It is very important to carry out a thorough and accurate dental assessment. This will help in the treatment planning stages, and is important for medico-legal records. The assessment can be divided into the following stages:
1. The interview.
2. Dental radiographs (Dental Panoramic Tomograph, bitewings and full-mouth periapical radiographs).
3. Digital photographs (A full series of extraoral and intraoral photographs. These can then be downloaded on a computer, image corrected in Adobe Photoshop, and saved into a PowerPoint ready for the consultation appointment).
4. Upper and lower accurate impressions for study models (use a rubber-based material rather than alginate for increased accuracy).
5. Facebow record to mount the study models on an articulator.
6. Inter-occlusal bite registration, using a hard and accurate material such as Luxabite (DMG). This can be taken in centric occlusion, or in centric relation as necessary.
7. Extraoral assessment of the facial and neck muscles and the temporo-mandibular joints.
8. A complete intraoral assessment.
9. A complete cosmetic evaluation (smile analysis).
We have developed a detailed smile analysis protocol which is only part of our comprehensive initial assessment. The following are some of the important parameters and measurements that are recorded with reasons as to why they are important.
• Patient’s main concerns
It is really important to ask the patient what cosmetic concerns they have regarding their upper teeth, followed by their lower teeth. Write down in detail all that the patient says to you as they look in a large mirror and show you. Do not assume what you see as wrong is of concern to the patient.
• What type of smile would you like?
See if the patient is after a Hollywood glamorous smile or a natural and beautiful one. Ask the patient to describe someone’s smile they really like and ask why they like this. It is important to understand from the outset what the patient’s realistic expectations are in order to avoid disappointment at the end.
• Assess the face carefully
1. Nose deviation (important with respect to the dental centreline)
2. Shape of the face e.g. square, tapering, rounded, etc
3. Side profile view – normal, concave or convex outline
4. Hair colour, skin tone
5. Patient personality
6. Any obvious asymmetries
7. Shape of lips (symmetry and size of upper and lower lips).
• Teeth showing on smiling
Ask the patient to smile fully when looking in a mirror and count how many teeth show. Typically four or five teeth on each side will show. This will then indicate how many units of teeth need to be involved in the smile design.
• Improved fullness
Record which teeth require improved buccal fullness. It is common for the premolars to be brought outwards to improve the lateral buccal corridors and produce a fuller and more attractive smile.
• Lip line and gingival display
Record if it is a high smile line (gums show) or a low smile line (gums do not show) when the patient smiles fully. It is important to assess if there is a ‘gummy smile’, and if it is of concern to the patient. If so, depending on periodontal pocket measurements, this will dictate whether laser correction or surgical crown lengthening is required for the ideal smile.
• Are the edges of the upper teeth parallel to the lower lip on smiling? This is a desirable criterion, but not always achievable due to the shape of the lower lip, or the maximum length possible of the upper anterior teeth.
• Incisal edges showing at rest position
Assess the rest position (ask the patient to lick their lips, say ‘M’ and then just relax their lips. As they are slightly parted, measure the amount of incisal edge of the central incisors that shows.
• Central incisors
The central incisors are the key to creating a fantastic smile. It is important to assess:
1. Symmetry (no more than 0.2mm variance in size in any direction between the two central incisors)
2. Correct width: height ratio (ideally the width should be about 80% of the height)
3. Line angles: Make the teeth look wider or narrower?
4. Midline: Is it in the middle of the facial midline, or to one side? Is there a cant (i.e. a slant to the midline either to the left or the right?). Studies have shown that it is acceptable to have a vertical midline that may be up to 2mm either side of the facial midline, but not acceptable to have a cant.
Mark the axial alignment of the teeth in the pre-operative position in a grid with arrows downwards. There should ideally be a five-degree slant in the axial direction of the teeth as you go distally, with the central incisors being vertical in their axial inclination.
• Colour of teeth
Assess and record the pre-operative shade of the upper incisor and the upper canine teeth using the Vita 3D Master Shade guide. Then give the patient the mirror and hold up a lighter shade for comparison. Get the patient’s views and record carefully what the patient approves.
Thorough pre-operative assessment and planning is an important pre-requisite for successful cosmetic dentistry. It will help in developing the ideal treatment plan for the patient, and is also very important in laboratory communication for the purposes of creating ideal wax-ups based on precise aesthetic and occlusal principles.
Rahul Doshi and Ashish Parmar will be speaking at Private Dentistry 07, Central Hall, Westminster, London, on 30 November 2007. Other speakers include Kevin Lewis, Philip Newsome, Lina Craven and Komal Suri. For more information, or to book your place, call 0800 371 652, email firstname.lastname@example.org or visit www.privatedentistry07.co.uk