Healing of a large periapical lesion in the palate following

nonsurgical endodontic treatment 

A.M. Al-Kandari, BDS, MDS, MPH*, D. Cnanasekhar, BDS, MScD**,
O.A. Al-Quoud, BDS, MSc, PhD**,  S.A. Al-Anzi, BDS, MSc** 
Dental Department, Al-Adan Hospital, Riqqa, P.O. Box 3234, Salmiyah 22033, Kuwait
**Dental Center, Kuwait.

a large periapical cystic lesion in tne palate or a patient is presented. Conventional endodontic treatment was done on the involved teeth. The case was followed for a period of thirty-three months, and apart from a small residual lesion, complete resolution occurred. This report suggested that even large periapical lesions could respond favorably to non-surgical endodontic treatment.

Periapical lesions may develop as a sequelae to diseases of the pulp. They are often asymptoma­ tic and are discovered on routine radiographic examination, sometimes after having become quite large.

An earlier view on the treatment of periapical lesions is typified by Grossman's statement "root canal treatment alone is contraindicated for tooth with a cyst, since the cyst will continue to develop unless the epithelial lining is completely removed by surgical means".1 However, during the past thirty years there had been a gradual change in the attitude to surgical treatment of periapical lesions. In 1956, Baumann and Rossman2 reported a 90 to 95 per cent success rate with nonsurgical endodontic treatment. Later reports3,4 described the possible healing mechanism of periapical cystic lesions when treated by nonsurgical techniques. Since then, there had been a renewed interest in treating periapical lesions conservatively. There have been only few reports4,5,6 of periapical cystic lesions treated successfully by conservative means. Here we present a patient with a large periapical cystic lesion in the maxilla. The lesion healed with only conservative treatment, thus supporting the approach of nonsurgical management of periapical lesions of endodontic origin.

A 25-year-old male was referred to the Endodontic Clinic of Al-Adan Hospital for treat­ ment of a swelling in the palate. He had injured his upper lip and upper anterior teeth in an accident seven years earlier. The patient had several episodes of dull pain for which he did not seek treatment. The swelling was first noticed ten months previously and he was given several courses of antibiotics before being referred to this hospital.

Examination revealed a well circumscribed, 2 cm diameter fluctuant swelling in the palate [Fig. 1]). The left central and lateral incisors and cuspids were tender on percussion and sensitive to thermal and electric pulp testing. Intraoral radiographs [Figs. 2, 3] showed a large radiolucent lesion with well defined margin. When the root canals of the involved teeth were opened, suppurative fluid oozed out. More fluid was expressed through the root canals by compressing the palatal swelling. A clinical diagnosis of dental cyst was made.

Once no more fluid could be drawn out through the root canals, the opened root canals were debrided by mechanical and chemical means and the access openings were sealed with a tempo­ rary filling. A week later the canals were once again debrided and the left central incisor and cuspid were obturated with gutta percha. Since the left lat­ eral incisor had an incompletely formed apex with a wide open apical foramen, it was filled with cal­ cium hydroxide mixed with barium sulfate and anesthetic solution. Some calcium hydroxide was extruded from the canal into the periapical lesion [Fig. 4]. The patient was lost to follow up for a period of nine months. When he returned, the treatment was continued. Radiographs taken at this time showed the periapical lesion to have decreased in size [Fig.5] and a calcified bridge had formed at the apex of the upper lateral incisor. There was also some resorption of the extruded cal­ cium hydroxide. The calcium hydroxide from the canal was removed and the canal was obturated with gutta percha [Fig. 6]. The patient was reviewed every 6 months during the following two years. At present there is a small residual radiog­ raphic lesions |Figs. 7, 8], but the palatal swelling has completely disappeared [Fig. 9] and the patient is asymptomatic.

The exact mechanism by which periapical lesions are formed is not clearly understood. But it seems that products released by microorganisms and dead pulp may initiate the process invoking, at the same time, an inflammatory reaction.7,8. Periapical granulomas respond well to nonsurgical endodontic treatment,9 while radicular cysts are generally considered to require surgery. However, Oehlers5 reported that many periapical lesions, including cysts, left in situ are eliminated by the body once the causative agents are removed. Bhaskar4,  supporting this view,  suggested  that endodontic instrumentation should be extended slightly beyond the apical foramen. This procedure would produce an inflammatory reaction which can destroy the epithelial lining of the cysts con­ verting them to granulomas which undergo resolu­ tion.

Our clinical diagnosis of periapical cyst was not confirmed by histological examination. Even microscopic examination of the cystic wall and its content does not always produce a definitive diag­ nosis.10 Treatment in our patient can be considered to have been successful since the swelling in the palate disappeared completely; the affected teeth remained asymptomatic and functional for more than two years and, radiographically, the periodontal ligament around the affected teeth appeared normal, it cannot be predicted if in this case a complete resolution of the cystic lesion would take place. It may persist as long as the extruded calcium hydroxide has not been com­ pletely resorbed. The residual radiolucent area may be a scar tissue which developed as a result of irreversible damage to one or both of the palatine cortical plates. In such cases, the residual radiolu-cency can be accepted provided the periodontal ligament is continuous and of norma! thickness.11

Large periapical lesions may not require surgery immediately after endodontic treatment. Periapical granulomas respond well to nonsurgical endodontic treatment9 and radicular cysts of endodontic origin can hea! withoutsurgery.2-6 Trial of non surgical management of periapical lesions including radicular cysts is justified.