[Smile-guided facial rejuvenation: Contributions of orthodontic analysis to cosmetic surgery of the lower third of the face—Proposal for a decisionmaking algorithm].

INTRODUCTION: Modern facial rejuvenation can no longer be limited to the "facelift": Perceived age is strongly influenced by the smile, incisor display, lip support, and the proportions of the lower third of the face. These parameters are shaped by orthodontics (especially clear aligners) as much as by aesthetic surgery. What are the orthodontic determinants of facial rejuvenation (smile/perioral region/lower third), and how can they be integrated into a surgical or medical-aesthetic rejuvenation strategy?

OBJECTIVE: The objective of this article is to propose a practical decision-making algorithm capable of determining in which cases orthodontics alone is sufficient and in which cases a combined orthodontic-facial rejuvenation strategy is more appropriate.

MATERIALS AND METHOD: A structured narrative review was conducted based on searches of the PubMed, Scopus, and Embase databases (1990-2025). Articles addressing smile aging, aligner predictability (torque, extrusion, rotations), facial aging anatomy (fat compartments/skeletal framework), and rejuvenation techniques (midface/lower third, perioral complex) were selected.

RESULTS: (1) Aging is associated with reduced maxillary incisor display and relatively increased mandibular incisor exposure, along with lip lengthening. (2) Clear aligners align and level effectively, but their accuracy varies depending on the type of movement, with extrusion and some torque/rotations remaining less clinically predictable. (3) Surgical and non-surgical rejuvenation strategies target both the "container" (skeletal structure) and the "content" (fat compartments/superficial muscular aponeurotic system [SMAS]), as well as the perioral complex, in order to restore proportions perceived as more youthful. A simple algorithm for co-planning orthodontic treatment and facial rejuvenation can identify clinical warning signs that justify a combined strategy (orthodontics combined with injectables, lipofilling, lip lift, or cervico-facial rejuvenation).

DISCUSSION: An orthodontist-friendly framework for facial rejuvenation relies on four levers: (1) incisor display (at rest/during speech/when smiling), (2) incisor torque and smile arc, (3) lip support (avoiding retraction with an "aging-like" effect), (4) vertical dimension of occlusion and lower-third height.

CONCLUSION: Orthodontists are key partners in facial rejuvenation because they control major perioral aesthetic determinants. Shared planning (standardized photographs, dynamic smile analysis, and precise torque and lip-support objectives) improves the naturalness of outcomes and reduces aesthetic discrepancies.