Smile Aesthetic Features to Consider for
Clear Aligner Treatment Planning
Aesthetic smile planning is a process that involves analysing the desired result in a virtual setup using digital software and clinical photographs before performing any clinical orthodontic movements.
Virtual systems have made backward planning the standard in dentistry, aiming for optimal treatment results from the very start.
- Midline Face/Dental: The midline of the face and upper dental midline should align. It is still considered normal when they are parallel within 2mm. There is no need to correct the lower dental midline for aesthetic reasons. It is important that the midlines of the upper and lower arches are parallel to each other.
- Visible upper incisor in speaking and rest position of the upper lip: It is considered normal when the amount of exposure of the upper incisors is approximately 2 to 4.5 mm in women and 1 to 3 mm in men.
- Visible teeth and gingiva during smiling: It is ideal when the upper central incisors and interproximal gingiva are visible. A slight gingival exposure up to 2mm during smiling is considered aesthetically pleasing in women.
- Smile Arc: The curvature formed by the incisal edges of the upper incisors and canines should follow the contour of the lower lip during a smile.
- Gingival symmetry: The gingival margins of the central incisor should be exactly on the same level. The gingival margin of the lateral incisor lies below a line connecting the gingival margins of the central incisors and canines. It is still considered as symmetric when the gingival margins of the centrals, laterals and canines are in the same line.
- Interdental papilla: There should be no black triangles or diastema visible between incisors and canines, and interdental papilla should be present. To avoid black triangles in the virtual setup, keep the roots of incisors and canines together and apply interproximal reduction (IPR) if possible.
- Buccal corridor: The posterior teeth should be visible in a smile. The size of the buccal corridor can be changed by changing the arch form. Plan overcorrection for expansion of the arch form.
- Teeth proportions: The proportional width of the teeth in relation to the inter-canine distance is considered ideal according to the golden percentage method: 25% for the central incisor, 15% for the lateral incisor, and 10% for the canine.
- Incisal line: The incisal line follows the edges of the maxillary anterior teeth. A frontal view of young patients should show the incisal edges of the central incisors positioned below the edges of the lateral incisors and canines.
- Axial axis of the maxillary anterior teeth: The maxillary anterior teeth are aligned when the apexes of the teeth are more pronounced moving distally in the arch.
- Embrasures: There should be a progressive increase in the dimensions of the embrasures in a posterior direction as they move away from the midline.
- Contact points: The contact points should be positioned progressively more apical as they move distally from the midline in a symmetrical manner.
- Connectors: The contact between the central incisors should present an ideal area of 50% of the length of the central incisor. The contact between the central and the lateral should be 40% of the length of the central incisor, while the contact between the lateral and the canine should be 30% of the length of the central incisor.
- Central incisor proportion: The width of the central incisor should be smaller than its height, in a proportion of 66% and 80% respectively. The size of both central incisors should be the same.
These considerations collectively contribute to the planning and execution of orthodontic treatment with clear aligners to achieve an aesthetically pleasing smile.
They illustrate the precision and attention to detail involved in dental aesthetics and orthodontic care to meet patient desires and clinical standards.