Pediatric Dentistry · patient case question
Which appliance is indicated for the space left by tooth T?
Patient case: Premature loss of primary molars in the mixed dentition
Patient: Female, 6 years old
Chief Complaint: Referred after two primary molars were extracted because of gross caries.
Background: Tooth T (the mandibular right second primary molar) and tooth L (the mandibular left first primary molar) have both been lost prematurely.
Current Findings: The permanent mandibular first molars have not yet erupted. The permanent lateral incisors are unerupted. No crowding is evident in the anterior segment. She is otherwise healthy.
Show answer and explanation
Correct answer: C. A distal shoe
- A. The Nance holding arch is maxillary and bilateral, and it also depends on erupted permanent molars for anchorage.
- B. Doing nothing allows the permanent first molar to erupt mesially, shortening arch length and causing impaction of the second premolar.
- C. CORRECT. Tooth T is the SECOND primary molar, and the permanent first molar has not yet erupted. Nothing distal remains to band, and the erupting first molar will drift mesially into the space unless it is guided. The distal shoe carries an intra-alveolar extension into the tissue that contacts the mesial surface of the unerupted permanent first molar and directs its eruption. It is fixed and unilateral.
- D. A band and loop requires an abutment DISTAL to the space. With the second primary molar gone and the first permanent molar unerupted, there is no such abutment.
Note: The distal shoe demands a healthy periodontium and is contraindicated where infection risk is high — the intra-alveolar blade sits in the tissue. It is replaced with a band and loop once the permanent first molar erupts.
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