Kiyong An1, Insan Jang1, Dong-Soon Choi1, Paul-Georg Jost-Brinkmann2, Bong-Kuen Cha3. 1. Department of Orthodontics, College of Dentistry, Gangneung-Wonju National University, 120, Gangneung Daehangno, 210-702, Gangneung, Korea. 2. Department of Orthodontics, Dentofacial Orthopedics and Pedodontics, Center for Dental and Craniofacial Sciences, Charité - Universitätsmedizin Berlin, Berlin, Germany. 3. Department of Orthodontics, College of Dentistry, Gangneung-Wonju National University, 120, Gangneung Daehangno, 210-702, Gangneung, Korea. korth@gwnu.ac.kr.
Abstract
PURPOSE: The purpose of this retrospective study was to assess the stability of buccal and lingual alveolar bone surfaces for superimposing three-dimensional (3D) digital models of dental casts. MATERIALS AND METHODS: The pre- and posttreatment dental casts and lateral cephalometric radiographs were obtained from 10 adult patients who had undergone orthodontic treatment entailing the extraction of four premolars. Five of them had bilateral mandibular tori and the other 5 patients had no torus. Dental casts were scanned with a three-dimensional (3D) surface scanning system and 3D digital models were reconstructed using 3D reverse modeling software. The pre- and posttreatment digital models were superimposed on the following reference areas by the best-fit method: Area 1, bilateral lingual surfaces of the alveolar process of the posterior teeth; Area 2, the lingual alveolar surface of the anterior and posterior teeth; Area 3, bilateral surfaces of the posterior teeth's buccal and lingual alveolar surfaces; Area 4, bilateral mandibular tori. The horizontal and vertical movements of the mandibular central incisors and first molars were measured on cephalometric radiographs and on the 3D digital models. RESULTS: In the 5 patients without a mandibular torus, the median differences between cephalograms and 3D digital models ranged from 0.8-1.9 mm and the maximum differences from 1.5-10.0 mm. The median and maximum differences between cephalograms and 3D digital models superimposed on Area 2 were greater than those superimposed on Areas 1 and 3. In the patients with mandibular tori, the median differences between cephalograms and 3D digital models were under 1.0 mm, the maximum difference being 0.7 mm. CONCLUSION: The buccal and lingual alveolar surface near the dentition seems to be inappropriate as a reference area for superimposing 3D mandibular digital models of patients without a mandibular torus. Mandibular tori in adult patients are stable structures which can be used as reference areas for the superimposition of 3D mandibular digital models.
PURPOSE: The purpose of this retrospective study was to assess the stability of buccal and lingual alveolar bone surfaces for superimposing three-dimensional (3D) digital models of dental casts. MATERIALS AND METHODS: The pre- and posttreatment dental casts and lateral cephalometric radiographs were obtained from 10 adult patients who had undergone orthodontic treatment entailing the extraction of four premolars. Five of them had bilateral mandibular tori and the other 5 patients had no torus. Dental casts were scanned with a three-dimensional (3D) surface scanning system and 3D digital models were reconstructed using 3D reverse modeling software. The pre- and posttreatment digital models were superimposed on the following reference areas by the best-fit method: Area 1, bilateral lingual surfaces of the alveolar process of the posterior teeth; Area 2, the lingual alveolar surface of the anterior and posterior teeth; Area 3, bilateral surfaces of the posterior teeth's buccal and lingual alveolar surfaces; Area 4, bilateral mandibular tori. The horizontal and vertical movements of the mandibular central incisors and first molars were measured on cephalometric radiographs and on the 3D digital models. RESULTS: In the 5 patients without a mandibular torus, the median differences between cephalograms and 3D digital models ranged from 0.8-1.9 mm and the maximum differences from 1.5-10.0 mm. The median and maximum differences between cephalograms and 3D digital models superimposed on Area 2 were greater than those superimposed on Areas 1 and 3. In the patients with mandibular tori, the median differences between cephalograms and 3D digital models were under 1.0 mm, the maximum difference being 0.7 mm. CONCLUSION: The buccal and lingual alveolar surface near the dentition seems to be inappropriate as a reference area for superimposing 3D mandibular digital models of patients without a mandibular torus. Mandibular tori in adult patients are stable structures which can be used as reference areas for the superimposition of 3D mandibular digital models.
Entities:
Keywords:
Mandible; Mandibular torus; Superimposition; Three-dimensional digital models; Tooth movement
Authors: Jennifer L Ashmore; Brenda F Kurland; Gregory J King; Timothy T Wheeler; Joseph Ghafari; Douglas S Ramsay Journal: Am J Orthod Dentofacial Orthop Date: 2002-01 Impact factor: 2.650