2013 Volume 51 Issue 3 Pages 326-332
In the field of pediatric dentistry, management of occlusion change from primary to permanent dentition is important for prevention and early treatment of malocclusion. Mandibular growth and tooth inclination are important phenomena related to human facial growth. Presently, when dental casts are used to analyze the dental arch form and all teeth in a 3-dimensional manner, those casts and the cranio-mandibular skeleton are separately measured and analyzed. However, since 3-dimensional changes in dental and craniomandibular form occur together during growth, it is desirable to analyze them using a single integrated coordinate system.In the present study, landmark points were marked on lateral cephalograms and dental casts of examined subjects. The landmark coordinates of each subject were integrated and transformed to a standardized plane, and used to clarify the characteristics of permanent and primary tooth-crown inclinations. The maxillary tooth-crown inclination in most of the subjects showed significant age-related differences, while only the second premolar and primary second molar significantly differed in the mandible. Furthermore, the maxillary molars were parallel to the corresponding mandibular molars and correlated, whereas the primary molars were not. Our results suggest that similarities and differences among the inclinations of primary and permanent teeth are related to changes in craniomandibular form that occur during growth.
