Purpose: to compare the variables of the Orofacial Evaluation with Scores Protocol between nasal, oral and oronasal breathers. Methods: a sample consisting of three distinct groups subdivided into nasal, oral and oronasal breathers, both genders, with ages ranging from 6 to 12 years. The characteristics of the orofacial musculature were measured using the protocol. Results: there was a significant difference between oral and oronasal breathers compared to nasal ones (p=0.0007) in specific variables such as palatal conformation (p=0.0073); mobility of tongue (p: 0.0111) and lip (p=0.0451), with a significant difference between the groups evaluated, also observed for the total protocol score (p=0.0007) and posture (p: 0.0073), where the nasal respirators differ from the oral and oronasal ones, the latter being similar. As for lip (p=0.0451) and tongue (p=0.0111) mobility, the groups studied presented different results among themselves. Conclusion: when comparing the groups of oral and oronasal breathers, in relation to the variables of the AMIOFE protocol, no statistically significant difference was seen between these two groups, which allows the conclusion that the orofacial myofunctional behavior between oral and oronasal breathers in this research, was similar.