CASE REPORT Annals of Nuclear Medicine Vol. 9, No. 4, 243-245, 1995 Intense accumulation of Tc-99m MDP and Ga-67 in multiple periapical cemental dysplasia Suzuka TAKI,* Norihisa ToNAMI,** Junichi TAKI,** Toshimi MUROKI,*** Etsuhide YAMAMOTO*** and Kinichi HrsADA**** *Department of Radiology, Tonami General Hospital **Department of Nuclear Medicine, ***Department of Oral Surgery, Kanazawa University Hospital ****Hokuriku Central Hospital A case of multiple periapical cemental dysplasia is presented and intensive accumulation of Tc-99m MDP and Ga-67 is described. A 53-year-old woman was admitted with an intermittent pain and swelling of the left buccal region. The radiograph showed multiple sclerotic masses covering entire periapical regions of the teeth, in both the maxilla and mandibula. Biopsy of the maxilla facilitated a definitive diagnosis of multiple periapical cemental dysplasia. Key words: multiple periapical cemental dysplasia, bone scintigraphy, Ga-67 scintigraphy INTRODUCTION PERIAPICAL CEMENTAL DYSPLASIA is considered a non-neo-plastic proliferation of fibrous tissues and cementum-like hard tissues usually occurring in the periapical regions of teeth. This lesion is often found in middle-aged women on routine radiographic examination.1 Periapical cemental dysplasia occurs predominantly in the mandibular incisor regions.2 Multiple occurrences in both jaws are rare.3 We encountered a case of multiple periapical cemental dysplasia which showed intense accumulation on both Tc-99m MDP and Ga-67 scintigraphy. To our knowledge, the scintigraphic findings of periapical cemental dysplasia have not yet been reported. CASE REPORT A 53-year-old woman was admitted to Kanazawa University Hospital with intermittent pain and swelling of the left buccal region. Physical examination revealed swelling of the bilateral buccal region, hard palate and alveolar regions (Fig. 1). Pus was excreted from the left gingiva to the oral cavity and a fistula from the left gingiva to the infected left maxillar sinus was noted. The radiograph showed sclerotic masses covering the entire periapical regions of teeth in both the maxilla and mandible. Opacification of the left maxillary sinus caused by sinusitis was also noted (Fig. 2). Tc-99m MDP scintigram revealed marked accumulation in entire areas of the maxilla and periapical region of mandible (Fig. 3). Subsequent Ga-67 scintigram demonstrated high accumulation in the same areas seen on the Tc-99m MDP scintigram (Fig. 4). A biopsy of the maxilla was performed, and histological speclmens revealed the proliferation of irregular-shaped cementum-like hard tissues and a small amount of fibroblastic tissues. The histological diagnosis was periapical cemental dysplasia. The patient underwent partial maxillary resection to treat the associated left maxillar sinusitis. Postoperatively, her complaints were improved. DISCUSSION The etiology of periapical cemental dysplasia is unknown . It is considered to be a reactive process rather than a neoplastic lesion.4 This lesion is commonly found in the periapical regions of vital mandibular incisors of middle aged women. It is usually asymptomatic and is often found accidentally during routine radiographic examination. Multiple occurrence in the maxilla and mandible as in this case is rare. According to WHO's classification, this lesion is classified into 3 stages of development (an osteolytic stage, a cementoblastic stage, and a mature, inactive stage).5 Radiographically, the lesions exhibit a radiolucency in the osteolytic stage that resembles periapical inflammatory diseases. In the cementoblastic stage, formation of hard tissue usually occurs in the center of radiolucent areas. These lesions then become radiopaque in a mature, inactive stage due to an increase in hard tissue. Histologically, ear]y leslons consist of fibroblastic tissue, and then forrnation of hard tissue such as cementicles, cementum-like tissue and occasional woven bone occur in the cementoblastic stage, followed by the increase and fusion of hard tissue in the mature, inactive stage.6 From the radiographic and histological findings, this case was considered to be in the cementoblastic or mature stage. In this case, a Tc-99m MDP scintigram showed high radio-nuclide accumulation corresponding to the radiopaque mass seen on the radiograph. It is assumed that Tc-99m MDP accumu]ated at the site of cementicles formation, cementum-like tissues and woven bone. This finding suggests that the leslons were still active and progressive. In this case, inlense accumulation in parts of the maxillary bone other than the periapical regions may be attributed to associated sinusitis. A Ga-67 scintigram also demon-strated intense accumulation in the same region as seen on the Tc-99m MDP scintigram. This finding is thought to indicate osteo- or cementoblastic activities of the lesions, as Ga-67 accumulates in fracture sites and sclerotic bone lesions. On diagnostic images, multiple periapical cemental dysplasia must be differentiated from chronic osteoscle-rotic osteomyel itis , fibrous dysplasia and other odontogenic lesions. From Its characteristic location and radiographic findings, it may not be very difficult to differentlate thls case from other lesions, but for definitive diagnosis, biopsy is still recommended. Tc-99m MDP scintigram was useful for estimating the activity and extension of the leslon in this case. Ga-67 was also useful, but it could not offer any information additional to the Tc-99m MDP scintigram. REFERENCES 1 . Falace DA, Cunningham CJ. Periapical cemental dysplasia. Simultaneous occurrence in multiple maxi]Iary and man-dibular teeth. J Endod 10: 455-456, 1984. 2. Bernier JL, Tompson HC The histogenesis of the cemen- toma, report of 15 cases. Amer J Orthodont 32: 543-555, 1946 3. Scannel JM . Cementoma. Oral Surg,Oral Med. Oral Pathol 2: I 169-1 180, 1949. 4. Schafer WG. Hine MK. Levy BM. A textbook of ora] pathology. Philadelphia, WB Saunders company, pp. 297-298, 1983. 5. PindborgJJ, KramerIRH. Histological typingofodontogenic tumors, jaw cysts and allied lesions. Gingiva, World Health Or anization 1971. 6. Tanaka H, Yoshimoto A, Toyama Y, Iwase T, Hayasaka N, Moro l. Periapica] cementa] dysplasi a with multiple lesions. Int J Oral Maxillofac Surg 1 6: 757-763, 1987.