Revised, CT- based Lekholm and Zarb Jawbone Quality Classification
A, Al-Ekrish . 2018
Aims: To propose a revised L&Z classification that takes into account all possible combinations of compact and trabecular bone, and to provide guidelines for increased reproducibility of the classification.
Methods: Three new classes were added to the previous classification. The new classes have been designated as subclasses of bone types 2 and 3, as follows: Type 1: Entirely homogenous compact bone; Type 2a: Thick layer of compact bone surrounds a core of dense trabecular bone; Type 2b: Thick layer of compact bone surrounds a core of medium density trabecular bone; Type 2c: Thick layer of compact bone surrounds a core of low-density trabecular bone; Type 3a: Thin layer of compact bone surrounds a core of dense trabecular bone; Type 3b: Thin layer of compact bone surrounds a core of medium-density trabecular bone; Type 4: Thin layer of compact bone surrounds a core of low-density trabecular bone. Three interpretation guidelines were recommended to increase the reproducibility of the revised classification. Three experienced examiners were trained using the revised classification and provided with computed tomography (CT) sectional images of edentulous jaw bones for classification. Each examiner classified the images twice with at least a one week interval. The intra-observer agreement was measured.
Results: The kappa statistic for the intra-observer agreement of the examiners ranged from 0.835-0.919 (p value < 0.001).
Conclusion: The high reproducibility of the proposed revised CT-based L&Z classification obtained in the current study suggests its efficacy in distinguishing between the various combinations of compact and trabecular bone.
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