Ameloblastoma and odontogenic keratocyst (OKC) are known as aggressive benign odontogenic neoplasms (ABONs) due to their aggressive behavior. They have substantial potential to grow to enormous size with resulting bone deformities, invade the adjacent tissues and spread beyond their normal clinical and radiographic margins. Because of the aforementioned features, they may have a high rate of recurrence1,2,3. In the current academic literature, there is considerable controversy about treatment based on the clinical, radiographic and/or histopathologic characteristics of ABON. Previously, there has been general consensus advising the complete eradication of these lesions using an aggressive surgical approach, such as marginal or segmental resection with or without reconstruction2,4,5,6. However, resection without reconstruction may create severe postoperative deformities that have adverse psychosocial consequences, particularly in young patients; while resection with reconstruction may prevent such adverse psychosocial consequences, it entails additional surgery and is prohibitively expensive4,6. On the other hand, recent advances in the understanding of the biological features of these lesions may provide evidence of the benefits of conservative surgical treatment that is not only affordable, but also preserves both structural and functional integrity3,4,5,7.

Prior reported conservative treatment options for ABON include marsupialization, decompression, enucleation, curettage, and a combination of these techniques2,4. Of the aforementioned conservative surgical procedures, enucleation by itself has a high tumor recurrence rate; in order to reduce this risk, adjunctive procedures, such as peripheral ostectomy, Carnoy's solution and cryotherapy, have been reported, but each have their respective benefits and risks2,7. Carnoy's solution can penetrate and fix tissue to the depth of 1.54 mm into bone after 5 minutes of exposure8. Due to this property, it reduces rate of recurrence in ABON. On the other hand, the surgical space created by the removal of these lesions requires packing with aseptic dressing material to achieve uneventful wound healing because primary closure may lead to infection given the large amount of dead space3,7,9. Ideal dressing materials used in the mouth should be able to reduce postoperative pain, promote healing and prevent infection. Iodoform is one such dressing material as it is shown to reduce wound fluids through fibrinolytic activity, exhibit antimicrobial activity after topical application to wounds, and reduce pain by covering denuded bone surface10,11.

This case series was performed by a single operator to evaluate the success of treating ABON using a conservative surgical procedure, specifically enucleation with or without Carnoy's application followed by iodoform gauze dressing.

Ameloblastoma and OKC are two of the most aggressive ABONs, which is demonstrated by their relatively high recurrence rate, rapid growth and tendency to invade adjacent tissues3,4,6,7,9,13,14,15. Treatment of ameloblastoma and OKC remains a controversial subject. The treatment approach should be based on the size and site of the lesion, recurrence status and radiographic evidence of cortical perforation. There has been a general consensus in the literature, guided by the aforementioned characteristics, for complete lesion eradication with aggressive surgical approaches, such as resection with or without reconstruction. These aggressive approaches may lead to deformities, which can have adverse psychosocial consequences, particularly for young patients. Therefore, the primary aim should be the preservation of structural and functional integrity whenever possible3,6,7,14,15,16.

Previous studies reported high recurrence rates with enucleation alone, but recurrence rates can be reduced when performed with adjunctive procedures6,9,17,18. However, adjunctive procedures, including peripheral ostectomy, Carnoy' s solution, and cryotherapy, come with additional risks7. For example, Carnoy's solution and other chemical cauterization could potentially damage nearby vital structures such as the IAN and/or permanent tooth buds in mixed dentition. When operating near such vital structures, the appropriate choice would instead be marsupialization or decompression7,9. However, if lesions are not near the aforementioned vital structures, then the application of Carnoy's solution is commonly accepted given its ability to penetrate and fix tissues up to a depth of 1.54 mm into the bone after 5 minutes of exposure6,7, 8,17,18. Cryotherapy is another adjunctive procedure with similar results, but its application can be complicated and wound dehiscence is observed in all cases7,19. Peripheral ostectomy is impractical in large lesions due to the presence of very thin bony walls, and should be avoided in cases with ameloblastoma because it may implant ameloblastoma foci more deeply in the bone7,14. On other hand, a large surgical cavity created by enucleation should undergo secondary wound healing rather than primary wound closure to reduce the risk of postoperative infection secondary to dead space3,7,9. Dressing material used for secondary wound healing in the mouth should have the following properties: reduction of postoperative pain, promotion of healing and prevention of infection. Iodoform is one such dressing material because it reduces wound fluids by fibrinolytic activity, exhibits antimicrobial activity after topical application and covers denuded bone surfaces to reduce pain10,11. Recent studies reported that decompression and marsupialization alter the epithelial lining of keratocystic odontogenic tumor into a less aggressive form, and some tumors have completely resolved clinically and radiographically with treatment3,7. Based on the above findings, the author recommends performing enucleation with or without Carnoy's solution application followed by iodoform gauze dressing for all cases.

Recent studies suggest that management of Ackermann histological subtype-1 ameloblastoma by enucleation is associated with good prognosis. However, in cases with cortical perforation, the tumor behaves like a solid ameloblastoma and should therefore be managed accordingly. On other hand, if there is IAN involvement, then the application of Carnoy's solution should be avoided to limit postoperative paresthesia 1,7,13. Typically, the management of case 1 would involve radical surgery with or without reconstruction1, but given the young age of the patient, the author opted for a conservative approach of enucleation followed by iodoform gauze packing. The application of Carnoy's solution was contraindicated because the involvement of IAN and exposed periosteum increased the risk of paresthesia had it been applied. Case 2 followed a similar approach because developing tooth buds were a contraindication for Carnoy's solution application. However, case 3 did not have any such contraindications, so it was managed by enucleation with Carnoy's solution application followed by iodoform gauze dressing. There was no evidence of recurrence during the follow-up period for any of the cases.

Zhou et al.7 reported requiring local anesthesia for the first two dressing changes, observing minor bleeding during each dressing change for the first two months that ultimately resolved after repacking, and noting that the average duration of required packing was 10.2 months (range, 7-15 months) and packing was performed by clinical assistants. In the current case series being reported, no local anesthesia was required in any dressing changes, slight bleeding was observed in the first 4 dressing changes (1 month) that resolved by repacking, and the average duration of required packing was 3.67 months (range, 2-5 months); packing was performed by a doctor. These differences could be due to differences in postoperative care by a doctor as compared with clinical assistants. Other possible reasons could be the difference in the age of the patients and size of the lesions.

Yildirim et al.3 and Hadziabdic et al.20 reported that radiographically complete bone healing was achieved in about 12 and 16 months in their respective studies. Similar results were achieved in cases 1 and 3, but a considerably shorter duration of complete bone healing was achieved in case 2 (about 5 months). This shorter duration of healing might be due to the age of the patient and size of the lesion.

Management of ABON remains controversial, but in light of prior clinical trials, there is a general consensus recommending complete lesion eradication with radical surgical procedures, which may cause deformity. These deformities can have adverse psychosocial consequences, particularly for young patients. Therefore, the primary aim should be to preserve structural and functional integrity for a better postoperative quality of life for patients. Enucleation with or without Carnoy's solution application followed by iodoform gauze dressing can be recommended as a good conservative treatment option that has a low recurrence rate with uneventful secondary healing for ABON. The author also recommends a long clinical and radiographic follow-up due to the aggressive nature of ABON.