A retrospective analysis of complications associated with tooth-borne anterior maxillary distraction for managing cleft maxillary hypoplasia: A 12-year experience

Purpose: To evaluate the intra- and post-operative complications of tooth-borne anterior maxillary distraction in management of cleft maxillary hypoplasia over a 12-year period, and to establish whether the procedure involves a learning curve. Materials and methods: All patients with cleft maxillary hypoplasia satisfying the inclusion and exclusion criteria and undergoing anterior maxillary distraction with a tooth-borne palatal distractor between June 2007 to June 2018 were retrospectively studied by retrieving their individual medical records, which included radiographic (lateral cephalogram analysis at three different intervals) and speech assessment records. The presence of intra- and post-operative complications developing in this study period was noted. Furthermore, the frequency of intra- and post-operative complications occurring from years 2007-2018 were evaluated to study whether there was a decrease in the frequency of complications with increasing time. This was done to establish whether there was a learning curve associated with the surgical procedure. The results thus obtained were tabulated using SPSS 25.0 (SPSS Inc., Chicago, IL) and subjected to statistical analysis using the chi-squared test. A p value of less than 0.05 was considered statistically significant. Results: Out of the 458 patients included in the study, 78.82 % (n = 361) had no complications. In the remaining 97 patients, a total of 137 complications (46 intra-operative and 91 post-operative) were observed, making up for a complication rate of 21.17%. The intra-operative complications noted were appliance dislodgement (n = 19), palatal mucosal tears (n = 12), hemorrhage (n = 8), dental injuries (n = 6) and inadvertent fracture of the anterior segment (n = 1). The post-operative complications noted were anterior open bite (n = 24), gingival inflammation (n = 14), appliance dislodgement (n = 13), dental injuries (n = 10), relapse (n = 8), hemorrhage (n = 5), soft tissue infections (n = 4), palatal fistula (n = 3), speech impairment (n = 3), wound dehiscence not related to infection (n = 3), need for re-operation (n = 2), avascular necrosis of the anterior segment (n = 1) and maxillary sinusitis (n = 1). A statistically significant decrease (p < 0.001) in the frequency of complications with each passing year from 2007 to 2018 was observed. Most complications were seen to occur in the first 4 years (i.e. 2007-2010; a total of 74 complications in 54 patients), making up 11.79% of the complications. In the following 8 years (i.e. 2011-2018), 63 complications were noted in 43 patients, making up the remaining 9.38 % of the complications. These observations indicate that a learning curve was involved before carrying out the procedure without many complications. Conclusion: Tooth-borne anterior maxillary distraction in managing cleft maxillary hypoplasia is associated with a wide range of complications: some avoidable and related to surgeon's experience; some related to the surgical procedure itself; and some unavoidable and related to the distractor appliance. Understanding potential complications allows the surgeon to ensure safe care through early intervention and to correctly inform the patient in the pre-operative discussion. The procedure involves a learning curve before it can be accomplished safely without many complications. (C) 2020 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.