ABSTRACT
BACKGROUND: Micro-implant screws as an absolute anchorage, instead of traditional anchorage that requires patient's high matching and affects beauty, has been paid more attention.OBJECTIVE: To compare the changes in 3 different places following implantation of micro-implant screws. DESIGN, TIME AND SETTING: The controlled study was performed at the Hospital of Stomatology Affiliated to Foshan College of Sciences and Technology from January 2004 to December 2007.PARTICIPANTS: A total of 45 patients who demand powerful anchorage during the orthodontic treatment were assigned to 3 groups: free gingiva group, mucogingival junction group, and mucosa group.METHODS: By using incomplete flap micro-implant screw implantation, micro-implant screws were implanted in the free gingiva, mucogingival junction and mucosa, with 30 screws in each area.MAIN OUTCOME MEASURES: Loosening and defluvium of micro-implant screws were measured. Pain duration and degree were determined in patients undergoing implantation of micro-implant screws 7 days following surgery. Soft tissue surrounding the micro-implant screws and bleeding rate during probing were detected 56 days following surgery.RESULTS: The number of screw loosening was greatest in the free gingiva group (9 screws), while lowest in the mucogingival junction group (2 screws). Patients suffered from severe flare and pain in the mucosa, and the reaction was mild in the free gingiva following implantation. The reaction was not obvious, but severe pain was found in the mucogingival junction following implantation compared with the free gingiva. Soft tissue surrounding the micro-implant screws and bleeding rate during probing were greater in the mucosa group than in the free gingiva group and mucogingival junction group (P<0.05).CONCLUSION: The incomplete flap micro-implant screws in the mucogingival junction contribute to the increase in success implantation rate and the decrease in inflammatory degree, and prevent the occurrence of potential risk.
ABSTRACT
<p><b>OBJECTIVE</b>The aim of this study was to evaluate quantitatively the effectiveness and feasibility of the modified supracrestal fiberotomy (MSF) and the contact point reproximation (CPR) in decreasing the relapse of anterior segments rotating and/or crowding after orthodontic treatment.</p><p><b>METHODS</b>A total of 129 patients with crowding and/or rotated anterior teeth were selected for this study, and the average age was 13.07 years (54 males, 75 females). The modified supracrestal fiberotomy was performed on the anterior segments of patients in the experimental group (48 cases). After the anterior teeth were aligned, 23 of the 48 cases received a further treatment of the contact point reproximation on the anterior segments (the subgroup of MSF + CPR), and the other 25 subjects did not receive this treatment (the subgroup of MSF). The control group consisted of 81 cases. All cases wore Hawley retainers for 1.8 to 2.3 years, and all the patients were revisited 2.4 years postretention. The maxillary and mandibular dental models of all the patients were taken before treatment (T1), at the end of the treatment (T2) and 2.4 years postretention (T3).</p><p><b>RESULTS</b>The relapse rate in the experimental group [(T3-T2)/T1 x 100%] was 21.6%, lower than that in the control group (P < 0.001). The relapse rate of mandible in the subgroup of MSF + CPR was 6.56% lower than that of the subgroup of MSF (P < 0.05). But the relapse rate of maxillary in the subgroups of MSF + CPR was similar as that of the subgroup of MSF (P > 0.05).</p><p><b>CONCLUSION</b>The modified supracrestal fiberotomy can effectively alleviate relapse after orthodontic treatment of the crowding and/or rotation of anterior teeth. The treatment combining MSF and CPR can help maintain the stability of post-retention of mandibular anterior teeth.</p>