Can braces provoke oral lesions in Crohn disease?

Abstract

To the Editors: In Crohn disease (CD) the combination of hereditary and environmental factors leads to an immunoregulatory imbalance manifesting itself as a chronic inflammation with increased permeability and morphologic changes of the intestinal mucosa. The disease may affect the whole or part of the gastrointestinal tract. There is also a wide range of possible extraintestinal manifestations (1). It is well known that perianal disease or oral lesions, which can be the sole presenting symptoms, should raise the suspicion of CD (2,3). Over recent years we have experienced five children with CD presenting as oral lesions but without obvious gastrointestinal symptoms. All children had worn dental braces for a period of time before the outbreak of the oral lesions. Two cases are reported in detail. CASE 1 Case 1 is a 13-year-old boy, one of male triplets, who are very much alike and probably homozygous. His grandmother has systemic lupus erythematosus. He had worn dental braces for 9 months. He presented with a 3-week history of swelling of the right cheek and the right side of the upper lip. He denied any gastrointestinal or perianal symptoms. His height was –0.5 SD for age and his weight +0.5 SD. On examination the oral mucosa was slightly reddish and chafed on the right side of the soft palate and in the right bucca. Biopsy of the buccal mucosa showed a chronic granulomatous inflammation. A small bowel follow-through showed suspected inflammatory changes in 30 cm of mid-ileum. On colonoscopy the colonic and distal ileal mucosa was macroscopically normal, but histology of colon biopsy specimens revealed a granulomatous inflammation suggestive of CD. CASE 2 Case 2 is a 16-year-old boy, another one of the triplet brothers in Case 1. For some years he had occasionally had attacks of abdominal pain and frequent periods of constipation. A few months before presentation he was given dental braces. A few weeks later he developed changes in the oral mucosa adjacent to the left upper premolars. On presentation he was fully pubertally developed. His weight was + 2 SD for age and his height ± 0 SD. A mucosal biopsy from the gingival and buccal mucosa showed a granulomatous inflammation with giant cells and epithelioid cells consistent with CD. Small bowel follow-through was normal. Colonoscopy showed slight changes in the distal ileum, but the colonic mucosa looked normal. Microscopically there were epithelioid cell granulomas in both the ileal and colonic mucosa, slight inflammation in the ileum, and changes consistent with CD. The gastrointestinal mucosa is bombarded with antigenic material of the luminal content including bacterial and food antigens. This evokes a mucosal inflammation. In individuals genetically predisposed to CD, the inflammation is maintained by T-cells without being properly downregulated (4). This leads to a chronic condition with harmful effects on the mucosa (e.g., infiltration of the lamina propria by lymphocytes; ulceration; crypt abscesses; and, most typically, non-caseating granulomas). Any part of the gastrointestinal tract may be affected, although in some individuals the oral mucosa seems to be the most vulnerable. Thus, inflammatory manifestations of the oral mucosa were reported in 27 to 80% of children with CD (3,5). The etiology of oral lesions in CD remains unknown. Several theories have been proposed, (i.e., food intolerance (6), contact hypersensitivity (7), and infections (8)). Excellent reviews on the subject of oral lesions in CD, including numerous references to the literature, were recently published by Field (9) and Pittock et al. (3). Our case reports raise the possibility that dental braces in subjects with a hereditary propensity for CD may trigger oral CD lesions, perhaps by a mechanical, traumatic effect, or by intolerance to some plastic or metal component in the material of the brace. It can be speculated that injury to the oral mucosa in an individual genetically predisposed to CD might lead to breakdown of the protective mucosal barrier and initiate a process leading to systemic CD. It might be appropriate to exert caution when considering application of a brace in children and adolescents with a family history of inflammatory disease. Finally, it might be of interest for the reader to learn that the third triplet boy never got braces. His mother refused and he remains in good health without any sign of inflammatory bowel disease. Lotta Högberg Lars Stenhammar Lars Björkengren-Johansson Gunnar Jansson