[The effect of Class III intermaxillary orthopedic force loading on the maxilla of puberty rhesus: a histomorphologic...

The purpose of this study is to quantitatively study the remodling changes of circummaxillary sutures of puberty rhesus loaded with Class III intermaxillary orthopedic force.

The animal model was established with 6 puberty female rhesus, which were randomly divided into experimental group (wore Class III Twin-block magnet appliance, each 2 rhesus for 3 and 6 months respectively) and control group(did not wear any appliance, each 1 rhesus for 3 and 6 months respectively ). The specimens were stained by hematoxylin and eosin, and image analysis system (IAS) was used in the quantatitive study of sutures width and cell density. One-way analysis of variance (ANOVA) was employed, and LSD analysis was used when interclass significance was found.

Compared to the control group, different changes were shown in different sutures.New bone formation was observed in all experimental animal. There was no significance difference between palatomaxillary suture and pterygomaxillary suture in cellular density (P>0.05). Zygomaticotemporal suture showed no difference between 3-month experimental group and control group;however, 6-month experimental group was significantly higher than 3-month experimental group (P<0.01).For frontomaxillary suture, 3-month experimental group was significantly higher than the control group, and 6-month experimental group was significantly higher than later one (P<0.01).Zygomaticomaxillary suture in the experimental group was significantly higher than the control group (P<0.01);meanwhile, 3-month experimental group was significantly higher than 6-month experimental group (P<0.05). Furthermore, the width of sutures were different in these groups. Palatomaxillary suture became significant narrower in 3-month experimental group (P<0.01),but zygomaticotemporal suture became significant wider (P<0.01). The width of sutures restored at 6th month (P>0.05). The width of pterygomaxillary suture was not different between 3-month experimental group and the control group (P>0.05),but it became significant wider in 6-month experimental group (P<0.05). Frontomaxillary sutures of the experimental group were significantly narrower than the control group, and 6-month experimental group was significantly narrower than 3-month experimental group (P<0.01). For zygomaticomaxillary suture, the experimental groups were significantly wider than the control group;meanwhile, there was no difference between the experimental groups.

Proper Class III orthopedic force can promote the physiological remodling of maxillary sutures.