Horizontal versus Vertical Bitewing Radiographs in Opening Interproximal Tooth Contacts

Early diagnosis of occult lesions like incipient interproximal caries is critical to preserve healthy tooth structure. Bitewing radiographs are highly effective in opening interproximal tooth contacts and are used to provide visual detail of surfaces between adjacent teeth. Based on intraoral film position, bitewings may be classified as horizontal and vertical. Objectives: Vertical bitewings often do not capture the distal of canine and also fail to open all interproximal tooth contacts thus requiring re-taking the radiograph. The wider image field and more comfortable intraoral film position of horizontal bitewings may open more interproximal surfaces more consistently. A comparative analysis of horizontal versus vertical bitewings was performed to evaluate the effectiveness of each method in capturing the distal of canine and in opening interproximal tooth contacts. Methods: A sample of 30 horizontal and 30 vertical premolar bitewings was randomly chosen from a teaching file of dental patient radiographs. Exclusion criteria helped eliminate 4 horizontal and 2 vertical bitewings. Interproximal contacts between Canine-Premolar, Premolar-Premolar and Molar-Molar were observed for open and overlapped contacts. Six surfaces of each bitewing yielded a total of 324 interproximal surfaces. Results: Horizontal bitewings opened interproximal contacts in 67.9% of cases whereas only 38.0% of vertical bitewings did the same. Also, the percentage of vertical bitewings that did not capture the distal of canine was 64.3% when compared to 26.9% of horizontal bitewings. Conclusions: Horizontal bitewing radiographs may be a better choice for routine cases with no history or evidence of advanced caries or bone loss. Nevertheless, the longer image of vertical bitewings may still make them the ideal choice for patients with severe caries experience and or alveolar bone loss. Further research in this area could be useful in developing selection criteria when choosing the best bitewing radiograph for individual patient.