When you have patients that are missing lateral incisors, there are multiple factors that need to be taken into consideration. The management of adult patients that happen to have their lateral incisors and need them extracted is an entirely different process than patients with congenitally missing laterals. Single tooth implants are not suggested for young patients until they have completed their growth cycle.
For these young patients that are congenitally missing their lateral incisors, canine substitution can be an excellent, esthetic treatment option. However, there are certain criteria that must be met to help guarantee this procedure will be a success and yield predictable results:
Occlusal considerations: From an occlusal standpoint, there are two situations that are appropriate, the first one being a Class II individual free of mandibular crowding. In this case, the molars would remain in Class II but the pre-molar is brought forward to act as the canine, while remaining in a Class I relationship with the lower canine. The other situation is a Class I individual with sufficient mandibular anterior crowding that would necessitate pre-molar extractions on the lower arch.
Nice profile: Ideally, the patient would have a profile that is relatively flat or slightly convex. Patients without either of these characteristics would most likely benefit from a treatment modality that manages the esthetic profile.
Canine shape and color: If the canines are going to be sitting in the lateral site, evaluation of canine shape and color is necessary. Canines are generally larger than lateral incisors and hence the width of canines should be evaluated. However, it’s not the overall width that is important but rather the width at the CEJ (as that cannot be narrowed). The wider the tooth at the CEJ, the more difficult it will be to make them look like lateral incisors. Color-wise, out of all the teeth in the mouth, canines are the teeth that are the most saturated with chroma. A canine that is smaller in shape and doesn’t have an over-saturation of chroma would make an excellent candidate for canine substitution.
Smiling lip level: Depending on how high the smile line is, their lip level may show the canine eminence. Large canines often have an obvious root prominence, and high lip levels may reveal that there is an unnatural eminence in the lateral sight. Canine substitution can be an excellent treatment alternative for congenitally missing maxillary lateral incisors. Patient selection is critical and depends on the type of malocclusion, profile, canine shape and color, and smiling lip level. Pre-treatment evaluation of these selection criteria is necessary to insure treatment success and predictable esthetics.