Mark Piraino, 40, from Redhill, Surrey, was originally sentenced by a judge at Guildford Crown Court in February.
BBC: Redhill osteopath Mark Piraino's sentence increased
2.
Lady Justice Hallett, who headed the panel of judges, said Piraino, whose oldest victim was 31, "carried on offending" until he was "preying on quite young boys".
BBC: Redhill osteopath Mark Piraino's sentence increased