A new classification of the sagittal root positioning of the mandibular anterior teeth in relation to their anterior buccal bone using cone-beam computed tomography (CBCT)

Omid Moghaddas,Irana Behravan

doi:10.34172/japid.2020.014

Abstract

Background This study aimed to develop a classification for the sagittal root positioning (SRP) of mandibular anterior teeth in terms of their anterior buccal bone for use before placing immediate implants. Methods A retrospective review of CBCT images was conducted on 150 patients (75 males and 75 females; mean age: 47.5 years) who met the inclusion criteria. The root position of the tooth samples was classified as buccal, middle, or lingual types according to their respective sagittal position and subtypes a, b, c, or d, according to the morphology of their osseous housing. Results The frequencies of the root positions of each classified group of the sample teeth were as follows: 14% buccal type, 77% middle type, and 8% lingual type; 18.0% subtype a, 4.33% subtype b, 75.55% subtype c, and 2.11% subtype d. As a complementary procedure for data collection, the sagittal position of the apex was classified into Class I (buccally angulated apex: 4.6%), Class II (apex with no angulation: 78.2%), Class III (lingually angulated apex: 0.7%) and Class IV (exposed root: 16.3%). In addition, the results of the examination of the buccal undercut showed that in 1.6%, 32.0%, and 66.3% of the sample teeth, the undercut was located coronally, medially, and apically, respectively. Conclusion Considering these results, the newly proposed SRP classification system can be used to study the mandibular anterior buccal bone morphology as a diagnostic tool for immediate implant treatment.

Highlights

Due to the ever-increasing use of dental implants, the importance of a sagittal root position (SRP) for the most suitable treatment planning has increased in the anterior esthetic zone
To the best of our knowledge, this is the first report on the analysis of the SRP of mandibular anterior teeth relative to the buccal bone to introduce a new classification system for the anterior region of the maxilla and mandible
The alveolar buccal bone in the mandible’s anterior region is relatively thin and undergoes rapid resorption during the healing procedure compared to the lingual plate

Summary

Introduction

Due to the ever-increasing use of dental implants, the importance of a sagittal root position (SRP) for the most suitable treatment planning has increased in the anterior esthetic zone. A classification system for sagittal positioning of the root apex was suggested by Kan et al[4] after studying the SRP of maxillary anterior teeth in their osseous housing. A new classification system was introduced by Xu et al[5] to determine changes in the thickness of the buccal bone of maxillary anterior teeth in terms of the SRP of maxillary central incisors. To the best of our knowledge, this is the first report on the analysis of the SRP of mandibular anterior teeth relative to the buccal bone to introduce a new classification system for the anterior region of the maxilla and mandible

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Discussion

Conclusion