A retrospective study of micro-implant anchorage in the upper posterior region to improve gummy smiles

Objective To analyze the ability of micro-implant nails placed in different locations in the posterior region to improve the hard and soft tissues of the labiodental region in patients with gummy smiles to provide a reference for clinicians. Methods This study was reviewed and approved by the Ethics Committee, and informed consent was obtained from the patients. Thirty young female patients with anterior tooth protrusions and gummy smiles were included in the retrospective study; 18 patients had micro-implant nails implanted between the premolars (group A), and 12 patients had implant nails placed between the roots of the premolar and the molar and an intraoperatively placed rocking-chair archwire (group B). The preoperative and postoperative distances from the incisal end of the upper mesial incisors to the lower point of the upper lip (U1-Stms), the vertical distance from the incisal end of the upper mesial incisors to the palatal plane (U1-PP), the vertical distance from the point of the alveolar ridge to