Collagen Fibre Architecture in the Periodontal Ligament

According to a recent review published by the Medical Research Council (1977), periodontal disease is the major cause of tooth loss in adult life.Despite the enormous incidence of periodontal disease, many aspects concerning the basic structure and properties of the attachment tissues of the teeth remain unclear.The question of the nature of the arrangement of the collagen fibres in the periodontal ligament has vexed dental histologists for many years.Careful descriptions of the periodontal ligament were published by Black (1887, 1899), who considered that the periodontal collagen was organized into principal fibre bundles which passed directly from tooth to bone and which supported the tooth rather in the fashion of a sling.Sicher (1923Sicher ( , 1942) ) proposed that the principal fibre bundles did not pass directly from tooth to bone but that instead they formed a spliced arrangement in the middle of the ligament, most clearly defined in continuously erupting teeth.Many authors have questioned the existence of the intermediate plexus (see Zwarych & Quigley 1965) and Ciancio et al. 1967 suggested that it was a histological artefact arising as a result of the section plane lying oblique to the principal fibre bundle direction.Recently, a technique which allows satisfactory examination of the periodontal ligament in the scanning electron microscope (SEM) has been developed (Sloan et al. 1976) and has been used to examine the fibrous architecture of the periodontal ligament in some teeth of continuous growth (Sloan 1978).It was considered that this method might be employed to examine the arrangement of the periodontal collagen in some teeth of limited growth, where the ligament resembles that of man histologically.