Aesthetics is a major factor in Orthodontic treatment and a primary concern among patients seeking orthodontic treatment. Clear aligner therapy is a treatment that consists of a set of clear dental appliances that are custom-made to fit the patient's teeth. These are alternative to traditional braces that are used to guide teeth into appropriate alignment. Clear aligners, like braces, utilize a progressive force to regulate tooth movement, but without the need of metal wires or brackets given by Sanjana Shetty and Naazia Shaikh. 4D printed aligners have the ability to change with time (the fourth dimension), upon given environment condition. 4D aligners generate 0.30-0.70N forces at different temperatures such as 37 degreesC,45 degreesC,55 degreesC which are in the range of acceptable physiological orthodontic forces. Orthodontic treatment involving clear polyurethane aligners has started dominating the market and existed for almost two decades now, it is not indicated for all type of patients. Controversies exists in the aligner's treatment. Indication in orthodontic cases without skeletal disharmonies with mild crowding, Invisalign may be suitable for even moderately complex orthodontic cases.