Is there enough evidence that mouthguards do not affect athletic performance?: a systematic literature review - Ferreira, Gustavo Barbosa; Guimarães, Ludmila Silva; Fernandes, Cláudio Pinheiro; Dias, Reinaldo Brito e; Coto, Neide Pena; Antunes, Livia Azeredo Alves; Antunes, Leonardo Santos (International Dental Journal, 2018)