An implant was placed at tooth #8 when the patient was 15 years old. At age 22 tooth #9 appears 2 mm longer than the implant crown. What happened?

Correct answer: B. Continued craniofacial growth and eruption of the adjacent natural tooth, leaving the ankylosed implant infraoccluded

• A. Two millimetres of ceramic wear in this pattern is not plausible and would not change the gingival margin level.
• B. CORRECT. An osseointegrated implant behaves like an ANKYLOSED tooth — it is rigidly fixed to bone and cannot move with the alveolus. Adjacent NATURAL teeth continue to erupt throughout life along with continuing vertical alveolar growth, and this continues well beyond the cessation of skeletal growth. The result is a progressively INFRAOCCLUDED implant crown with an increasingly visible discrepancy in incisal edge position and gingival margin height. This is precisely why implants are contraindicated in growing patients.
• C. Supra-eruption from lack of contact would require an unopposed tooth; #9 is in normal occlusion.
• D. Implants do not extrude — they have no periodontal ligament and no eruptive mechanism.

Note: Wait for skeletal maturity — confirmed with serial cephalometric radiographs or hand-wrist films, generally around 17–18 in girls and 20–21 in boys. Even then, some continued change is expected in the esthetic zone.