RESUMO
Obesity is an important risk factor related to osteoarthritis, but it′s role in post-traumatic osteoarthritis on young people need to further study. The internal mechanism except the mechanical loading may be associated with adipose exosomes. To examine the effect of obesity induced by high fat diet and adipose exosomes on knee post-traumatic osteoarthritis caused by destabilization of medial meniscus (DMM) surgery in young mice, 20 6-week-old C57BL/6J mice were randomly assigned to the control diet group (CD, n = 5), the DMM group (n = 5), the high fat diet group (HFD, n = 5) and the HFD plus DMM group (HFD+DMM, n = 5). The CD and DMM group were fed with a control diet, and the HFD and HFD+DMM group were fed with a high fat diet. We did the DMM surgery and the sham surgery on the mice when it was 10 weeks old. Extract obese and normal adipose exosomes, identify exosomes in vitro, and proceed fluorescence imaging in vivo using DiR staining. DMM+HFD-Exo group and DMM+CD-Exo group were injected the exosomes from the tail vain once a week (100 μL per shot with a concentration of 1 μg·μL-1). Second, 15 6-week-old C57BL/6J mice were randomly assigned to the DMM group (n = 5), the DMM plus obese adipose exosomes group (DMM+HFD-Exo, n = 5), and the DMM plus control diet adipose exosomes group (DMM+CD-Exo, n = 5). Animal welfare and experimental process are in accordance with the regulations of the Experimental Animal Ethics Committee of Nanjing University (IACUC-D2204005). All mice were sacrificed at the age of 18 weeks, the knee joints of the mice were harvested and fixed. We used micro CT to examine the samples and measured the bone volume/tissue volume, trabecular thickness, trabecular number and trabecular separation. Then the samples were decalcified and embedded in paraffin, and 4 μm thickness sections were stained with H&E and safranin O/fast green to observe the histological changes of the knee joint. The results showed compared with the control diet group, high fat diet induced obesity can aggravate the pathological changes of the post-traumatic osteoarthritis caused by DMM surgery, which shows in having a higher Mankin score. The surface of knee articular cartilage in the HFD+DMM group was rough, and the subchondral bone has an increase in bone sclerosis. Compared with the DMM group, obese adipose exosomes can exacerbate the pathological changes of the knee articular cartilage, while not influencing the subchondral bone. In conclusion, high fat diet induced obesity can aggravate the post-traumatic osteoarthritis caused by DMM surgery in young mice. The obese adipose exosomes mainly affect the surface of the knee articular cartilage.
RESUMO
Objective: To compare the effect of bone-anchored versus tooth-borne rapid palatal expansion (RPE) combined with maxillary protraction in the treatment of skeletal class Ⅲ patients with maxillary hypoplasia. Methods: Twenty-six skeletal class Ⅲ patients with maxillary hypoplasia in the late mixed or early permanent dentition were selected. All the patients underwent RPE combined with maxillary protraction in the Department of Orthodontics, Nanjing Stomatological Hospital, Medical School of Nanjing University from August 2020 to June 2022. The patients were divided into 2 groups. Thirteen patients were enrolled in the bone-anchored RPE group [4 males and 9 females, aged (10.2±1.7) years] and the others were in the tooth-borne RPE group [5 males and 8 females, aged (10.1±1.0) years]. Ten sagittal linear indices [Y-Is distance (the distance from the incisor edge of the maxillary incisor to the vertical reference axis), Y-Ms distance (the distance from the mesial contact point of the maxillary first molar to the vertical reference axis), the relative distance between the maxillary and mandibular molars, overjet, etc.], 6 vertical linear indices [PP-Ms distance (the distance changes from Ms to the palatal plane), etc.] and 8 angle indices [SN-MP angle (the upper external angle of the intersection of the sella-nasion plane and the mandibular plane), U1-SN angle (the lower internal angle of the intersection of the long axis of the maxillary central incisor and the sella-nasion plane), etc.] were measured on the cephalometric radiographs before and after the treatment. Six coronal indicators (the inclination of the left and right first maxillary molar, etc.) were measured on cone-beam CT images before and after the treatment. The proportion of skeletal and dental factors in the changes of overjet were calculated. The differences of the index changes between groups were compared. Results: After the treatment, the anterior crossbite were corrected in both groups, and classⅠor classⅡ molar relationship were attained. In bone-anchored group, the changes of Y-Is distance, Y-Ms distance and maxillary and mandibular molar relative distance were (3.23±0.70), (1.25±0.34) and (2.54±0.59) mm, respectively, significantly less than those in the tooth-borned group in which the corresponding changes were (4.96±0.97) mm (t=-5.92, P<0.001), (3.12±0.83) mm (t=-7.53, P<0.001) and (4.92±1.35) mm (t=-5.85, P<0.05), respectively. The change of overjet in the bone-anchored group was (4.45±1.25) mm, significantly less than that in the tooth-borned group (6.14±1.29) mm (t=-3.38, P<0.05). Skeletal and dental factors accounted for 80% and 20% of the overjet changes in the bone-anchored group, respectively. While in the tooth-borned group, skeletal and dental factors accounted for 62% and 38% of the overjet changes, respectively. The PP-Ms distance change in the bone-anchored group [(-1.62±0.25) mm] was significantly less than that in the tooth-borned group [(2.13±0.86) mm] (t=-15.15, P<0.001). The changes of SN-MP and U1-SN in the bone-anchored group were -0.95°±0.55° and 1.28°±1.30°, respectively, significantly less than those corresponding indices in the tooth-borned group (1.92°±0.95°, t=-9.43, P<0.001; 7.78°±1.94°, t=-10.04, P<0.001). In the bone-anchored group, the inclination changes of maxillary bilateral first molars in the left and right sides were 1.50°±0.17° and 1.54°±0.19°, significantly less than the corresponding indices in the tooth-borned group (2.26°±0.37°, t=6.47, P<0.001; 2.25°±0.35°, t=6.81, P<0.001). Conclusions: The bone-anchored RPE with maxillary protraction could reduce the adverse tooth compensation effect, including the protrusion of maxillary anterior incisors, the increase of overjet and mandibular plane angle, and the mesial movement, extrusion and buccal inclination of maxillary molars.