What makes a smile beautiful? Many dental, oral, and facial parameters and the way they harmonize as a whole determine the aesthetic assessment of a smile. Throughout this website we are talking about specific shortcomings of the aesthetic zone of the dental arch and how it can be corrected with porcelain veneers. A very rare and rather challenging condition is that of a canted smile line and a canted dental midline (see the blue line in the upper image).
Ideally, the incisal edge follows the inner border of the lower lip, while the incisal plane is perpendicular to the dental midline. One of the most aesthetic parameters in human anatomy is symmetry. The human eye is very keen when it comes to the perception of differences of line angles. This is particularly applicable to the human face. While no face is perfectly symmetric, there is a threshold of variation, at which attention is drawn to the dissonance of facial harmony. Good examples are the facial asymmetries that are seen in stroke victims, asymmetric muscle tone after poorly balanced botox injections, and the paralysis of some facial muscles due to trauma or right after local anesthesia of oral tissue.
The case presented here demonstrates how a canted smile line and midline can distract from the overall appraisal of a smile. One is more drawn to the facial disharmony than to the intention of the smiling person. This changes entirely once the dento-facial harmony has been established. The smile becomes more appreciable and "softer" with all the subtle messages and nuances that a commonly smile entails.
This result can only be predictably obtained by careful analysis of the dental models, a diagnostic wax-up of all the teeth involved and as they relate to each other, transfer of the diagnostic wax-up as provisional acrylic restorations into the patient's mouth, an analysis of how the newly designed teeth harmonize with all oral and facial functions, and how they harmonize aesthetically with the composition of all facial structures at various modes of expressions. Once the provisional restorations have been optimized and approved as an aesthetically fully integrated unit, the dental laboratory will be advised how to proceed with the fabrication of the porcelain veneers.
Once the outline and line angles of the new teeth have been determined, we can now focus on aesthetic elements, such as the degree of incisal translucency, the composition and variation of shades and colors, as well as micro-elements, such as incisal embrasures, incisal notching, central dominance versus Golden Proportions, and much more. All this is established in close communication with the patient. Dr. Rabanus' motto that "you don't have to be a dentist to make an educated choice" is carried through the entire process of designing a new smile. The patient will get any and every support to be able to make a choice about all the aesthetic elements involved while the dentist assures total functional harmony.
References:
Claude R Rufenacht. Fundamentals of Esthetics. Chicago, IL: Quintessence Publishing; 1990.
Claude R Rufenacht. Principles of Esthetic Integration. Chicago, IL: Quintessence Publishing; 2000.
Chiche GJ, Pinault A. Esthetics of Anterior Fixed Prosthodontics. Chicago, IL: Quintessence Publishing; 1994.
Morley J. The role of cosmetic dentistry in restoring a youthful appearance. J Am Dent Assoc. 1999;130:1166-1172.
Morley J, Eubank J. Macroesthetic elements of smile design. J Am Dent Assoc. 2001;132:39-45.
Kokich VO, Kokich VG, Kiyak HA. Perceptions of dental professionals and laypersons to altered dental esthetics: asymmetric and symmetric situations. Am J Orthod Dentofacial Orthop. 2006;130:141-151.
Dawson PE. Functional Occlusion: From TMJ to Smile Design. St. Louis, MO: Mosby; 2007.
Carruthers J, Carruthers A. BOTOX use in the mid and lower face and neck. Semin Cutan Med Surg. 2001;20:85-92.
