A 7-year-old child shows premature loss of primary mandibular canines. He has no caries in his remaining teeth. This situation strongly suggests:

Early loss of primary canines is more common due to erupting permanent lateral incisors resorbing the roots of primary canines rather than caries. Early loss of primary canines leads to arch length deficiency by closure of space by the mesial movement of the posterior teeth or by lingual displacement of the anterior incisors.