How is her CHRONOLOGICAL age compared to her DENTAL age?

Correct answer: D. Behind — her dental development is advanced relative to her chronological age

• A. Dental age is routinely assessed from a panoramic radiograph using eruption sequence and stages of root formation (for example Demirjian's method).
• B. If development were on schedule, a 5-year-old would still be in the full primary dentition with no permanent teeth erupted.
• C. 'Ahead' would mean she is older than her dental development suggests — the opposite of what is described.
• D. Correct — and the direction of the comparison is the whole trick. First permanent molars and mandibular central incisors normally erupt at about SIX years of age. This child is FIVE and already has all four first molars plus lower permanent incisors erupted, so her DENTAL AGE is ADVANCED — which means her CHRONOLOGICAL age is BEHIND her dental age.

Note: ⚠️ READ THE DIRECTION OF THE QUESTION. It asks about CHRONOLOGICAL age relative to DENTAL age, not the reverse. Advanced teeth means the calendar age lags behind. Reference eruption ages: first permanent molars and mandibular centrals about 6 years; maxillary centrals 7-8; the '6-year molar' is usually the first permanent tooth to erupt.