Pediatric Dentistry · patient case question
Which cells are responsible for internal root resorption?
Patient case: A young patient in the mixed dentition
demo: 5-year-old female
chief: Routine examination. Her mother is worried that her front teeth are coming through early.
history: Healthy. The family moved recently from a community with fluoridated water to one with none. Her mother reports the older sibling had a similar early pattern.
meds: None.
findings: Both mandibular permanent central incisors are fully erupted. A 3 mm midline diastema is present in the maxilla between the primary central incisors. A periapical film of a maxillary lateral incisor shows an invagination of enamel and dentin extending into the pulp chamber.
Show answer and explanation
Correct answer: A. Odontoclasts derived from the inflamed pulp
- A. Correct. Internal resorption begins within the canal. Chronic pulpal inflammation, usually following trauma or deep caries, recruits monocyte-derived odontoclasts to the canal wall, which resorb dentin outward. The classic sign is a smooth, symmetrical, ballooned widening of the canal that moves with the tooth on a shifted radiograph, unlike an external lesion.
- B. The resorbing cell is the same odontoclast whatever surface it attacks; the distinction that matters is whether it approaches from the pulp or from the periodontium.
- C. Cells from the periodontal ligament produce external resorption, which attacks from outside the root inward.
- D. Ameloblasts form enamel and are lost once the crown is complete.
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