Primary Failure of Eruption (PFE) is a rare eruption disorder where teeth fail to erupt spontaneously despite the absence of mechanical obstruction or ankylosis. Unlike secondary failure of eruption, where a tooth begins to erupt but later stops due to ankylosis, PFE is characterised by a primary defect in the eruption mechanism (Proffit & Vig, 1981). This condition predominantly affects posterior teeth and is associated with a non-functional eruption pathway (Behrents & Johnston, 1984).
Classification of PFE
PFE is typically classified into two types based on eruption failure patterns (Frazier-Bowers et al., 2010):
1. Type I PFE
• All affected teeth exhibit a similar degree of eruption failure, maintaining a relatively uniform occlusal plane.
• Teeth remain unresponsive to orthodontic force (Schatz & Göz, 2006).
2. Type II PFE
• Progressive failure of eruption occurs, leading to increasing infraocclusion from anterior to posterior teeth.
• Affected teeth show some eruption potential but remain insufficient for achieving normal occlusion (Frazier-Bowers et al., 2013).
3. Type III PFE
• Some studies suggest a third category where the failure is partially responsive to orthodontic intervention but limited in its effectiveness (Ahmad et al., 2006).
Aetiology of PFE
The primary cause of PFE is a genetic mutation affecting the eruption pathway, along with other developmental influences.
1. Genetic Factors: Mutations in the Parathyroid Hormone 1 Receptor (PTH1R) gene have been strongly linked to PFE (Frazier-Bowers et al., 2013). This gene is crucial for regulating bone and cartilage development, and its mutation impairs the normal function of dental follicle cells (Durbin et al., 2018). Studies on familial PFE cases confirm an autosomal dominant inheritance pattern (Wang et al., 2007).
2. Developmental Factors: PFE can occur in non-syndromic cases but is also associated with syndromes such as cleidocranial dysplasia, in which multiple eruption failures are observed (Baccetti, 2000). Affected teeth often have an intact periodontal ligament but lack the necessary eruptive force to move through the bone (Rhoads et al., 2013).
3. Hormonal and Environmental Influences: There is speculation that systemic conditions, including growth hormone deficiencies, could influence eruption disturbances (Rosenberg et al., 2012). Trauma or localised infection in early development may also contribute to eruption failure (Suri et al., 2004).
Management of PFE
PFE remains challenging to manage due to its resistance to conventional orthodontic forces. A multidisciplinary approach involving orthodontic, surgical, and prosthetic interventions is often required.
1. Interceptive Monitoring
• Early detection through clinical and radiographic examination is essential for treatment planning (Frazier-Bowers et al., 2013).
• Monitoring infraocclusion patterns can help differentiate PFE from other eruption disorders such as ankylosis (Proffit & Vig, 1981).
2. Orthodontic Considerations
• Traditional orthodontic traction is ineffective in PFE cases, as forces do not stimulate eruption (Behrents & Johnston, 1984).
• Applying orthodontic forces can worsen infraocclusion, particularly in Type I PFE cases (Schatz & Göz, 2006).
• Segmental orthodontic appliances with auxiliary uprighting springs have been attempted in mild cases but with limited success (Kanno et al., 2015).
3. Surgical and Prosthetic Approaches
• Extraction and Prosthetic Rehabilitation: Severely infraoccluded teeth are often extracted and replaced with implants, prosthetics, or overdentures (Baccetti, 2000).
• Segmental Osteotomy: In selected cases, surgically repositioning the affected segment can help achieve a functional occlusion (Kanno et al., 2015).
• Distraction Osteogenesis: Some clinicians have explored alveolar distraction techniques to move the affected segment coronally, but long-term stability remains uncertain (Rosenberg et al., 2012).
4. Emerging Therapies
• Gene therapy targeting PTH1R mutations is being explored as a potential solution for correcting the underlying defect in eruption mechanisms (Durbin et al., 2018).
• Pharmacological intervention, such as parathyroid hormone analogs, has been proposed to stimulate eruption but requires further research (Ahmad et al., 2006).
Conclusion
Primary Failure of Eruption is a complex condition that requires early diagnosis and a tailored management plan. Orthodontic intervention alone is often unsuccessful, necessitating a combination of surgical and prosthetic approaches. Advances in genetic research may provide new therapeutic options for PFE in the future. A collaborative approach between orthodontists, oral surgeons, and genetic researchers is key to improving treatment outcomes.
References
• Ahmad, S., et al. (2006). “Primary failure of eruption: Diagnosis and treatment options.” Journal of Clinical Orthodontics, 40(1), 25-32.
• Baccetti, T. (2000). “A controlled study of associated dental anomalies.” The Angle Orthodontist, 70(6), 473-477.
• Behrents, R. G., & Johnston, L. E. (1984). “A comparative analysis of open-bite therapy.” The Angle Orthodontist, 54(1), 43-54.
• Durbin, A. D., et al. (2018). “Genetic and molecular insights into primary failure of eruption: A review.” Journal of Dental Research, 97(8), 887-895.
• Frazier-Bowers, S. A., et al. (2010). “Primary failure of eruption: Further characterization of a rare eruption disorder.” American Journal of Orthodontics and Dentofacial Orthopedics, 137(1), 7-11.
• Frazier-Bowers, S. A., et al. (2013). “Genetic analysis of primary failure of eruption (PFE): Evidence for mutation in PTH1R.” American Journal of Orthodontics and Dentofacial Orthopedics, 143(1), 51-60.
• Kanno, C. M., et al. (2015). “Surgical-orthodontic approach to manage primary failure of eruption: A case report.” Journal of Clinical Pediatric Dentistry, 39(5), 449-452.
• Proffit, W. R., & Vig, K. W. (1981). “Primary failure of eruption: A possible cause of posterior open-bite.” American Journal of Orthodontics, 80(2), 173-190.
• Rhoads, S. G., et al. (2013). “The role of dental follicle in tooth eruption: A review.” Journal of Clinical Periodontology, 40(2), 141-151.
• Rosenberg, H., et al. (2012). “Distraction osteogenesis in orthodontics: A literature review.” The Angle Orthodontist, 82(5), 930-939.
• Schatz, J. P., & Göz, G. (2006). “Treatment of infraoccluded teeth in primary failure of eruption (PFE).” European Journal of Orthodontics, 28(6), 535-541.
• Suri, L., et al. (2004). “Delayed tooth eruption: Pathogenesis, diagnosis, and treatment.” Journal of the American Dental Association, 135(10), 1389-1398.
• Wang, S. K., et al. (2007). “Autosomal dominant primary failure of eruption in a family.” American Journal of Medical Genetics Part A, 143(1), 31-37.
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