Improvement of suture expansion on growth and development of maxillary bone

Aim: To detect proliferating cell nuclear antigen (PCNA) positive expression in suture cells around maxilla, and explore the improvement of suture expansion on the growth and development of maxilla. Methods: The experiment was accomplished at the Laboratory of Oral and Maxillofacial Surgery, Stomatology College of the Fourth Military Medical University of Chinese PLA between March and September 2005. Twelve mongrel dogs of 15 weeks old were randomly assigned into four groups: one-week experimental group (n=4), one-week control group (n=2), four-week experimental group (n=4) and four-week control group (n=2). The dogs of experimental groups were fitted with distraction devices, and traction hook was educed from palatine foramen, with rubber ring as connection between device and hook. Forward elastic traction was exerted respectively for 1 week and 4 weeks at 600 g force. All the dogs were executed at the end of force application, then transverse palatine suture (TPS), premaxilla-maxillary suture (PMS), zygomaticomaxillary suture (ZMS) and zygomaticotemporal suture (ZTS) were harvested. PCDA monoclonal antibody was stained with immunohistochemical technique, while the distribution and amount of proliferating cells in sutures were detected and analyzed statistically. Results: There were 12 dogs surviving until prearranged observation period. 1More PCNA-positive expressions were observed in cells of TPS and ZMS in one-week experimental group than in one-week control group (One-week experimental group: TPS: 48.69±5.42, ZMS: 46.44±3.72; One-week control group: TPS: 34.00±3.26, ZMS: 33.75±5.58, P < 0.05). 2And PCNA-positive expressions were higher in cells of all these sutures in four-week experimental group than in four-week control group and one-week experimental group (Four-week experimental group: PMS: 70.78±3.58, TPS: 69.9±2.62, ZMS: 68.56±4.15, ZTS: 64.25±2.82; Four-week control group: PMS: 32.95±3.24, TPS: 34.83±5.68, ZMS: 34.26±3.37, ZTS: 33.46±3.47; One-week experimental group: PMS: 38.97±4.25, TPS: 48.69±5.42, ZMS: 46.44±3.72, ZTS: 36.06±4.34, P < 0.05). Conclusion: Significantly increased proliferating cells and their activities are observed in maxilla after suture expansion, which implies suture expansion can improve the growth and development of maxilla.