During the 20 ^th century, functional appliances evolved from night time wear to more flexible appliances for increased day time wear to full time wear with Twin Block appliances. The current trend is toward fixed functional appliances and this paper introduces the Fixed Twin Block, bonded to the teeth to eliminate problems of compliance in functional therapy. TransForce lingual appliances are pre-activated and may be used in first phase treatment for sagittal and transverse arch development. Alternatively, they may be integrated with fixed appliances at any stage of treatment.