Getting a products child category

Question

I am looking for a way to get a products most child like category. For example if I have

    category1 -> category1.1 -> category1.1.1

I then need category1.1.1

Assuming I have a product that belongs to all three categories is there a specific way to call the most deeply rooted category.

I know I can return all categories belonging to a product by doing this:

    echo $_product->getCategoryIds()

But I need a programmatical way to know which is the deepest child.

Answer 1

For anyone needing the same solution I managed it like this:

The products deepest category happens to be related to the product through an attribute set up previously. It was simply a case of calling the attribute then to get the category

    $mainCategory = Mage::getModel('catalog/category')->load($_product->getMainCategory());