Dr Maurizio De Stefano and Luca Ruggiero RDT show the successful treatment of a patient wearing removable prostheses who for many years had lots of discomfort that affected her every day and social life.
In recent years, the social aspects of the elderly have taken increasing importance. And as a result, a series of factors have changed the parameters of their aesthetic treatment demands and difficulties.
The first factor is that an elderly population increase is due to the decrease of the mortality rate. A recent WHO report noted that currently 125 million people in the world have reached the age of 80. In other words, human age longevity has increased significantly. According to the studies, the mortality rate has dropped significantly between 1900 and the present day. It is also estimated that by 2050 there will be 550 million seniors in the world.
This will mean that within five years, the current elderly population total will eclipse that of children under the age of five, and by 2050, the over 60 population will increase from the current 900 million people to almost 2 billion.
The concept of everyone seeing the elderly as fragile and dependent will perish. The new ways that the elderly can contribute to society must be sorted out. People must accept this as part of the norm quickly. This will allow our future society to make the status of the elderly a dignified one in society. Not one of shame.
Large-scale longitudinal studies from 1916 to 1958 showed the prevalence of most severe world-wide diseases has decreased. Yet the less serious ones haven’t decreased.
There is little evidence to prove the fact that lives nowadays are a little healthier than the lives of previous generations of the same age. Obviously taking COVID-19 out of the equation. Clearly, disease prevention is the best way to ensure that our golden years are healthy ones. This ensures that the 70s can become the new 60s.
However, those who live longer and in better conditions generally become part of the most advantaged segment of society.
Some individuals age faster than others. Within the same individual there are many organs that age faster than others. DNA double helix is key in discovering specific genetic sequences. You can identify some molecules that are bound in the form of methyl groups.
But nobody knows why the cell’s DNA methylation process accurately tells you the biological age of an individual. In the near future, ways of counteracting ageing will be worked on. The main feature being the reduction of the level of DNA methylation.
But at the moment, as seen with the demographic increase in elderly, an important professional role for the dentist, and a consideration for the lab technician, is to try to close the difference between biological age and the perceived age. You can do this by counteracting tooth loss. Also, counteracting the consequent dimensional volume change of the hard and soft tissues of the face. This negatively affects the relationship between perceived and biological age.
Tasks of the clinician
One of the main tasks of the clinician is to preserve. This is thanks to science and conscience, the structure and aesthetics of the lower third of the face. Early scientific evidence concerning the adaptation of the tissues after a dental extraction have already been discovered (in the early 60s). We have seen that it is possible to counteract. At least in part, crest resorption by utilising clinical procedures about using bone substitution materials.
It was also noted that when more complicated extractions are carried out, anatomic changes due, to the remodelling process, occur up to 60% of the time, within a full 12-month period (Botticelli, 2004). Furthermore, it was shown that overtime are completely edentulous ridge may undergo further detrimental changes. This is linked to route absence which eventually leads to resorption of the bone. Also, the presence of occlusal function, preserve adequate vascularisation of the functional support of the periodontium. This keeps the crystal bone levels intact.
Further thought should be given to when a prosthesis is not correctly applied to an edentulous ridge without any follow-up appointments.
In this article we want to introduce you to a clinical example. One where the patient wears removable prostheses. For many years she had lots of discomfort that affected her every day and social life. The issues the patient complained about we are both aesthetic and functional. In particular related to the impossibility of chewing because of excessive denture mobility. Also because of painful mucus membranes that caused lacerations. Furthermore the patient avoided smiling because of the older looking appearance of the lower third of the face.
Patient Angela D is 67 and presented for observation related psychological problems. This is due to the fact that her very old prostheses resulted in her inability to smile and chew properly. They were completely worn out and not at all stable. Her request was to restore aesthetics and function (Figure 1).
An anatomical impression of the edentulous arches was taken in order to capture compressed tissue. This was done by using edentulous impression trace and by using a party material combined with an alginate wash. The two materials are made to be compatible with each other thanks to a specific type of adhesive we used (Figures 2 and 3). Preliminary models were created in the laboratory with a class III plaster (Figures 4 and 5) And the limits of the future prostheses were outlined on them with a pencil (Figures 6 and 7).
We illustrated to the patient that she will receive new and better prostheses by placing her current prosthesis on the newly made models (Figure 8) and then pointing out the structure discrepancy between the previous prosthetic border and the new design plant for the development of the new prosthesis. The current nuances reported by the patient, such as instability and her masticatory difficulty, could be attributed to the absence of lingual space as well as to the fact that the previous mounting position of the prostheses was to lingually orientated.
The impression traits were made in compliance with two basic requirements for the technique used. They were built without spaces in order to join the buccal mucosa and the shape of the handle and to simulate the shape of the dental arch. The latter was done in order to support the lip during the impression taking phase.
Before proceeding with the actual impression we border-moulded the extension of the individual tray with silicon paste (Figures 9 and 10). The areas of contact of the silicone material with the tissues are carved back to avoid over extensions of the prosthetic border. The prosthetic border is then optimised by using heated and shaped thermoplastic pastes (Figures 11 and 12).
Subsequently, we proceeded to the final impressions but use on a zinc oxide eugenol paste (Figures 13 and 14), believed to be presently the best choice when we encounter edentulous ridges. The impressions were sent to the laboratory and then poured. A master model was made using a class IV plaster and distilled water mixed together (Figures 17 and 18). According to the standard parameters, the upper and lower ridge height average is 40 mm, divided into 22 mm for the upper and 80 mm for the lower.
The position of the occlusal plane in relation to the upper ridge is determined using a special leveller and identifies the floor of the camper. The lower ridge’s wax is applied In a standard way, starting with 18 mm in the front and then a third of the way up in the retromolar area (Figures 19 to 22). The purpose of the wax blocks is to establish a correct vertical dimension. Also to ensure ideal support of the perioral tissues as shown by photographs (Figures 23 to 26). The next clinical steps were to record intermaxillary ratios in the frontal plane, Verifying of the VEDO in the horizontal plane, and then registering the centric inclusion position (as explained by Dawson).
The next phase
During the next phase, the clinical steps were:
- Evaluation of the correct inclination of the occlusal plane of the upper ridge In comparison with the camper plane, with the fox plane in mind
- Levelling the lower costs according to aesthetic, phonetic and postural criteria
- The ridge, the median line and lateral lines corresponding to the extension of the nasal wings and the line corresponding to the upper and lower lip design when the patient smiled were all evaluated. Adjustments were made (Figures 27 to 31). By the end of the adjustments, her lip support already appeared more natural (Figure 32).
Centric keys were made with a special wax that we use for occlusal registration purposes. Therefore, in the laboratory, the two edges can be repositioned with respect to each other. This is so we don’t alter the centric inclusion position just registered (Figures 33 and 34). At this stage the wax blocks are temporarily placed in the articulator.
On the occlusal surface of the upper wax block, the lower ridge is highlighted with a wax outline. This subsequently allows for the correct positioning of the upper and lower teeth (Figure 38).
On the occlusal surfaces of the wax we placed excursion recording plates for intra and extraoral recording. The only point of contact between the archers is the central support pin. Thereby respecting the previously recorded VDO (Figures 39 to 41).
Terminal hinge axis is simulated
At this point, the terminal hinge axis is simulated. This positions the writing type of the articulator 13 mm from the tragus on the line that connects the lateral and corner of the eye (Figures 42 and 43). Thanks to the interposition of a calibrated cardboard, the movements relative to the condyle are registered. This is by having the patient repeat preclusive movements many times (Figure 44).
Gothic recording device
At this point we used a Gothic recording device to record the centric relation position. This was done with a wax crayon and a black plate (Figures for 45 and 46). Lateral, proclusive and retrusive excursions were recorded on the plate. This allowed us to record the centric occlusion and centric relation points in order to verify the concept of occlusal freedom in centric, according to Gerber’s book (Figures 47 and 48). With an appropriate paste, the two plates are fixed in the centric occlusion position just established (Figures 49 and 50).
The models are repositioned
At this point, the models are repositioned on the Gerber Condylator articulator With the aid of a facebow (Figure 51). The analysis of the models showed the interalveolar relationship between the upper and lower ridges in the frontal and horizontal planes (Figures 52 to 56). The upper front and lower front teeth were then placed according to standard aesthetic and phonetic parameters (Figures 57 and 58). The anterior occlusion is now set with the physical stability of the prostheses in mind (Figures 59 to 61). The lower denture was replaced with the silicone index made earlier. This shows the midline and also the point in which the canine was in line with the nasal alae (Figures 62 to 64). After completing the dental assembly, everything was tested out intraorally.
The patient wore the prostheses and an aesthetic/functional verification was performed before finalising the prostheses (Figures 65 to 69). Finally, the laboratory processed the prostheses in acrylic and then the prostheses were delivered (Figures 70 to 72).
Centric occlusion and centric relation contacts were checked, in addition to the relationship the prostheses had with the tissues.
The patient was extremely pleased with both the aesthetics and function of the prostheses. They were also pleased that we verified in the various interim tests that were done. She was truly satisfied.
The rehabilitation of the lower third of the face using removable prostheses is intimately linked to the expectations of the patient. The main request of the patient was ideal aesthetics with the hope that the prosthesis will be stable during mastication.
Immense attention to detail was the main factor that resulted in harmoniousness between the teeth and the face. The shape of the arches and the final shape of the teeth are added factors to the success of new prostheses. In this case, and with all cases, the most important success parameter is patient satisfaction.
This paper is reprinted from Spectrum Dialogue Vol 17, no 9 – pages 32-47