A genetic or developmental disorder can be the basis for the failure of a normal dental development, resulting in the absence of 1 or more teeth. For genetic research or the development of a plan of treatment, it is important to determine whether certain patterns of dental agenesis are more common than others. In the present article a new method is described where unique values are assigned to certain patterns of tooth agenesis. Using the idea of binary arithmetic, the absence or presence of teeth are represented by 1 and 0, and translated into corresponding unique values, the ‘tooth agenesis code’ (TAC). This procedure has advantages over existing methods in that it allows for easier data analysis, can contribute to genetic research into the aetiology of tooth agenesis and enables researchers to communicate unequivocally the phenotypes of their studied case. It can also be used in other areas of oral pathology that require pattern recognition.

In a retrospective study, the prevalence of carotid artery calcifications on routine screening panoramic radiographs of a Dutch Oral & Maxillofacial Surgery department was investigated. Individuals older than 45 without a history of CVA, TIA or head and neck radiotherapy were included. Technically useful radiographs were available for 145 males (mean age 59.6 years) and 303 females (mean age 58.5 years). Both a dentist and an oral maxillofacial surgeon examined these radiographs for radio-opaque lesions adjacent or below the C3-C4 intervertebral space. Forty-two individuals with asymptomatic carotid artery calcifications were identified (9.4% of the study population; mean age 68.2 years): 18 men (12.4%; mean age 66.2 years) and 24 women (7.9%; mean age 69.7 years). In 90% of cases the calcifications were bilateral. These results indicate that panoramic radiographs obtained during the course of routine dental treatment may identify calcified carotid atheromas in asymptomatic subjects.

The obstructive sleep apnea syndrome is characterised by repeatedly occurring complete or partial obstructions of the upper airway during sleep, which can be accompanied by serious oxygen desaturations. This can result in cardiovascular co-morbidity and excessive daytime sleepiness, with an increased chance of motor vehicle accidents and diminished performance at work. The use of a mandibular advancement device appears to be an effective therapy. In the long term, however, the possibility of dental side effects should be taken into consideration. Development of a relative mesio-occlusion has frequently been observed. Side effects are usually mild and transient. To objectively evaluate whether the side effects are stable or progressive, a thorough follow-up is needed. It is therefore desirable that treatments with a mandibular advancement device are carried out by dentists or specialists with experience and special expertise in this area.

The first part of this article is a translation of an editorial which appeared in the journal Gerodontology. The author warns that a great increase is expected in the number of dementia patients in the United Kingdom and he argues that care for these patients be given a high place on the national agenda. Dementia was also a major issue at the meeting of the International Association for Dental Research in March 2007. Several international studies presented there indicated that elderly people with dementia constitute a group at risk with respect to oral health. In the evaluation of the editorial, the situation in The Netherlands is described. There is also serious concern in The Netherlands about the statistics with respect to dementia. Due to the growing number of frail elderly people having a natural dentition, the need for professional oral care will increase. General practitioners have the important task of providing adequate oral health care for elderly people suffering from dementia who are still living at home. Guidelines for Oral Care, having to do with the improvement of oral care in institutions, appeared recently. With the guidelines, a good basis for developing adequate oral health care of frail elderly people is available. However, the implementation of these guidelines will require some attention.

One month post extraction of the second left maxillary molar the alveolar extraction site showed no signs of healing and was painful. The patient had been using an oral bisphosphonate during 3 years. Therefore, the lesion was diagnosed as bisphosphonate-induced maxillary osteonecrosis. Treatment was conservative. Since one month later the pain had increased and the wound healing had decreased, a biopsy was carried out. Histopathologic examination revealed a non-Hodgkin lymphoma.

Nocturnal pins and needles and other sensory disturbances in the median nerve innervated fingers are caused by local pressure on this nerve in the carpal tunnel. Carpal tunnel syndrome is the most frequently encountered peripheral nerve entrapment. In The Netherlands, the prevalence of carpal tunnel syndrome is estimated 9% among adult women and 0.6% among adult men. Several risk factors have been identified. For dental professionals, the most relevant seem forceful use of the hand during scaling and extractions, use of vibrating ultrasonic equipment and frequent working with the wrist in flexion or in extension. The diagnosis of carpal tunnel syndrome is based on the characteristic complaints, confirmed preferably by abnormal electrophysiological tests. Depending on the degree of impact on daily functioning, treatment for carpal tunnel syndrome may be expectative, conservative or surgical. Adjustment of the working conditions may prevent the development of a carpal tunnel syndrome.