Text: Laura Iisalo
Photos: Harri Tarvainen

Malocclusions are common oral health problems, which are treated with significant public funds. They have an impact on oral functions including eating and speech but also on aesthetic appearance, social interaction, self-esteem, and psychological wellbeing. Researchers and clinical practitioners have lately shown interest in individual impacts of malocclusions on quality of life but on a population-level the subject has been rarely researched.

– Most of the studies were conducted among children and adolescents. In that sense our study population is unique and significant because it consists of adults, which means that we can evaluate the impacts of malocclusions on a long-term basis, tells Linnea Närhi, a dentist and doctoral student at the University of Oulu, who is currently working on a thesis funded by a grant from the Cultural Foundation to investigate the connection between malocclusions and orthodontic treatment, and oral health-related quality of life.

Quality of life research supports patient-centered health care

Närhi's investigation is part of the Northern Finland Birth Cohort 1966 study conducted with research material originally comprising of the children born in 1966 in the provinces of Oulu and Lapland. Närhi was involved in the 46 year-olds' follow-up study. The study group consisted of 1964 volunteers, who participated in a standardized clinical oral and dental examination, including the registration of occlusion and digital 3D dental casts.

In addition, the participants filled in a questionnaire concerning their oral health-related quality of life. So far the results have strengthened the idea that malocclusions really are associated with oral health-related quality of life.

"We found out that men had more severe malocclusions but women experienced greater impact on their quality of life."

– It was surprising that the gender difference was so significant. We found out that men had more severe malocclusions but women experienced greater impact on their quality of life. On the other hand the research revealed that people can adapt to their condition, and may not experience remarkable impacts of even severe malocclusions, Närhi tells.

The results of the three-part research are aimed for publishing in international high quality orthodontic journals, and presented in international congresses. The first sub-study of the thesis is already complete, and it was published in May 2019 in the European Journal of Orthodontics. The concrete benefit of the study will be seen in health care as an increased understanding of the impacts of malocclusions.

– Thanks to the research we will be better at understanding what is significant for the patient, and defining which malocclusions should be treated. Health care resources are limited, and so it is important to determine, which patient groups benefit from treatment the most. Quality of life research is intended to explain patient's perspective, which should always be taken into consideration when assessing the demand of orthodontic treatment, Närhi concludes.

Dentist and researcher Linnea Närhi received a 31 500 euro grant in 2020 to study the connection between malocclusions and oral health-related quality of life.