Effects of torque overcorrection on mandibular incisor intrusion using clear aligners in the first premolar non-extraction and extraction conditions: a finite element analysis study

During mandibular incisor intrusion, the torque overcorrection design may help reduce the lingual tipping tendencies of the incisors, relieve the compressive stress on the periodontal tissues, and protect the anchorage from the canines and premolars. When the first premolar was extracted, similar overcorrection degrees are required if the incisor retraction was not designed. However, more overcorrection degrees are required if the incisor intrusion and retraction were designed synchronously.