Voorspelbaarheid van impactie van derde molaren

Voor een orthodontische behandeling is het van belang al vroeg inzicht te krijgen in de ontwikkeling van de blijvende dentitie. Deense onderzoekers probeerden met behulp van intraorale röntgenopnamen die over een langere periode werden gemaakt de kans te voorspellen op een al dan niet doorbreken van derde molaren.

Serial standardized intraoral radiographs (Eggen technique) were taken annually of the mandibular third molar region from 132 subjects (71 male and 61 female) from 15 to 20 years of age. Based on the films, 264 lower third molars were classified into an eruption and an impaction group. Root development was recorded according to a quantitative method described by Haavikko (1970), and the eruption status was analyzed using logistic regression.
In total, 155 (59%) of the M3 inf erupted, and 109 (41%) were impacted at age 20. In 44 (33%) patients both M3 inf were impacted, in 21 (16%) patients one tooth was erupted and the contralateral tooth impacted, and in 67 (51%) patients both M3 inf were erupted. The more mature a tooth was at age 15, the higher was the probability of eruption (odds ratio: 3.89, P < .001). The growth rate of the root development stage was statistically significantly associated with the probability of eruption (odds ratio: 10.50, P  =  .041).
Delayed mandibular third molar root development is associated with impaction. Radiographs taken at age 15 may predict the risk of impaction and thereby guide decision making for the orthodontist or the oral and maxillofacial surgeon

Bron
Lauesen SR, Andreasen JO, Gerds TA, Christensen SS, Borum M, Hillerup S. Association between third mandibular molar impaction and degree of root development in adolescents. Angle Orthod 2013; 83: 3-9. doi: 10.2319/102911-667.1. Epub 2012 Jun 14.