Biomedical subjects

Rupert Dempf

Publications and source records attributed to Rupert Dempf.

7 recordsLinked to original sources

PubMed2006

Mini- and micro-screws for temporary skeletal anchorage in orthodontic therapy.

OBJECTIVE: Mini- and micro-screws are of increasing interest in orthodontic therapy in cases where maximum anchorage is requested. In this study we aimed to identify the criteria that influence the clinical success of micro-implants. MATERIAL AND METHODS: 239 micro-implants were inserted for skeletal anchorage in 85 patients undergoing orthodontic therapy. The survival rates of the first 133 implants were analyzed and those results were later applied in treating subsequent patients. RESULTS: In so doing, we were able to reduce the loss rate from 23% to 5%. Using thicker implants on the labial side of the lower jaw and the lingual side of the upper jaw was an important factor in reducing failure rates. We found the lower jaw's lingual side to be an inadequate region for inserting micro-implants. Thinner micro-implants were selected for the upper jaw's labial side. CONCLUSION: By following these guidelines, practitioners may find mini- and micro-screws to offer reliable orthodontic support.

Adolescent↗

PubMed2005

Pneumosinus dilatans frontalis: two case reports.

INTRODUCTION: Pneumosinus dilatans was described first in 1898 by Meyes. Up to now only 60 cases have been published worldwide dealing mainly with young men between 20 and 30 years of age. The aetiology remains unknown. Whilst frontal sinuses are affected most often other sinuses can also be involved. The expansion of the pneumosinus is not only an aesthetic problem but may also have functional consequences. There may be a bulging of the roof of the orbit with consequent global displacement, ocular alterations and ptosis. Other features are headache and anosmia. PATIENTS: Two male patients with a pneumosinus dilatans of the frontal sinus are presented. They were 22 and 25 years old. The main complaints were aesthetic disfigurement. Treatment consisted of craniofacial repair of the malformation. RESULTS: While one patient was lost to follow-up, the other still is happy and has a stable aesthetic long-term result.

Adult↗

PubMed2005

Efficacy of dental implants placed into fibula-free flaps for orofacial reconstruction.

OBJECTIVES: The transfer of the osseofasciocutaneus fibula-free flap has become a routine procedure in the reconstruction of comprehensive orofacial defects. Besides its length, major advantages of the fibula-free flap include the trigonal diameter of the fibular bone, which usually allows the placement of dental implants. PATIENTS AND METHODS: In a prospective study, 16 consecutive patients who received free fibula grafts and in total 51 dental implants between 1999 and 2001 were examined. All implants were inserted secondary after bone grafting and loaded after 3 months of submerged healing. The observation period extended 2.5 years on average. The implant success was controlled clinically, radiographically and by resonance frequency analysis. RESULTS: One implant that was located at the interface between the fibula graft and the mandible was lost due to dehiscence and local infection during the healing period. In two other patients, one implant had to remain unexposed as 'sleeper' due to an unfavourable soft tissue situation. The success rate calculated by Kaplan-Meier analysis was 96.1% after an observation period of 1400 days. Resonance frequency analysis (ISQ-values) revealed significant differences related to the orientation (vestibulo-oral/mesio-distal; vo/md) of the transducer unit (P < 0.01). In general, a high primary stability for implants placed in free fibula grafts could be achieved (vo/md 66/74.1), which on average increased slightly during the healing period (vo/md 67.4/75.4) and within 12 month of functional loading (vo/md 72.1/79.9). Additional augmentation with iliac bone grafts or reconstructions with a double barred fibula resulted in an improved reconstruction of the alveolar process, thus allowing superior individual implant positions or angulations, but no elevation of the ISQ-values. CONCLUSION: The fibula-free flap provides a consistent bone graft that allows a reliable and predictable restoration with dental implants.

Adult↗

PubMed2004

Nasalance measures in German-speaking cleft patients.

The purpose of this study was to evaluate nasalance measures in German-speaking patients with different types of repaired cleft lip and palate and to find out if significant nasalance gender differences exist in the different cleft groups. A total of 125 German-speaking cleft patients (74 male and 51 female) were included in this study: 18 patients with isolated unilateral cleft lip (UCL; mean age: 13.00 +/- 2.03 years), 66 patients with complete unilateral cleft lip and palate (UCLP; mean age: 14.80 +/- 3.45 years), 25 patients with isolated cleft palate (CP; mean age: 14.60 +/- 3.48 years), and 16 patients with complete bilateral cleft lip and palate (BCLP; mean age: 14.30 +/- 3.61 years). Nasalance data were collected and computed using the NasalView hardware/software system (Fa. Tiger Electronics, Seattle, WA). Speech stimuli according to a modified Heidelberg Rhinophonia Assessment Form (sustained vowels "a," "e," "i," "o," and "u"; oral and nasal sentences; and three oral-nasal reading passages) were used to obtain nasalance scores. Nasalance distance and ratio were also calculated for the oral and nasal sentences and for one of the oral-nasal reading passages. Unpaired t tests showed no significant gender nasalance differences in each cleft group. Analysis of variance showed no significant differences in mean nasalance distance and ratio. For the nasal sentence, a significant difference (P = 0.032) in mean nasalance scores was found between the UCL and UCLP groups.

Adolescent↗

PubMed2004

Reliability and validity of a modified lateral cephalometric analysis for evaluation of craniofacial morphology and growth in patients with clefts.

In previous intercenter studies on craniofacial morphology in patients with unilateral cleft lip and palate, probable surgical-induced changes in mandibular morphology and spatial position related to posterior vertical maxillary morphology were identified by our group. These changes could not be detected in other cephalometric cleft studies because posterior vertical maxillary height and vertical mandibular ramus length were not measured simultaneously. This study presents a modified digital lateral cephalometric hard and soft tissue analysis (Onyx Ceph software, version 2.5.6.; Image Instruments GmbH, Chemnitz, Germany) to evaluate craniofacial morphology and growth patterns in patients with clefts. Forty controls without clefts were used to evaluate the accuracy, reliability, and validity of this analysis for future cleft research. Measurement error according to the method of Bland and Altman was less than 1.00 degrees and 1.00 mm, whereas squared correlation coefficients (r) according to the method of Sackett et al showed a high reliability. Method comparison tests according to the method of Bland and Altman clearly showed that the modified digital cephalometric analysis ("test") was valid for future cleft research compared with the "gold standard" (conventional cephalometry).

Cephalometry↗

PubMed2004

Craniofacial reconstruction by transport distraction osteogenesis: corticotomy versus osteotomy--an experimental study.

Transport osteogenesis is a modified technique of callus distraction appropriate for the reconstruction of extended osseous defects of long or flat bones. The aim of this study was to determine the regenerative potential of this technique related to the degree of mobilization of the transport segment. In 10 adult sheep, critically sized defects of the calvaria were treated by gradual movement of a transport segment consisting of calvarial bone. The transport segments were either corticotomized (n = 5) or osteotomized (n = 5). The latency period was 5 days; the rate of distraction was 1 mm/d, extended for approximately 40 days. The consolidation period was 28 days. Specimens were investigated by conventional radiography, computed tomography scans, immunofluorescence, and histological examination. In both groups, transport osteogenesis resulted in a complete closure of the defect. The volume and thickness of newly formed bone at the defect site did not differ significantly between the groups, nor did the extent of vascularization. Bone formation and remodeling occurred during the entire period of distraction and consolidation. Osteotomized transport segments became smaller during distraction, whereas the volume of corticotomized segments remained relatively constant. In conclusion, transport osteogenesis resulted in reliable closure of extended skull defects in adult organisms; corticotomy and osteotomy of the transport segment led to a similar extent of bone formation.

Age Factors↗

PubMed2002

Alveolar bone grafting in patients with complete clefts: a comparative study between secondary and tertiary bone grafting.

OBJECTIVE: This investigation evaluated the results of alveolar bone grafting in patients with complete clefts, comparing secondary alveolar bone grafting (during the mixed stage of dentition) versus tertiary bone grafting (after completion of the second stage of dentition). DESIGN: This was a retrospective study. Of 140 osteoplasties, which all were operated according to the same standardized surgical technique, a clinical and roentgenological follow-up investigation was carried out in a collective of 85 osteoplasties. Clinically we searched for oronasal fistulae, assessed the periodontal status, determined the extent of the gingival attachment in the area of the osteoplasty, and searched for vertical growth disturbances in the area of the osteoplasty. Roentgenologically the height of the alveolar bone in the former clefted area was ascertained. SETTING: Records were obtained from a clinical and radiological study of the Department of Oral and Maxillofacial Surgery of the Medical University of Hannover (Germany). INTERVENTIONS: All patients were operated with the same standardized surgical method. The osteoplastic bridging of the alveolar cleft was performed via a vestibular gingival marginal incision and exclusively by grafting of cancellous bone from the iliac crest. RESULTS: The best results of alveolar bone grafting in cases of secondary osteoplasty were obtained when the lateral incisor or canine had grown into the transplant and had led to a functional stress of the transplanted bone. Approximately good results were to be found in tertiary osteoplasty when the transplanted bone had been stressed functionally through a dental implant. Comparing the secondary with the tertiary osteoplasty, there was a trend of lower resorption in secondary osteoplasty. CONCLUSIONS: Secondary osteoplasty should represent an integral component of any concept for the comprehensive treatment of patients with cleft lip and palate.

Adult↗