Orthodontics corrects alignment and bite issues, and the timing of treatment is highly individualized. While waiting for all permanent teeth to erupt seems logical, many conditions benefit from intervention while a child is still growing. The decision to start treatment depends on specific dental and skeletal issues, rather than simply counting the remaining baby teeth.
When Treatment Starts During Mixed Dentition
Orthodontic treatment often begins before all primary teeth are shed, during the mixed dentition stage (ages six to twelve). This period involves a combination of permanent and baby teeth. Starting treatment now is called interceptive orthodontics, focusing on problems that could become more severe later. The goal is to create space for incoming permanent teeth and correct issues involving jaw growth.
Early intervention addresses significant skeletal problems, such as a severe crossbite or an underbite. Correcting these issues while the child’s bones are developing allows the orthodontist to guide growth, a powerful tool unavailable once the jaw has matured. Treatment may involve appliances like palatal expanders to widen the upper jaw or limited braces placed on a few permanent teeth. For most children, however, treatment is not required until all or most permanent teeth have erupted.
Defining Phased Orthodontic Treatment
Early treatment is often part of a planned two-phase approach, reserved for a minority of patients with complex issues. This phased treatment is divided into two distinct parts separated by a resting period. Phase I, or interceptive treatment, focuses on correcting bone discrepancies and creating a better environment for permanent teeth to erupt. It solves urgent problems that could negatively affect facial and dental development.
Phase I uses specialized appliances to modify skeletal growth, such as correcting severe crowding or guiding protruding teeth to reduce injury risk. This initial phase typically lasts 9 to 12 months. It is followed by a resting period where the child is monitored while the remaining permanent teeth emerge. A retainer may be worn during this gap to maintain the corrections made.
Phase II, or comprehensive treatment, begins once most permanent teeth have erupted (ages 12 to 14), involving full upper and lower braces or aligners. The purpose is to precisely align all permanent teeth and establish an ideal bite relationship. Phase I work simplifies this comprehensive treatment, potentially shortening the overall time needed in Phase II.
Criteria for Comprehensive Braces
The final, comprehensive stage depends on dental developmental status rather than age. Comprehensive braces—the full alignment of all teeth—are initiated when nearly all permanent teeth have erupted, excluding wisdom teeth. This stage achieves the final positioning of each tooth for a balanced bite and a stable, long-term result.
For patients who did not require Phase I treatment, the orthodontist waits for the transition to permanent dentition to be complete. Readiness for full treatment is confirmed by X-rays showing that permanent teeth have erupted and have sufficient root development. The goal is to correct any remaining misalignment, rotation, or spacing issues across both arches. While a few lingering baby teeth do not prevent the start of full treatment, the majority of the dentition must be permanent for comprehensive alignment.