Primary Failure of Eruption (PFE) and ankylosis of permanent molars: the surgeon’s experience

Abstract

Eruption abnormalities involving permanent molars are clinically rare and can be particularly challenging to treat. When there is an obstacle in the eruption pathway, these teeth can be successfully set in the arch most of the time, once the obstacle is cleared. On the other hand, teeth afflicted with ankylosis or Primary Failure of Eruption (PFE) cannot be orthodontically displaced.PFE has a genetic origin and leads to open bite that can be severe, in relation to a reduced alveolar height. PFE is often also associated with class III malocclusion and dental agenesis, which makes the treatment plan even more complicated.This article first describes the characteristics of PFE and ankylosis and then presents our own experience, through several clinical cases. One case illustrates and discusses the limits of orthodontics in managing molars showing PFE, despite alveolar corticotomies and bone anchorage devices. Two other clinical cases describe global rehabilitation by osteotomy, bone graft and extensive prosthetic replacement.