Consistency of diet and its effects on mandibular morphogenesis in the young rat

Abstract

The purpose of this study was to evaluate the relationship between mandibular morphogenesis and masticatory function in 30 male Sprague-Dawley rats, 28 days of age. Animals were randomly divided into three groups and they received diets of different consistency: liquid, normal (as control group) and elastic diet. The experiment lasted 28 days, at the end of which lateral radiographs of the cranium and photographs of the hemimandibles were made. These images were magnified fourfold and analysed in two dimensions (V = vertical dimension; S = sagittal dimension). Condylar morphology was also assessed. The photographic analysis of the hemimandible showed a significantly higher growth of the mandibular ramus stimulated by the elastic diet: V2 2.4 mm, V3 2.4 mm, V4 1.9 mm, V5 4.1 mm (p < 0.05). In contrast, a statistically significant (p < 0.05) lengthening of the mandibular corpus occurred in the rats subjected to liquid diet (S1 4.5 mm, S2 2.7 mm, S3 1.6 mm, S4 2.6 mm). Measurements were taken on both the radiographic and the photographic records. The variation coefficient showed that photographic analysis was more accurate than the radiographic analysis. From these data it appears that an increase in the tonus of the protrusive muscles could be beneficial in mandibular hypoplasia and the increased tonus of the masticatory muscles in skeletal open bite.

Micro-evolutionary divergence patterns of mandible shapes in wild house mouse (Mus musculus) populations

“…The intuitively most important environmental factor that could influence mandible shape is diet and we have therefore paid particular attention to this. Previous studies on the influence of diet differences had found that food consistency has an effect on mandible shape [15,16,35-37]. But we have asked here for the first time how strongly these effects might confound measured differences between wild mouse populations.…”

“…In the mouse mandible, environmental influences have traditionally been investigated using hard diet vs. soft diet experiments, and diet consistency has indeed been found to influence mandible growth and shape [15,16,35-37]. However, the magnitude of the shape change introduced by the difference in diet consistency in relation to the shape differences between natural populations has not been addressed in these studies.…”

Morphometric analysis of the mandible in the Durban Metropolitan population of South Africa

“…There appeared to be paucity in the literature regarding this particular relationship. In this regard, Luca et al [10] proposed that mastication and dietary habits may influence the growth of the mandible. They recorded that individuals who consumed an abrasive diet had larger jaws in comparison to those that had a soft diet.…”

Craniofacial Development in Rats Fed on Powdered Diet Following Extraction of All Upper Molars

“…Numerous studies have shown a relationship between masticatory muscle function and craniofacial growth (4)(5)(6)(7). Mastication has a marked influence on mandibular growth and development (8). The mandible is known to change shape with different diets; ramus height was found to be greater in rats fed a hard diet than in those on a soft diet, (9,10).…”