January 1, 2011
by David R. Farkouh, BSc, DMD, MSc, FRCD(C)
One of the most challenging scenarios for dentists treating school-aged children is how to effectively treat hypoplastic first permanent molars. Hypoplastic and hypomineralized first permanent molars are a frequent finding in children. Studies have reported that approximately one in five 7-13 year olds have at least one hypoplastic first permanent molar.1,2 The exact causes of these enamel defects are not always obvious from a thorough clinical examination or medical/dental history. A number of local, systemic and genetic conditions have been associated with enamel hypoplasia of the first permanent molars, including trauma to the adjacent primary tooth, the ingestion of high levels of fluoride and amelogensis imperfecta.3 The first permanent molars calcify from around birth to 2.5 years of age and therefore any interruption to the tooth during this time frame can potentially result in enamel hypoplasia.
Size, shape and location of enamel defects can vary greatly which in many cases leaves the tooth impossible to restore with conventional cavity preparations.3 Many dentists find themselves spinning their wheels when conventional direct restorations such as composite resins and amalgam fail on hypoplastic permanent molars. The ideal restorative treatment modality for these teeth should aim at reliably restoring lost and weakened tooth structure, alleviating pain or sensitivity, and maintaining occlusion.
Full-coverage restorations are the treatment of choice for moderate to severely hypoplastic permanent molars with the stainless steel crown being the recommend treatment for children.3 Stainless steel crowns are simple restorations to place, and if properly adapted and cemented to the prepared tooth they can be reliable restorations for many years. Although in many cases stainless steel crowns can last well into adult years the ideal treatment is to replace them with a cast metal or PFM crown when the patient stops growing.3
If single or multiple teeth are extensively involved, or are deemed unrestorable the timely extraction of hypoplastic first molars may be considered. If extraction is to be considered, the optimal age for doing so is between 8.5 and 10.5 years, which coincides with the calcification of the bifurcation of the second molar.3 This will allow for the second molar to drift into the space of the lost first molar. Extraction of these teeth should be done in consultation with an orthodontist or pediatric dentist.
In this issue of Oral Health we will explore a potpourri of some common and not so common dental findings in our pediatric patients. Its intention is to help us as clinicians better understand and treat our young patients. Enjoy! OH
1. Jalevik, B. Enamel hypomineralizations in permanent first molars. Clinical histomorphological and biochemical study. Swed. Dent. J. Suppl. 149: 1-86. 2001.
2. Leppaniemi, A., Lukinmaa, PL, Alaluusua, S. Non-fluoride hypomineralizations in the permanent first molars and their impact on the treatment need. Caries Res. 35(1): 36-40.2001.
3. Mahoney, EK. The treatment of localized hypoplastic and hypomineralized defects in first permanent molars. N Z Dent. J. 97(429): 101-105. 2001.