Primary failure of eruption (PFE): a systematic review.
BACKGROUND
Primary failure of eruption (PFE) is a rare disease defined as incomplete tooth eruption despite the presence of a clear eruption pathway. Orthodontic extrusion is not feasible in this case because it results in ankylosis of teeth. To the best of our knowledge, besides the study of Ahmad et al. (Eur J Orthod 28:535-540, 2006), no study has systematically analysed the clinical features of and factors associated with PFE. Therefore, the aim of this study was to systematically evaluate the current literature (from 2006 to 2017) for new insights and developments on the aetiology, diagnosis, genetics, and treatment options of PFE.


METHODS
Following the PRISMA guidelines, a systematic search was performed using the PubMed/Medline database for studies reporting on PFE. The following terms were used: "primary failure of tooth eruption", "primary failure of eruption", "tooth eruption failure", and "PFE".


RESULTS
Overall, 17 articles reporting clinical data of 314 patients were identified. In all patients, the molars were affected. In 81 reported cases, both the molars and the premolars were affected by PFE. Further, 38 patients' primary teeth were also affected. In 27 patients, no family members were affected. Additional dental anomalies were observed in 39 patients. A total of 51 different variants of the PTH1R gene associated with PFE were recorded.


CONCLUSIONS
Infraocclusion of the posterior teeth, especially if both sides are affected, is the hallmark of PFE. If a patient is affected by PFE, all teeth distal to the most mesial tooth are also affected by PFE. Primary teeth can also be impacted; however, this may not necessarily occur. If a patient is suspected of having PFE, a genetic test for mutation in the PTH1R gene should be recommended prior to any orthodontic treatment to avoid ankylosis. Treatment options depend on the patient's age and the clinical situation, and they must be evaluated individually.
['Hanisch|Marcel|M|', 'Hanisch|Lale|L|', 'Kleinheinz|Johannes|J|', 'Jung|Susanne|S|']
D000367:Age Factors D001641:Bicuspid D002675:Child, Preschool D005260:Female D005500:Follow-Up Studies D006801:Humans D007223:Infant D008297:Male D008963:Molar D050793:Orthodontic Extrusion D011862:Radiography, Panoramic D012737:Sex Factors D020254:Tooth Ankylosis D014078:Tooth Eruption D014094:Tooth, Deciduous D014097:Tooth, Unerupted
Primary failure of eruption PFE Systematic review Rare diseases Orthodontics PTH1R Eruption disorder