Differences between dentitions with palatally and labially located maxillary canines observed in incisor width, dental morphology and space conditions.

AIM To analyze the interrelationship between incisor width, deviations in the dentition and available space in the dental arch in palatally and labially located maxillary ectopic canine cases. MATERIALS AND METHODS Size: On dental casts from 69 patients (mean age 13 years 6 months) the mesiodistal widths of each premolar, canine and incisor were measured and compared with normal standards. Dental deviations: Based on panoramic radiographs from the same patients the dentitions were grouped accordingly: Group I: normal morphology; Group IIa: deviations in the dentition within the maxillary incisors only; Group IIb: deviations in the dentition in general. Descriptive statistics for the tooth sizes and dental deviations were presented by the mean and 95% confidence limits for the mean and the p-value for the T-statistic. Space: Space was expresses by subtracting the total tooth sizes of incisors, canines and premolars from the length of the arch segments. RESULTS Size of lateral maxillary incisor: The widths of the lateral incisors were significantly different in groups I, IIa and IIb (p=0.016) and in cases with labially located ectopic canines on average 0.65 (95% CI:0.25-1.05, p=0.0019) broader than lateral incisors in cases with palatally located ectopic canines. Space: Least available space was observed in cases with labially located canines. The linear model did show a difference between palatally and labially located ectopic canines (p=0.03). Space related to deviations in the dentition: When space in the dental arch was related to dental deviations (groups I, IIa and IIb), the cases in group IIb with palatally located canines had significantly more space compared with I and IIa. CONCLUSION Two subgroups of palatally located ectopic maxillary canine cases based on registration of space, incisor width and deviations in the morphology of the dentition were identified.