Changes In Adjacent Structures Of Maxilla Following Quadruple Premolar Extraction

Quadruple premolar extraction is commonly employed in orthodontic treatment, aimed at achieving a balance between tooth and bone quantity. Existing evidence from clinical research reveals changes in adjacent structures of maxilla following quadruple premolar extraction. Therefore, this work aims to assess the impact of orthodontic tooth extraction on temporomandibular joint and maxillary sinus in patients, providing orthodontists with valuable insights for clinical practice. Patient inclusion and exclusion criteria establishment(The study period lasted from April 2016 to June 2023. Patient data were collected from the hospital's medical record database and carefully reviewed.) 2. Data collection 3. Superimposition profiles and Coordinate system establishment 4. Maxillary sinus analysis & 3D TMJ analysis 5. Statistical analysis 1.Spatial Changes of Maxillary Sinus:Post-treatment scans revealed a significant increase (P = 0.044) in the distance between the apex of the second premolar and the maxillary sinus floor, with an average augmentation of 1.0141 millimeters. 2.Spatial Changes of Temporomandibular Joint:1)A significant posterior shift of the condyle was detected (P≤0.01), averaging a 0.41mm retraction; 2) The posterior joint space narrowed by 0.32mm post-treatment; 3) A medial tilt of 0.62° in the condyle’s long axis was observed in the frontal plane. This work revealed the alterations in the TMJ and maxillary sinus among adults undergoing orthodontic treatment involving the extraction of four premolars.