Clear aligner treatment does not exclude the use of fixed biomechanics. In certain clinical situations (particularly those involving root control after extraction space closure) a sectional arch offers a level of precision that is difficult to replicate through digital programming alone.<\/p>\n
This is not a limitation of aligners. It is a biomechanical decision<\/strong>. And it should be presented to the patient in exactly those terms: not as a failure of the system, but as a deliberate choice within a larger plan.<\/p>\n After closing extraction spaces with aligners, root parallelism between canines and premolars frequently requires refinement. Software can program root movements, but the clinical expression of those movements in these specific situations often needs mechanical reinforcement.<\/p>\n A short sectional (typically involving three to four brackets in the relevant zone) allows for a more direct and controlled root moment to be applied. The objective is not to restart treatment with fixed appliances. It is a localized, time-limited intervention with a specific mechanical purpose.<\/p>\n The critical distinction: this intervention should be anticipated from the start of treatment, not improvised<\/strong> at the end.<\/p>\n Integrating a sectional requires more than simply bonding a bracket. The aligner trimming in that area must be specifically designed to accommodate the bracket and active arch without interfering with the mechanics.<\/p>\n Standard button cutouts are often insufficient in these situations. When the plastic encroaches on the active zone, the system loses efficiency and requires repeated manual adjustments on every tray.<\/p>\n The correct approach is to request a specific cutout from the technician: one that reduces the aligner contour in that zone while maintaining full coverage of the rest of the arch. The aligner continues stabilizing the remaining dentition while the sectional works independently in the target area.<\/p>\nWhen sectionals become relevant<\/h3>\n
The trimming design determines the compatibility<\/h3>\n