Unilocular Radiolucency Between Mandibular Premolar Roots

A 63-year-old male presented to the Department of Periodontics, Army Postgraduate Dental School, Fort Eisenhower, Georgia, seeking sinus augmentation and implant therapy in the maxillary left posterior sextant. His medical history was significant for hypertension, high cholesterol, arthritis, and depression, along with a documented penicillin allergy. Extraoral and intraoral examinations showed no evidence of swelling, lymphadenopathy, or other abnormality. Probing depths (PDs) were three millimeters or less generally, with isolated four- to six-millimeter PDs limited to the molar areas. After nonsurgical periodontal therapy, the only residual five-millimeter PDs were found at the mesial line angles of the mandibular left first molar (Figure 1). A review of the patient’s radiographs revealed a wide, shallow infrabony defect at the mesial aspect of the mandibular first molar, incipient cupping of the interproximal alveolar bone in the remainder of the sextant, and an ovoid radiolucency between the mandibular left premolars midway between the interproximal alveolar crest and the apices of the teeth (Figure 2). Both mandibular left premolars were pristine teeth with no restorations or caries experience. Both teeth exhibited normal sensibility when challenged with a thermal stiumulus.