Factors to consider when treatment planning for patients seeking comprehensive aesthetic dental treatment

What does the patient want and why?

The first and most important step for both clinician and patient is the detailed investigation of why the patient is unhappy with his/her dental appearance. What is the motivation for seeking aesthetic dental treatment and what are the patient's expectations? A point-by-point breakdown of specific aspects of the smile with which the patient is unhappy, ideally with the help of good clinical images, either displayed on a PC or Mac or, alternatively, using a large face mirror held by the patient, will help to give structure to the goals of treatment and guide discussions about different options available.

Grossly exaggerated expressions of concern with what may seem relatively minor imperfections should raise concerns. It has been estimated that up to 15% of patients seeking cosmetic dental treatments may suffer from body dysmorphic disorder.5

What else do we need to know?

Alongside details of concerns with appearance, a detailed and more general history regarding pain, functional problems, previous dental experience, oral hygiene practices, etc is clearly of great importance prior to planning treatment.

A detailed medical and drug history may identify important factors which will have an impact on treatments and influence the risks of secondary caries and periodontal disease, which should be accounted for when treatment planning.

Current oral hygiene practices should be documented to establish whether improvements to this routine are required before treatment can begin.

Clinical examination

In addition to the identification and diagnosis of disease, a clinical examination and appropriate special tests will enable assessment of the occlusion and dental appearance.

Aesthetic assessment (Table 1)

Table 1. Summary of Aesthetic Assessment.

	Extra-Orally: Dento-facial Assessment
Lips at Rest	Incisal display (Figure 1)
Smiling Position	Dental midline (Figure 1) Incisal line parallel to inter-commissure line Incisal line perpendicular to dental and/or facial midline
	Intra-Orally: Dental Assessment
Shade	Evidence of staining General tooth shade Discoloured teeth which are visibly noticeable
Evidence of Tooth Surface Loss	Wear facets Erosive wear patterns Cervical abrasion/abfraction cavities Vertical enamel fractures
Tooth Shape/Proportions	Width/length ratio (ideal ratio between 0.75–0.8) (Figure 2a) Labial tooth anatomy Bulbosity, curvature, mammelons etc Mesio-distal width of incisors and the mesial aspect of the canine (based on the Golden Proportion of 0.618, though 0.6–0.8 may be aesthetically acceptable) (Figure 2a) Central incisor dominance
Alignment	Extent of vertical overbite Convergence of the long axes mesially, from incisors to canines (Figure 2b) Crowding, rotations and cross-bites
	Gingival Perspective
Gingival Aesthetics	Gingival symmetry Excessive gingival display – the ‘gummy smile’ Black triangles Depth of gingival triangles (determined by tooth morphology) Position of the free gingival margin (Figure 2d) Contact point position Gingival biotype

Extra-oral perspective

Aesthetic treatment planning involves careful consideration of the patient's smile from various perspectives, including facial, dento-facial, dental and gingival, as well as an appreciation of ‘black spaces’.7 When assessing a patient's existing dental aesthetics, good quality clinical images are essential. It is important to compare our professional assessment of the patient's smile with the patient's complaints.

Various facial landmarks and their relationship to the smile should be assessed. The initial assessment should be carried out with the patient ‘at rest’; at this point we should check the relationship between the lips and maxillary teeth. This will be influenced by a patient's age, race and gender. Greater amounts of incisal display at rest are associated with a youthful, feminine appearance. In fact, the level of maxillary incisal display can often be inversely proportional to a patient's age.6 When treatment planning, one must consider the patient's age, gender, etc when deciding upon the desired amount of incisal display.

As well as assessing the lips and maxillary teeth at rest, the patient should be asked to adopt a relaxed smile. This allows the evaluation of various lines and the relationships between them (Figures 1a and b):6

Dental and facial midlines: ideally these should be coincident;

The inter-pupillary line and its relationship to the incisal plane, which ideally should run parallel to one another;

Midlines, both facial and dental, should ideally be at 90 degrees in relation to the incisal and inter-pupillary planes;

The smile line should follow the outline of the lower lip line;

The incisal line ideally should be parallel with the inter-commissure line (a line drawn between the commissures of the lips).

With the patient adopting a ‘full smile’, the presence of dark (negative) space, known as the buccal corridors, is often considered normal. Elimination of these dark spaces, however, may be part of a patient's desires when he/she seeks treatments to improve appearance. Elimination of these negative spaces may give a sense of falseness to a smile, whilst too prominent a buccal corridor can overpower the smile. Ideally, the buccal corridors should confer a sense of proportionality to the anterior teeth, and have the effect of ‘bordering’ the smile.6 Buccal corridors can be influenced by the use of orthodontics, the importance of which as part of treatment planning will be discussed later.

Dental perspective

Dunn et al conducted a survey using standard format photographs of eight male and eight female smiles and demonstrated that tooth shade was the most important determinant of a smile being attractive.11 However, opinions are divided about the relative importance of shade and one may argue that the primary aim is to achieve a uniform shade for all the visually important teeth, and that this shade is not noticeably dark for the patient's complexion. Attractiveness is inevitably linked to the appearance of youthfulness and, where teeth are concerned, the determinants of a ‘youthful smile’ are:12

Shape (absence of tooth surface loss);

Correct size and position in relation to the lips and gingivae;

Shade.

Though there have been various theories as to the determinants of incisor tooth shape, they are essentially a blend of three shapes: circles, squares and triangles.13

Important determinants of anterior dental aesthetics from a dental perspective are (Figures 2a and b):14

Width/length ratio (one should consider the ideal ratio, which has been reported to be between 0.75–0.8, with ratios less than 0.6 being considered ‘too long’);

Central incisor dominance;

Extent of vertical overbite;

Bulbosity, curvature, mammelons, etc (presence or absence of these features may be decided based upon gender, race, age and personality);

Mesio-distal width of incisors and the mesial aspect of the canine (which should be based on the Golden Proportion of 0.618, though 0.6–0.8 may be aesthetically acceptable);

Convergence of the long axes mesially from incisors to canines.

In order to plan any proposed changes to tooth size and shape, etc a diagnostic wax-up, using wax of a different colour from the study cast can be a valuable stage in the planning process.

Orthodontic assessment

Orthodontics has an important role in the achievement of an aesthetic and functional smile. Orthodontists can work synergistically with prosthodontic and periodontal colleagues to produce a result that is more than the sum of the disciplines. Assessment of the need for orthodontic treatment is achieved using the Index of Orthodontic Treatment Need (IOTN) developed by Shaw, Richmond and O'Brien at Manchester Dental School in the 1990s, based loosely on the Index of the Swedish Medical Health Board.15^,16^,17 IOTN is used to assess the needs of orthodontic treatment based on dental health grounds and is an objective and reliable way to select those who will benefit most from treatment. The accurate use of IOTN requires training.

IOTN has two components:

Dental Health Component (DHC)

Aesthetic Component (AC)

The Dental Health Component (DHC) has 5 grades: Grade 1 – ‘No need for treatment’ to Grades 4 and 5 – ‘needing treatment’.

The Aesthetic Component is a scale of 10 colour photographs originally arranged in order of attractiveness by a panel of laypersons (Figure 2c). Grade 1 represents the most and Grade 10 the least attractive arrangements of teeth. An IOTN aesthetic component score reflects the attractiveness of a patient's teeth. The clinician aims to rate where the patient falls on a 1 to 10 scale, as opposed to attempting to match the patient to one of the photographs.

Gingival perspective (Figure 2d)

Occasionally, dental aesthetics may be compromised by the position of the gingival margins. The position of the gingival margins should be evaluated so that the option of periodontal surgery, or orthodontics, if appropriate, can be discussed with the patient. Where results of prosthodontic treatment alone would be compromised without such surgical or orthodontic intervention, a series of good quality images to demonstrate the importance of the ‘gum margins’ will help. Correct placement of contact points, natural emergence profiles and natural incisal embrasures are important to help the avoidance of unsymmetrical gingival tissues and interdental black triangles, all of which can be influenced by the judicious use of orthodontics.14

Formulating a treatment plan

Upon the gathering of all necessary information, a list of diagnoses should be drawn up, prioritized and explained to the patient. The treatment planning is an organic process that continually changes. It starts the very first moment a clinician meets a patient, continues as they discuss concerns, and throughout the planning, provision and maintenance phases of treatment. The formulation of a step-by-step treatment plan should really flow as the conversations continue with our patients, regarding: findings, the options, the risks and the benefits of any proposed therapy. As a conversation, the input of both parties is crucial. Though clinicians bring knowledge and expertise of what dentistry can offer, it is the patient who provides the key information as to either what they want or, just as importantly, what they want to avoid. For a patient's consent to be valid, it is inherently informed, voluntary, and given by a patient with the capacity to make the decision.18

The conversation around the treatment plan will, of course, be centred on the patient's main concerns. However, it is important that the patient's concerns are tempered with reasonable and achievable clinical goals. As important as ensuring patients understand their options is the education of patients regarding the causes, and future prevention, of disease. Careful consideration of a patient's motivation for aesthetic treatment is needed. His/her perception of the problem should fit broadly with the clinical reality as seen by the dentist. Exaggerated expressions of unhappiness or depression resulting from what may appear clinically to be relatively minor imperfections in tooth shape, shade or position may be a manifestation of a psychological disorder, such as body dysmorphic disorder.19

It is essential that the discussion of treatment options for a patient with aesthetic concerns includes:

When discussing the issue of materials to improve maxillary anterior teeth, patients should be informed regarding issues such as:

Profiling the various merits and limitations of porcelain versus composite is beyond the remit of this paper. However, an important step in treatment planning and the consent process is that the patient is aware of conservative treatment options, such as dental bleaching using carbamide peroxide and the subsequent re-shaping/re-contouring of teeth using a nanohybrid aesthetic composite material.20 Patients should be made aware that tooth preparation for techniques such as porcelain laminate veneers or full coverage crowns involves significant removal of healthy tooth tissue. The risk of pulp devitalization during preparation for full coverage restorations should be discussed in depth. If one is to apply the ‘Daughter Test’, whereby a dentist should not perform treatments on patients that he or she would not perform on their own daughter, we must consider that less invasive bonding techniques, such as application of direct composite, combined with tooth whitening, can achieve aesthetic results and conserve healthy tooth tissue.20

A study of 145 patients, who retrospectively evaluated the cosmetic improvements to pictures of patients treated by porcelain veneers (10 cases) or direct-composite veneers (10 cases) indicated that patients found no differences in the perceived cosmetic improvements. The factors that most influenced their decision as to which they would prefer were those concerned with tooth preservation, cost of repair, and cost of replacement. Most patients favoured the direct composite veneers over the indirect porcelain.21

In cases where derangements in tooth position create the unaesthetic dental appearance, restorations alone may not be sufficient to change this. In such situations, orthodontic treatment should be discussed with the patient. This will result in a less invasive procedure with a reduced biological cost compared to the former (Figures 3a and b).

It is impossible to give an exact formula for exactly how much each patient needs to know about each treatment to which they are consenting. Essentially, they need to know as much information as a ‘reasonable patient’ would wish to know. The difficulty lies in deciding what is and what is not, reasonable. This will vary from patient to patient and, indeed, from clinician to clinician. If in doubt, it is prudent to err on the side of giving the patient more information.

The opportunity to review a treatment plan, following each phase of treatment, should be built in to any plan. This helps both the clinician and patient to reconsider the direction treatment is taking. It allows for changes to be made and, should the patient wish to cease treatment for any reason, at least at that stage, the patient should be in a better position than when he/she began.

Summary

In summary, the treatment planning process for cosmetic cases should start with an extensive information gathering exercise, which may take several visits. Planning should involve making any proposed significant changes on study casts prior to embarking upon irreversible treatments. Patients should be made aware of all options available to them together with the risks and costs involved, both financial and biological. The clinician should spend time getting to know his/her patient and appreciate the motivation for treatment. Where possible, less invasive procedures should be encouraged and the plan should be phased, with reviews at various stages and fallback positions built in, should things not go as anticipated.