Dietary consistency and craniofacial development related to masticatory function in minipigs

Area of Science:

• Oral biology
• Craniofacial development
• Evolutionary biology

Background:

• The hypothesis that strenuous mastication promotes oral-facial growth has existed since the 1890s.
• Lack of masticatory function from refined foods is a suspected cause of malocclusion in industrialized populations.
• Previous experimental evidence is limited to rat models.

Purpose of the Study:

• To test the "disuse" theory of malocclusion using a larger, more occlusally relevant animal model (Yucatan minipigs).
• To investigate the impact of dietary consistency on craniofacial and occlusal development.

Main Methods:

• Four Yucatan minipigs were fed a hard diet (HD) and four a softened diet (SD) for eight months.
• Occlusal and osteometric data were collected after the experimental period.
• Statistical analysis, including Q-mode principal coordinates analysis, was used to compare groups.

Main Results:

• Significant differences in craniofacial morphology and occlusion were observed between the HD and SD groups.
• Hard diet consumption led to greater body weight and significantly larger masseter and temporalis muscles.
• Softened diet resulted in facial prognathism, narrower dental arches, tooth crowding, maleruption, and specific mandibular bone differences.

Conclusions:

• Dietary consistency significantly influences craniofacial growth and occlusal relationships.
• The findings support the theory that reduced masticatory load contributes to malocclusion.
• This study provides strong evidence in a relevant animal model, controlling for other orthodontic etiologies.