Theoretically, it is a permanent procedure. However, it is important to note that while you may no longer see weight gain in the face, it will compensate for this in other areas. Also, it is impossible to remove all possible fat cells. Therefore, the left behind cells can expand. However, patients tend to enjoy their results for a significant number of years and have few issues with fat build up under the chin again.
Patients can experience other causes if a double chin. For example, with age the skin may lose elasticity and tightness. This can lead to sagging skin that may take on the appearance of a double chin. Procedures such as facelift or neck lift can help remedy this.