Rapports de cas de santé bucco-dentaire

Recurrence of the Anterior Open Bite After Orthognathic Surgery: 3D Analysis of Dental, Soft Tissue, Skeletal and Airway Changes in Unraveling the Aetiology of Relapse

Abstract

Suttorp CM, Camardella LT, Desmedt DJS, Baan F, Maal TJJ and Breuning KH

Several treatment approaches have been used to correct anterior open bites, but high relapse rates are reported. This report shows the orthognathic surgical correction of a severe anterior open bite of a 23 years old woman with a mouth breathing habit. Although the treatment outcome was regarded as successful, progressive recurrence of the anterior open bite was found during 2 years retention. Digital dental models, 3D facial scans and CBCT were superimposed to analyse the dental, soft tissue, skeletal and airway volume changes during treatment and 2 years retention in three dimensions (3D). The Ortho Gnathic Analyser software tool was used to analyse in detail the skeletal dimensional changes (translations and rotations) of the maxilla and mandible in 3D. Relapse of the upper arch expansion was found in the posterior region. The impaction, advancement and clockwise pitch of the maxilla by the Le Fort 1 osteotomy were very unstable. The mandibular advancement and counter-clockwise pitch by the BSSO showed significant relapse. During retention a counter-clockwise roll of the maxilla was noticed, and considered as an adaptation to the relapse. The upper airway volume was reduced and the improvement of the soft tissue profile appeared to be unstable. 3D superimpositions made it possible to relate the oropharyngeal airway volume changes to the stability of the corrections of the dentition, maxilla and mandible and soft tissues. The orthognathic surgical treatment had reduced the upper airway volume, which maintained the mouth breathing habit, suggesting that this was the major cause of the dental, soft tissue and skeletal relapse. It is mandatory to collecting more 3D data on stability of hard and soft tissue and airway volume changes in unravelling the aetiology of relapse after orthognathic surgical correction of anterior open bites.