Int. J. oral Surg. 1972: 1:195-214 (Key words; endodontic surgery; radiology, dental) Radiographic criteria for the assessment of healing after endodontic surgery JORGEN RUD, J. O. ANE~REASEN AND J. E. M~3LLER JENSEN Dental Department, University Hospital and Departments of Oral Pathology and Oral Radiology, Royal Dental College, Copenhagen, Denmark ABSTRACT - - A radiographic classification system is presented for healing assessment after periapical surgery. The use of the classifica- tion requires an observation period of at least one year. Radiographic- ally the following four groups are described: Group 1, Complete healing; Group 2, incomplete healing (scar tissue); Group 3, uncertain healing and Group 4, unsatisfactory healing (failures). Of 120 cases examined histologically, it was found that all cases in the unsatia'- factory healing group were severely inflamed. In the complete healing group inflammation was in some cases not depicted radiographically because of the projection. In Groups 2 and 3 inflammation was found in 61 and 86 %, respectively. Scar tissue was found in 91% of cases in Group 2. When the subjective and objective symptoms from 1,000 cases treated with endodontic surgery were correlated with the various healing groups, it appeared that these symptoms were concentrated mainly within the group unsatis/actory healing, and only a few cases showed symptoms within the groups complete and incomplete healing. When testing the precision of the radiographic classification it was found that the three authors agreed on cases with complete healing in more than 90 % of the cases. Most discrepancy was found regarding the uncertain healing group, where the authors were only 70- 76 % in agreement. Repeated readings of consecut]]ve cases by the authors showed discrepancies of 5-13 %. Two dent~l'surgeons, informed about the classification through the description and illustrations only, had a precision of 76- 79 % respectively, compared to the joint decisions of the present authors. (Received)Car publication 1 September, accepted 16 September 1972) Criteria for assessing the condition after periapical surgery should enable the observer to decide whether healing has been satis- factory and can be expected to remain as such without inflammation or whether the condition is uncertain, i.e. success or failure cannot yet be determined and the case should be followed-up for a longer period of time, or finally, whether the outcome is a failure and necessitates re-operation or extraction of the tooth. There can be no doubt that histologic