Three-dimensional evaluation of upper anterior alveolar bone dehiscence after incisor retraction and intrusion in adult patients with bimaxillary protrusion malocclusion

Abstract

Abstract:Objective: The purpose of this study was to evaluate three-dimensional (3D) dehiscence of upper anterior alveolar bone during incisor retraction and intrusion in adult patients with maximum anchorage. Methods: Twenty adult patients with bimaxillary dentoalveolar protrusion had the four first premolars extracted. Miniscrews were placed to provide maximum anchorage for upper incisor retraction and intrusion. A computed tomography (CT) scan was performed after placement of the miniscrews and treatment. The 3D reconstructions of pre-and post-CT data were used to assess the dehiscence of upper anterior alveolar bone. Results: The amounts of upper incisor retraction at the edge and apex were (7.64±1.68) and (3.91±2.10) mm, respectively, and (1.34±0.74) mm of upper central incisor intrusion. Upper alveolar bone height losses at labial alveolar ridge crest (LAC) and palatal alveolar ridge crest (PAC) were 0.543 and 2.612 mm, respectively, and the percentages were (6.49±3.54)% and (27.42±9.77)%, respectively. The shape deformations of LAC-labial cortex bending point (LBP) and PAC-palatal cortex bending point (PBP) were (15.37±5.20)° and (6.43±3.27)°, respectively. Conclusions: Thus, for adult patients with bimaxillary protrusion, mechanobiological response of anterior alveolus should be taken into account during incisor retraction and intrusion. Pursuit of maximum anchorage might lead to upper anterior alveolar bone loss.

Likelihood of needing facial bone augmentation in the anterior maxilla of Chinese Asians: A cone beam computed tomography virtual implant study

“…At the lateral incisor sites, the fenestration rate even reached 42.6%. In the present study, the incidence of fenestration is higher than that reported in the edentulous anterior maxilla, and this might be explained by differences in the alveolar bone profile, which exist between Asians and other races . The average RA measured in the anterior maxillary area was 125.76 ± 7.44°, which was bigger than that in Chan's study.…”

“…The initial facial bone profile cannot be ignored, especially for Asians, because of the differences in the alveolar bone profile among different races . The protrusion of the anterior maxilla is commonly observed in Asians, while protrusion of the anterior maxilla is less prevalent in Europeans . Given these characteristics of the facial bone profile in the anterior maxilla, the prevalence of fenestrations and/or dehiscences may be higher if the implants are positioned in a restoration‐driven position.…”

“…2 The protrusion of the anterior maxilla is commonly observed in Asians, while protrusion of the anterior maxilla is less prevalent in Europeans. [15][16][17] Given these characteristics of the facial bone profile in the anterior maxilla, the prevalence of fenestrations and/or dehiscences may be higher if the implants are positioned in a restoration-driven position. However, these conditions can hardly be modified by excessive bone augmentation, so more attention should be paid to anterior ridge protrusion by clinicians and researchers treating Asian patients.…”

Assessment of Corticotomy Facilitated Tooth Movement and Changes in Alveolar Bone Thickness - A C T Scan Study

“…For this reason 3-D evaluation is required which could provide 3 dimensional displacement for dentoalveolar changes [22]. It was found that width of the alveolar bone irt maxillary anteriors had improved to a considerable level in the corticotomy group, which may be attributed to the osteoinductive graft material added during the surgical procedure.…”

Association between mandibular posterior alveolar morphology and growth pattern in a Chinese population with normal occlusion

“…These results could be used in forecasting the morphology of the mandibular posterior tooth-alveolar bone complex in clinical treatment. The inclination of molars, average thickness of the cortical bone, and the height of the mandibular bone can be obtained only by CBCT (Wang et al, 2012) or spiral CT (Guo et al, 2011), while the FHI can be obtained using cephalometric film, which is cheaper and easier to acquire in the clinic. The tooth-alveolar complex morphology of patients may be approximated by doctors by assessing the FHI in cephalometric film.…”