Dental According to Schour & Massler the crown completion of both permanent maxillary and mandibular first molars is: A 1½ - 2 years B 2½ - 3 years C 3 - 4 years D 4 - 5 years 💡 Explanation According to Schour & Massler the crown completion of both permanent maxillary and mandibular first molars is: ✓ Correct Answer: B. 2½ - 3 years