Howard Gluckman1, Carla Cruvinel Pontes2, Jonathan Du Toit3. 1. Director, Implant and Aesthetics Academy and the Implant Clinic, Cape Town, South Africa. Electronic address: docg@mweb.co.za. 2. Research Associate, the Implant Clinic, Cape Town, South Africa. 3. Resident, Department of Periodontics and Oral Medicine, School of Dentistry, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa.
Abstract
STATEMENT OF PROBLEM: The biological and esthetic challenge of the post-extraction ridge is relevant to restorative implant dentistry, most significantly in the anterior esthetic zone. Previous authors have discussed facial bone wall dimensions and classified their variations. A reclassification may be pertinent. PURPOSE: The purpose of this observational, clinical study was to introduce a new classification system for anterior maxilla tooth position with guidelines for immediate implant placement. Data for facial and palatal bone wall height and thickness are also presented. MATERIAL AND METHODS: Maxillary anterior teeth (n=591) were analyzed as viewed in the radial plane of cone beam computed tomography (CBCT) scans from 150 patients. Each tooth was classified according to its position and inclination within its alveolus (class I, middle of the alveolus; IA, thick facial bone; IB, thin facial bone; class II, retroclined; IIA, thick crestal bone; IIB, thin crestal bone; class III, proclined; class IV, facially outside bone envelope; class V, both thin facial and palatal bone with apical isthmus). Bone thickness was measured for both facial and palatal walls at the following points: crestal (A), mid-root (B), apex (C), and 4 mm beyond the apex. Bone wall height was also evaluated. RESULTS: A thin facial bone wall predominated (≤1 mm) at the crest (83%) and the mid-root point (92%). Most palatal walls were thin (<1 mm) at the crest (63%) and thick (≥2 mm) at the mid-root point (98%) and apex (99%). Class I tooth position accounted for 6.1%, class II for 76.5%, class III for 9.5%, class IV for 7.3%, and class V for 0.7%. CONCLUSIONS: Maxillary anterior teeth have predominantly thin facial bones, making palatal bone thickness a crucial variable. The new classification system for radial plane tooth position is a pragmatic clinical analysis for immediate implant treatment planning.
STATEMENT OF PROBLEM: The biological and esthetic challenge of the post-extraction ridge is relevant to restorative implant dentistry, most significantly in the anterior esthetic zone. Previous authors have discussed facial bone wall dimensions and classified their variations. A reclassification may be pertinent. PURPOSE: The purpose of this observational, clinical study was to introduce a new classification system for anterior maxilla tooth position with guidelines for immediate implant placement. Data for facial and palatal bone wall height and thickness are also presented. MATERIAL AND METHODS: Maxillary anterior teeth (n=591) were analyzed as viewed in the radial plane of cone beam computed tomography (CBCT) scans from 150 patients. Each tooth was classified according to its position and inclination within its alveolus (class I, middle of the alveolus; IA, thick facial bone; IB, thin facial bone; class II, retroclined; IIA, thick crestal bone; IIB, thin crestal bone; class III, proclined; class IV, facially outside bone envelope; class V, both thin facial and palatal bone with apical isthmus). Bone thickness was measured for both facial and palatal walls at the following points: crestal (A), mid-root (B), apex (C), and 4 mm beyond the apex. Bone wall height was also evaluated. RESULTS: A thin facial bone wall predominated (≤1 mm) at the crest (83%) and the mid-root point (92%). Most palatal walls were thin (<1 mm) at the crest (63%) and thick (≥2 mm) at the mid-root point (98%) and apex (99%). Class I tooth position accounted for 6.1%, class II for 76.5%, class III for 9.5%, class IV for 7.3%, and class V for 0.7%. CONCLUSIONS: Maxillary anterior teeth have predominantly thin facial bones, making palatal bone thickness a crucial variable. The new classification system for radial plane tooth position is a pragmatic clinical analysis for immediate implant treatment planning.
Authors: Diogo M Rodrigues; Rodrigo L Petersen; Caroline Montez; José R de Moraes; Alessandro L Januário; Eliane P Barboza Journal: Clin Oral Investig Date: 2021-09-16 Impact factor: 3.606
Authors: Julio Rojo-Sanchis; David Soto-Peñaloza; David Peñarrocha-Oltra; Miguel Peñarrocha-Diago; José Viña-Almunia Journal: BMC Oral Health Date: 2021-03-22 Impact factor: 2.757