Mechanism of Human Tooth Eruption: Review Article Including a New Theory for Future Studies on the Eruption Process
Drawing and panoramic radiograph (of a 20-year-old female) showing secondary retention of a permanent first molar in the left side of the maxilla. This first molar erupted normally, but ankylosed in the periodontal membrane after eruption. Therefore, the tooth could not continue the eruption course by “continued eruption” as other teeth do until growth ends after puberty. An arrow indicates that the process often begins interradicularly. The cause of the ankylosis is unknown.