Tehran University of Medical Sciences Frontiers in Dentistry 2676-296X 21 0 2024 03 13 1 4 Mehrsa Paryab Department of Paediatric Dentistry, Tehran University of Medical Sciences, Tehran, Iran 2022 08 28 2023 10 02 Hypodontia is the most common dental developmental disorder. Several underlying mechanisms have been proposed to be involved in its pathogenesis. Occurrence of hypodontia as an isolated trait due to genetic mutations has also been reported. Hypodontia most commonly involves the mandibular premolars, maxillary lateral incisors and second premolars. However, hypodontia of permanent second molars is a rare occurrence. To the best of the author’s knowledge, only two studies on orthodontic patients have reported hypodontia of permanent second molars in Iran. This case report describes non-syndromic bilateral missing of permanent mandibular second molars in a 10-year-old child. Clinical examination revealed no systemic underlying condition, and no clinical evidence of any syndrome, or hereditary or familial pattern. Due to the potential impact of hypodontia on the function of dentition, prompt management of hypodontia is imperative. Furthermore, due to the possible mutations associated with hypodontia, additional screening for cancer susceptibility may be recommended. https://fid.tums.ac.ir/index.php/fid/article/view/4579 https://fid.tums.ac.ir/index.php/fid/article/download/4579/2038