Reconstruction of the oral cavity can be very challenging because of its tridimensional structure and its fundamental function for all humans. In small defects after transoral surgery, lost tissue is limited, and flap reconstruction is not necessary. However, tongue reconstruction is mandatory in advanced cases with large defects in order to reestablish tongue function. Many reconstructive options are available in the literature. Calculating the dimension of the defect flap design can be planned to fit correctly and give the tongue mobility without giving an over bulging effect. CTS has the advantage of leaving a predictable defect. For this, in the last few years, a well-tailored flap design has demonstrated to respond to all demands for oral cavity reconstruction. As with the modularity of CTS, flap design can also be modular in order to add or remove other parts to reconstruct in flap design and volume. This chapter seeks to offer a comprehensive understanding of reconstruction properties along with practical technique enlightenment of flap harvesting and design for oral tongue.