Smile rejuvenation: A case report.

Mesiodens is the commonly occurring supernumerary tooth seen between the maxillary central incisors which causes compromised aesthetics and malocclusion. Till date orthodontic therapy provides an excellent solution for the management of mesiodens. Recently, Restorative Space Management (RSM) has been used successfully to correct tooth shape, proportions and colour with minimal tooth preparations. This case report describes the successful management of an unaesthetic smile due to presence of a mesiodens in the midline primarily using aesthetic treatment only.

INTRODUCTION

In recent times, there is an increase in the number of patients seeking cosmetic dental procedures to enhance their smile and personality. Hence esthetic dentists today should be well equipped to meet the demands of modern society.

An individual's facial and dental appearance influences their personality and social interactions to a great extent.[1] The heightened demand for aesthetic restorations by today's patients has challenged dentists to plan and deliver their treatment in a more organized and systematic manner.[2] The value of a captivating smile is undeniable.[3] It plays a major role in building one's self image and boosting their self-confidence.

Till date orthodontic therapy has proven to be an excellent, predictable means of achieving tooth movement to address aesthetic and functional concerns. This is particularly true for patients with marked overlapping and malaligned teeth. But some patients refuse orthodontic treatment due to occupational limitation of time and the unaesthetic appearance during treatment.

Restorative Space Management (RSM) is defined by Kim et al., as a therapy that uses tooth preparation techniques and designs to accomplish the goals of orthodontic therapy. In this procedure, the clinician can perform selective removal of tooth structure in certain strategic areas followed by the addition of cosmetic restorative materials. Unlike orthodontic therapy, RSM allows the correction of tooth shapes and dimensions to improve tooth proportions, as well as color correction. With the advancements in adhesive and ceramic technology restorative dentists are thus in a position to restore optimal aesthetics with minimal tooth preparation.[4]

Supernumerary teeth are those in excess when compared to the normal series.[5] ‘Mesiodens’ is a supernumerary tooth present in the premaxilla between the two central incisors with an incidence rate of 0.15-3.8% in the permanent dentition.[6] This always poses a restorative challenge and complicates the treatment planning.

The following case describes the successful management of an unaesthetic smile due to presence of a mesiodens primarily with aesthetic treatment alone.

CASE REPORT

A 23-year-old female patient reported to the Department of Conservative Dentistry, Endodontics and Aesthetic Dentistry with the chief complaint of an unaesthetic smile. She was concerned about the presence of an extra tooth, proclined upper anteriors and discolored teeth [Figure 1a–d].

Figure 1

(a) Front profile picture without smile, (b) Front profile picture with smile and inter-pupillary distance and midline corelation (c, d) Side profile pictures (e) Pre- operative intra-oral view, (f) Proximal view showing generalised hypoplasia and proclined upper anteriors, (g) Lip Trap with the respect to right upper lateral, (h) Diagnostic model, (i) Wax-up on the model, (j) Maxillary arch form corrected

The patient's diagnostic models were made, studied and keeping in mind her basic concerns an initial treatment plan was suggested. She was given an option of surgical extraction of the mesiodens followed by correction of the proclination and the resultant space available with orthodontic therapy. She, however, was strictly against extraction and a long-term orthodontic therapy. She desired an alternative approach which could address her complaints within a definitive time frame. Considering the patient's requirements and her time constraints an alternative treatment was planned.

In the following appointment, series of photographs of facial profile, close-up views of smile were taken. Combining the findings and clinical examination, study of the diagnostic models, photographic analysis, a complete aesthetic evaluation was done and the following observations were noted [Figure 1e–h]

Patient had generalized enamel hypoplasia.

Patient had a conical shape mesiodens right on the facial and dental midline.

There was proclination and irregular alignment of the maxillary anteriors

Presence of lip trap with respect to right lateral incisor as she smiled.

Increased over-jet and over-bite due to proclined upper anteriors and retroclined lower anteriors.

Presence of a cant in the smile line on the left side.

Uneven gingival zenith with respect to the upper anteriors.

After the aesthetic evaluation, the following treatment goals were set:

Correction of the midline.

Correction of her tooth proportions

Correction of the proclination.

Management of the enamel hypoplasia by means of natural looking restorations.

Correction of the lip trap.

Restoring the smile line and the anterior guidance.

The greatest challenge in this case was the presence of the mesiodens which the patient desired to retain. Therefore, this tooth was planned to be crowned as the left central incisor, while the left central was to be crowned as left lateral and the left lateral incisor to be veneered as the left canine. In addition, it was decided to veneer the right lateral incisor in order to enhance the smile.

Ideal width and length was estimated accordingly to obtain the ideal tooth proportions. With this blue-print, to have a three-dimensional visualization, wax-up was done on the cast [Figure 1i and j]. Since the mesiodens had deep dental caries at the cervical aspect, endodontic treatment was done. Endodontic treatment was also performed for the left central incisor to correct the severe proclination and provide more room to shift and correct the midline [Figure 2a].

Figure 2

(a) Radiograph showing endodontically treated mesiodens and left central incisor, (b) Initial toothpreparation, (c) Smile restored with temporary material, (d) Final correction of the preparation. (e) Try in on patient's mouth, (f, g) Post-operative view after final cementation, (h, i) One year follow up radiograph and intra-oral view

In order to have a more conservative preparation, before the actual tooth preparation the putty index obtained from the final diagnostic wax-up was sectioned labio-palatally and the labial section was positioned against the upper anteriors in the patient's mouth. The surfaces on the teeth of interest that were in contact with the putty index were marked and trimmed such that there was even amount of space between the index and the tooth surfaces. Following this temporary Bis-acrylic material was loaded on to the putty-index to restore the tooth with temporary material according to the final wax-up.

Actual tooth preparation was then done with the temporary on the teeth to restrict the preparation to as conservative as possible. The teeth were then restored with temporary material. This revealed that the patient had an obvious midline shift of 4 mm toward the right side [Figure 2c]. The patient's phonetics was also evaluated with “F” and “V” sounds to check the initial length, display, and inclination of the maxillary central incisors. The anterior guidance was also checked.

Following this, the preparations were modified. A slice preparation was done on the distal aspect of the right central incisor to obtain a better emergence profile and to get more room to shift the midline [Figure 2d]. The corrected smile was then verified with a new set of temporaries.

Now, the following observations were noted:

The teeth proportion was brought to 75-80%.

Proclination was corrected and the teeth were brought into arch form.

The midline deviation was brought within acceptable limits (less than 2 mm).

Lip trap was eliminated.

The new smile line followed the contour of the lower lip.

As the patient had hypoplastic teeth, shade selection was a very critical factor for this case. The shade selection was done based on the patient's skin tone and her desire for natural looking teeth. The shade selection was done using both Vita Classical and Vita 3D Master shade guides (Vident). The underlying stump shade of the hypoplastic tooth structure was noted and conveyed to the ceramist to avoid show through effect in the final restorations (a more opaque core was suggested).

All the above information was then communicated to the laboratory, and the final all-ceramic crowns and veneers (IPS e-max, Ivoclar Vivadent) were fabricated.

The procured restorations were then tried in the patient's mouth [Figure 2e]. During the try-in procedure, the marginal fit of the restorations, shade match, incisal display, smile line, and arch form were all evaluated. As the patient was well satisfied with the aesthetic outcome, the restorations were cemented using dual cure resin cement (Vario-Link, Ivoclar Vivadent) [Figures 2f and g]. One-year follow-up of the case shows complete functionality [Figures 2h and i].

DISCUSSION

According to Pascal Magne, there are various subjective and objective criteria for the assessment of an ideal smile.[7] Midline symmetry is one such criterion which holds the key to facial aesthetics and smile architecture. Midline is an imaginary line located on the center of the face, perpendicular to the inter-pupillary line and coincides with the dental midline. In a totally symmetrical face the dental midline and the facial midline should coincide but this is often not the case. According to Kokich, a midline deviation greater than 4 mm is detected by the general public. But Johnston concluded that a midline deviation of 2 mm remains undetectable by laymen.[8]

In the present case the primary challenges were:

Presence of mesiodens on the midline.

Midline deviation of over 4 mm.

Need for only restorative treatment.

Need to align the upper anteriors according to the arch form.

Non-surgical and non-orthodontic treatment plan.

With the present treatment, the conical-shaped mesiodens was converted to a central incisor, midline was adjusted to an accepted level, lip trap on the right side with respect to the lateral incisor was corrected and all the maxillary anteriors could be brought into arch form. However, the gingival zenith was not a critical factor since the patient had a low lip line.

Diagnostic wax-up often reveals the need for additional treatment that may not be evident during clinical examination. Hence, it acts as a dynamic visual and functional aid in achieving predictable results.[9] In this case, the diagnostic wax-up was helpful initially for visualizing and planning the final outcome of the treatment.

However, it may be difficult for patients to envision the final result only by means of the diagnostic wax-up. An additional aid is the indirect mock-up with composite resin on the patient's cast or direct mock-up using Bis-acrylic material in the patient's mouth. This gives a three-dimensional perspective which is helpful for confirming the expected aesthetic outcome.[9]

It is, therefore, recommended that before any elective aesthetic treatment, the patient should be enabled to visualize the projected results along with their limitations to help them understand the realistic results. Involving patients in the decision-making process will lead to a mutually satisfying outcome.[9]

In the present case during diagnostic wax-up procedure it was realized that estimation of the final width and length of the maxillary anteriors was critical. Lombardi explained the importance of the proportion between width and length in the dimensions of individual teeth and between the respective sizes of anterior teeth. Ideally, width to length ratio should be 80%. A higher width/length ratio means a squarer tooth and a lower ratio means a longer and slender appearance.[10]

Lastly, advancements in the field of ceramics and adhesive technology have clearly paved the way for rational and satisfactory substitutes for conventional treatments. The IPS e-max Press system (Ivoclar Vivadent) is a glass ceramic, composed primarily of a modified lithium disilicate glass ceramic. It has superior strength and higher translucency suitable for the fabrication of all ceramic crowns, inlays, onlays and veneers. The newer core ceramics are of low fusing glass with optimal aesthetics, permitting light to pass through available in a variety of shades. The combination of composite-based resin luting systems and low fusing porcelains has marked a major milestone in aesthetic restorative dentistry.[11] They make it possible to fabricate restorations of great beauty, function, and strength.

CONCLUSION

This is an interesting case where Restorative Space Management (RSM) using adhesive restorations alone was employed to optimally rejuvenate an unaesthetic smile. Here, it was not possible to recreate the “ideal smile” due to the presence of the mesiodens. Considering the extra-ordinary circumstances where the patient had constraints for time frame and refused for a conventional approach an alternative approach was planned which enabled us to achieve a “balanced smile” that was overall pleasing. Finally, as aesthetic dentists we need to apply the right balance of prudence and wisdom with knowledge and progress to enhance our patients smile.[1]