Achieving Natural Esthetics in Complete Dentures

While patients' faces typically are not symmetrical, denture technicians traditionally have sought to create symmetry in their removable prosthetics, which usually include stock denture teeth. One concept that can be utilized in the pursuit of such symmetry to match the patient's facial features is the Golden Proportion, or Golden Ratio, which is a ratio of 1.618.¹ The Greeks of ancient times discovered it in nature, and notable Greek scholars such as Euclid, Phidias, and Pythagoras applied the proportion to mathematics, arts, and architecture—including the Parthenon on the Acropolis of Athens.²American mathematician Mark Barr coined the term of "Ratio of PHI" to honor Phidias, who used the Golden Proportion extensively in his works.³

This concept has been utilized in orthodontics/orthognathics,⁴ crown-and-bridge dentistry,^5,6,7 and more, but the author has found that utilizing the Golden Proportion also can help dentists and dental laboratory technicians in fabricating high-end complete dentures, screw-retained implant hybrid prostheses, diagnostic waxups, and fixed dental prostheses. Obtaining each individual patient's facial proportions is the key.

A young female patient complained that the dentures she had been wearing for 3 years looked fake and unnatural (Figure 1). She stated that their appearance showed no esthetics at all.

The patient presented with a canted smile, cervical lines showing no symmetry, incisal edges covered by her lower lip, and a poor-fitting denture.

The treatment team decided to approach the case by utilizing the "Ratio of PHI" concept for complete dentures to provide the patient with the smile she deserved. The author believes this was the first time this concept has been utilized in the restoration of a complete edentulous patient. The Golden Proportion philosophy was implemented, taking into consideration the patient's natural facial proportions. The author utilized one of his own innovations (Phi, the Golden Proportion Tool-Guide, Kolbeck Dental) along with a caliper (Figure 2).

The first step was evaluation of the vertical proportions of the patient's face, which was accomplished by measuring from the inner canthus of the eyes to the ala of the nose in order to determine the incisal edge position (Figure 3). The patient was asked to wear her old dentures during this evaluation, in order to allow the treatment team to determine the best outcome and properly obtain the necessary measurements.

The next step was measuring from the outer canthus of the eye to follow the width of the mouth (Figure 4). Then, the caliper position was kept the same as the width of the mouth was evaluated (Figure 5).

The width of the mouth was measured to obtain the width of the nose (Figure 6), and the caliper position was kept the same as the width of the nose was evaluated (Figure 7). The caliper was then repositioned to measure the width of the nose to obtain the size of the two central incisors (Figure 8). This was accomplished by keeping the caliper in the same position as the size of the centrals was measured (Figure 9). A difference also can be observed from the patient's previous dentures to the new measurements obtained from her facial proportions in terms of the width of her present centrals.

The measurement obtained by following the natural facial proportions for each individual patient provides the size of the two central incisors together (Figure 10). This measurement is divided in half in order to obtain the width of one central. For example, if the measurement of the two centrals together is 18 mm, then the width of one central should be 9 mm. After selecting the maxillary centrals with those measurements, the technician can identify the appropriate denture tooth mold for the patient—through noting the patient's facial shape and interdental arch form—to select the rest of the 1x28 set of denture teeth (SR Vivodent S DCL teeth, Ivoclar Vivadent, ivoclarvivadent.us), prioritizing incisal translucency, proximity to a natural look, and good buccal and occlusal surface anatomy (Figure 11).

The occlusal plane was established to achieve an accurate denture teeth arrangement following the Fox Plane position parallel to the Camper's Line (Figure 12). The six maxillary anteriors were arranged by following the patient's facial proportions obtained via the previous steps in order to achieve symmetry and to continue with the full setup of the remaining arches. Each tooth position was checked with the Phi Tool-Guide (Figure 13).

The technician then proceeded with the denture teeth arrangement, following the occlusal plane. Bilateral balanced occlusion is easily and accurately achieved by following the occlusal measurement plane (OMP) concept of complete denture setups (Figure 14). An injection system (IvoBase System, Ivoclar Vivadent) was utilized for processing the denture base, due to the accuracy and consistent results (Figure 15). Utilizing an injection system allows the technician to obtain a consistent polymerization, accurate fit, and precision. The shrinkage of the resin is compensated for during polymerization to achieve optimal processing results.

The esthetic try-in (Figure 16) showed that the patient's facial contours, canted smile, and cervical lines in the posterior had been corrected. The shape of the denture teeth matched her facial proportions, and symmetry had been accomplished.

Approaching complete denture restorations by utilizing the patient's facial proportions is a process that combines the beauty of symmetry with the natural aspects of each individual patient. The patient in this case was very pleased with her dentures (Figure 17 through Figure 19).

The author thanks Young S. Kang, DDS, FACP, for the clinical work on this case.

Josef Kolbeck, CDT
Dental Technician/Dental Laboratory Consultant
Kolbeck Dental
Bradenton, FL