[The ratio of soft and hard after bimaxillary operations in patients with skeletal class III malformations].
OBJECTIVE
To study the ratio between soft and hard tissue on the horizontal plane after the operations of maxillary Le Fort I advancement osteotomy and mandibular setback osteotomy in patient with skeletal class III malformations. It can help to predict precisely the post-operational profile.


METHODS
20 patients with skeletal class III malformation were taken cephalometric films pre-and post-operationally. The coordinate of landmarks were given from two films by computer analysis system. Different values in X axis were analysed statistically.


RESULTS
All mandibular soft tissue landmarks were correlated with hard tissue landmarks (r<0.5, P>0.05). The ratios were 1:1 except the Pogonion(<1:1). Point of Sn was not correlated with the maxillary hard tissue significantly(r<0.5, P>0.05).


CONCLUSIONS
The poor correlation between maxillary Sn and hard tissue was affected by many factors. It is easy to mark the mandible landmarks clearly. The ratio should help to predict the post-operation profile in patients with skeletal class III malformations.
Zhang
Hua
H
Department Of Oral Maxillofacial Surgery, Ninth People's Hospital, Shanghai Second Medical University, Shanghai 200011, China.
Zhu
Min
M
Tang
You-sheng
YS
Cheng
Jian-yu
JY
Fang
Bing
B