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7 Factors complicating success

Prognosis and justification

Each diagnosis and treatment plan should be qualified with a prognosis – an indication of the likely outcome of the condition, or the proposed treatment. Without this information, the patient is unable to make an informed choice about which treatment modality to pursue – and so it is important to remember to discuss this and record the discussions within the patient notes. Just as important as the prognosis is the justification for how this decision is reached. A comprehensive and thoroughly recorded assessment will facilitate this process. The factors below are considered to be risk factors when constructing removable prostheses (Figure 7.2).

Risk factors

Patient factors

 Patient confusion or uncertainty – If patients are unsure about why they are receiving a prosthesis, or they feel that there is little need, then they are less likely to wear the finished product. You must be clear about what your treatment aims are, and this should be checked and reinforced at each patient appointment.

 Pain over the full denture-bearing area (DBA) – An ache or a burning sensation over the entire DBA (on either arch) can be difficult to diagnose accurately and manage. This may happen if the occlusal vertical dimension is excessive, meaning that the denture bearing area is perpetually overloaded. Leaving one or both dentures out can help to confirm the diagnosis. This type of pain can also present if there is an allergy or an intolerance to materials in the denture base. If this is suspected, it will be important to send the patient for patch testing for sensitivity to denture-base materials.

 Immediate intolerance – It is always a concern when the patient is unable to retain a prosthesis in the mouth for any time at all. Occasionally this may be because of acute trauma from the prostheses, making fully seating them painful. However, it is often the case that patients are reluctant to insert their prostheses – and begin to reject them before they are even fully inserted into the mouth. This rejection may also be accompanied with a gag reflex, which is discussed further below. There are often psychosocial problems that will complicate the acceptance of a removable prosthesis and it is important that the patient feels comfortable enough to highlight any concerns. You must also be sensitive to the fact that some patients may have experienced traumatic events in the past that have manifested as oral intolerances. Be prepared on some occasions to refer patients, via their general practitioner, for counselling.

 Received multiple consecutive sets – Patients that present with a bag full of previous dentures should be assessed very carefully. The previously failed prostheses are usually a warning sign that risk factors have been missed – it is also often the case that patient expectations have been mismanaged. In this case, just assess the set of dentures that the patient prefers or wears most frequently.

 Lack of recent prosthetic experience – Patients presenting without any dentures, or who have not been wearing any recently, must be informed that the acclimatisation process will necessarily be longer. It also makes prescribing the tooth positions and the vertical dimension more challenging.

 History of non-perseverance – If patients are unable or unwilling to persevere in order to overcome minor problems with their prostheses, then it is likely that the prognosis will be significantly affected.

 Poor neuromuscular control or dexterity – If the patient has suffered a stroke, or has been diagnosed with Parkinson's disease or other neuromuscular disorders, then the prognosis will be significantly affected.

Clinical factors

The following clinical factors can significantly compromise the outcome of denture provision:

 Restricted intraoral access

 Dry mouth

 Widespread or significant ulceration (especially if the patient is taking nicorandil)

 A gag reflex when the DBA is palpated

 Obvious hyperactivity of the tongue or lateral tongue spread

 Superficial mental nerves causing pain on palpation

 Significant tori that will impede extension or full seating of a prosthesis

 A large discrepancy between the current intercuspal position and the retruded arc of closure

 Problems or difficulties with the patient's ability to sit upright in a dental chair

Ridge anatomy

It is generally accepted that an atrophic ridge means that the prognosis will be affected, especially on the lower arch. In these cases, more attention needs to be paid to accurate extensions, functional border moulding and tooth position. However, it is often assumed that high and rounded ridges means a high chance of ‘success’ – but be careful – patients with ridges of this type often present with pain on the crest of the ridge. Ridges should also be inspected for the height of the muscle attachments – are they near the crest of the ridge (which means you need to be very careful to accommodate them in function) or are they low or absent? Also look for significant ridge undercuts, which may mean that you need to consider a specific path of insertion, or even pre-prosthetic surgery.

Technical factors

Poor communication with the laboratory means that technical aspects may be suboptimal. Make it clear on your communications to the laboratory why you are making the prostheses and ask the technician to contact you if they encounter any problems or suboptimal clinical work.

Ultimately, success is compromised by poor communication between operator, patient and technician – be honest about your likelihood of success and document the discussions carefully in the patient notes.