Bolus hardness preference and cranial structure

Objectives: Recent studies show the association between reduced mastication and impaired cognition, both in animals and humans. In this preliminary study, the hypothesis that food consistency preferences could be related to craniofacial structure, and particularly the vertical dimension, will be tested. Methods: A total of 108 patients (44 males, mean age 14,3 ± 3.9 [years,months]; 64 females, mean age 16,9 ± 9,1 [years,months] with dental malocclusion were included. Essential clinical data were collected: medical and dental history, clinical investigation, study casts, OPG, LL and PA teleradiographies and cephalometric analysis, intra- and extraoral photos. Patients were divided in three groups according to SpP^GoGn angle: hypodivergent (10°±5°); mesodivergent (20°±5°); hyperdivergent (30°±5°). Three structured questionnaires (Q) were administered, evaluating bolus consistency perception (between hard and soft boluses) (Q1), habitual dietary preferences (Q2) and preference between similar foods with different consistency (e.g. bread crum/bread crust; Q3). Results: Patients in all three groups correctly perceived bolus consistency and reported a greater difficulty in chewing hard boluses (Q1). Patients in the mesodivergent group reported a significant preference for foods with a softer consistency (p<0,05; Q2). Concerning preferences between similar foods with different consistency (Q3), there was a general preference for softer foods in all three groups, with a tendency towards harder foods in the hypodivergent. Conclusions: This preliminary study suggests a link between bolus consistency and cranial structure. A general pattern of preference towards softer, easier to chew foods correlates with the recent evolution of cranial structures towards less robust features. Hypodivergent subjects develop more intense masticatory forces and have more stable occlusal patterns when compared to mesodivergent and hyperdivergent subjects, which might explain their observed tendency to prefer harder boluses. The results of this study suggest a link between the consistency of the diet and cranial structure, worth investigating in greater depth.