DOI: 10.36347/sjds.2018.v05i05.009

Pages: 298-305

The formation of mandibular third molar and its position depends upon the development. Reduced eruption space between lower second molar and ramus is considered as an important etiological factor for mandibular third molar impaction. Prediction of mandibular third molar impaction by measuring the retromolar distance and its association with developmental stages of the mandibular third molars.The study included pretreatment orthopantomograms and lateral cephalographs of 50 orthodontic patients (33 females and 17 males) of age group between 9 and 18 years old. The mandibular third molar calcification stages were assessed by Nolla’s method. The retromolar space was measured from the distal surface of the first molar to the most concave point on the anterior border of the ramus to the mandible. Statistical analyses included t-tests and analyses of variance for group differences and the Pearson product. High correlation between calcification stage of third molar and retromolar space (r=0.726) was observed. The calcification stage increased with age. The retromolar distance increased with age and was greatest between 10 and 15 years. An increase of 5 mm of retromolar space corresponds to a 2.4 stage in tooth maturation. The developmental formation of mandibular third molar is associated with the available retromolar space. An increase in retromolar space a higher chance of eruption, an advanced stage of development of the mandibular third molar might be an additional predictor of future eruption.