Main Instructor Yu-Ting Wu
Department / Institution Orthodontic Department, Chung Shan Medical University Hospital
Classification Case report
「Case」 This is a 25y11m female, with retained primary canine. Through x-ray findings, we found the patient had congenital missing of maxillary canines. After diagnosis, the patient had convex profile and Angle’s molar class II malocclusion, the treatment plan was to extract retained primary canines and close the space with premolar substitution. The final treatment result was acceptable with harmonious profile and stable occlusion.
「Discussion and Summary」 Permanent maxillary canines are known to be one of the most variably positioned teeth with palatal or facial displacement or ectopically eruption from the dental arch. Congenital canine agenesis is a rare condition. Two major treatment approaches for congenital missing of canines are space retained for prosthodontic treatment or orthodontic space closing with premolars. The decision of the treatment plan is due to the size, morphology or color of the premolar, the dentition and profile of the patient. In this case, the patient had convex profile and Angle’s molar class II malocclusion, so we suggested primary canine extraction and space closure with premolars. But it is concerned that the clinical crown length of premolar is shorter than canine, substituting maxillary premolar for canine may cause esthetic problems especially for patients with gummy smile. Local gingivectomy or surgical crown lengthening may recommend for these cases to achieve better result esthetically. Furthermore, we should pay more attention about the type of functional occlusion of the patient and adjusted replaced tooth. In conclusion, how to position the canine to achieve proper esthetic with good functional occlusion is important in premolar substitution for canine.
Premolar Substitution in Congenital Missing Canine