Clinical
all information on the biological issues that may be affecting the patient (caries, restorative, periodontal, occlusal, general health etc), but no treatment should commence until the defi nitive end result has been visualised and agreed. In this way, treatment is not carried out on teeth that, while savable, may perhaps be better lost as part of the overall plan. When aesthetics are involved, this type
of ‘facially generated treatment plan’ can save considerable time and effort.
The facially generated treatment plan The starting point is to see what the desired aesthetic result would be. Only then can you design a plan to achieve it. While there are many guidelines to aesthetics and smile design, it is ultimately subjective and wax-ups on models are of limited use as they don’t show how the patient’s lips move and it is diffi cult for patients to relate them to their situation. If skilled in Photoshop, imaging can be employed. The simplest planning tool, however,
is to set up the upper six to eight denture teeth directly in the patient’s mouth. In this way, it is possible to work with the patient and move the teeth until the patient accepts the result. As a general guide, (age and gender dependant), aim for approximately ı-2mm of the incisal edges to show at rest and (with normal lip mobility of 6mm) approx- imately 7-9mm of incisal show during a wide smile. Photographs from before the patient lost their teeth can be especially helpful. Simply bringing the lowers up to meet the new aesthetic design of the uppers (in centric relation) provides the new vertical dimension of occlusion – or shows what additional treatment may be required to realise the aesthetic goals (Figs ı and 2). Speech can be assessed and it is possible
to see immediately if any over-eruption of the lowers has occurred and if it is acceptable or not. Often an over-erupted lower anterior segment will be accepted as a compromise once the uppers can be seen again. If the compromise is still unac- ceptable, then reduction of the lowers is required. (This could be through restora- tive, orthodontic or surgical means). If the lowers are suffi ciently compro-
mised to require removal, and implants are being considered, it is important that the surgeon is advised to reduce the alveolar ridge to provide sufficient restorative space. Failure to do so is a common mistake and can result in an unacceptably thin over- denture or bridge, diffi cult oral hygiene management and frequent fractures. Once the aesthetic goals have defi ned
Upper anterior teeth on wax rim can be moved to determine incisal edge position Fig 1
Fig 2
Bringing lower teeth up to meet the new upper aesthetic. Incisal edge position determines the OVD
Fig 3
Close-fi tting special tray impression with ‘compound’ post dam
Fig 4-5
Mucocompressive, border moulded saddle impressions for split cast impression technique and split cast working model
the space requirements for upper and lower, it is possible to plan the restorative phase. For the majority of cases, an upper complete denture against a lower bilat- eral, free-end saddle denture will be the simplest conventional solution. A number of considerations are required:
Upper complete denture Impression technique for fl abby anterior ridge. Various options are suggested by prosthodontists with the goal of any tech- nique being to provide a good fi tting, stable and retentive base. For a conventional upper denture impression, a mucocom- pressive technique (close-fi tting special tray) is thought to provide optimal loading and, therefore, comfort during function. The fl abby ridge, however, can cause
a displacing effect if it is compressed during the impressing, so a technique that allows it to remain non-compressed is recommended – a mucostatic technique. A combination technique is therefore recommended. Possible solutions are:
ı. Two-part special tray 2. Open special tray and plaster of paris 3. Spaced special tray 4. Perforated special tray over the fl abby ridge.
The simplest is the spaced/perforated
tray – the number of spacers depend on the material being used; for a monophase silicone or polyether – one spacer over the palate and ridges and three (with perfora- tions) over the fl abby ridge. Use of green stick compound over the post dam and to create a ‘stop’ together with tuberosity border moulding. Once taken, the impres- sion should be reseated to confi rm good retention (Fig 3).
Lower partial denture If an upper complete denture is the treat- ment of choice, then posterior support is essential and a lower shortened arch should not be accepted. It doesn’t matter how good a fi tting upper
Continued » Scottish Dental magazine 51
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