Transverse maxillary deficiency in Class II and Class III malocclusions: a cephalometric and morphometric study on postero-anterior films.

OBJECTIVES: The aim of the present study is to evaluate the dentoskeletal features of subjects with either Class II or Class III malocclusions in the mixed dentition using both conventional cephalometric analysis and TPS morphometric analysis applied to posteroanterior (PA) cephalograms. DESIGN: TPS analyses of PA cephalograms on 49 Cl-II, and 20 Cl-III subjects. Tracings were done by hand. SETTING AND SAMPLE POPULATION: The Department of Orthodontics, University of Florence. OUTCOME MEASURE: Size and shape differences between Cl-II and Cl-III malocclusions. RESULTS: Maxillary width was smaller in both Cl-II and Cl-III subjects compared with normal as measured conventionally. The TPS analysis revealed transverse plane compression and extension in the vertical plane. CONCLUSION: In Cl-II and Cl-III subjects the maxillary width was smaller 2.5 and 4 mm, respectively. TPS analyses corroborate these findings.