FIGURE 3 Black triangle due to recession between teeth 1.1 and 2.1.
FIGURE 6A Initial presentation of patient unhappy with her smile.
FIGURE 6B Examination of the smile reveals a medium lip line, thick and flat periodontium, malpositioned teeth, and a diastema bet...
FIGURES 7A,B,C Right, frontal, and left images allow a more accurate examination of the lip and its relationship to the periodonti...
FIGURES 8A,B,C Closer examination of the teeth and tissues reveal discrepancies with gingival contour, gingival bulk, and proporti...
FIGURE 10 Provisional restorations in place after crown lengthening.
FIGURE 12A Frontal image shows loss of tooth 2.2 with a medium lip line. The papillae about tooth 2.2 are not present.
FIGURE 12B Closer examination reveals a soft tissue deficit where the tissue has begun to lose contour.
FIGURE 13 Appearance of restoration when first placed on the area. Note obliteration of papillae and unnatural emergence profile.
FIGURES 16, 17 Further modification of the extraction site 2-3 weeks later to relieve pressure from the provisional restoration, w...
FIGURE 18 Satisfactory soft tissue profile with the recreation of papillae and an ovate socket space.
FIGURES 19A,B,C Impression taken with Take 1 (Kerr Corporation). Metal coping in place.
FIGURES 11A,B Full face and frontal image show final result with the restoration of the patient's medium lip line and the establis...
FIGURES 20A,B Pickup impression taken with Take 1 (Kerr Corporation) and metal coping in place. Final result.
Cosmetic Dentistry: Aesthetics in The Anterior Zone: What Are the Considerations Prior to Treatment?
In the dental management of the anterior zone, aesthetic, as well as functional principles are considered upon diagnosis and relayed to the treatment phase. The ubiquitous presence of the term "aesthetic" may serve to adorn and beautify a procedure, but in reality, this is an adjective that must be inherent to any formula applied to the anterior zone. Today's dental patient will expect an aesthetic result from the practitioner and current standards dictate the importance of avoiding procedures that will result in aesthetic compromise as well as the concept of providing patients with improved aesthetics whenever possible. This article will outline the factors and importance of the analysis of aesthetic smiles during diagnosis.
The appearance of the gingival tissues surrounding the teeth plays an important role in the aesthetics of the anterior maxillary region of the mouth. Abnormalities in symmetry and contour can significantly affect the harmonious appearance of the natural or prosthetic dentition. Consequently, any dental procedure performed in this zone can be an aesthetic challenge due to the visibility of the dentogingival interface. This article will use two cases to illustrate how the alteration of the dentogingival complex with periodontal surgery and with the insertion of a bridge while preserving soft tissue profiles may alter the dentogingival interface.
A critical goal of treatment is long-term stability of the result. As such, much attention is devoted to the meticulous accumulation of diagnositic data prior to treatment in order to preserve the integrity of the dentogingival junction and ensure the harmonious existence of the prosthetic dentition and periodontium. Rufenacht (1990), Chiche and Pinault (1994) discussed the development of aesthetic principles related to dentistry. From these, the analysis and factors related to the development of the aesthetic smile will be discussed. Before this examination begins, the tissues should obviously be deemed healthy.
Examination of the smile beings with the lips. The lips actually define and delineate the aesthetic zone. The smile is classified as having a low, medium or high lip line based on the position of the upper lip in relation to the maxillary central incisors. The smile line is defined as a hypothetical line drawn along the incisal edges of the maxillary anterior teeth. The incisal edges and the smile line are expected to coincide or silhouette the curvature of the inner border of the lower lip.
The ideal or medium lip line is defined as that which follows the CEJ of the maxillary anterior teeth, only the interproximal papillae are visible (Fig. 1a). The dentogingival interface is not visible in patients with a low lip line. This may lead the patient to ignore aesthetics in this area but this cannot be a presumption on the part of the practitioner (Fig. 1b). Lastly, patients with a high lip line present an aesthetic challenge since the dentogingival interface is prominently displayed (Fig. 1c).
Subsequently, periodontal biotype of the patient's periodontium is classified. Clinical observations have led clinicians to identify two basic human periodontal biotypes (Olsson 1991), thick and flat biotype which is present in 85% of the population and thin and scalloped biotype present in less that 15% of the population (Sanavi 1998).
The teeth in the thick and flat periodontium (Fig. 2a) are usually more bulbous and square in shape. The interproximal contacts are located more apically and are broad incisogingivally and faciolingually. Consequently, there is not a great disparity between the gingival margin found midfacially and interproximally. The gingiva tends to be thick or dense and as a sequela of inflammation, pocket formation tends to occur.
On the other extreme, teeth surrounded by thin and scalloped periodontium are more subtle and triangular (Fig. 2b). The interproximal contacts are located more incisally. Because they are more incisal, there is a pronounced disparity between the gingival heights midfacially and interproximally. The papilla is longer and narrower which creates a more scalloped appearance. The underlying bone and gingiva are usually thin and in the presence of inflammation, recession (instead of pocket formation) tends to occur facially and interproximally. Furthermore, when the interproximal papillae recede, "black triangles" usually result (Fig. 3). It becomes obvious how the mangagement of the thin and scalloped periodontium is much more challenging as any insult will lead to tissue loss and thus a decreased esthetic result.
The next factor of consideration is the contour of the gingival margin. As a general rule, a line drawn at the level of the free gingival margin of the anterior sextant will show the free gingival margin of the central incisors and the cuspids to be at the same height and that of the lateral incisors to be slightly coronal (Fig. 4). Furthermore, the most apical point of the gingiva or the gingival zenith is located just distal of the long axis of the central incisors and cuspids, whereas the gingival zenith for the lateral incisors coincide with their long axis (Rufenacht 1990) (Fig. 5).
The final observations are made on the teeth. Principles to allow for teeth of the anterior maxillary sextant to be proportional, symmetrical and in harmony with each other were discussed by Gillen (1994). The central incisors are typically the widest teeth. They are 25% wider than the laterals and 10% wider than the canines when viewed facially. The central incisors and canines are approximately equal in length and are 20% longer than the lateral incisors. The length to width ratio for the central incisors is 1.1:1 and for the lateral incisors and canines, it is 1.2:1.
As mentioned above the assessment of the aesthetic smile begins with the lips at the outer limits and ends with the teeth at its inner limit. It is the harmonious synchronization between these factors, namely, the teeth, gingiva and lips that lead to an aesthetic or pleasing smile. Careful registration of these factors will lead to a sound diagnosis and treatment plan which will facilitate treatment and provide for more stable and aesthetic results.
TREATMENT PLANNING
The sequence of events in this first case highlights the importance of interdisciplinary communication for a result that is pleasing both to the patient and the dentists involved. The patient presented with a chief complaint of not liking her smile which included rotated teeth and a diastema (Figs. 6a, 6b). Upon examination, it was noticed that the patient had a medium lip line (Fig. 6b) and flat, thick periodontium (Figs. 7a, 7b, 7c). The contour of the gingival margin is irregular in that the free gingival margin is at the same height for all six anterior teeth, whereas the margin for the lateral incisor should be coronal to that of both the central incisor and cuspid. As well, the papilla between teeth #1.1 and #1.2 is bulkier than between teeth #2.1 and #2.2. Lastly, the teeth are not proportional with each other. Instead of being 20% shorter than the centrals and cuspids, the lateral incisors are the same length as these teeth. There are diastemas between teeth #1.1 and #2.1 and teeth #1.2 and #1.3. Both lateral incisors lean mesially and are slightly palatally positioned (Figs. 8a, 8b, 8c).
The treatment plan agreed upon was to restore the anterior dentition with veneers for teeth 1.2 to 2.2 but crown lengthening was required to ensure adequate biologic width for teeth which would be rendered longer. The need to elongate the teeth is used to maintain a 75% width/ length ratio for the maxillary central incisors and insure proportionality with the lateral incisors as the excess interdental space is spread evenly between the the four maxillary incisors. In the prosthodontic planning stages, a diagnostic wax-up of the proposed restoration revealed that the buccal margin of the veneers was deemed to interfere with the dentogingival complex. Consequently the patient was referred for periodontal surgery to relocate the bone to an ideal level and maintain the biological width.
Using the diagnostic wax up a surgical stint was created to help guide the periodontist to insure a predictable outcome. Surgical treatment involved the reflection of a full thickness flap with split thickness incisions on the papillae to secure their preservation. In addition, the surgical stint guides the osseous recontouring so that it will take into account the final gingival contour and the distal placement of the gingival zenith of the central incisors. The flap is replaced and secured with interrupted sutures (Fig. Surg 1). This is allowed to heal for 3-6 months (Fig. Surg 2). Bragger et al., (1992) reports that there can be recession in the anterior segment for up to 6 months, therefore careful monitoring of recession is imperative during the healing phase.
Final prosthetic restoration was completed at 4 months post-operatively. The four incisors were prepared ensuring that the proximal finish lines were left palatally to the contact points so that there was sufficient interproximal emergence profile. The prepared teeth were impressed with Take 1 (kerr Corporation, Orange California) and subsequently temporized with Point 4 (Kerr Corporation, Orange California) (Figs. 9 & 10). The final result shows the restoration of a medium lip line showing only interproximal papillae, symmetrical gingival contour, correct tooth inclination, proportions and position (Figs. 11a & 11b). The patient is pleased with both an aesthetic and functional restoration.
The second case involves the loss of a lateral incisor and replacement with a crown and pontic. The treatment will be outlined as in the first case demonstrating that the same principles apply when dealing with the anterior aesthetic zone despite using different modalities of treatment.
The patient presented with fracture of tooth #2.2 below the gingival margin and the tooth was deemed to be non-restorable. Upon examination, the lip line is medium and the periodontium is again thick and flat. The gingival contours and the position and proportion of the teeth are favourable. Thus the restoration of this site will have to recreate both the lost tooth but just as importantly the soft tissue contours of tooth #2.2. Upon extraction of the root fragment, it is already evident how disharmonious the anterior sextant appears (Figs. 12a & 12b).
In order to reconstruct the gingival contour of tooth #2.2, a temporary restoration was fabricated which consisted of an ovate pontic for tooth #2.2. This will serve to recreate the papillae and reform the buccal gingival contour. The restoration (full crown on tooth # 2.3 and #2.2 pontic) was placed and assessed for further modification (Fig. 13). With this provisional restoration, the papillae was obliterated and tooth #2.2 did not have a natural emergence profile. The pontic is modified to have an ovate apical extension, which applies pressure into the extraction socket and the mesial and distal edges are relieved at the apical end so as to allow for the repositioning of the papillae (Figs. 14 & 15).
After being in place for 2-3 weeks, the tissue began to take form and the papillae once again appeared to be constricted. The provisional was removed, the tissue recontoured with a diamond bur and the provisional was replaced for further healing (Figs. 16 & 17). When the soft tissue contours were satisfactory (Fig. 18), an impression was taken with Take 1 (Kerr Corporation, Orange CA.) and a metal coping was fabricated (Figs. 19a, 19b, 19c). With the metal coping in place, a pickup impression was taken to relay the soft tissue contours which were recreated in order to construct a final restoration which respect the periodontium and replaces the missing tooth (Figs. 20a & 20b).
CONCLUSION
This article emphasized the importance of assembling and using all available data on the anterior aesthetic zone when faced with restoration or reconstruction in this area. A harmonious balance of the relationship between the lips, gingivae, and teeth is essential to the creation of an esthetically and functionally pleasing result.
In addition, it is imperative to note that even though the patient may be motivated only by aesthetic goals, it remains the practitioner's responsibility to ensure function and stability of treatment. This is partially attributed to existing and continued health of the periodontium.
Dr. Livia Silvestri is a clinical instructor at the University of Toronto, Department of Periodontics and maintains a private practice in Toronto limited to periodontics and implant surgery.
Oral Health welcomes this original article.
Acknowledgements
Dr. Silvestri wishes to acknowledge Dr. Peter Birek for the surgical treatment of these cases and Dr. Jordan Soll for the restorative component.
REFERENCES
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2. Chiche G, Pinault A. Esthetics of Anterior Fixed Prosthodontics. Chicago, Quintessence Publishing, 1994.
3. Gillen RJ, RS Schwartz, TJ Hilton and DB Evans, An Analysis of Selected Normative Tooth Proportions. Int J Prosthodont 7(5): 410, 1994.
4. Olsson M, Lindhe J. Periodontal characteristics in individuals with varying forms of upper central incisors. J Clin Periodontol 18:78, 1991
5. Rufenacht C. Fundamentals of Esthetics. Chicago, Quintessence Publishing, 1990.
6. Sanavi F, Weisgold AS, Rose LF. Biologic Width and its Relation to Periodontal Biotypes. J Esthetic Dent 10(3):157, 1998.
