Applicability of the CIELAB and CIEDE2000 Formulae for Detection of Colour Changes in Colour-Changeable Chewing Gum for Evaluating Masticatory Function.

INTRODUCTION: Mastication is one of the essential stomatognathic functions and is impaired when mandibulectomy is performed for removal of head and neck lesions.

AIM: The purpose of this study was to investigate the correlation between perceived chewing ability {Masticatory Score (MS)} and objective mixing ability (∆E) in patients who had undergone marginal mandibulectomy.

MATERIALS AND METHODS: Twenty normal dentate subjects as control group and twenty mandibulectomy patients who had undergone marginal mandibulectomy and wearing a dentomaxillary prosthesis were enrolled. Perceived chewing ability MS and objective ∆E were evaluated using a food intake questionnaire and the colour-changeable chewing gum, respectively. They were instructed to chew the gum continuously for 100 strokes on their usual side. The chewed gum was measured using the CIELAB colour space defined by a colourimeter and L, a* and b* were obtained. The change in colour of the gum after chewing was calculated using CIELAB (∆Eab) and the CIEDE2000 (∆E00) formula. The relationships of a*, ∆Eab, and ∆E00 with MS score were analyzed using the Spearman's rank correlation coefficient.

RESULTS: A correlation was found between perceived chewing ability (MS) and objective mixing ability (index of the masticatory function {∆E}) in marginal mandibulectomy patients. (∆E00 = 0.481, a* = 0.587, ∆Eab = 0.668).

CONCLUSION: Within the limitations of this study, it can be concluded that the CIEDE2000 formula for calculation of colour difference can be used to evaluate masticatory function in patients who have undergone marginal mandibulectomy.