In this article, Keith Alexander, Principal Maxillofacial Prosthetist at Royal Berkshire Hospital, details how he changed the life of an oral cancer patient by designing a mouthpiece using Iconic 2mm Dual Laminate Thermoforming material to increase moisture in the mouth. Upon wearing the appliance, the patient expressed gratitude to Keith at having 8 hours sleep for the first time since his treatment.
What is Xerostomia?
Xerostomia, (or dry mouth) is where the salivary glands fail to produce enough saliva to maintain the required moisture level in the mouth, and in some cases no saliva is produced at all. There are hundreds of causes of dry mouth, including: Alzheimer’s disease, Parkinson’s disease, medications for high blood pressure, anxiety, damage from radiotherapy and chemotherapy treatments for cancer.
A male patient presented in clinic complaining of Xerostomia following surgery for oral cancer and radiotherapy treatment.
The patient had undergone major oral surgery to remove a tumour which resulted in the need for radiotherapy and skin grafts to the affected area. The patient was now faced with a permanent loss of salivary production as well as sensitivity, irritation issues, and a reduced opening of the mouth.
"His cheeks would stick to his teeth and swallowing became difficult. After freeing his cheeks and lubricating his mouth by drinking water (as this gave the longest respite) he could then sleep for another 2 hours before having to go through the process again.."
He desperately needed a solution to improve the quality of his life. He stated that although the condition was uncomfortable during the day, he could manage it using a mouth spray and frequent fluid intake. His biggest problem was the disrupted sleep pattern he faced - it was impossible to sleep for more than 2 hours before waking to lubricate his mouth.
His cheeks would stick to his teeth and swallowing became difficult. After freeing his cheeks and lubricating his mouth by drinking water (as this gave the longest respite) he could then sleep for another 2 hours before having to go through the process again, although drinking a glass of water every 2 hours also meant frequent visits to the bathroom.
From Idea to Research, to Design
The patient came with the idea of an appliance similar to a vacuum formed sleep apnoea appliance featuring a liquid reservoir to release fluid during sleep. I explained that this would be unsuitable as the size of it would not fit into his mouth. As an alternative, I suggested a smaller appliance along the lines of a soft bite guard. After a further discussion about the possible outcomes for the patient, it was decided a maxillary vacuum formed appliance with relief areas to hold a lubricating gel would be the best option.
The design process for the appliance:
- Step 1 - Upper and lower dental impressions were taken and the models were cast.
- Step 2 - I decided the best area for the gel reservoir would be in the palatal region adjacent to the remaining teeth, with small spurs between the dentition, and small holes drilled to release the gel.
- Step 3 - I placed one hole between the central incisors and one hole each side - between the first molar and premolar. Pressure could be applied to the raised reservoir to push the gel through the holes and thereby lubricate the mouth.
Cast model ready for the wax reservoir to be added.
The material needed to be firm enough to hold the gel, yet flexible enough to release it when pressure was applied to the reservoir. I first tried a 1mm thickness orthodontic retainer material, but this was too rigid and the edges were not ideal. I then tried a 2mm thick soft mouth guard material and, although this was more comfortable, it was too flexible.
After further research, I came across the ideal material; Iconic 2mm dual laminate from DB Orthodontics. It is more rigid than a sort mouth guard, yet flexible enough to allow the gel to be released. It is the best solution as it offers soft coverage of the oral tissue and the rigidity of the thin, harder covering.
Model prep & appliance construction
- Step 1 - Models are cast in hard dental stone.
- Step 2 - The models are trimmed to be in occlusion when resting on the back edge. This makes it easy to check the bite when placing the gel reservoir.
- Step 3 - The lubricating gel reservoir is built up using wax on the palatal side of the remaining maxillary teeth with the 3 small spurs waxed between the teeth as previously described. These will be the channels for releasing the gel.
Having the reservoir on the palatal side and adjacent to the teeth makes it easier for pressure from the tongue or lower teeth to push the gel through the holes. It also means that any palatal undercuts do not cause a problem with fitment or removal of the appliance.
Model with waxed reservoir ready for duplication.
Duplicated model ready for vacuum forming the appliance.
- Step 4 - Once the size and position of the reservoir is created, the model is duplicated and cast - making the reservoirs part of the plaster model.
- Step 5 - The 2mm dual laminate blank is placed in the vacuum forming machine, heated in accordance with the manufacturer’s instructions, and formed over the plaster cast.
- Step 6 - Once cooled, it is removed from the machine and trimmed to the required shape; ensuring maximum palatal coverage to avoid irritation of the tongue.
- Step 7 - 3 holes are drilled at the end of the spurs between the teeth and 3 further holes drilled in the palatal area. This allows any excess gel to escape (this was an adjustment made to the appliance following the patient’s feedback).
Model showing where holes will be drilled in the appliance.
Trial appliance with insufficient palatal coverage. Pencil line shows the required adjustment.
Appliance on model showing placement of holes to be drilled.
Positive patient feedback
The initial patient feedback I have received has been great. He reported having his first full 8 hour night’s sleep since his surgery & radiotherapy treatment and thanked me for my work. The patient is still having follow up appointments so the long term success of the appliance can be monitored. It is at times like this I realise how dramatically my work can improve the quality of people’s lives. And, it is a very satisfying feeling.
This case is a perfect example of how patient input and feedback contribute to the development of innovative appliances. The initial idea actually came from the patient himself, and with continual development and communication, we managed to create an appliance that, on initial reports, has resolved the disrupted sleep pattern caused by the dry mouth condition – all in a relatively short time period. Due to the success of this case, we are researching the potential for using this appliance for more cases in the future.
About Keith Alexander
Keith Alexander is Principal Maxillofacial Prosthetist at Royal Berkshire Hospital. Following 8 years of placements and study towards a City & Guilds in Dental Technology and advanced City & Guilds in Orthodontics, Keith has spent his subsequent 25 years at the Royal Berkshire Hospital in Reading. Here, he obtained the Maxillofacial Prosthetics qualification; researched, developed and wrote articles on EPG plates in conjunction with Reading University; and also published papers on prosthetics & metal casting.
Upcoming thermoforming courses
ICONIC MASTERCLASS - DATE TBC.
To be placed on the mailing list for future dates, call Education Coordinator Karen Hiscoe on 01535 650579.
CPD: 6 Hours
About the course
The course will build on the delegates thermoforming skills, and advance
their knowledge in the fabrication of Iconic thermoformed materials.
An Iconic Masterclass certificate is awarded on completion of the course.
Course lead is Mr. Ed Payne from The Eastman Dental Institute.
To advance the knowledge of the delegate in Iconic thermoformed materials.
To understand the theory and have practical knowledge:
- In the construction of an Iconic Original orthodontic retainer
- In the construction of an Iconic bleaching tray
- In the construction of an Iconic sports mouthguard
- In the construction of an Iconic bruxism guard