Association between maxillary canine impaction and other dental anomalies: radiological study of a mixed dentition children's cohort from an orthodontic clinic.

PURPOSE: To investigate the significance of association between maxillary impacted canines and various dental anomalies. METHODS: Files of 874 orthodontic patients were evaluated for the presence of maxillary impacted canines. From this sample, a group of 97 patients (39 males and 58 females) with at least 1 impacted maxillary canine consisted the study group. This group was compared to a control group of 97 patients (42 males and 55 females) that was created by random selection from the initial sample without maxillary canine impaction. The impaction diagnosis was made from the panoramic radiographs. Chi-square test was used to perform the analysis for significant associations. Stepwise discriminant analysis, binary logistic regression and classification tree were used to identify best combinations. RESULTS: Statistically significant difference was found for peg-shaped maxillary lateral incisors and infraoccluded deciduous molars. The presence of peg-shaped upper lateral incisors arises the probability of impacted canine to 83.3%, a distal displaced unerupted second premolar to 63.16% and the impaction of any other teeth to 80% as showed by the classification tree. CONCLUSIONS: The presence of peg-shaped maxillary lateral incisors and infraocclusion of deciduous molars can be considered major valuable early risk indicators for maxillary canine impaction, because they manifest before the maxillary canine eruption. Special consideration should be given on distal displaced unerupted second premolar and the impaction of any other teeth. Patients with these dental anomalies are candidates for future interceptive treatment for canine eruption.

Validity of computerized predictions of dentoskeletal and soft tissue profile changes after mandibular setback and maxillary impaction osteotomies.

The aim of the present investigation was to evaluate the validity of the predictions of a computerized cephalometric system (Dentofacial Planner) regarding dentoskeletal and soft tissue profile changes after mandibular setback and maxillary impaction osteotomies. Tracings of lateral cephalograms taken at the end of preoperative orthodontics (within 1 week before surgery) and approximately 1 year after the operation were digitized and entered into the Dentofacial Planner. For the mandibular setback group, the computerized predictions tended to place the mandible less posteriorly than the actual situation and to significantly underestimate the mandibular plane angle, the total anterior skeletal and soft tissue facial heights, the lower anterior skeletal facial height, and the upper lip height. In the maxillary impaction group, the prediction printouts significantly overestimated the total anterior soft tissue facial height, the upper lip height and the inclination and curvature of the lower lip and underestimated the soft tissue thickness in the regions of pogonion and point B.