Oral diseases

The manifestation, diagnosis, aetiology, pathogenesis, and epidemiology of oral diseases are topics of fundamental importance to the field of dentistry. The term “Oral diseases” covers pathological conditions in both the soft and hard tissues of the oral cavity. For decades, the Department of Dentistry at Health has made internationally recognized research contributions within a wide range of oral diseases. These include diseases in the supportive tissues around the teeth (periodontal disease) and in the hard tissues of the teeth themselves (dental caries, erosion, mineralization disturbances, and tooth anomalies).

Nevertheless, many unresolved questions continue to call for intensive research in oral diseases. Given that the oral cavity is an important entryway into the body, and that functional teeth and healthy oral
tissues are preconditions if people are to function well and thrive in the broadest sense of the word, studies of oral diseases are and will remain important and ever relevant. In addition, new questions and issues that also require research regularly arise, instigated by such factors as the rapid pace of change in our modern world. This pace leads to changes in the way people interact and behave, and it influences health, living conditions, and lifestyles.

Research on global oral health and disease
The research carried out at the Department of Dentistry focusses on clinical manifestations and
variations of diseases in the oral tissues. Studies are conducted in Denmark and elsewhere around the globe. We especially focus on oral bacteria implicated in the initiation and progression of disease – such as the development of cavities (caries) or loose teeth (periodontal disease) – but also focus on other factors – hereditary, environmental, health-related, behavioural, and social – which may be implicated in the development of disease.

One manifestation of marginal periodontitis is a loss of attachment around the teeth. This can be diagnosed by clinical examination.

In recent years, research on an aggressive form of periodontal disease has gained international attention. Over decades, we have accumulated extensive knowledge about a virulent bacterial clone of the oral microorganism Aggregatibacter actinomycetemcomitans (more specifically called the JP2 clone). The prevalence of this particular clone is very high in the northern and western parts of the African continent, but it is also frequently found in individuals of African origin, living in Denmark and in other countries that are geographically widespread.

People who carry this bacterial clone in the oral cavity have an 18-times higher risk of developing an aggressive form of periodontal disease, compared to those who do not carry this clone. Based on our findings we can contribute to early diagnosis of this disease in the young, enabling preventive efforts to begin in a timely fashion. In cases where the disease has already become evident, we can help to organize and carry out a more specifically targeted treatment regimen for this aggressive form of periodontal disease.


  1. The Department of Dentistry is conducting a variety of interesting and noteworthy projects that primarily focus on diagnostics of oral diseases, including clinical, radiographic, functional, microbiological, and genetic examinations. Many of these projects are based on interdisciplinary and intersectorial collaboration with researchers from other universities and other types of institutions and organizations, within Danish borders and beyond.
  2. Periodontal attachment loss in children and adolescents. Collaborative projects involve departments at Aarhus University and universities on the African continent and in Europe, North America, South America, and Asia.
  3. Diagnostic research relating to dental caries and periodontal diseases.
  4. Factors relating to the treatment, development, and healing of apical periodontitis, and the development of the endodontic status in an adult Danish population.
  5. Molar Incisor Hypomineralization. Collaborative projects involve Danish municipal services, paediatric departments at Danish hospitals, and international universities.
  6. Oral manifestations of rare diseases, such as hereditary rickets, amelogenesis imperfecta, and osteogenesis imperfecta.


Increased risk for development of periodontal attachment loss in carriers of the JP2 clone of Aggregatibacter actinomycetemcomitans
(Haubek D. Lancet. 2008;371:237–42)

Microevolution and patterns of dissemination of the JP2 clone of Aggregatibacter (Actinobacillus) actinomycetemcomitans.
(Haubek D. Infect. & Immun. 2007;75:3080–8)

Implications of caries diagnostic strategies for clinical management decisions
(Baelum V. Community Dent Oral Epidemiol. 2011 Epub ahead of print)

Risk factors for developing apical periodontitis in a general population
(Kirkevang L-L. Int Endod J. 2007;40:290–9)

Defining a periodontitis case: analysis of a never-treated adult population
(Baelum V. J Clin Periodontol. 2011. Epub ahead of print)

Clinical variation of amelogenesis imperfecta – mutations of the genes involved in the amelogenesis
(Haubek D. Int J Paediatr Dent. 2011;21:407–12)

Manifestation of hereditary rickets in oraland craniofacial tissues
(Gjørup H. Am J Med Genet. 2011;155:2654–60)


Research in the field of oral diseases comprises a wide range of methods used to perform clinical, radiological, microbiological, genetic, histological, functional, and epidemiological investigations. Some of the scientific methods and special skills are:

  • Design and analysis of clinical trials, casecontrolled studies, and cohort studies
  • Systematic collection of clinical data related to oral conditions and/or diseases
  • Generation and interpretation of radiographicimages, and scientific handling of radiological data
  • Analysis of biological materials, such as teeth, dental plaque, saliva, and tissue and blood samples
  • Scientific handling of data from various Danish electronic public registers and databases, and combination of these with scientific data within the field of odontology
  • Qualitative and quantitative methods
  • Epidemiological and statistical methods.