A reduced overbite can often result in no incisal contact at all producing an âAnterior Openbiteâ this may be the result of a soft tissue interface or Skeletal discrepancy. An increased overbite is where the lower incisors bite on the palatal gingivae (gums) or mucosa.
The Region: The Sahel region is an eco-climate zone located on the southern edge of the Sahara desert. The region spans across Nigeria, Sudan, Senegal, Mauritania, Mali, Burkina Faso, Niger, and Chad (Ethiopia and Somalia are sometimes included in the Sahel region). The name, Sahel, comes from the Arabic work for âborderâ or âmarginâ.
The Sahel is also a cultural transition zone separating the Arab and Muslim dominated countries of North Africa from the African and Christian (and/or animist) peoples of sub-Saharan Africa.Note how the presence of Islam tails off dramatically as one leaves the Sahel and enters sub-Saharan Africa.he East African Rift Valley System is an example of a fissure in the Earthâs crust in which the continent is splitting apart, causing an extensive series of valleys, fingerlike freshwater lakes and volcanoes to form. The map below shows how dominant savanna zones are in sub-Saharan Africa, in particular the Sahel.