Cleft lip and cleft palate is an "umbrella term" for a collection of orofacial clefts. Four branchial clefts (also called "grooves") form during the development of a human embryo. Cholesterol clefts or asteroid bodies are present within or outside granulomas. Humans sought shelter in clefts and caves among the rocks. Such clefts are caused by shrinkage of mucin during tissue fixation and staining. The most common cranial anomaly seen in combination with facial clefts is encephalocele. The Migunburri buried their dead in caves and rock clefts. The nose anomalies found in facial clefts vary. These clefts can occur bilaterally or unilaterally. Cholesterol clefts, fibrin, and mucin may also be present in areas of necrobiosis. Sphincter pharyngoplasty is mostly used for horizontal clefts of the soft palate. Clinical diagnosis based on orofacial clefts and lip pits typically occurs shortly after birth. Horses with deep clefts, or narrow or contracted heels are more at-risk to develop thrush. In fish the pouches line up with the clefts, and these thin segments become gills. It has been noted that the prevalence of orofacial clefts varies by race.