The removable functional appliance enables forward growth of the face and jaws and either improvement or resolution of cranial strains. The forward growth allows for more space for crowded teeth, an improved profile, increased space for the tongue, improved head and shoulder posture and improved breathing capabilities. It also allows for temporomandibular joints to settle in the appropriate physiologic position. 

 
The removable functional appliance  is best for children who have a mixture of baby and permanent teeth present in their mouth. The age range for this appliance tends to be between the ages of 6-12. This functional appliance is worn at all times except for tooth brushing and is usually followed by braces or clear aligner therapy when they child has all of his or her permanent teeth present. When treating adolescents and teens this appliance is followed by conventional orthodontics (braces).