Missing inferior labial and lingual frenula in Ehlers-Danlos Syndrome - Authors' reply

Sir—In our opinion, there are several weak points to Stephanie Böhm and colleagues' argument that invalidate their main conclusion: absence of a matched control population; unclear frenulum classification criteria—in our data series, all cases were documented photographically and assessed independently; and no information about the within-familial relationships. The latter is of relevance to a potential lack of independence on statistical inference results and to the subsequent conclusion. Nevertheless, given the prevalence of mandibular frenulum abnormalities observed in our control population (one of 154), three of 16 oral frenulum abnormalities reported by Böhm and colleagues is significantly higher than in the controls. Their findings, therefore, seem to confirm, rather than oppose, our observation of a significant association between developmental oral frenula abnormalities and EDS. Possible explanations for this significant discrepancy include selection criteria and potential pheno-type-genotype differences. The well known EDS phenotypic and genetic heterogeneity1 might account for the discrepancies between our findings and those of Böhm and colleagues.