A Conservative Approach to Restoring a Canted Smile

[Anonymous]

INTRODUCTION

What constitutes a beautiful smile? There are a number of criteria that are viewed as essential components of an attractive smile. The lips frame the smile, so we as dentists must balance what is seen in the interaction between the teeth and the lips.¹ The analysis of the teeth is broken down into micro- and macro-aesthetic components. Micro-aesthetics concern how an individual tooth looks with respect to internal color, shape, positions of the line angles, and how the tooth looks in respect to the adjacent teeth. Macro-aesthetics encompass those characteristics that are seen from a distance: How much tooth or incisal display is revealed? What is the color and shape of all the teeth in relation to the upper and lower lip? Does the smile fill the buccal corridor? Are the teeth angled in the correct orientation? What are the shapes of the incisal embrasures, and how is the gingiva framing the teeth?² 
The discussion in this article will concentrate on a case study related to the macro-aesthetic elements of a smile.

ESTABLISHING BEAUTY: MACRO-AESTHETIC CRITERIA 
Among the many criteria of beauty, the incisal plane and dental midline play a role in this perception. In the ideal smile, the midline of the teeth would match the midline of the face. The interproximal contact area of the central incisors would be perpendicular to the horizon, a horizontal line parallel to the ground. The contact area of the anterior teeth are in a progression from the largest contact area between the central incisors, to a slighter contact between the laterals and cuspid.³ In this ideal smile, the incisal plane would be perfectly horizontal, follow the lower lip-line, and would bisect the angle formed from a line from nasion to cupid’s bow, continuing down through the contact area of the maxillary central incisors (Figures 1 and 2).⁴

Figure 1. The ideal incisal edge follows the lower lip-line.	Figure 2. The incisal plane is perpendicular to the dental midline.

Drawings reproduced with permission of American Academy of Cosmetic Dentistry.

Macro-aesthetic variations would be most evident when you first see someone’s smile. Differences from an ideal (“perfect”) smile become more visible as any defect becomes more pronounced. One such area of deviation relates to a perfectly level line of the maxillary incisal edges. Related to this is the contact area of the central incisors. A study by Kokich, et al⁵ has been done that analyzes the amount of deviation from the midline that would be acceptable to the human eye, with evaluation done by orthodontists, general dentists, and nondental professionals. Among other characteristics of a smile, the study also determined the amount of vertical cant of the incisal plane and midline that would be noticeable. The results were: a 4-mm shift of the midline was noticeable by general dentists and laypeople, where a dentist could detect a one-mm plane asymmetry compared to a 3-mm cant by a layperson. This study shows the importance of correcting as many deficiencies of a smile when we diagnose and treat our patients.

        

[drsushant]

 CASE REPORT

Treatment Planning and Diagnosis
A 27-year-old female who was unhappy with her smile presented to our office. A comprehensive examination was performed,6 which included evaluation of the temporomandibular joint (TMJ), a full periodontal examination, and evaluation of the teeth with shape and color noted. A complete intraoral radiographic and photographic series was taken. Her smile was then evaluated, and it was clinically evident that she had an incisal cant that was higher on the right side than on the left. This was apparently caused by a developmental asymmetry that allowed her left condyle to grow longer than her right side. Her face, lips, and teeth were all lower on the left side (Figures 3 and 4). She had completed orthodontic treatment several years earlier, but the asymmetry was not corrected. As a result, the axial inclinations of the individual teeth were also inappropriate (Figures 5 to 7).

Figure 3. The patient’s left side lower lip is canted downward.	Figure 4. Preoperative photo showing the canted lip and incisal plane.
Figure 5. The teeth are angled medially, with more angulation toward the posterior.	Figure 6. Preoperative retracted full-mouth view (1:2 magnification).

Figure 7. Preoperative retracted close-up view (1:1 magnification).

 

        

[drsushant]

 Evaluation of her TMJs was done and loading was comfortable.⁷ However, she had tension headaches originating from the temporal area, and she felt that she had more than one bite. Based on this information, it was decided to establish a stable occlusion first through the use of an occlusal/muscle deprogrammer. It was anticipated that the occlusion could be stabilized and treatment would be conservative in its approach, utilizing direct resin bonding in some fashion. Models were taken for the deprogrammer, sent to the dental laboratory, and then delivered a few weeks later. Once her occlusion was comfortable, diagnostic models from new impressions were fabricated. The plaster models were then mounted, using a bite registration that was taken with the deprogrammer in place, on a Panadent articulator (Panadent). Then a diagnostic equilibration was done. A diagnostic wax-up, which would simulate a level incisal plane, was created by our dental laboratory team (Figure 8). A putty matrix (Sil-Tech [Ivoclar Vivadent]) was molded over the wax mockup on the plaster model. 

When the patient returned to the office at her next visit, a temporary BIS-GMA resin (Protemp Plus [3M ESPE]) was injected into the prefabricated putty matrix and placed into her mouth for 3 minutes. Removal of the putty matrix left the temporary resin in place over the teeth. This allowed the patient and me to view and evaluate the shape of the proposed treatment that would align her anterior teeth. The patient was very pleased, and we decided to proceed with the definitive treatment. Options of treatment included: porcelain veneers with tooth preparation; prepless veneers; and conservative direct resin bonding, which would lengthen the teeth only, leaving the rest of her anterior teeth untouched. It was anticipated that a no-preparation technique (except to lightly sand the facial surfaces with a coarse Sof-Lex [3M ESPE] disc, to aid in retention) would be used.

        

[drsushant]

 

Technology Implications: Dentrix Brings “Intelligent Technology” to Its Software

Lou Shuman, DMD For almost 20 years, Dentrix has demonstrated consistent growth as a dental practice management system, integrating clinical charting systems with business administration tools. Dentrix has always placed high importance on its reporting abilities and, as a result of this focus, they have recently launched Practice Advisor. For the first time, Dentrix users are able to see a financial snapshot of their practice along with recommendations for improvement.  Practice advisor helps practices analyze key performance indicators on a single report and compares the practice’s actual numbers to benchmarks developed by leading practice management consultants. This technology is the first of its kind to allow to dentists to run critical reports that compare their office to norms. The variance column shows the difference between the practice’s numbers and these benchmarks. If a practice is underperforming compared to the benchmarks, a list of recommendations is printed at the end of the report. Practice Advisor is an “intelligent” technology that provides easy-to-implement action steps and consolidates this information into one report, making it easier for the practice to improve its business performance and thus increase productivity and profitability. KEY FEATURES OF DENTRIX PRACTICE ADVISOR  Ability to customize the benchmarks. The benchmarks are matched to those of a general practice with a solo practitioner, but these numbers can be changed to match the profile of your practice. An easy way to determine the active patient base. Practice Advisor allows dentists to identify how many patients have been seen within the last 18 months. Tracks the number and cost of unfilled hours. Not only can you see, at a glance, how many unfilled hours  you have but you will also be able to talk with your team about the true costs of these unfilled hours. The Dentrix Practice Advisor then offers solutions to decrease missed appointments. Treatment acceptance percentages. Now you can track your case acceptance rate, comparing your diagnosed treatment to the treatment that was actually accepted by the patient.  Accounts receivable (AR) statistics. If the report shows your AR is high compared to the benchmark and your own goals, Practice Advisor will bring up your aging reports showing exactly who owes you money. Practice Advisor will then offer recommendations to bring your AR to a healthy level. Colorful, easy-to-read charts and graphs. You can compare your current performance to the previous month and year-to-date performance numbers.  Continuing care statistics. These tell you, at a glance, the number of hygiene patients seen within the last 12 months, the number of patients due to be seen, and the number due to be seen with an appointment already scheduled, among other barometers of a healthy continuing care department.  Can be e-mailed. If you are working with a practice management consultant, accountant, or even want to e-mail the information to your home computer, you can easily do so.  In our opinion at the Pride Institute, we feel Dentrix Practice Advisor has raised the bar as an essential practice management tool to assist in engaging in critical thinking, problem solving, and most importantly, implementation.

        

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