ABSTRACT
When selecting implant guidance methods or judging whether the patient can be implanted, many doctors ignore or only use visual inspection to estimate a patient's mouth opening. This phenomenon often leads to failure to complete the implantation due to insufficient mouth opening or the deflection of the implant due to limited angle, resulting in the high incidence of corresponding complications. The main reason is that doctors lack accurate analysis and control of the overall geometric conditions of the intraoral surgical area, and three-dimensional position blocking of surgical instruments occurs during the operation. In the past, mouth opening was defined as the distance between the incisor edges of the upper and lower central incisors when the patient opens his mouth widely, and the implant area could be in any missing tooth position. When it is in the posterior tooth area, the specific measurement scheme of the mouth opening could not be simply equivalent to the previous measurement method in the anterior tooth area. However, how to measure quickly and conveniently the mouth opening of any surgical area to determine whether it could be implanted and meet the needs of the selected guidance method remains unclear. This paper introduces new concepts, establishes new classification and corresponding accurate measurement scheme of implant area, and establishes a decision tree of implant methods guided by the actually measured value. Results provide a quantitative basis for rational formulation and implementation of implant treatment.
Subject(s)
Humans , Mouth , Dental Implantation, Endosseous/methods , Incisor , Clinical Decision-Making , Dental ImplantsABSTRACT
Objective@#To investigate changes in the three⁃dimensional position of the maxillary canine during the distal movement of the maxillary first molar by a mini⁃implant combined with a CD appliance.@*Methods@#Ten typodont models of class II malocclusion were selected, and one side was randomly chosen as the experimental group. The CD ap⁃ pliance was bonded to the maxillary canine and first molar of the experimental group, and 1.2 mm stainless steel wire was bent as the anchorage, which was fixed on the model to simulate mini⁃implants implanted in the zygomatic alveolar ridge. Then, 180 g orthodontic force was applied to the canine of the experimental group; the other side was recognized as the control group and was not used for strengthening. Six mini⁃implants were implanted in different parts of the mod⁃ el and used as a reference before and after the experiment. The models were placed in an incubator and heated at 56 ℃ in a water bath for 2 min. The models were scanned before and after thermostatic water bath treatment with a 3⁃shape scanner. Then, the digital models were overlapped through the reference points, and the positions of the canines and first molars were measured before and after the experiment.@*Results@#The sagittal movement distance of the first molar in the experimental group was ( 0.25 ± 0.33) mm, and the vertical movement distance was (0.25 ± 0.28 )mm, which was significantly different from the control group (P < 0.05), while the transverse change was not significantly different (P > 0.05). There was no significant difference in the root position of the first molar in the experimental group (P > 0.05). The lateral and vertical displacement distances of the maxillary canine crown in the experimental group were (4.03 ± 2.11) mm and (1.86 ± 1.01) mm, respectively, which were significantly different from those in the control group (P < 0.001), while the sagittal changes showed no significant differences (P > 0.05). In the experimental group, there was no significant difference in the position of the apex of the maxillary cusp (P > 0.05).@*Conclusion@#Our in vitro study showed that the maxillary canines inclined buccally accompanied by a small amount of intrusion during molar distaliza⁃ tion by a mini⁃implant combined with a CD appliance.
ABSTRACT
Objective@#To evaluate the clinical effect of a digital whole-process surgical guide for immediate implantation in the molar area. @*Methods @#Twenty-six patients with molar extraction plans were accepted for preoperative CBCT and model construction. Computer software was used to design the ideal three-dimensional position of the implant. The control group of 13 patients underwent immediate implantation with a free hand operation, whereas the experimental group of 13 patients underwent preparation and implant insertion under the guidance of a surgical guide. Bone grafting was performed, and a good initial stability was achieved. After 5 to 6 months, osseointegration was achieved, and the final restoration was delivered. After surgery, the accuracy of the three-dimensional position of the implants was measured, and at the 6 month return visit, the modified Plaque Index (mPLI), modified Sulcular Bleeding Index (mSBI) and probing depth (PD) were measured. @*Results @# In the control group and experimental group, the vertical errors at the top of the implants were 1.246 ± 0.072 mm and 0.628 ± 0.046 mm (t = 26.078, P < 0.001), respectively, and the horizontal errors were 1.563 ± 0.086 mm and 0.546 ± 0.056 mm (t = 35.813, P < 0.001), respectively; and the vertical errors at the root of the implants were 1.352 ± 0.042 mm and 0.532 ± 0.030 mm (t = 57.021, P < 0.001), respectively, and the horizontal errors were 1.645 ± 0.076 mm and 0.625 ± 0.072 mm (t = 35.086, P < 0.001), respectively. For the experimental group, the mPLI value was 0.923 ± 0.760, the mSBI value was 0.846 ± 0.689, and the PD value was 3.460 ± 0.713 mm, which were significantly lower than those of the control group. For the control group, the mPLI value was 1.769 ± 0.927 (t = 2.546, P = 0.018), the mSBI value was 1.692 ± 0.947 (t = 22.605, P = 0.016) and the PD value was (4.579 ± 0.475) mm (t = 4.709, P < 0.001). @*Conclusion@#A digital surgical guide plate can increase the precision of immediate implantation and the peri-implant health in the molar area.