Relationship Between "Clinical Classification of Occlusion" Newly Established and Lateral Cephalometric Analysis in Patients Treated by Two-Jaw Surgery

  • Graduate school student Jun Nihara, Division of Orthodontics, Niigata University Graduate School of Medical and Dental Sciences, Japan
  • Assistant professor Masaki Takeyama, Division of Orthodontics, Niigata University Graduate School of Medical and Dental Sciences, Japan
  • Associate Professor Tadaharu Kobayashi, Division of Reconstructive Oral and Maxillofacial Surgery, Niigata University Graduate School of Medical and Dental Sciences, Japan
  • Assistant professor Junichi Fukuda, Division of Oral and Maxillofacial Surgery, Niigata University Graduate School of Medical and Dental Sciences, Japan
  • Yuichi Muto, Department of Dentistry and Oral-Maxillofacial Surgery, Niigata Rosai Hospital, Japan
  • Professor Chikara Saito, Division of Reconstructive Oral and Maxillofacial Surgery, Niigata University Graduate School of Medical and Dental Sciences, Japan
  • Professor Ritsuo Takagi, Division of Oral and Maxillofacial Surgery, Niigata University Graduate School of Medical and Dental Sciences, Japan
  • Professor Isao Saito, Division of Orthodontics, Niigata University Graduate School of Medical and Dental Sciences, Japan

Purpose: Adequate analysis of craniofacial morphology is essential for the diagnosis of surgical orthodontic treatment. The diagnosis is performed making reference to lateral and/or frontal cephalometric analysis. Recently, we have used “Clinical classification of occlusion (CCO)” newly established based upon geometric analysis of morphology without the value of cephalometric measurements. The aim of this study was to examine the relationship between CCO and lateral cephalometric analysis.
Materials and Methods: Subjects comprised 50 skeletal Class III patients surgically treated by Le Fort I osteotomy in the maxilla combined with SSRO or IVRO in the mandible at Niigata University Medical and Dental Hospital, Japan. All cases were classified by CCO. We made a cephalometric analysis of 3 groups, 1) protruding lower jaw (Progenia group), 2) retruding upper jaw and protruding lower jaw (Complex group), 3) no anteroposterior deformities (ND group).
Results: There were significant differences in SNB, ANB, SNP, Fa, Convexity, Y-axis, GZN, FMIA, between Progenia group and ND group indicating that the mandible of Progenia group is larger or more forward than that of ND group. Significant differences in SNA, ANB, Convexity, U1FH were found between Progenia group and Complex group, which was due to maxillary deficiency and dental compensation such as labial inclination of the upper incisors in Complex group.
Conclusions: This study revealed that CCO was related to conventional analysis in some angular measurements in skeletal Class III surgically treated. Close relation may therefore exist between this new classification based upon orthodontist’s geometric recognition and conventional cephalometric analysis.