The tonic postural system controls the equilibrium of posture when the body is completely at rest and when it is moving. It is a complicated mechanism that can call into action a variety of modalities including the assistance of the feet, the skin, the eyes, the masticatory system, the Central Nervous System and the efferent muscles, with all elements working reciprocally. Orthodontists should make a postural assessment before undertaking any treatment. If problems are found they should be dealt with by a multi-disciplinary team. But in every case orthodontists should be aware that their efforts have an effect on posture and can modify the corporal schema of the patient. Orthodontists should pay special attention to patients with scoliosis or any deformity of the spinal column.