In lagomorph dental development, when are deciduous premolars and molars replaced?

• A. Deciduous premolars replaced at 2 weeks; Molars replaced at 4 weeks
• B. Deciduous premolars replaced at 4 weeks; Molars replaced at 4 weeks
• C. Deciduous premolars replaced at 4 weeks; Molars replaced at 2 weeks
• D. All teeth replaced by 6 weeks

Answer: (B)

Timing of replacement of deciduous cheek teeth in lagomorphs. In these animals, the deciduous premolars and molars are replaced by their permanent counterparts at about 4 weeks of age. This timing supports the shift from a milk diet to solid feed by ensuring the cheek teeth that do the grinding are fully functional as the animal begins to wean. The molars and premolars emerge in a way that maintains proper occlusion and chewing efficiency as the jaw grows. Replacing them earlier (around 2 weeks) would be premature for functional chewing, while waiting until 6 weeks would leave the animal with inadequate grinding surfaces during the critical early digestive period.