Orthopedic effects with "conventional" fixed orthodontic appliances: a preliminary report

This retrospective study involved sixty previously treated patients between the ages of 9 and 14 years, all of whom initially had Class II dental malocclusions. The primary purpose of the investigation was to determine whether orthodontic treatment with a specific round-wire edgewise technique (no extraoral forces) was simply producing dentoalveolar manipulations or was actually affecting measurable skeletal or orthopedic alterations in the craniofacial system. The mean linear changes before and after orthodontic treatment in the maxilla (Ar-ANS), mandible (Ar-PGN), and lower facial height (ANS-MN) were statistically compared with an untreated control group (the Burlington Growth Study). The study sample was analyzed selectively according to sex and also according to the angulation of the mandibular base to the anterior cranial base (the SNMP angle). Apparently, from the observations in this study, the particular edgewise technique employed for the orthodontic treatment of the sixty sample patients did statistically affect more than merely dentoalveolar alterations. The normal forward growth of the maxilla appeared to be hindered, the lower facial height was significantly increased (usually without an appreciable increase in the SNMP angle), and the mean increased growth of the mandible was also statistically significant. Admittedly not its primary purpose, this preliminary report appeared to at least indirectly compare, if not the actual treatment modalities, at least the treatment results between a specific fixed orthodontic appliance and certain removable "functional" appliances.