Microapical surgery of a periapical cyst caused by apical ramification: a case report and review of the literature.

backgroundThe destruction of tooth apical bone mainly comes from odontogenic apical cysts caused by pulp necrosis, chronic inflammation, or trauma. Some affected teeth can be cured by modern root canal treatment or non-surgical retreatment, but some affected teeth do not heal after treatment. Apical surgery should be considered when root canal therapy has failed, root canal retreatment through the crown channel is difficult, or true cysts are present. This article explores the use of microapical surgery to treat a periapical cyst caused by apical ramification, emphasizing a minimal surgical approach for this lesion. CASE PRESENTATION: A 47-year-old female (Han nationality) presented with a chief complaint of recurrent buccal mucosal fistula in their maxillary posterior teeth for 1 year. Clinical examination revealed a porcelain-fused-metal crown of the maxilla of the left second premolar (tooth 25) and buccal mucosa fistula. X-ray assessment showed a high-density shadow in the root canal and low-density transmission from the root apex to the middle third of distal root surface. Microscopic apical surgery was performed under local anesthesia. The apical ramification was exposed and a root apex of 3 mm was cut off. Then the apical foramen of buccal root canal, palatal root canal, and apical ramification were filled retrogradely with mineral trioxide aggregate, and finally sewn up. Follow-up X-ray at postoperative 12 months and 24 months showed that the bone density of the root apex and distal root surface was higher compared with the values measured immediately after operation. There were no clinical symptoms, and normal mucosa.

conclusionThe patient presented with a recurrent buccal mucosal fistula in the maxillary left second premolar. Microscopic apical surgery was performed under local anesthesia. After minimally invasive surgery, apical resection, inverted preparation, and mineral trioxide aggregate treatment, at postoperative 24 months, the outcome was satisfactory, with recovered apical bone, normal mucosa, and no clinical symptoms. For periapical cysts, X-ray and cone-beam computed tomography images should be read carefully before the operation. The semicircular low-density transmission image around the apical sidewall indicates the apical ramification, and that root canal treatment or microapical surgery should be performed. The operating microscope enhances visibility and provides the surgeon with a better understanding of canal anatomy, a better surgical view, and the ability to undertake more complex but predictable apical resection techniques.