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J Am Dent Assoc, Vol 137, No 2, 160-169.
© 2006 American Dental Association | ![]() |
COVER STORY |
| ABSTRACT |
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Approach. This article describes an interdisciplinary approach to the diagnosis and management of anterior dental esthetics. The authors practice different disciplines in dentistry: restorative care, orthodontics and periodontics. However, for more than 20 years, this team has participated in an interdisciplinary dental study group that focuses on a wide variety of dental problems. One such area has been the analysis of anterior dental esthetic problems requiring interdisciplinary correction. This article will describe a unique approach to interdisciplinary dental diagnosis, beginning with esthetics but encompassing structure, function and biology to achieve an optimal result.
Clinical Implications. If a clinician uses an esthetically based approach to the diagnosis of anterior dental problems, then the outcome of the esthetic treatment plan will be enhanced without sacrificing the structural, functional and biological aspects of the patients dentition.
Key Words: Interdisciplinary dentistry; anterior dental esthetics; crown length; anterior tooth wear; gingival levels; crown lengthening; orthodontic intrusion; width-to-length ratio; resting lip level; diagnostic wax-up
In the past 25 years, the focus in dentistry has changed gradually. Years ago, dentists were in the repair business. Routine dental treatment involved excavating dental caries and filling the enamel and dentinal defects with amalgam. In larger holes, more durable restorations may have been necessary, but the focus was the same: repair the effects of dental caries. However, with the advent of fluorides and sealants, as well as a better understanding of the role of bacteria in causing both caries and periodontal disease, the needs of the dental patient have changed gradually. Many young adults who are products of the sealant generation have little or no caries and few existing restorations. At the same time, our image of the value of teeth in Western society also has changed. Yes, the public still regards teeth as an important part of chewing, but today the focus of many adults has shifted toward esthetics ("How can my teeth be made to look better?"). Therefore, the formerly independent disciplines of orthodontics, periodontics, restorative dentistry and maxillofacial surgery often must join forces to satisfy the publics desire to look better.
This trend toward a heightened awareness of esthetics has challenged dentistry to look at dental esthetics in a more organized and systematic manner, so that the health of the patient and his or her teeth still is the most important underlying objective. But some existing dentitions simply cannot be restored to a more esthetic appearance without the assistance of several different dental disciplines. Today, every dental practitioner must have a thorough understanding of the roles of these various disciplines in producing an esthetic makeover, with the most conservative and biologically sound interdisciplinary treatment plan possible.
We have worked in such an environment for the past 20 years. As prosthodontist, orthodontist and periodontist, we have belonged since 1984 to an interdisciplinary study group consisting of nine dental specialists and one general dentist.1 We have met monthly since that time to educate one another about the advances in each of our respective areas of dentistry and to plan interdisciplinary treatment for some of the most challenging and complex dental situations.
One of these interdisciplinary areas is esthetics. The purpose of this article is to provide the reader with a systematic method of evaluating dentofacial esthetics in a logical, interdisciplinary manner.
However, if the treatment planning sequence proceeds from biology to structure to function and finally to esthetics, the eventual esthetic outcome may be compromised. Therefore, we proceed in the opposite direction: we start the treatment planning process with esthetics and proceed to function, structure and, finally, biology. We do not leave out any of the important parameters; we simply sequence the planning process from a different perspective. We choose this sequence because the decisions made in each category, especially esthetics, will directly affect the decisions made in the categories that are assessed subsequently. If the treatment planning sequence proceeds from biology to structure to function and finally to esthetics, the eventual esthetic outcome may be compromised.
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SEQUENCING THE PLANNING PROCESS
TOP
ABSTRACT
SEQUENCING THE PLANNING PROCESS
BEGINNING WITH ESTHETICS IN...
STEPS TO INTEGRATING FUNCTION...
DETERMINING IF ADEQUATE...
BIOLOGY: LAST BUT CERTAINLY...
SEQUENCING THE THERAPY
SUMMARY
REFERENCES
Historically, the treatment planning process in dentistry usually began with an assessment of the biology or biological aspects of a patients dental problem. This could include the patients susceptibility to caries, periodontal health, endodontic needs and general oral health. Once the biological health was re-establishedthrough caries removal, modification of the bone and/or gingiva, endodontic therapy or tooth removalthen the restoration of the resulting defects would be based on structural considerations. If teeth were to be restored or repositioned, the function of the teeth and condyles would be of paramount importance in dictating occlusal form and occlusal relationships, respectively. Finally, esthetics would be addressed to provide a pleasing appearance of the teeth.
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BEGINNING WITH ESTHETICS IN MIND
TOP
ABSTRACT
SEQUENCING THE PLANNING PROCESS
BEGINNING WITH ESTHETICS IN...
STEPS TO INTEGRATING FUNCTION...
DETERMINING IF ADEQUATE...
BIOLOGY: LAST BUT CERTAINLY...
SEQUENCING THE THERAPY
SUMMARY
REFERENCES
When beginning with esthetics, we must begin with an appraisal of the position of the maxillary central incisors relative to the upper lip (Figure 1
). This assessment is made with the patients upper lip at rest. Using a millimeter ruler or a periodontal probe, we determine the position of the incisal edge of the maxillary central incisor relative to the upper lip. The position of the maxillary central incisor can be either acceptable or unacceptable. An acceptable amount of incisal edge display at rest depends on the patients age. Previous studies have shown that with advancing age, the amount of incisal display decreases proportionally.2,3 For example, in a 30-year-old, 3 millimeters of incisal display at rest is appropriate. However, in a 60-year-old, the incisal display could be 1 mm or less. The change in incisal display with time probably relates to the resiliency and tone of the upper lip, which tends to decrease with advancing age.
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Maxillary incisor inclination. Once we have established the correct incisal edge position and midline relationship of the maxillary incisors, the next step is to evaluate the labiolingual inclination of the maxillary anterior teeth. Are they acceptable, proclined or retroclined? When orthodontists evaluate labiolingual inclination, they rely on cephalometric radiographs to determine tooth inclination.19 However, general dentists do not use these radiographs. Another method of assessing the inclination of the maxillary anterior teeth is to evaluate the labial surface of the existing maxillary central incisors relative to the patients maxillary posterior occlusal plane. Generally, the labial surface of the maxillary central incisors should be perpendicular to the occlusal plane. This relationship permits maximum direct light reflection from the labial surface of the maxillary central incisors, which enhances their esthetic appearance.20 If teeth are retroclined or proclined, correction may require either orthodontics or extensive restorative dentistry and, possibly, endodontics to establish a more ideal labiolingual inclination.18
The next step is to evaluate the maxillary posterior occlusal plane relative to the ideal location of the maxillary incisal edge. The maxillary incisal edge will be either level with the posterior occlusal plane (Figures 4
and 5
, pages 165 and 166, respectively), coronal to the posterior occlusal plane (Figure 1
) or apical to the posterior occlusal plane (Figures 2
and 3
). Correcting the posterior occlusal plane position will require orthognathic surgery,21,22 restorative dentistry or both.18 The amount of tooth abrasion, the patients vertical facial proportions and the position of the alveolar bone will help determine the correct solution of posterior occlusal plane discrepancies.
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Determining gingival levels.
The next step in the process of determining the esthetic relationship of the maxillary anterior teeth is to establish the gingival levels. The gingival levels should be assessed relative to the projected incisal edge position. The key to determining the correct gingival levels is to determine the desired tooth size relative to the projected incisal edge position (Figures 2
, 4
and 5
). It is important to remember that the incisal edge is not positioned to create the correct tooth size relative to the gingival margin levels. Using the gingiva as a reference to position the incisal edges is risky, because gingiva can move with eruption or recession. Therefore, the ideal gingival levels are determined by establishing the correct width-to-length ratio of the maxillary anterior teeth,2628 by determining the desired amount of gingival display15 and by establishing symmetry between right and left sides of the maxillary dental arch.18
If the existing gingival levels will produce a tooth that is too short relative to the projected incisal edge position, then the gingival margins must be moved apically. This adjustment can be accomplished by means of either gingival or osseous surgery,29,30 orthodontic intrusion,11 or orthodontic intrusion and restoration.3133 The key factors that determine the most appropriate method of correction include the sulcus depth, the location of the cementoenamel junction relative to the bone level, the amount of existing tooth structure, the root-to-crown ratio and the shape of the root.34 In some situations, it is more appropriate to lengthen the crowns of the maxillary incisors surgically (Figures 2
and 4
) to establish the correct gingival levels.10 In other situations, orthodontic intrusion (Figure 5
) and restoration of the incisal edge is more appropriate.34
The next step in the process of establishing the correct esthetic position of the maxillary anterior teeth is to assess the papilla levels relative to the overall crown length of the maxillary central incisors. Research has shown that the average ratio is about 50 percent contact and 50 percent papilla.35 If the contact is significantly shorter than the papilla (Figures 2
and 4
), it usually indicates moderate-to-significant incisor abrasion, which tends to shorten the crowns and, therefore, shortens the contact between the central incisors.30 If the contact is significantly longer than the papilla, it could suggest that the gingival contour or scallop over the central incisors is flat, which could be caused by altered passive or altered active eruption of the teeth.36 Either gingival or osseous surgery10 or orthodontic intrusion13 or extrusion34 may be necessary to correct the level of the papillae between the maxillary anterior teeth.
Arrangement, contour and shade.
The clinician now has established the incisal edge position, the midline, the axial inclination, the gingival margins and the papillary levels of the maxillary anterior teeth. The next step is to determine if the arrangement of the maxillary anterior teeth can be accomplished restorativelyand if not, whether the patient will require orthodontics to facilitate restoration. If in doubt, the clinician should perform a diagnostic wax-up (Figure 2
) to confirm whether the arrangement is possible restoratively.18,34,37 In addition, the contour and shade of the anterior teeth must be addressed. Does the patient have any specific requests concerning tooth shape or tooth shade? Remember, the more alterations one makes in these parameters, the more teeth one will be treating and the more involved the treatment plan will become. A good guide to esthetic treatment planning is to determine the ideal endpoint of treatment, then compare it with the patients current condition. Treatment is indicated when the desired endpoint and the current condition do not match. The actual method of treatment then can be chosen on the basis of the magnitude of the difference.
Developing the esthetic plan for the mandibular teeth.
Now that the esthetic relationship of the maxillary incisors has been established, the mandibular incisors must relate to the maxillary tooth position. First, evaluate the level of the mandibular incisal edges relative to the face. Do they have acceptable display or excessive display, or are they not visible at all? If they have excessive display, equilibration, restoration or orthodontic intrusion are possible methods of correcting the problem.34 If they are not visible, either restoration or orthodontic extrusion may be necessary.38,39 Next, determine the relationship of the mandibular incisors relative to the posterior occlusal plane. Are the incisors level with the posterior occlusal plane? If not, then they are either coronal or apical to the posterior occlusal plane. Correcting either of these relationships could require restoration (Figure 1
), equilibration or orthodontics.4 Finally, the labiolingual inclination of the mandibular incisors must be evaluated. This relationship is determined partially by the projected position of the maxillary incisors. If the inclination is either proclined (Figure 3
) or retroclined, orthodontics could be a useful adjunct in adjusting the labiolingual position of the mandibular incisors.34 The final mandibular incisal edge position usually is determined during the functional and structural phases of the treatment planning (Figures 2
5![]()
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).
The gingival levels of the mandibular dentition may need to change when the different options for leveling the mandibular occlusal plane are considered. If orthodontics is selected to either intrude or extrude teeth, the gingival margins will move with the teeth.40 However, if equilibration, restoration or both are necessary to level the mandibular occlusal plane, then the gingival levels may need to be relocated with osseous surgery.10
At this point, based on the esthetic determination of the projected positions of the maxillary and mandibular teeth, the clinician should be able to determine which teeth will need restoration41that is, the maxillary anterior, maxillary posterior, mandibular anterior and/or mandibular posterior teeth. Then, once the maxillary and mandibular occlusal planes have been established through esthetic parameters, the clinician must determine how to create an acceptable occlusal relationship between the arches.
| STEPS TO INTEGRATING FUNCTION AND ESTHETICS |
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As the proposed esthetic treatment plan is transferred to the mounted casts, the clinician will be able to determine if only restoration will accomplish the desired occlusion, or if alteration of the occlusal scheme through orthodontics, orthognathic surgery or both will be necessary. This is especially true when the clinician is planning to level the occlusal planes. A key question to ask is whether leveling of the occlusal planes creates an acceptable anterior dental relationship. If the answer is yes and the leveling would involve only the mandibular incisors, then the patients existing vertical dimension can be maintained. If, however, the answer is no or the leveling would involve mandibular posterior teeth, the existing vertical dimension may need to be altered. The clinician must determine whether altering the vertical dimension will result in acceptable tooth form and anterior relationships. There is no replacement for mounted dental casts and a diagnostic wax-up when these critical questions are being addressed.
| DETERMINING IF ADEQUATE STRUCTURE EXISTS FOR TOOTH RESTORATION |
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The methods for increasing the retention of restorations are buildup, surgical crown lengthening,10 orthodontic forced eruption33,40 and bonding of the restoration. Each clinical situation must be evaluated carefully to determine the appropriate structural solution.
| BIOLOGY: LAST BUT CERTAINLY NOT LEAST |
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The biological aspects include any need for endodontic care, periodontic care or orthognathic surgery. The primary objective of biological treatment planning is to establish a healthy oral environment with the tissue in the desired location. To accomplish this objective, the clinician may need to perform endodontic procedures on teeth that are salvageable structurally and periodontally. In these cases, the endodontic therapy must be completed first, before the restorative phase of dentistry begins. The definitive periodontal therapy must be established to create a healthy periodontium based on the esthetic, functional and structural needs of the restorations. Any elective periodontics must be completed next, in conjunction with the restorative plan. Finally, if there are any skeletal abnormalities that require orthognathic surgical correction, these must be accomplished before the definitive restorative phase of treatment.
| SEQUENCING THE THERAPY |
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The sequence of any treatment plan always should begin with the management or alleviation of acute problems. Then the remaining treatment plan can be sequenced in a manner that seems the most logical and facilitates the next or following phase of treatment, provided the result can be identified clearly, communicated and achieved for the pertinent phase. When we establish the sequence of treatment for an interdisciplinary patient, we list the steps in the treatment plan based on our collective opinion before treatment begins.34,37 Every member of the team receives a copy of the written treatment sequence. This step ensures that each member of the team will be able to follow the steps in the esthetic, functional, structural and biological rehabilitation of our mutual dental patient.
Patient type. The economics of the interdisciplinary esthetic treatment plan obviously is of primary importance. In a previous article,43 the types of patients in the modern dental practice have been divided into four types (I, II, III and IV). Patients of types I and II generally do not require significant esthetic restoration. However, those of types III and IV typically will require the type of esthetic evaluation that we have outlined in this article.
The type III patient is a healthy adult with no occlusal disease and no periodontal problems but a desire for an esthetic change (Figure 1
). The type III patient could be described as the esthetic patient, one who is dentally healthy but wishes to make a change in appearance. The hallmark of treating the true esthetic patient is the requirement of time on the part of the dentist.
The most challenging situation is the type IV patient (Figures 2
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), whom we have described in this article. This is an adult whose dentition is failing and who may have occlusal disease, periodontal disease, multiple restorative needs and missing teeth. The type IV patient is the complex reconstruction patient in any dental practice. The hallmark of this patient is multiple appointments over months or even years, depending on his or her orthodontic, periodontal, endodontic, surgical and restorative needs. Owing to the increased number of appointments and laboratory fees, the clinician must adjust the fees to reflect the amount of time commitment. For ideas on establishing appropriate fees in these types of patients, the reader is referred to a previous article.43
| SUMMARY |
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| FOOTNOTES |
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| REFERENCES |
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This article has been cited by other articles:
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G. R. Samorodnitzky-Naveh, S. B. Geiger, and L. Levin Patients' satisfaction with dental esthetics J Am Dent Assoc, June 1, 2007; 138(6): 805 - 808. [Abstract] [Full Text] [PDF] |
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P. F. Fabel ANTERIOR DENTAL ESTHETICS J Am Dent Assoc, May 1, 2006; 137(5): 584 - 584. [Full Text] [PDF] |
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