Nearly worldwide, tropical and temperate regions.
Genera 4, species ca. 20 (1 genus, 2 species in the flora).
The placement of Orthodontiaceae is currently undergoing rapid revision. B. Goffinet et al. (2008) placed the family in the order Rhizogoniales with Aulacomniaceae and Rhizogoniaceae. This is quite different and distant from the order Bryales, with which Orthodontiaceae has traditionally been associated. W. Frey (2009, part 3) more recently recognized the family in the order Orthodontiales and segregated the other two families to their own orders, Aulacomniales and Rhizogoniales. Orthodontium was elevated to family status by W. R. Buck and Goffinet (2000); however, the genus was retained within Bryaceae by B. H. Allen (2002), who adopted a broader generic view of that large and complex family. Orthodontiaceae is widespread in tropical and temperate regions and primarily epiphytic on coniferous trees, decaying coniferous wood, or in terrestrial habitats.