Biomedical subjects

Oskar Bauss

Publications and source records attributed to Oskar Bauss.

10 recordsLinked to original sources

PubMed2005

Effect of different splinting methods and fixation periods on root development of autotransplanted immature third molars.

PURPOSE: The aim of the present study was to assess the influence of suture splinting for 1 week or rigid fixation for 4 weeks on final root length, root length increment, and mobility of autotransplanted immature third molars. PATIENTS AND METHODS: The sample consisted of 63 patients with a total of 65 transplanted immature third molars. All transplants had reached one-half (n = 29) to three-fourths (n = 36) of their expected root length. In 24 of the transplants, postoperative fixation was carried out with a rigid acid-etch composite and wire splint for 4 weeks (rigid group), and in 41 transplants, with a suture splint for 1 week (suture group). The fixation method depended on the initial stability of the transplants. All transplants were followed up clinically and radiologically for a mean period of 3.9 years. RESULTS: Transplants in the rigid group revealed a significantly lower final root length ( P = .002) and root length increment ( P = .001) than those in the suture group. The differences were found to be more pronounced in transplants at earlier developmental stages. No differences were found in transplant mobility. CONCLUSIONS: The results of the present study indicate that prolonged rigid fixation of autotransplanted immature third molars has a significantly negative influence on final root length and root length increment, especially in transplants at earlier developmental stages.

Adolescent↗

PubMed2004

Torque deformation characteristics of plastic brackets: a comparative study.

AIM: The purpose of this study was to compare the torque deformation characteristics of seven commercially available plastic brackets, both amongst each other and with stainless steel brackets. MATERIAL AND METHODS: Ten brackets each of (1) pure polycarbonate, (2) ceramic reinforced polycarbonate, (3) fiberglass reinforced polycarbonate, (4) ceramic reinforced polycarbonate with metal slot, (5) fiberglass reinforced polycarbonate with metal slot, (6) polyurethane, and (7) polyurethane with metal slot were exposed to torsion in a torquemeter, following an aging process according to ISO 10477. Ten stainless steel brackets served as a control group. Torsion was applied continuously using a material testing machine (Zwick Z2.5, Zwick Materialprüfung, Ulm, Germany). RESULTS: The results showed within the group of plastic brackets that metal slot reinforced brackets were subject to the lowest degree of deformation, followed by the brackets made of pure polyurethane, pure polycarbonate and fiberglass reinforced polycarbonate. The ceramic reinforced polycarbonate brackets showed the highest deformation under torque stress. The plastic deformation of the ceramic reinforced, fiberglass reinforced and pure polycarbonate brackets started even in the recommended torque range of 10-20 Nmm. The additional ceramic and fiberglass in the plastic brackets investigated in this study did not improve the torque stability of the polycarbonate brackets. The pure polyurethane brackets showed no significant difference from the pure polycarbonate brackets at the moment of 15 Nmm which is the optimal torque for a maxillary incisor. CONCLUSION: A comparison with the stainless steel brackets illustrated that plastic brackets are suited for clinical application only if they have a metal slot.

Biomechanical Phenomena↗

PubMed2004

Influence of orthodontic derotation and extrusion on pulpal and periodontal condition of autotransplanted immature third molars.

The aim of this study was to determine the influence of orthodontic treatment on the pulpal and periodontal condition of 91 transplanted immature third molars. In patients with atrophy of the alveolar process or unfavorable root morphology, transplants had to be placed in extreme rotated or infraoccluded positions. After 3 to 6 months, these transplants were derotated (45 degrees to 90 degrees) to a correct position in the dental arch (derotation group; n = 28) or extruded to the occlusal plane (extrusion group; n = 21). Finally, approximal spaces were closed in both groups. A sample of 42 transplanted third molars with no orthodontic treatment need served as the control group. All transplants were followed clinically and radiologically for a mean period of 4.0 years. With respect to pulpal and periodontal conditions, no significant differences were observed between the control and the extrusion group. In contrast, compared with the control group, transplants in the derotation group had a significantly poorer pulpal and periodontal condition. In the derotated transplants, a significant correlation was detected between pulp necrosis and orthodontic treatment of multi-rooted transplants. This study indicates that orthodontic extrusion and minor lateral movements of autotransplanted immature third molars, as well as rotation of single-rooted third-molar transplants, represent no additional risk to transplant survival. In contrast, rotation of multi-rooted transplants seems to initiate later severance of the vascular and nerval supply to the pulp.

Adolescent↗

PubMed2004

Temporomandibular joint dysfunction in Marfan syndrome.

OBJECTIVE: The aim of this study was to examine the prevalence of signs and symptoms of temporomandibular joint (TMJ) dysfunction in persons with Marfan syndrome. STUDY DESIGN: A questionnaire was distributed to 350 patients with Marfan syndrome. Twenty-one patients were additionally subjected to a clinical examination and magnetic resonance imaging (MRI) of the TMJ. RESULTS: The prevalence of symptoms of TMJ dysfunction was 51.6% (n=145), with 24.2 % (n=68) indicating symptoms of subluxation, and 34.9% (n=98) of the patients already undergoing medical treatment for their TMJ problems. Anterior disc displacement with and without reduction was observed in 17 of the examined patients (81.0%), with 4 of these patients additionally showing osteoarthrosis of the affected temporomandibular joints. CONCLUSION: TMJ dysfunction appears to be an important aspect in Marfan syndrome.

Adult↗

PubMed2004

Influence of orthodontic movement on root length of autotransplanted immature third molars.

The aim of this study was to investigate the influence of orthodontic extrusion or derotation on final root length and root length increment in 75 autotransplanted immature third molars. Depending on the condition of the recipient site and the root morphology, transplants had to be placed in extreme rotated or infra-occluded position. Three to six months after transplantation, these transplants were derotated to a correct position in the dental arch (derotation group, n = 19) or extruded to the occlusal plane (extrusion group, n=18). Thirty-eight transplants with no orthodontic treatment need served as controls (control group). Transplants were followed clinically and radiologically for a mean period of 4.0 yr. No statistically significant differences were observed between the extrusion and the control groups or between the single-rooted transplants in the different groups. In contrast, multi-rooted transplants in the derotation group showed a statistically significantly shorter final root length than multi-rooted transplants in the extrusion and the control groups. However, as these differences may be considered to be of minor clinical importance (<1 mm), it can be concluded that the effect of orthodontic movement on root development of transplanted immature third molars is of only negligible clinical significance.

Adolescent↗

PubMed2004

Prevalence of traumatic injuries to the permanent incisors in candidates for orthodontic treatment.

The dental records made on presentation of 1367 consecutive patients (731 females and 636 males) for orthodontic treatment at a private orthodontic practice between 1998 and 2002 were examined for data relating to trauma to the permanent incisors. The results showed that 10.3% of these patients had suffered from dental trauma before the onset of orthodontic treatment. The highest prevalence of dental trauma was determined in the 11-15 years age group, corresponding to the dental developmental stage of the late mixed dentition. The most frequently affected teeth were the maxillary central incisors (79.6%), and the most common types of trauma were fracture of enamel-dentin without pulpal involvement (42.7%) and fracture of enamel (33.8%). Compared to patients with normal overjet and adequate lip coverage, the frequency of dental trauma was significantly higher in patients with increased overjet and adequate lip coverage (P = 0.028) or with increased overjet and inadequate lip coverage (P = 0.003). The results of the present study indicate that a significant percentage of candidates for orthodontic treatment, and especially those with increased overjet and inadequate lip coverage, suffer trauma to their permanent incisors before the onset of orthodontic treatment. It might also be concluded that preventive orthodontic treatment of such patients should be initiated and completed before the age of 11, i.e. in the early to middle mixed dentition.

Adolescent↗

PubMed2003

Results of transplanting developing third molars as part of orthodontics space management. Part 2: results following the orthodontic treatment of transplanted developing third molars in cases of aplasia and premature loss of teeth with atrophy of the alveolar process.

MATERIAL AND METHODS: The aim of this study was to assess the effects of atrophy of the alveolar process and subsequent orthodontic treatment on the transplantation results of developing third molars. The material consisted of 35 teeth transplanted to an atrophied alveolar process. 19 of these teeth were treated orthodontically subsequent to transplantation. The control group consisted of 61 developing molars transplanted to a new extraction socket. The transplanted teeth were followed up clinically and radiographically for a mean period of 3.2 years. RESULTS: The success rate was 85% for transplants to new extraction sockets and 84% for transplants to atrophied jaw sections with subsequent orthodontic treatment. In contrast, transplants to atrophied jaw sections without subsequent orthodontic treatment showed a significantly (p < or = 0.001) lower success rate of only 37.5%. These poorer results were due to persistent infraocclusion and ankylosis. CONCLUSIONS: Even in cases with atrophy of the alveolar process, a transplantation with subsequent orthodontic treatment represents a promising treatment concept, whereas teeth without subsequent orthodontic treatment showed a lower success rate. Orthodontic tooth movement had no negative effect on the healing rates of transplanted developing third molars.

Adolescent↗

PubMed2003

In vitro study on the fatigue limit of single-lap joints.

Lasting adhesion between attachment and tooth is an essential prerequisite for all adhesive techniques in dentistry. However, the maximum static fatigue load is only one material-related parameter for the quality of this adhesion. Another parameter is the dynamic loading capacity of a bonded joint, which was determined in the present study for Dual adhesive resin by means of fatigue testing. This revealed a significant correlation between the recorded static and dynamic fatigue load and the gap width, which varied between 0.01 mm, 0.15 mm and 0.5 mm in the experimental setup. At 18.8 MPa, the median gap width of 0.15 mm yielded the highest static resistance, with a dynamic resistance 15% below this figure. Both the smaller and the larger gap showed significantly lower static fracture strengths (0.01 mm: 13.6 MPa; 0.5 mm: 13.7 MPa), whereas a dynamic load on the 0.01 mm bond, in contrast to the 0.5 mm bond, led to only a 5% reduction in bonding strength.

Biomechanical Phenomena↗

PubMed2002

Results of transplanting developing third molars as part of orthodontic space management. Part 1: clinical and radiographic results.

PATIENTS AND METHOD: The aim of the present study was to contribute to a more accurate indication and better integration of developing third molar transplantation into orthodontic space management, using the results gleaned from the authors' own pool of patients. For this purpose, a clinical and radiographic examination of 61 transplanted developing molars in 57 patients was carried out after an average of 3.3 years. RESULTS: The overall success rate was 85%. Failure was due in 10% of cases to impaired periodontal healing (inflammatory root resorption, ankylosis, or increased pocket probing depths) and in 5% of cases to insufficient or arrested postoperative root development accompanied by increased transplant mobility. The incidence of postoperative cessation of further root development was significantly higher (p = 0.011) in transplants at early developmental stages, which also had a negative impact on the final root length, the crown-root ratio and the mobility values of these transplants. CONCLUSIONS: The transplantation of developing third molars should be given stronger consideration in treatment plans for orthodontic space management although it represents a real alternative to orthodontic space closure only in exceptional cases. However, unlike implantological or prosthodontic treatment, it offers an opportunity to replace a missing or non-retainable tooth with a patient's own vital and fully functional tooth, provided the appropriate transplant is selected.

Adolescent↗

PubMed2002

Autotransplantation of immature third molars: influence of different splinting methods and fixation periods.

Different data were published documenting the influence of fixation methods and periods on the outcome of autotransplantations of teeth. Besides studies reporting increased ankylosis and disturbances of pulpal revascularization following rigid or extended fixation, there are studies revealing no connection in this matter. The clinical and radiological results of 76 transplanted germs of third molars were to be assessed after a rigid fixation for 4 weeks or after a suture splinting for 7 days and compared with each other. The choice of fixation method depended on the initial stability of the transplant. After a mean observation period of 3.4 years (range 1.0-6.1 years), 92.9% of the teeth stabilized with a suture, but only 73.5% fixed with an acid-etch composite and wire splint could be classified as successful (P = 0.029). The significant increases in ankylosis (P = 0.036) and pulp necrosis (P = 0.041) were the factors for the less favorable results of the rigidly fixed teeth. Our data support the results of other experimental and clinical studies with regard to the negative influences of an extended and rigid fixation on the success of tooth transplantation. However, apart from a correlation with the method and period of fixation, we also suspect the influence of an incongruity between the transplant and recipient site.

Adolescent↗