Bitewing Radiography for Caries Diagnosis in Children: When and Why?

The 2013 Children's Dental Health Survey found that 31% of 5-year-olds had obvious caries in the primary dentition.¹ The average number of decayed teeth was 0.9 but for those with caries it was 3.0.¹ Thirteen per cent of 5-year-olds suffer from severe and extensive decay, and 54% of 8-year-olds had a mean of 1.1 primary teeth affected by untreated caries into dentine, with 28% of 5-year-olds and 38% of 8-year-olds having decay into dentine.^1,2 The Care Index indicates that the proportion of carious teeth that are restored was 11.8% in England for 5-year-olds in 2016–2017, meaning only around 1 in 8 carious primary teeth were treated.³

Caries is a burden for patients, affecting confidence, sleeping and eating.⁴ When not treated, severe decay can lead to pain and sepsis, and treatment under general anaesthetic with associated morbidity and mortality risks. It is also a significant public health problem. In 2015/2016 there were 43,700 hospital admissions of children under 16 with a primary diagnosis of dental caries, mostly requiring extractions.⁵ Detection of caries before cavitation allows use of preventive measures, such as oral hygiene instruction, dietary advice and fluoride use to arrest lesions. In both primary and permanent teeth, between 33% and 100% of caries lesions in the outer dentine are cavitated, and the deeper the lesion has penetrated dentine, the more likely it is to have cavitated.⁶ If cavitation exists, the efficiency of preventive treatment is reduced, as removal of bacteria from the cavity is difficult. In consequence, more invasive treatment requiring local or general anaesthesia may be necessary. Further, in primary molars with proximal caries, teeth are often pulpally involved at an early stage, therefore early diagnosis to allow restoration to avoid infection is necessary.⁷