 This is the driving force of osmotic gradient differences that lead to increases in internal hydrostatic pressure, driving fluid into the cyst. The World Health Organization 2017 classification of head and neck tumors recognizes two main types of inflammatory odontogenic cysts: Radicular and collateral.4 Radicular cysts, also known as periapical cysts or apical periodontal cysts, are the most common type of inflamma- tory odontogenic cysts associated with a nonvital tooth, occurring pre- dominantly in the maxilla and at a 1Private practice, Potomac, Maryland, USA. mean age of 37.5 years in males.5 2University of Maryland School of Dentistry, Baltimore, Maryland, USA. 3Department of Dermatology, Johns Hopkins University School of Medicine, Conservative conventional therapy Baltimore, Maryland, USA. of radicular cysts includes root canal treatment followed by apical sur- Correspondence to: Dr Ahmad Soolari, 11616 Toulone Dr, Potomac, MD 20854, USA. 6 Fax: (240) 845-1087. Email: [email protected] gery if the radiolucency persists. The residual cyst remaining after Submitted May 6, 2019; accepted July 16, 2019. ©2020 by Quintessence Publishing Co Inc. extraction of the affected tooth Volume 40, Number 2, 2020 © 2020 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER. e36 Fig 1 (below) (a) Normal mandibular right side. (b) Large bony lesion on the mandibular left side. Fig 2 (right) The patient presented with a fistula, deep probing, bleeding on probing, purulent exudates, significant bone loss, and occlusal disharmony. a b and lateral radicular cysts associ- ed by the referring pediatric dentist. the lingual plate and interruption ated with a lateral root canal also fall The patient had received orthodon- suspected in the buccal plate. The under the radicular cyst category. tic treatment between 2014 and lamina dura adjacent to the lesion Included in the collateral inflamma- 2016. Clinical and conventional and in the interproximal area was tory cyst category are paradental radiographic evaluation disclosed missing along the mesial aspect of cysts, arising from third molars, and deep probing, bleeding on probing, the second premolar and distal as- mandibular buccal bifurcation cysts purulent exudates, significant bone pect of the first premolar, but there on the buccal surface of first and loss, and occlusal disharmony (Fig were no changes to the root apex second molars.5 2). Since the lesion was not typical of and both teeth were alive on vitality Actinomyces are opportunis- periodontal disease, a cone beam testing. tic anaerobic, gram-positive, rod- computed tomography (CBCT) im- Differential diagnosis included shaped bacteria known to cause age was taken, which disclosed a radicular cyst, odontogenic kerato- actinomycosis. Actinomyces species well-defined unilocular low-density cyst, calcifying odontogenic cysts, are highly susceptible to β-lactam lesion extending from the crest to and lateral radicular cyst. To con- antibiotics such as amoxicillin or the root apices, approaching the firm a diagnosis of the findings, the penicillin G.7 Gomes et al reported mental foramen. The intraosseous authors performed an incisional Actinomyces israelii to be the most lesion in the axial cut (mesial-distal biopsy to rule out odontogenic commonly identified microorganism direction) was 8.40 × 10 mm, with tumors. The biopsy confirmed an in radicular cysts.8 10.00-mm buccolingual dimen- inflamed odontogenic cyst with Ac- sions (Figs 3 and 4). The sagittal cut tinomyces colonization. There was showed close proximity of the lesion no evidence of malignant or neo- Case Report to the mental foramen with thinned plastic processes. Although cyst cortical plates. No other pathology fluid samples and culturing were not A 16-year-old Caucasian girl was re- was detected in the oral cavity. performed, 150 mg of the antibiotic ferred for periodontal evaluation of The lesion had a speck of lin- clindamycin was prescribed (three a bony lesion at the interproximal ear high density within it (a possible times a day for 10 days) along with space of the mandibular left first odontogenic remnant). From the the anti-inflammatory methylpred- and second premolars (Fig 1). The buccolingual dimensions, the lesion nisolone, 800 mg of the analgesic patient was asymptomatic, with an was estimated to extend between ibuprofen, and a chlorhexidine rinse atypical large radiolucency detect- the cortical plates, with thinning of (Acclean 0.12% oral rinse USP, twice The International Journal of Periodontics & Restorative Dentistry © 2020 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER. e37 daily). Periodontal regenerative therapy was offered to rebuild the hard and soft tissue that had been compro- mised by the inflammatory response. The patient and her parents accepted the treatment plan. Panoramic radiographs were taken on December 24, 2011; July 25, 2013; and September 1, 2017 (Fig 5); these radiographs show that the mandibular first pre- molar erupted in 2011 (Fig 5a) and that the mesial root Fig 3 The CBCT scan disclosed Fig 4 The lesion was in of the second premolar caused a delay in eruption in an 8.40 × 10-mm intraosseous close proximity to the mental 2013 (Fig 5b), but all permanent premolars were pres- lesion in the axial cut (mesial- foramen. distal direction) and 10.00-mm ent and the crowding had been corrected by 2017 (Fig buccolingual dimensions of 5c). The premolar arrangement, however, differed be- bone resorption. tween the mandibular left and right sides: A large space was observed between premolar roots on the left side but not the right side. Both sides presented symmetri- cally up until 2013, before orthodontic treatment. Treatment The CBCT images were read by a board-certified oral and maxillofacial radiologist whose report was re- a viewed with the patient and her parents; they agreed to proceed with the treatment plan, which was a biopsy of hard and soft tissues followed by periodontal therapy to regenerate lost tissues. Anesthesia was achieved with one carpule of lidocaine (2%) with epinephrine (1:100,000). The pretreatment photo (Fig 6a) showed the presence of a fistula at the interproximal area of the mandibular left first and second premolars. Two verti- cal incisions were made (Fig 6b) from the distal aspect b of the second premolar and mesial aspect of the first premolar using a no. 15 blade (carbon steel, Benco Dental), and an intrasulcular incision connected the two vertical incisions. A full-thickness flap was raised and extended beyond the mucogingival junction to en- able full access to the bony defects and to facilitate the ridge-augmentation procedure followed by coronal ad- vancement. The full-thickness flap was used instead of a partial-thickness flap to assist in locating the mental nerve and avoiding injury to the neurovascular bundle c near the surgical area. Reflection of the flap (Fig 6c) dis- Fig 5 Panoramic radiographs showing that (a) the first premolar closed a large bony lesion (8.40 × 10 mm) in the verti- erupted in 2011, and (b) the mesial root of the second premolar cal and horizontal directions at the interproximal area caused a delay in eruption in 2013. (c) By 2017, all permanent premolars were present and the crowding had been corrected. and a paper-thin lingual plate. In addition, the buccal Volume 40, Number 2, 2020 © 2020 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER. e38 Fig 6 (a) Initial clinical impression of the infected area and a draining fistula were noted interproximally to the first and second premolars, along with slight gingival discoloration. (b) Excavated cystic area interproximally to the premolars, showing the length and depth of bone resorption. (c) Packed allograft bone graft. (d) Membrane placement and gingival approximation before closing. a b c d plate was partially missing on the fitted to the interproximal area (Fig The nonresorbable membrane first premolar. The inferior border 6d). The facial flap was coronally ad- was removed 2 months later due to of the bony lesion approached the vanced to cover the membrane and premature exposure. The area was mental foramen. secured into position with simple in- left to heal for closure and com- The debridement of the bony terrupted 4.0 monofilament sutures plete soft tissue remodeling.