Downloaded from http://journals.lww.com/jcraniofacialsurgery by BhDMf5ePHKbH4TTImqenVI1NGeaZoDmOlWAzeLocZNBhgA8KUNsPsD4ola6Xh8I87Go1S1loCak= on 12/15/2019 Copyright © 2019 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited. Histologic Evaluation of Healing Lip Defects Treated With Injected Onabotulinum Toxin A and Topical Mitomycin C Arezoo Jahanbin, DDS, MS,  Parastoo Namdar, DDS, MS, y Narges Ghazi, DDS, MS, z and Mozhgan Kazemian, DDS, MS § Objective: Using an experimental rat model, the efficacy of injected Onabotulinum Toxin A (BoNT-A) versus topical Mitomy- cin C in surgical wound healing of rat lip defects was evaluated. Methods and Materials: Sixty-seven male Wister rats received a triangular cut (7  7  4 mm) on their upper lip. Then they were divided randomly into 4 equal groups: group A (topical Mitomycin C plus injected BoNT-A); group B (topical Mitomycin C); group C or control group (saline solution) and group D (injected (BoNT-A). After 3 months, the animals were euthanized and scars were evaluated using hematoxylin and eosin and Masson’s trichrome. For qualitative analysis, inflammatory cell density, new capil- lary formation, fibroblast proliferation, and collagen deposition were reported using relative ranks from 0 to 3 (absence, mild, moderate, marked). Data were analyzed by post hoc and Kruskal– Wallis tests. The significance level was P < 0.05. Result: Mean collagen deposition values and fibroblast proliferation in the 4 groups showed statistically significant differences with each other (P value < 0.001). A significant difference between group A and controls existed for fibroblast proliferation (median 1 versus 2, P value < 0.001); also, collagen deposition (median 1 versus 2, P value < 0.001). A significant difference existed between the control and group D (median 2 versus 1, P value ¼ 0.004); also, group A and B (median 1 versus 2, P value ¼ 0.002) for collagen deposition. However, no significant differences existed between the 4 groups regarding inflammatory cells and angiogenesis (P value > 0.05). Conclusion: Local injection of BoNT-A plus Mitomycin C followed by BoNT-A alone provided less collagen formation and fibroblastic proliferation in the healing lip defect in a rat model. Key Words: Cleft lip and palate, mitomycin C, onabotulinum toxin A, scar (J Craniofac Surg 2019;30: 2646–2649) O rofacial clefts are one of the most common congenital birth malformations in the oral and maxillofacial area, with a global prevalence ranging from 1:200 to 1:2500 live births depending on ethnic and socioeconomic status. 1 These malformations have a negative impact on the patient’s facial appearance as well as their psychological and physiological status. 2 Lip reconstruction or cheiloplasty is an important issue for these patients, and is performed around 3 months of age. Unfortunately, the cheiloplasty scar is inevitable and permanent, but this does not mean that measures should not be considered to enhance the functional and aesthetic outcome of patients because the scar can result in a lifelong social stigma of a cleft lip operation. 3 Techniques have been to reduce the cheiloplasty scar. However, regardless of careful and atraumatic surgical techniques, still some scars will remain, mostly due to weak formation or inadequate replaced of collagen fibers underneath the dermis following unilat- eral or bilateral cleft lip reconstruction surgery. 4–6 Based on previous literature, many drugs, such as steroids, silicone gel sheeting, interferons, and 5-fluorouracil, have been suggested for the treatment of hypertrophic scars by means of intralesional injection. 7–11 However, there are variations in the therapeutic efficacy of each treatment, and they all have side effects. 12 Thus, hypertrophic scar treatment continues to be a clinical challenge. In recent years Mitomycin C has been used because of its potential to control surgical scar tissue because of its potential to inhibit fibroblast proliferation. 13 Mitomycin C is an antibiotic produced from the Streptomyces caespitosus and is a common chemotherapeutic agent. 2 However, its effects on the healing process of surgical wounds are still poorly understood. In 1 study, it was shown that topical Mitomycin C in surgical wounds of a rat model was able to slow scar tissue formation. 14 In this regard, Ribeiro et al demonstrated that the rats that received only topical Mitomycin C presented milder inflammatory signs and conse- quently had a less intense healing process than the control group three months after surgery. The group treated with a combination of both topical and injected Mitomycin C presented results compara- ble to those of the control group. 15 Botulinum toxin is derived from Clostridium botulinum and is a potent neurotoxin that indirectly blocks neuromuscular transmis- sion. Many serotypes of botulinum toxin (A through F) exist; however, botulinum toxin type A is used extensively to improve facial rhytides. 16 Gassner et al has reported significantly better From the  Department of Orthodontics, School of Dentistry, Mashhad University of Medical Sciences, Mashhad; y Department of Orthodontics, School of Dentistry, Mazandaran University of Medical Sciences, Sari; z Department of Oral and Maxillofacial Pathology, School of Dentistry, Mashhad University of Medical Sciences, Mashhad; and § Oral and Maxillofacial Diseases Research Center, Mashhad University of Medical Sciences, Mashhad, Iran. Received February 20, 2019. Accepted for publication August 13, 2019. Address correspondence and reprint requests to Parastoo Namdar, DDS, MS, Department of Orthodontics, School of Dentistry, Khazar Square, Sari, Iran; E-mail: dds.pnamdar@gmail.com AJ, PN, and MK have equally contributed to this study. The authors have no conflicts of interests to disclose. This study was supported financially by Vice Chancellor for Research of Mashhad University of Medical Sciences (grant number:961648), and was approved by the Ethics Committee of the Mashhad University of Medical Sciences, Mashhad, Iran. Supplemental digital contents are available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s Web site (www.jcraniofa- cialsurgery.com). Copyright # 2019 by Mutaz B. Habal, MD ISSN: 1049-2275 DOI: 10.1097/SCS.0000000000005953 SCIENTIFIC FOUNDATION 2646 The Journal of Craniofacial Surgery  Volume 30, Number 8, November/December 2019