Soft tissue changes after double jaw surgery in skeletal Class III malocclusion

Cho, Eun Jung; Yang, Won Sik

Abstract

The purpose of this study was to evaluate the amount and interrelationship of the soft and hard tissue changes after simultaneous maxillary advancement and mandibular setback surgery in skeletal Class III malocclusion. The sample consisted of 25 adult patients(13 males and 12 females) who had severe anteroposterior skeletal discrepancy. These patients had received presurgical orthodontic treatment and surgical treatment which consisted of simultaneous Le Fort I or Le Fort II osteotomy and bilateral sagittal split ramus osteotomy. The presurgical and postsurgical lateral cephalograms were evaluated. The computerized statistical analysis was carried out with SPSS/PC+ program. The results were as follows: 1. The correlation of maxillary hard and soft tissue horizontal changes were high and the ratios for soft tissue to A point were 71% at Sn, 67% at SLS and 37% at LS. 2. The correlation of mandibular hard and soft tissue horizontal changes were very high and the ratios were 84% at LI, 107% at ILS, 96% at Pog' and 97% at Gn'. 3. The correlation of mandibular hard tissue horizontal changes and soft tissue vertical changes were moderate. 4. The upper to lower lip length were increased(P<0.001). 5. The soft tissue thickness were decreased in upper lip and increased in lower lip(P<0.001). The postsurgical changes were reversely correlated with initial thickness in upper lip.