This can happen due to many reasons which may include obstruction from primary teeth, bone surrounding the unerupted tooth or other mechanical factors.

[1] The term primary failure of eruption was named by William Proffit and Katherine Vig in 1981.

This often results in posterior open bite in patients mouth who have primary failure of eruption.

Type I involves failure of eruption of teeth distal to the most mesial affected tooth to be all same.

Type II involves a greater eruption pattern, not complete, among the teeth distal to the most mesial affected tooth.

This type of failure of eruption takes place when the affected tooth is ankylosed to the bone around it.

[6][7] On a percussion test, a tooth with mechanical failure of eruption will have a dull metallic sound.