Periodontics · patient case question
How is this periodontal phenotype described, and what is its clinical significance?
Patient case: A thin gingiva and a fractured incisal edge
Patient: Female, 29 years old
Chief Complaint: “I chipped the corner off my front tooth.”
Background: Healthy, non-smoker, excellent plaque control. No history of periodontal disease.
Vital Signs: BP 112/70 mmHg · HR 68 bpm
Findings: Tooth #8 has an uncomplicated fracture of the mesio-incisal angle involving enamel and dentine with no pulp exposure; a Class IV composite is planned. The gingiva is delicate and translucent with a highly scalloped margin, a narrow band of keratinised tissue, and root outlines visible through the soft tissue. Crowns are narrow and triangular.
Show answer and explanation
Correct answer: B. Thin scalloped — higher risk of recession after surgery, restoration or implant placement
- A. Thick flat tissue does not preferentially recede. Dense, fibrotic, abundant keratinised tissue over thicker bone is the resilient pattern.
- B. CORRECT. The THIN SCALLOPED phenotype is characterised by delicate translucent tissue, a narrow band of keratinised gingiva, a highly scalloped gingival margin, slender triangular crowns with contact points near the incisal edge, and thin underlying bone prone to dehiscence and fenestration. Its clinical significance is that it responds to inflammation, surgery, restorative margins and implant placement by RECEDING rather than pocketing. It also SHOWS THROUGH — a metal crown margin or a grey implant abutment is visible beneath it — and interdental papillae are considerably harder to preserve or regenerate.
- C. This reverses the association. It is the THICK phenotype that tends to respond to inflammation by pocketing, while the thin phenotype recedes.
- D. Thick flat is the opposite phenotype, and it is the one that RESISTS recession. Pairing it with a high recession risk inverts both halves.
Note: Current terminology prefers PHENOTYPE over biotype, because the tissue characteristics can be modified — by connective tissue grafting, for instance — whereas ‘biotype’ implied something genetically fixed. Practical consequences for this patient: keep restorative margins SUPRAGINGIVAL wherever possible, handle the tissue minimally, and if an implant is ever contemplated in this aesthetic zone, plan soft tissue augmentation from the outset. Note too that triangular crowns in a thin phenotype are the anatomy that produces black triangles.