Sapporo Medical Journal

Abstract : The maxillary posterior teeth-sinus link is neglected. When planning the orthodontic intrusion of the posterior teeth, it is vital to understand the anatomical connection between the maxillary sinus floor (MSF) and the maxillary posterior teeth (MPT), since a close distance may induce root resorption or impede tooth movement. Treatment planning and MSF-root apices relationship evaluation employ periapical and panoramic radiographs. Materials and methods (1) sample size collection, (2) Linear and angular measurement, (3) statistical analysis. The aim of the present study is to assess the relation between maxillary posterior root apices and the sinus floor in different facial types by using 3 dimensional CBCT imaging. Results Hyperdivergent roots were closer to the sinus floor than hypodivergent or norm divergent roots. If hyperdivergent face biotype patients need second molar intrusion to address anterior open bite, this may not work. Conclusion: 36 scans were categorized by Tweed triangle into norm divergent (12), hypodivergent (12), and hyperdivergent (12). To corroborate the group and FMA angle, reconstructed lateral cephalometry evaluated total anterior face height and FH-SN angle. Root apices scored: score (0): the root of the tooth is away from the cortical border of the sinus, with a zone of cancellous bone in between; score (1): the root is laterally projected, away from the sinus; score (2): the tip of the root is in contact with the sinus; score (3): the root tip