Background: Most of the evidence on periodontitis in young individuals originates in case series or case‐control studies of poor quality. We investigated the intraoral distribution of clinical attachment level (CAL) and probing depth (PD) and the associations between the oral hygiene parameters and the signs of periodontitis (CAL and PD) in adolescents.Methods: This study consisted of 87 cases presenting with CAL ≥3 mm in at least two of the 16 teeth recorded and 73 non‐cases who did not fulfill this inclusion criterion, nested in a fully enumerated adolescent population, who were screened for signs of periodontitis. The 160 subjects were reexamined by a single trained and calibrated periodontist. The intraoral patterns of periodontal destruction were described graphically.Results: Cases had more supragingival plaque, more supragingival calculus, and more bleeding on probing than non‐cases. The intraoral patterns of periodontal destruction were similar in cases and non‐cases. The site‐specific associations between the putative determinants supragingival plaque, supragingival calculus, and bleeding on probing and the signs of periodontal destruction were highly positive.Conclusion: The results of this study lend little support to the notion that a particular intraoral pattern of breakdown is specific to young cases of severe periodontitis, nor do the results support the view that destruction is incommensurate with oral hygiene parameters.