Augmented Corticotomy on the Lingual Side in Mandibular Anterior Region Assisting Orthodontics in Protrusive Malocclusion: A Case Report

Abstract

Adequate alveolar bone volume is a prerequisite condition for successful orthodontic tooth movement and posttreatment stability. Mandibular anterior teeth are more likely to exhibit dehiscence and fenestration in adult patients, which make orthodontic treatment in adults challenging, especially when the amount of retraction of the anterior teeth is large. Herein, we report the treatment of augmented corticotomy only on the lingual side in the mandibular anterior region to increase the volume of soft and hard tissue assisting orthodontics in a Class I bialveolar protrusive malocclusion and propose management strategies of mandibular incisor retractions. A 22-year-old female with a chief complaint of protrusive mouth presented to the Department of Orthodontics for orthodontic treatment, diagnosed with Class I bialveolar protrusive. The orthodontic treatment plan involved the extraction of four premolars and extensive retraction of the anterior teeth using microimplant anchorage. In consideration of the fenestration and dehiscence in the mandibular anterior alveolar bone and the pattern of tooth movement, augmented corticotomy was performed on the lingual side combined with bone grafting. Clinical and radiographic evaluation after treatment revealed significant improvements in the facial profile and in periodontal phenotype. Augmented corticotomy assisting orthodontic treatment could be a promising treatment strategy for adult patients with alveolar protrusion to maintain periodontal health.

Keywords: bone graft; fenestration and dehiscence; lingual corticotomy; mandibular incisor retraction; protrusive malocclusion.

Figure 1

Pretreatment extraoral and intraoral photographs.

Figure 2

Pretreatment radiographs and cephalometric graph. (A) Panoramic radiograph; (B) Lateral cephalogram; (C) cephalometric tracings; (D) CBCT graphs.

Figure 3

Clinical images of detailed treatment progress. (A) Retraction of the mandibular incisors immediately after the extraction of the premolars; (B) retraction of the maxillary incisors immediately after the extraction of the premolars; (C) before surgery; (D) space closure continued after surgery.

Figure 4

Clinical images of augmented corticotomy of the lingual side. (A) Initial intraoral image; (B) papillary preservation incisions; (C) piezoelectric corticotomy; (D) placement of bone grafts; (E) placement of bioabsorbable collagen membrane; (F) sutures.

Figure 5

Pretreatment and posttreatment mandibular anterior teeth on lingual side. (A) Initial visit; (B) extraction of mandibular first premolars; (C) after augmented corticotomy; (D) orthodontic treatment completed.

Figure 6

Posttreatment extraoral and intraoral photographs and superimposition photographs.

Figure 7

Posttreatment cephalometric graphs and CBCT graphs. (A) Lateral cephalogram; (B) cephalometric tracings; (C) cephalometric superimposition; (D) CBCT graphs.

Figure 8

Tooth-movement patterns of retraction.

Figure 9

Decision tree for the management of mandibular incisor-retraction cases. * Extensive retraction may move teeth out of the bony housing, resulting in lingual bony defects, in which augmented corticotomy may be required despite no dehiscence and fenestration on the lingual side.