The present study was designed to evaluate the use of inverted-L osteotomy of ramus combined with iliac bone graft for the treatment of mandibular hypoplasia inadult patients.

Intraoral or extraoralinverted-L osteotomy of ramus and iliac crest bone grafting were used for the treatment of mandibular hypoplasia in 11 adult patients (aged 19 to 29 years) from 2010 to 2016. Data were collected from the patients' records, photographs andradiographs.

The height and width of the mandibular ramus were significantly augmented by inverted-L osteotomy and iliac crest bone grafting with minimal complications in all patients, resulting in remarkable improvements both in facial appearance and occlusion.

Our preliminary results showed that the inverted-L osteotomy of ramus and iliac crest bone grafting is safe and effective, and should be considered as a good alternative for the patients with mandibular hypoplasia.

To explore the anti corrosion ability of laser welded composite wire in artificial saliva containing salivary amylase and pancreatic amylase, and to compare the effect of two kinds of amylase on corrosion resistance of wire and its mechanism.

The corrosion resistance of composite wire was evaluated by electrochemical polarization and immersion test. The soluble corrosion products after 28 d immersion in artificial saliva were detected by plasma spectrometer. The surface morphology was analyzed by scanning electron microscope, energy spectrometer and atomic force microscope.

Salivary amylase and pancreatic amylase could improve the corrosion resistance of the composite arch wire; the same isomerase would have different effects on the same alloy corrosion resistance.

When the new metal biological material is applied to the oral cavity, the amylase may have influence on its corrosion resistance.