Final answer:
Hypothyroidism primarily delays the dental eruption timetable due to the lack of thyroid hormones, which are crucial for normal growth and development, including the timing of tooth eruption.
Step-by-step explanation:
Hypothyroidism affects the dental developmental pattern primarily by delaying the eruption timetable of teeth. This condition is due to the underproduction of thyroid hormones, which can cause a low metabolic rate and associated symptoms such as weight gain, sensitivity to cold, and reduced mental activity. In children, it can manifest as cretinism, leading to growth defects and developmental delays. The lack of thyroid hormones during crucial developmental periods can result in a delayed timeline for various developmental milestones, including the eruption of teeth.