Interview with Ole Rasmus Theisen,
dentist and researcher at the TAKO centre (national resource centre for oral health in rare disorders, Norway)

My name is Ole Rasmus, and I am a 39-year-old dentist from Norway. My relationship with OI stems back from working with researchers who have studied OI extensively as well as seeing some patients. My role includes writing reviews about oral health in rare disorders, including OI. I am fascinated by how rare disorders demand us clinicians understand more about everything from clinical set-up, materials used and the underlying biology. Rare diagnoses may point in what direction we ought to aim to do better for all.

You and your work experience?

I was educated in Norway, Denmark and South Africa. Before the pandemic and two small children, I organised regular dental missions to East Africa, and I have also worked for several years in Finland. My passion is to improve clinical work. I love how dentistry merges knowledge about medicine, biomaterials and procedural techniques with a spectrum of personalities and lives. I am also developing a web-based database and clinical support tool for dentists. It will allow for an easy assessment of rare findings in the oral cavity and the rest of the body. We hope to aid dentists in making the first step towards a diagnosis and provide information and links to more resources for dental personnel seeing anyone with a known diagnosis. The prototype is undergoing user feedback at the moment, and it will be available in Norwegian and English in 2023. The project is financed by the Norwegian national advisory unit for rare disorders.

Tell us a little bit about the TAKO centre!

The TAKO-centre is a national resource centre for oral health in rare disorders. It was established in 1993 and is situated at the Lovisenberg Diaconal Hospital in Oslo. Our mandate is to build experience by seeing patients with rare disorders and oral findings, through clinical work and research. The centre communicates with dental and medical personnel in all of Norway. Our team is multidisciplinary, which is essential to manage the variety of disorders we see. Patients with more than 600 diagnoses have been assessed at our clinic.

What was the review of OI about?

It is about OI, oral health and dental management for clinicians and patients. We used the published literature and referred to research done at the TAKO-centre and globally. We also included clinical experiences from our centre and from colleagues abroad.

What are the dental problems of people with OI?

Dental issues vary a lot between individuals. The severity of the condition in general is not always linked to the severity of the oral findings. The main issues in OI are dentinogenesis imperfecta (DI) and malocclusions (misalignment between the teeth or jaws). Some may miss one or more teeth. The malocclusions are more severe in OI types III and IV. The most difficult malocclusion to manage is when the posterior teeth don’t occlude.

Were there any surprising findings?

Temporomandibular joint problems (jaw joint-related pain) also called TMJ affect the quality of life no more for people with OI when compared to the general population, contradicting expectations. This problem is often linked to stress in the general population. Perhaps people with OI could teach us all something about coping mechanisms?

What effect does bisphosphonates have on teeth in OI?

Bisphosphonates do not affect teeth, but may affect the risk of osteonecrosis («dead» bone) following oral surgery. The dosage, administration method (intravenously or tablets) and period of administration matter. However, not a single case of osteonecrosis has been reported in OI patients. This does not mean there is no risk, but in the short term, it seems low.

Can a person have dental problems due to OI without having DI?

Teeth are mainly composed of hard enamel, dentin and soft pulp tissue. In terms of volume, the most significant tissue component is dentin. Dentin protects the neurovascular pulp tissue from oral bacteria. DI means dentinogenesis imperfecta, weak dentin. The weak dentin provides less protection against potential bacterial infections and may lead to abscesses in untreated teeth without visible cavities. The teeth may be discoloured bluish-grey or brownish-yellow. The weak dentin provides weak support for the enamel, leading to fractures and rapid tooth wear if dentin is exposed. This is especially relevant for primary (baby) teeth, which are usually more affected by DI than permanent teeth. DI can also be «hidden» in OI, as microscopic images have revealed unstructured dentin in teeth without visible DI clinically.

What is the most important take home message for clinical work?

The dentist must know OI/DI before embarking on any treatment. It is not sufficient to know how to do a treatment, they also need to know what treatment is suitable and when to do it. In dentistry, a myriad of different materials and methods may be used, each with its own strengths and weaknesses. The clinic should allow for wheelchair access and systems to work clinically around these. Dentistry is a precise field, one millimeter may determine success or failure. It is important that the dentist can see well.

Were patients/patient organizations involved in your research?

Our text was reviewed by NFOI before publishing. I really appreciated the feedback from the OI-community. You are the experts.

How often should a person with OI see a dentist?

Children with OI should be seen when the first tooth erupts and frequently in childhood. Adult intervals are individualised and vary from four exams per year to one every two years. The number of formal dental sub-specialities varies from none to thirteen between EU countries. Dentistry is a clinical speciality in its own right. It is always wise to consult an experienced clinician updated on the current best practices. It is important that he/she demonstrates concern and interest in you as a patient, has relevant clinical experience and a network of colleagues to consult, so they can manage potential challenges. The most relevant dental specialists for OI patients are pediatric dentists, oral surgeons, orthodontists and endodontists.

What should people with OI do to take care of their teeth?

I like the 2x2x2 rule: 2 minutes of brushing with 2 cm toothpaste 2 times a day. Electric toothbrushes are great. Flossing the areas of the teeth from the point of contact to below the gums allows for the removal of bacterial plaque. Toothpaste with a higher content of fluoride or mouth rinses may be advantageous. I recommend consulting your dentist about which fluoride concentration is right for you, as this will vary.

Is Osteonecrosis a problem in OI?

With the available data, it does not seem so, but long-term follow-up of individuals who have started early with bisphosphonate therapy is necessary to evaluate properly before concluding.

In Norway dental treatment is mostly covered by the government if you have OI – can you briefly share how this works? Does it matter if you see a public or private dentist?

Dental services in Norway are provided by the public dental service and private clinics. The public dental service employs approximately 25 percent of all dentists and is responsible for treating the young and frail in the population according to the law. Three quarters of dentists work in private practice. An OI diagnosis entitles you to partial coverage from the Norwegian Health Economics Administration (HELFO) for dental treatment irrespective of the severity of OI. The price of the treatment is usually higher than the coverage. The patient has to pay the difference themselves.

Any final words for the readers of OIFE Magazine?

I am impressed by the strong spirit held by many with osteogenesis imperfecta. It seems the physical challenges you have to go through makes for some tough, optimistic and forward-looking individuals. Quite the opposite of brittle.