Lekholm and Zarb Classification
Pronunciation: LEK-holm and ZARB
A widely referenced system for classifying residual alveolar bone into four quality types (Types I–IV) based on the ratio of cortical to cancellous bone, used to guide implant treatment planning.
Full Definition
Proposed by Lekholm and Zarb in 1985, this classification system describes four bone quality types: Type I (almost entirely homogeneous cortical bone), Type II (thick cortical bone surrounding dense cancellous bone), Type III (thin cortical bone surrounding dense cancellous bone), and Type IV (thin cortical bone surrounding loose cancellous bone). It is one of the most commonly cited bone quality frameworks in implant dentistry literature and surgical protocols. Although partially superseded by the Misch bone density classification in some clinical contexts, it remains widely used in academic and regulatory documents. Editors should present 'Lekholm and Zarb' in full at first mention with 'Types I–IV' using Roman numerals.
Usage
Usage note: Use Roman numerals (I, II, III, IV) for the four bone types, not Arabic numerals. Spell out 'and' rather than using an ampersand in running text; reserve '&' for parenthetical citations per most style guides. Distinguish from the Misch bone density system (D1–D4), which uses a different scale.
In Context
- "The operative site was assessed as Lekholm and Zarb Type III, prompting modification of the drilling protocol." — Surgical report
- "The paper cited 'Lekholm & Zarb' in the text but 'Lekholm and Zarb' in the references; the editor standardized to the journal's ampersand policy." — Reference formatting note