Localization of the unerupted maxillary canine: How to and when to

Department of Pediatric Dentistry
Lutheran Medical Center

Resident’s Name: Chad Abby Date: 3/13/2009
Article title: Localization of the unerupted maxillary canine: How to and when to
Author(s): Stanley G Jacobs
Journal: American Journal of Orthodontics and Dentofacial Orthopedics
Volume (number): Volume 115, Number 3
Month, Year: March 1999
Major topic: unerupted maxillary canines
Minor topic(s): localization of unerupted maxillary canines – reasons for localizing impacted maxillary canines and methods of localization are described
Type of Article: Literature / clinical review
Main Purpose: To summarize current literature about the localization of the impacted maxillary canine and to provide further information on this subject
Overview of method of research: Method of research was to simply describe the method of localization and explain the importance
Findings: Three reasons make it important to localize impacted canines: 1) never extract a well-placed tooth in order to make space for a poorly positioned one. If a well-placed tooth is preserved, treatment time may be shortened considerably, and the result will be more certain. 2) Because of an error in localization, a flap could be raised and an uncovering or a removal attempted in the wrong area. 3) The clinician must be able to estimate the difficulty involved in uncovering a displaced canine. 4) If suitable clinical conditions exist, a palatally impacted canine may be induced to erupt in the line of the arch, and the only treatment is extraction of the deciduous canine.
Key points/Summary: There are three methods of localization of impacted canines: inspection, palpation and radiography – Inspection – clinician may see the bulge of the unerupted canine and observe the position of the adjacent lateral incisor is being influenced by the impacted canine. If the Impacted Maxillary Canine (IMC) is palatally placed, it may press on the root of the lateral incisor and push the root labially, and the crown moves palatally. Palpation – frequently IMC can be palpated Radiography – Parallax method – the apparent displacement of an image, relative to the image of a reference object, caused by an actual change in the angulation of the x-ray beam. Tube shifts can be done in both horizontal or vertical planes. For horizontal two occlusal radiographs are taken, for a vertical an occlusal and a pano are taken. A reference object of the radiograph is used and the tooth that is farther away from the x-ray tube moves in the same direction as the tube, and the image of the tooth closer to the x-ray tube moves in the opposite direction of the tube. Indications to suspect palatal impaction may occur in the future if the patient is less than 10 years of age and there is a family history of palatally IMCs or small peg-shaped, or missing lateral incisors or other missing teeth. Indications to suspect impaction may have occurred if the patient is more than 10 years of age if: 1) Asymmetry in palpation or a pronounced difference in eruption of canines between the left and right side. 2) The canines cannot be palpated and occlusal development is advanced suggesting an abnormal path of eruption 3) The lateral incisor is proclined and tipped distally, which may indicate a labial impaction of the canine.