Palatal bone support for orthodontic implant anchorage--a clinical and radiological study.
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When maximal anchorage is required during orthodontic treatment, additional aids are often needed to support the anchoring teeth. While intra-oral aids may be limited in their anchorage potential, extra-oral anchoring aids are often rejected by the patients. Endosseous implants may therefore be a valuable alternative for stable intra-oral anchorage. However, the possibility of using conventional implants is insufficient, e.g. for treating purely orthodontic patients with full dentition or where extraction sites are to be closed. Therefore, the mid-sagittal area of the palate is an alternative insertion site for the placement of implants for orthodontic anchorage. The limited bone height in this area inspired this comparison between bone thickness in the implantation site as verified by probing during the implantation of Straumann Ortho-system implants, and thickness as measured on the lateral cephalogram. The results suggest that vertical bone support is at least 2 mm higher than apparent on the cephalogram. In none of 12 patients was a perforation to the nasal cavity found. However, in five subjects the implant projected into the nasal cavity on the post-operative cephalogram. These results were supported by the study of the projections of palate and wires in wire-marked skulls where the wires were placed bilaterally on the nasal floor and on the nasal crest. It is therefore concluded that the mid-sagittal area of the palate lends sufficient bony support for the implantation of small implants (4-6 mm endosseous length, diameter 3.3 mm). (+info)
Design of a cast bar reinforced provisional restoration for the management of the interim phase in implant dentistry.
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Implant therapy is becoming the treatment of choice for the replacement of teeth in partially edentulous arches. The interim phase of implant treatment often presents particular problems because of the position of the remaining teeth, their periodontal status, and the loss of vertical dimension of occlusion. This case report will discuss the design and fabrication of a cast bar reinforced long-span provisional restoration based on a diagnostic wax-up to simplify the management of the interim phase. (+info)
Possible theophylline toxicity during anesthesia.
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Asthmatic patients who undergo outpatient anesthesia are typically prescribed one or more drugs for treatment. Some of these agents have narrow therapeutic ranges and are associated with potentially serious adverse reactions, toxic effects, or drug interactions. Various clinical signs of toxicity may be first uncovered during routine monitoring of an office anesthetic. The case reported here demonstrates the need for proper understanding of the asthmatic patient's medical history and an appreciation for the medications used to control the disease. A sudden cardiovascular event possibly related to drug toxicity is witnessed and treated in an asthmatic patient during intravenous sedation. A possible drug interaction with a non-asthmatic medication taken concomitantly by the patient is implicated and discussed. In addition to the case report, the broad classification of drugs employed for bronchial asthma and their effects is reviewed. (+info)
Bone response to orthodontic loading of endosseous implants in the rabbit calvaria: early continuous distalizing forces.
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The purpose of this experimental study was to evaluate the effect of early orthodontic loading on the stability and bone-implant interface of titanium implants in a rabbit model. Twenty-four short threaded titanium fixtures were inserted in the calvarial mid-sagittal suture of 10 rabbits. Two weeks following insertion, 20 implants (test group) were subjected to continuous distalization forces of 150 g for a period of 8 weeks. The remaining four implants (control group) were left unloaded for the same follow-up interval. Clinically, all implants except for one test fixture were stable, and exhibited no mobility or displacement throughout the experimental loading period. Histologically, all stable implants were well-integrated into bone. No differences could be found between the pressure and tension surfaces of the test implants relative to bone quality and density within a range of 1000 microns from the fixture surface. Similarly, qualitative differences were not observed between the apical and coronal portions of test fixtures. Morphometrically, a mean percentage bone-to-implant contact of 76.00 +/- 18.73 per cent was found at the test pressure sides, 75.00 +/- 11.54 per cent at the test tension sides, and 68.00 +/- 15.55 per cent at the control unloaded surfaces. No statistically significant differences in the percentage of bone-to-metal contact length fraction were found between test pressure surfaces, test tension surfaces, and unloaded control surfaces. Marginal bone resorption around the implant collar or immediately beneath it was found in roughly the same percentage of analysed sites in the test and control fixtures. In contrast, slight bone apposition was demonstrated at the implant collar of the test pressure surfaces, while no apposition or resorption were observed in the test tension zones. This study suggests that short endosseous implants can be used as anchoring units for orthodontic tooth movement early in the post-insertion healing period. (+info)
Initial orthopaedic displacement compared with longitudinal displacement of the maxilla after a forward force application. An experimental study in dogs.
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The aim of this study was to compare the initial orthopaedic displacement of the maxilla in vivo and the longitudinal changes after a forward force application. The sample consisted of five 1-year-old dogs. An anterior force of 5 N on the maxilla was applied by a coil spring system pushing between Branemark implants and a maxillary splint. The initial displacement of the maxilla after force application was measured by means of speckle interferometry. The longitudinal displacement of the maxilla after a force application during 8 weeks was measured by superimposing standardized lateral cephalograms. The initial, as well as the longitudinal, displacement of the maxilla of the dogs was in a forward direction with some counterclockwise rotation. There was no statistical difference between the initial and longitudinal displacement. The biological response after force application during 8 weeks can be predicted by the initial orthopaedic displacement. (+info)
Current trends in removable prosthodontics.
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BACKGROUND: This article discusses trends in the demographics and treatment of the edentulous patient. It is clear that there still is a tremendous need for removable-prosthodontic services today. While the basic process of making dentures has changed little over the past several decades, new materials and techniques can help laboratories and clinicians provide functional, esthetic restorations that offer exceptional value to patients. Implant treatment is a tremendous adjunct to removable prosthodontics in the treatment of edentulous patients, but it is not within the financial reach of all dental patients. CLINICAL IMPLICATIONS: The clinical skills required to deliver excellent complete denture care are also paramount to successful implant prosthodontics (fixed and removable) and esthetic dentistry. Even so, the opportunities to develop these skills and the interest appear to be decreasing at the same time that the need is projected to increase. In service to our patients, the profession must examine this trend closely. (+info)
Change in the width of the mandibular body from 6 to 23 years of age: an implant study.
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After the ossification of the mandibular symphysis, shortly after birth, changes in mandibular width would be expected to occur only by surface apposition or resorption on the buccal surfaces of the left and right mandibular halves. However, evidence for an opening hinge movement of the two mandibular halves around a vertical axis located in the region of the mandibular symphysis was recently found in longitudinal studies of 29 subjects with unilateral implant markers in the mandible. These subjects were followed from 8.5 to 15.5 years of age (Korn and Baumrind, 1990; Baumrind and Korn, 1992). The aim of the present investigation was to examine whether the presence of such an age-related increase in mandibular body width could be confirmed in a sample with bilateral implant markers in the mandible. The sample comprised 10 subjects (3F, 7M) from the files of another longitudinal study with implant markers (Bjork, 1968). A total of 122 pairs of annual lateral and postero-anterior (p-a) cephalometric records were available, covering longitudinal observation periods ranging from 8 to 16 years within an age interval of between 6 and 23 years. The width between a right and left side mandibular implant marker was measured with digital callipers on all p-a radiographs. Each measurement was corrected mathematically for various sources of radiographic enlargement. A small, but statistically significant increase in the distance between the right and left implant markers, i.e. in the bilateral width of the mandibular body, was observed in all subjects. The total increase in width in each subject ranged from 0.7 to 1.7 mm for the various periods of observation (P < or = 0.01). For the 12-year period from 6 to 18 years, the average total increase was 1.6 mm (P < or = 0.001, SD = 0.42), i.e. 0.13 mm/year. After this age there was no systematic trend. The mechanism for this increase in width is unknown. It is suggested that during postnatal growth, an increasing load from the masticatory occlusal forces might influence endosteal bone remodelling in the mandibular body, thus producing or allowing a gradual permanent outward bending of the right and left mandibular halves. (+info)
Congenitally missing maxillary lateral incisors and orthodontic treatment considerations for the single-tooth implant.
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Implant restorations have become a primary treatment option for the replacement of congenitally missing lateral incisors. The central incisor and canine often erupt in less than optimal positions adjacent to the edentulous lateral incisor space, and therefore preprosthetic orthodontic treatment is frequently required. Derotation of the central incisor and canine, space closure and correction of root proximities may be required to create appropriate space in which to place the implant and achieve an esthetic restoration. This paper discusses aspects of preprosthetic orthodontic diagnosis and treatment that need to be considered with implant restorations. (+info)