Ectopic Eruption of Maxillary Canines Dr. Juri Kurol During the mixed-dentition period, teeth may erupt out of their normal path of eruption. The deflection of the canines mostly causes a platal-medial path of eruption with a risk of more of less severe resorption of the roots of the permanent incisors. The prevalence is about two percent of the children. Depending on the position of the canine, degree of incisor root resorption and age of the individual, several clinical considerations may be discussed before choosing a treatment strategy. The disciplines involved are usually orthodontics, Maxillofacial radiology and oral surgery. Also prosthetic aspects are important. With canines in difficult positions, or when the patient is declining in extended periods of orthodontic treatment, surgical auto-transplantation may be a solution in special cases. With severe resorption of the maxillary lateral incisor roots there are basically two possibilities. The first is to retain the resorbed incisor in the arch and remove the canine or move it orthodontically. The second is to remove the resorbed lateral and move or auto-transplant the canine to replace the lateral, or to use a prosthetic replacement. With canines replacing the lateral incisors, shape and color of the canine crown are important to consider when planning treatment. However, with early diagnosis before the age of 13 years, extraction of the deciduous canines may result in spontaneous correction in about 80 percent of the cases with palatally erupting canines. The proper timing of diagnosis is important and various diagnostic procedures, including computer tomography (CT) may be chosen. Key Points: Resorptions on permanent maxillary incisors were often severe, extending into the pulp in one-half of the affected teeth. It was concluded that clinical supervision of canine eruption should be initiated no later than 10 years of age. Kurol believes that nearly 80 percent of all potentially impacted canines can be encouraged to erupt without surgical exposure by extracting the primary canines early. The trick is to identify the impacted tooth in a child as early as 10 years of age with the use of appropriate radiographs. Dr. Bill Proffit: Participants seemed eager to hear two presentations by Professor Bill Proffit, who did his best to act as if he was personally hosting us all while in the beautiful mountains of North Carolina. When teeth fail to erupt, the problem can be due to either mechanical obstruction of eruption or a failure of the eruptive mechanism. Determining which one it is and what to do about it proved to be enlightening. Proffit’s second presentation dealt with the pattern and control of human premolar eruption. It seems that high-precision optical measurements devices have been adapted for the study of premolars during the prefunctional stage of post-emergent eruption. Current experiments indicate that intermittent force applications to an erupting tooth have little effect on it eruption and don’t seem to be a part of the control mechanism.