This clinical report describes the diagnosis and the management of isolated-type recession defects of complex etiology in 2 healthy postorthodontic patients. The lesions were confined to 1 mandibular incisor and were associated with an abnormal buccolingual inclination of the affected tooth despite a lingual retainer made with a round stainless steel twisted wire. After careful questioning, it was determined that the recession defects were indirect effects of habitual onychophagia. The concomitant fingernail-biting habit and the lingual bonded retainer led to the indirect development of bone dehiscence and, consequently, gingival recession.

 Gingival recession is an apical shift of the gingival margin with respect to the cementoenamel junction, and bone dehiscence is the essential anatomic prerequisite for its development.1, 2 The orthodontic movement of teeth beyond the limits of the labial or lingual alveolar plate can lead to dehiscence formation,3, 4, 5, 6, 7 thus predisposing the patient to recession when there is inadequate plaque control or traumatic mechanical factors.8, 9, 10, 11, 12, 13 For this reason, clinicians generally correlate gingival recession with inadequate treatment planning or insufficient biomechanical tooth control during the orthodontic therapy.14

 This clinical report describes the diagnosis and management of isolated-type recession defects in 2 healthy postorthodontic patients. The lesions affected a mandibular incisor and were associated with an abnormal buccolingual inclination of the affected tooth despite a 6-unit lingual retainer bonded from canine to canine. Toothbrushing trauma and inadequate plaque control were excluded as possible developing factors, as well as orthodontic proclination of the mandibular incisors. Only slight mandibular crowding was present at the initial examination, and Class II elastics were not used during the therapy. The evaluation of these aspects and the distinctive site-specificity of the lesion suggested that a mechanical factor had acted on 1 mandibular incisor. After careful and prolonged questioning, it was discovered that both patients had a habit of pressing their fingernails tightly against the biting edge of the affected tooth, thereby exerting continuous pressure on it. They had been doing this unconsciously for a long time with no previously noticeable sequelae. After the lingual retainer was bonded, any lingual crown movement was prevented thus, the applied force resulted in buccal root displacement.

 The aim of this article was to describe the diagnosis and treatment of 2 postorthodontic isolated gingival defects, in which the concomitant presence of onychophagia and a 6-unit lingual bonded retainer led to the indirect development of bone dehiscence and, consequently, gingival recession.

 Source: Journal of Orthodontics and Dentofacial Orthopedics

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