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61.
Lateral luxation in primary maxillary incisors is a traumatic injury that can lead to darkening of the tooth, pulp necrosis, root resorption, and damage to the permanent teeth. Management of this kind of trauma typically includes pulpectomy or extraction in cases of root resorption. However, in young children, removal of the tooth may be psychological stressing, especially for the parents, while increased mobility can make immediate endodontic treatment difficult to perform. This article outlines a severe palatal luxation on the maxillary right central incisor treated with conservative management in a 2-year-old boy. At the one-year follow-up appointment, the surrounding bone was healthy, the roots displayed physiological resorption, the crowns showed color improvement, and there was no radiographically noticeable damage to the permanent teeth.  相似文献   
62.
The standard treatment modality of zygomatic fractures is open reduction and rigid fixation of the fractured segments. Although most of the zygomatic fractures deserve this attentive surgical manipulation to prevent late residual asymmetry, minimally depressed noncomminuted zygomatic fractures can be reduced and fixed percutaneously. Percutaneous intervention causes minimal scarring and morbidity than open techniques and it is possible to align fragments precisely by using high-quality three-dimensional computed tomography (3-D CT) imaging. Six patients with noncomminuted fractures of the zygomaticomaxillary skeleton were evaluated with plain radiographs of facial bones, axial, coronal and 3-D CT. Reduction of the displaced bone segments were achieved by traction of percutaneously applied screw. Either reduced segments were not fixated at all or one of the two new fixation techniques, described in detail in the article, were used for stabilization of reduced segments. In all patients, accurate reduction was obtained. None of the patients showed any recurrent displacement or infection during the follow-up period of six months. The screws were removed in the clinical settings without difficulty. Although percutaneous reduction and external fixation of noncomminuted zygomatic fractures has limited indications, it has its own advantages over open techniques. This method is a less invasive technique and can be performed without any problem in selected cases. Our technique is not suitable for complex zygomatic and periorbital fractures.  相似文献   
63.
Soft tissue expansion is a mechanical process that increases the surface area of local tissue available for reconstructive procedures. In most cases, adjacent tissue that matches the recipient site in color, texture, and hair-bearing quality is preferred for tissue expansion. In this particular case with neurocutaneous syndrome, the defects that resulted from removal of parts of a giant hairy nevus overlying the latissimus dorsi muscle bilaterally were grafted with a split-thickness skin graft. Two expanders were then placed under the latissimus dorsi muscles. After full expansion of the grafted area, some part of the remaining nevus surrounding the grafted area was removed and the defects were covered with the expanded skin graft obtained after deflation of the expanders. The expanders placed under the latissimus dorsi muscle in the first operation were reused in the second operation to obtain a second expansion of the skin graft. After the second expansion of the skin graft, the expanders were deflated and another portion of the remaining nevus surrounding the grafted area was removed. The resulting defects were again covered with the excess expanded skin graft. Although repeated expansion of the skin graft is a time-consuming and laborious process, it eliminates the need for taking repeated skin grafts; it decreases skin graft donor site morbidity; it decreases possible infectious complications of tissue expansion by decreasing the number of surgical interventions to the expander pocket; and it increases the aesthetic outcome by keeping all the surgical scars around the grafted area without extending them into healthy surrounding skin.  相似文献   
64.
AIMS: The aims of this study were to investigate the influence of commercially pure titanium (PTi) and titanium-aluminum-vanadium (Ti-6Al-4V) alloys (TiA) on the final shade of low-fusing porcelain bonded to them and to compare the shade changes with those of three conventional metal-ceramic systems. METHODS AND MATERIALS: A titanium casting unit was used to cast PTi and Ti-6Al-4V alloy specimens followed by A3 shade low-fusing porcelain (Noritake) being bonded to them. Gold-based (AuA), palladium-based (PdA), and nickel-chromium (Ni-Cr) alloys were cast with an automatic centrifugal casting machine, then A3 shade conventional porcelain material (Vita, VMK 95) was applied to them. Ten specimens of each metal were then fabricated. The CIE L* a* b* color coordinates of the specimens were measured with a spectrophotometer. RESULTS: All alloys had significant color changes when compared with A3 shade tabs. The color differences from the shade tabs were 5.79 for the Ti-6Al-4V group, 6.46 for PdA alloy, 8.12 for AuA alloy, 8.15 for Ni-Cr alloy, and 12.58 for PTi. The specimens differed from the shade tabs primarily because of the differences in a* and b* coordinate values. CONCLUSIONS: Predictable shade reproduction of metal-ceramic restorations (MCRs) may be impaired by the underlying metal. The PTi had the greatest color differences among all the tested metal when compared with the shade tabs, whereas the Ti-6Al-4V alloy had the lowest. PTi is more likely to affect the final shade of low-fusing porcelain than Ti-6Al-4V alloy.  相似文献   
65.
Effect of surface treatment of titanium posts on the tensile bond strength.   总被引:1,自引:0,他引:1  
OBJECTIVES: Retention of composite resins to metal can be improved when metal surfaces are conditioned. The purpose of this investigation was to investigate the effect of two conditioning treatments on the tensile bond strength of four resin-based luting cements and zinc phosphate cement to titanium posts. METHODS: The effect on tensile bond strength of (1) air-particle abrasion (50 microm Al2O3) and (2) silica coating (30 microm SiO(x)) and silanization of tapered titanium posts prior to luting with any of the four resin composite luting cements (Compolute) Aplicap, Flexi-Flow cemTM, Panavia 21 EX, Twinlook) were evaluated. The posts luted with zinc phosphate cement (Tenet) were considered as the control group. Following endodontic preparation of 100 intact anterior human teeth with hand instruments, the post spaces were prepared using the opening drills of the corresponding size of the posts. All posts were cemented into the roots according to the manufacturer's instructions of each cement. The specimens were first stored in water at 37 degrees C for 24 h and then subjected to thermocycling (5000 cycles, 5-55 degrees C, 30 s). The tensile strength values were measured on a universal testing machine at a cross-head speed of 0.5 mm/min. Data were analyzed statistically using ANOVA and corrected with Scheffé-test due to the significance levels (P<0.05). RESULTS AND SIGNIFICANCE: The composite resin luting cements did not show significant differences (P<0.05) showing values between (352+/-76N-475+/-104N) when the posts were air-abraded. After silica coating and silanization, significantly higher (P<0.05) tensile strengths were obtained for Compolute Aplicap (600+/-123N) than those of the other luting cements (Flexi-Flow cemTM: 191+/-62N; Panavia 21 EX: 375+/-77; Twinlook: 430+/-78N). No significant differences (P>0.05) were found between the tensile strength of the posts luted with zinc phosphate (414+/-102N) and the resin composite cements. Silica coating and silanization revealed the highest tensile bond strength in posts luted with Compolute Aplicap but it was not effective for the other experimental groups. Zinc phosphate cement exhibited tensile bond strength as good as resin composite cements.  相似文献   
66.
OBJECTIVE: To compare morphological and positional variations of the hyoid bone in unoperated infants with cleft lip and palate (CL/P) with those in noncleft infants. DESIGN: Retrospective, cross sectional. PATIENTS AND METHODS: Three-dimensional computed tomography scans were obtained from 29 unoperated CL/P infants of Malay origin aged between 0 and 12 months and from 12 noncleft infants in the same age range. Observations were made and measurements were obtained with a software package developed at the Australian Craniofacial Unit. The sizes of the hyoid bones and the position of the hyoid body and epiglottis in relation to the cervical spine were measured. Anatomical anomalies of the hyoid and prevalence of aspiration pneumonia were also documented. RESULTS: The hyoid bones and epiglottis were found to be located more inferiorly in CL/P infants compared with the noncleft infants. Also, 17% (5/29) of the CL/P infants had nonossified hyoid bodies. CONCLUSION: The results suggest that there are differences in the location and genesis of the hyoid bone in infants with CL/P that warrant further investigation.  相似文献   
67.
STATEMENT OF THE PROBLEM: The separation of core materials from titanium posts, which have a low modulus of elasticity, has been identified as a problem in restorative dentistry. PURPOSE: This study evaluated the resistance to torsional forces of various core materials adapted to differently conditioned titanium posts. MATERIAL AND METHODS: Seven hundred and twenty specimens were tested consisting of: 6 core materials and 5 surface conditioning techniques for 2 kinds of opaquers with 10 specimens in each group (6 x 5 x 2 x 10=600) plus 6 core materials and 2 opaquers were tested and considered as control groups on nonconditioned titanium posts, each group containing 10 specimens (6 x 2 x 10=120). The custom-made pure titanium posts were conditioned with the following products: Silicoater Classical, Silicoater MD, Rocatec, Kevloc, and Siloc surface-conditioning systems. Subsequently, 6 core materials with different compositions (Durafill, Adaptic, Coradent, Ti-Core, Hytac Aplitip, and Photac-Fil Aplitip) were applied to titanium posts that were previously coated with 2 types of light-polymerized opaquers, either Artglass or Dentacolor. Sixty air-abraded titanium posts (250 microm, 30 seconds) were used as controls for each core material. Following thermocycling (5 degrees -55 degrees C, 30 seconds, 5,000 cycles), maximum torsional forces were determined with an electronic torque movement key. Data were statistically analyzed by 1-way analysis of variance followed by 2-way analysis of variance (P<.05). RESULTS: Significantly higher mean torsional forces were observed with respect to Siloc (20.4 Newton decimeter [dNm]), Silicoater Classical (18.6 dNm), Silicoater MD (18.2 dNm), and Rocatec (17.0 dNm) systems compared with the mean for the untreated control group (14.6 dNm) (P<.001). The Kevloc system (10.4 dNm) demonstrated no significant difference compared with the control group (P>.001). The Kevloc system in combination with the Artglass opaquer and Photac-Fil Aplitip (0.00 dNm) core material showed no resistance against torsional forces. Significant differences were observed between hybrid core materials and microfilled composite, compomer, or resin-modified glass ionomer core materials (P<.001). CONCLUSION:Within the limitations of this study, the resistance to torsional forces for the core materials on titanium posts increased with the use of chemical surface-conditioning techniques and varied in accordance with the opaquer type. Type of core material also significantly influenced the resistance after thermocycling.  相似文献   
68.
Objective: The objective of this study was to explore effects of implant macrodesign and diameter on initial intraosseous stability and interface mechanical properties of immediately placed implants. Material and method: Mandibular premolars of four fresh‐frozen human cadavers were extracted. Ø 4.1/4.8 mm ITI® TE®, Ø 4.1 and 4.8 mm solid screw synOcta® ITI® implants were placed into freshly prepared extraction sockets. Resonance frequency analysis was conducted to quantify primary implant stability quotient (ISQ). Installation torque value (ITV) and removal torque value (RTV) of the implants were measured using a custom‐made strain‐gauged torque wrench connected to a data acquisition system at a sample rate of 10,000 Hz. The vertical defect depth around the collar of each implant was measured directly by an endodontic spreader. The bone–implant contact was determined in digitalized images of periapical radiographs and expressed as percentage bone contact. Results: The ISQ values of the TE® implant was higher than the Ø 4.1 mm implant (P<0.01), and comparable with the Ø 4.8 mm implants (P>0.05). ITVs and RTVs of TE® and Ø 4.8 mm implants were higher than the Ø 4.1 mm implant, although the differences between groups were statistically insignificant (P>0.05). The vertical defect depths around all types of implants were similar. In the radiographic analyses, percentage bone–implant contact of the TE® and Ø 4.8 mm implants were comparable at the marginal bone region and both were higher than that of the Ø 4.1 mm ITI® implant. Nonparametric correlations between groups revealed a significant correlation between ITV and RTV (r=0.838; P<0.001), but not between ISQ values and ITVs and RTVs (P>0.05). Conclusion: Immediately placed ITI® TE® implant leads to initial intraosseous stability and interface mechanical properties comparable with a wide diameter implant.  相似文献   
69.
This study emphasizes the importance of diagnostic first aid procedures to avoid the consequences of trauma due to foreign body. A 20-year-old man referred to our hospital with a history of having a sharp penetrating injury to his right eye. Computed tomography evaluation reported right globe perforation and intraorbital glass foreign body measuring 4 x 7 cm was removed. Perforated eye was repaired and traumatic cuts were sutured. Orbital and ocular injuries are common, and delays in management may lead to complication. A team approach is the best technique for these patients.  相似文献   
70.
Deviated cartilages structures of the nose can be affected by nasal muscles, and deviation becomes conspicuous when the patient smiles. This condition depends on activity of nasal muscles, particularly the levator labii alaeque nasi muscle. A total of 124 septorhinoplasty operations were performed to correct dorsal concave septal deviation between 2005 and 2009 years. The 70 women and 54 men included in the study had an average age of 28 years. The average follow-up period was 12 months. Open septorhinoplasty was preferred in all cases. The medial part of the levator labii alaeque nasi muscle was extensively dissected from the lateral crus and surrounding tissues. The lateral crura of the alar cartilages were separated from the upper lateral cartilages in the scroll area. The dorsal septal deviation was corrected by combination of bilateral spreader grafts, which reinforced cartilage with horizontal control sutures. Early postoperative period was uneventful. Nasal obstruction was reduced after surgery, and significant subjective postoperative improvements were observed in all patients. Comparison of preoperative and postoperative photographs demonstrated improved dorsal nasal contour. Revision operation was performed in 3 cases. The corrected septal cartilage was in a good position in all revised cases; therefore, septal surgery was not performed in the revision operations. In conclusion, surgical disruption of the anatomic relationship between the muscle with the dorsal septal cartilage and reinforcement of the dorsal septal cartilage with spreader grafts and horizontal control sutures can decrease risk of recurrence.  相似文献   
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