Abstract
Objectives
The present study aimed to identify factors predictive of increased treatment duration in patients presenting with impacted maxillary canines, and to assess the suitability of space opening as an alternative management technique compared to surgical exposure.
Methods
A retrospective investigation of case records and radiographs of 73 patients who presented with impacted maxillary canines was undertaken. A control group of 45 patients with matching age and gender profiles was also collected. Patient age, gender, treatment modality (orthodontic space opening and/or surgical exposure), and overall treatment duration were recorded. The variables describing canine location and orientation were assessed on two-dimensional orthopantomograms (OPGs).
Results
The treatment of labial/mid-alveolar sites of canine impaction took 32.1 weeks longer, and palatally-impacted canines 43.5 weeks longer, compared with conventional orthodontic cases. The assessment of multicollinearity found a significant correlation between the radiographic descriptors of canine impaction identified on OPGs. The group of variables was strongly associated with treatment time (p<0.001) and explained 24.03 per cent of the variability. Treatment by surgical exposure was associated with a statistically insignificant 32.3-week reduction in treatment time compared to space opening (p=0.07) while a change from space opening to surgical exposure was associated with a statistically insignificant 17.3-week reduction in treatment time compared to space opening (p=0.27). However, the case selection for surgical and non-surgical management of impacted canines differed significantly. All labial/mid-alveolar canines, and palatal canines in sectors I and II, or vertical (KPG) classification 1 were successfully treated by space opening. Most palatal impactions in sector IV, and all vertical (KPG) classification 4 canines required surgical exposure. For appropriately case-selected patients, treatment time did not differ significantly between space opening (128.9 weeks) or surgical exposure (136.0 weeks).
Conclusions
The increased total treatment duration for impacted maxillary canines is associated with worsening impaction as assessed on OPGs. Space opening is a valid treatment modality for all but the most severely impacted maxillary canines.