Use of Three-Dimensional Computed Tomography to Classify Filling of Alveolar Bone Grafting

Antonio Jorge V Forte,Renato Da Silva Freitas,Nivaldo Alonso

doi:10.1155/2012/259419

Abstract

Several authors have proposed classifications to analyze the quality over time of secondary alveolar bone grafting. However, little discussion has been held to quantitatively measure the secondary bone grafting for correction of nasal deformity associated to cleft palate and lip. Twenty patients with unilateral alveolar cleft, who underwent secondary alveolar bone grafting, were studied with 3D computer tomography. The height between the inferior portion of the pyriform aperture and the incisal border of the unaffected side (height A) and the affected side (height B) was measured using a software Mirror. A percentage was then obtained dividing the height B by the height A and classified into grades I, II, and III if the value was greater than 67%, between 34% and 66%, or less than 33%. Age, time of followup, initial operation, and age of canine eruption were also recorded. All patients presented appropriate occlusion and function. Mean time of followup was 7 years, and mean initial age for operation was 10 years old. 16 patients were rated as grade I and 4 patients as grade II. No cases had grade III. We present a new grading system that can be used to assess the success of secondary bone grafting in patients who underwent alveolar cleft repair.

Highlights

After initial cleft lip and palate repair, the residual bony defect is addressed with secondary bone grafting
Our goal is to propose a new grading system that can be used to assess the success of secondary bone grafting, at the level of the pyriform aperture, in patients who underwent alveolar cleft repair
The development of three-dimensional computed tomography enabled a better appreciation of volume that conventional two-dimensional plain radiographies are unable to provide

Summary

Introduction

After initial cleft lip and palate repair, the residual bony defect is addressed with secondary bone grafting. This approach carries the following advantages: (1) maxillary stabilization; (2) effective closure of oronasal fistulae; (3) better support for the defective alar base, reducing nasal asymmetry and impairment of facial contour; (4) faster malocclusion correction with orthodontic treatment [1, 2]. Kindelan et al proposed the use of a 4-point scale that measured the degree of bony filling in the cleft area when compared to its initial bone graft site, which was radiographed after orthodontic treatment and prior to surgery. Hynes and Earley proposed, in 2003, a modification for the Oslo grading system Their mean followup between grafting and radiographic assessment was 4.5 years. The occlusal level, the basal level, and the total height of the newly acquired bone in the alveolar cleft were graded using the Oslo system, and the bone graft height was compared with the expected height of normal interdental alveolar bone

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Conclusion