Biomedical subjects

K O Henkel

Publications and source records attributed to K O Henkel.

13 recordsLinked to original sources

PubMed2002

[Stimulating regeneration of bone defects by implantation of bioceramics and autologous osteoblast transplantation].

QUESTION: Does artificial stimulation of osteoconduction and osteogenesis lead to improved bone formation in defects of critical size? MATERIAL AND METHODS: Full-thickness, critical-sized defects in the anterior mandible were created in 24 adult mini-pigs. These defects were treated with a new kind of bioactive ceramic (60% hydroxylapatite and 40% beta-tricalcium phosphate), applied as a unique sol gel [9]. The bioceramic was tested alone and in combination with autologous osteoblasts. In a control group, periosteum was the only bone-producing source. After 5 weeks, the animals were sacrificed and the defects analyzed clinically, histologically, and by X-ray examination. The effects of periosteum, bioceramics, and osteoblasts were investigated in particular. RESULTS: The new bioceramic was degraded at the same speed as new bone was laid down. The rate of newly formed bone was highest in the bioceramic group at 72.3% (control group with periosteal covering only 59.3%). Additional transplantation of autologous osteoblasts did not result in faster bone production. CONCLUSION: It seems that this bioactive ceramic is successful as a bone replacement material and will be suitable as a carrier for osteoinductive substances such as bone morphogenetic proteins.

Animals↗

PubMed2002

[Millard gingivoperiosteoplasty. An alternative to osteoplasty of alveolar clefts].

PURPOSE: The gingivoperiosteoplasty according to Millard is a possible alternative treatment modality to osteoplasty; no second operation for harvesting the bone graft is necessary. The goal of this investigation was the comparison of gingivoperiosteoplasty with osteoplasty and a search for factors that led to an improvement of the prognosis of both techniques. MATERIAL AND METHODS: Long-term results of 53 patients with 72 alveolar clefts who underwent gingivoperiosteoplasty and 74 patients with 103 clefts of the alveolus were analyzed radiographically following an osteoplasty at the age of 12-14 years. The amount of bone in the alveolar cleft was determined and related to a number of factors such as number of teeth, unilateral or bilateral cleft, and orthodontic treatment. The statistical analysis was done with the Mann-Whitney U-test (p < 0.05). RESULTS: The rate of success was similar following gingivoperiosteoplasty and osteoplasty with a range of 68% to 73%. A postsurgical orthodontic expansion of the alveolus and the existence of lateral incisors improved the prognosis for both techniques significantly (p < 0.05). Teeth erupted into the new periosteally formed bone. This was observed in 82% of those patients in whom enough bone was formed. CONCLUSION: The gingivoperiosteoplasty according to Millard is a real alternative to a common osteoplasty at the age of 12-years if a lateral incisor is found at both cleft margins and if postsurgical orthodontic expansion of the upper jaw is performed.

Adolescent↗

PubMed2002

[Primary "swallowing" function in relation to cleft type after 18 years of interdisciplinary therapy].

PURPOSE: The aim of today's interdisciplinary treatment of clefts is complete aesthetic and functional rehabilitation of the patient. But is it possible to also achieve a physiological swallowing pattern? MATERIAL AND METHODS: At the Rostock cleft center patients are treated by an interdisciplinary approach from their day of birth until their 18th year of life. Tongue position during swallowing was investigated in 117 consecutive patients. They were assigned to four groups. The control group consisted of 197 age-matched patients receiving non-cleft orthodontic treatment. RESULTS: Patients with clefts of only the primary or only the secondary palate achieved physiological swallowing in 87% or 88% of cases at the age of 18. Of the unilateral CLP cases, 74% also had a physiological swallowing pattern, but in patients with bilateral complete clefts this pattern could be observed in only 46%. In comparison, 95% of non-cleft patients achieved a physiological swallowing pattern following orthodontic and speech treatment at the age of 18. The so-called anterior swallowing pattern was the pathological pattern found most often in cleft and non-cleft patients. CONCLUSION: In most cleft patients interdisciplinary treatment leads to a physiological swallowing pattern. Only patients with bilateral clefts of lip and palate have a critical prognosis. They need special care and attention.

Adolescent↗

PubMed2001

[Wavy incision of the soft palate. Modification of intravelar veloplasty].

PURPOSE: The problem with primary soft palate repair is shortness of the soft palate and a soft tissue deficit in this region. The authors introduce a modification of the intravelar veloplasty allowing lengthening of the soft palate at the time of primary closure. METHODS: The "soft palate wavy incision procedure" combines a wavy or undulating type of incision at the velar cleft margins with intravelar veloplasty. In 12 patients with complete clefts of the palate, postoperative breathing and speech was analyzed 3 years later. The investigator did not know whether a modification of the common procedure had been performed in these patients or not. RESULTS: It was found that the soft palate wavy line procedure is easy to perform and closure in three layers is possible even in wide clefts of the soft palate. No postoperative fistula was observed. An average lengthening of the soft palate of about 56% (24-83%) was achieved, measured immediately at the end of surgery. Three years later the patients have good speech results following this technique. CONCLUSIONS: Experience has shown that the soft palate wavy incision procedure is straightforward, safe, and easy. It seems that this technique leads to better results than classic intravelar veloplasty. This paper is only a first report, and further investigations are necessary.

Child, Preschool↗

PubMed2001

Closure of vertical alveolar bone defects with guided horizontal distraction osteogenesis: an experimental study in pigs and first clinical results.

PURPOSE: To evaluate the option of treating alveolar clefts by guided distraction osteogenesis instead of applying osteoplasty with autologous bone grafts from iliac crest, rib or fibula. MATERIAL AND METHODS: At first, 30 land-bred pigs were operated upon. Treatment of each animal included creating bony defects measuring 2, 4 or 8 mm in the maxilla, anterior to the canine region and up to the nasal periosteum. In 15 of the 30 animals, a new horizontal segment distractor was tested. The device was placed in situ prior to creating an alveolar segment posterior to the defect. This segment was then transported gradually by distraction, thus crossing and closing the defect. At the end of the distraction and stabilization periods the newly formed bony tissue was examined. RESULTS: The critical size of defects was found to be larger than 4 mm. In five of six animals with a horizontal defect of 8 mm, complete ossification of the defect had occurred following distraction osteogenesis. This technique was then applied to five patients successfully. CONCLUSION: It was shown that distraction osteogenesis is a valid alternative for treating alveolar clefts.

Adolescent↗

PubMed1999

Perioperative antibiotic prophylaxis in maxillofacial surgery: penetration of clindamycin into various tissues.

Although clindamycin is recommended for prophylactic use in oral and maxillofacial surgery, there is little data available regarding its ability to provide sufficient tissue concentrations at the operative site. We investigated tissue samples from 31 patients, who had to undergo oral and maxillofacial surgery and who received at least one dose of 600 mg clindamycin i.v. preoperatively, to determine clindamycin tissue concentrations in muscle, oral mucosa, fatty tissue, skin and bone between 15 min and 8 h after administration. After homogenization, clindamycin concentration was determined by bioassay. It was demonstrated that clindamycin concentrations above the MIC90 of those pathogens most likely to cause contamination were reached in all kinds of tissues investigated. Already 15 min after administration, tissue concentrations above the MIC90 were reached and were still detectable in the last samples taken between 4 and 8 h after the last clindamycin administration. From the pharmacokinetic point of view, clindamycin is suitable for perioperative prophylaxis during oral and maxillofacial surgery providing sufficient tissue concentrations with no intraoperative additional dosage necessary unless procedures exceed 4 h duration.

Absorption↗

PubMed1999

Dental implants in alveolar cleft patients: a retrospective study.

Since 1994, 15 cleft patients have received dental implants after treatment of the alveolar clefts by osteoplastic measures. Altogether 23 dental implants were undertaken. Twelve implants were inserted after tertiary osteoplasty, 7 with simultaneous repeat-osteoplasty, and another 4 implants following two-stage re-osteoplasty. In 11 patients with a total of 17 implants clinical and radiological follow-ups were performed. An individual crown was constructed on each of the implants. The radiological evaluation revealed that 70% of the implants were fully embedded in bone. All implants except one remained in situ and stable. Thus, the success rate was 96% retention. It is believed that a dental implant in the alveolar cleft may be lost because of its unfavourable location in terms of stability and function or because it was inserted too late. Scars resulting from previous surgery can also play a role in the failure of an implant. Therefore it is proposed that dental implants should not be inserted later than 6 to 8 weeks following osteoplasty of the cleft alveolus.

Adolescent↗

PubMed1998

[What effect does using the Latham devices have on craniofacial growth in uni- and bilateral lip-jaw-palate clefts].

Primary gingivoperiosteoplasty according to Millard consists of active presurgical orthopedic treatment with the Latham device at the age of 4 months and surgical covering of the alveolar cleft by local mucoperiosteum flaps at the age of 6 months. The aim of this investigation was to evaluate the facial growth following use of the Latham device. Lateral head X-rays and plaster casts from 146 patients with unilateral and bilateral clefts of lip and palate were investigated (follow-up of 16 years). Ninety-one of these patients formed the control group and received no Latham device and no gingivoperiosteoplasty. The same surgeon and orthodontist treated all of the 146 patients. Three-dimensional growth disturbance was observed after application of the Latham device and gingivoperiosteoplasty. Forty-two percent of patients with UCLP and 40% patients with BCLP had an "open bite" following closure of the alveolar cleft (control group 5%-10%): the length of the upper jaw was shorter than in the control group and the frequency of cross-bite was higher. These results demonstrate that treatment with a Latham device followed by gingivoperiosteoplasty disturbs facial growth. Therefore this treatment should be rejected.

Adolescent↗

PubMed1998

[Malignant epithelioid schwannoma of the inferior alveolar nerve.Case report with review of the literature].

Malignant epithelioid schwannoma is a very rare disease originating from the Schwann cells. It is a subtype of malignant schwannoma. The limbs are the main location of this entity. In our case study, the inferior alveolar nerve was involved in the mandible. The prognosis for patients with this disease is poor, because metastasis occurs in more than 50%. Clinical and histological features and treatment in a 42-year-old man are discussed in detail. In addition, a short review of the literature and treatment recommendations are given.

Adult↗

PubMed1998

Incidence of secondary lip surgeries as a function of cleft type and severity: one center's experience.

OBJECTIVE: This study was conducted to ascertain the frequency of surgeries typically required to adequately repair a cleft lip. MATERIAL: All operations performed on patients with clefts of the lip (alveolus and palate) from 1968 to 1990 in the Rostock Cleft Center were evaluated. METHODS: Procedures were classified as primary labioplasties versus secondary revisions. Patients were also classified according to cleft type, the anatomical segment revised, and the reason for lip revision. Two indices were calculated. The revision index related the number of revisions to the number of primary labioplasties. The index of indication related the number of patients with revisions to the number of primary labioplasties. RESULTS: During the period of study, 712 primary labioplasties and 771 secondary revisions were performed. The overall revision index was 1.10. The index of indication varied from 0.28 for unilateral complete clefts of the lip to 0.67 for bilateral complete clefts of the lip. Revision of the lip was the most common secondary procedure, followed by nostril and columella revision, and revision of the oral vestibule. CONCLUSIONS: The incidence of secondary surgery of the repaired cleft lip (index of indication) of about 35% is similar to previously reported data. However, the incidence varies with cleft type and is required more often with bilateral complete clefts of the lip.

Adolescent↗

PubMed1997

Analysis of primary gingivoperiosteoplasty in alveolar cleft repair. Part I: Facial growth.

The primary gingivoperiosteoplasty by Millard consists of presurgical active orthognathic treatment ('Latham device') of the alveolar margins at the age of 3 months and of surgical closure of the alveolar cleft with local gingivoperiosteal flaps at the age of 5 months. The aim of this investigation was to analyse the facial growth following this treatment. The following material was studied: lateral head X-rays and plaster casts from 146 patients with unilateral (UCLP) and bilateral (BCLP) clefts of lip and palate from birth to 16 years of age. Ninety-one of these patients formed the control group, who received neither gingivoperiosteoplasty nor pre-surgical active orthognathic treatment. The same surgeon and orthodontist treated all 146 patients. A three-dimensional growth disturbance after gingivoperiosteoplasty was observed: 42% patients with UCLP and 40% patients with BCLP had an 'open bite' following closure of the alveolar cleft (control group 5%/10%). The length of the upper jaw in patients who underwent gingivoperiosteoplasty was shorter than in the control group. The frequency of posterior cross bite was also higher in the gingivoperiosteoplasty group. These results demonstrate that treatment with a 'Latham device' disturbs facial growth. Therefore, this treatment should be abandoned.

Adolescent↗

PubMed1992

[Necrotizing sialometaplasia].

The necrotising sialometaplasia is a rare disease of the orofacial system. The minor salivary glands of the palate are the main localisation. It's clinical importance consists in the possibility of confusion with squamous cell carcinoma or the mucoepidermoid tumor. The authors report on 3 cases and discuss the etiology and the diagnostic of this disease.

Adult↗

PubMedDate not supplied

Biodegradation of titanium implants after long-time insertion used for the treatment of fractured upper and lower jaws through osteosynthesis: element analysis by electron microscopy and EDX or EELS.

Twelve patients underwent an osteosynthesis with titanium to treat upper and lower jaw fractures. Six to 12 months later, the miniplates were removed. Tissue samples were analyzed by light and electron microscopy for detection of a metallosis. The analysis showed new bone formation like callus tissue around the miniplates. In some cases small, rounded deposits and accumulation of colloid-like particles located next to bigger titanium artifacts were detected in the cytoplasm of histiocytes and in the matrix of connective tissue. The titanium was identified by elemental analysis using EDX in SEM as well as by EELS and electron diffraction in TEM. Both kinds of particles contain titanium, but they seem to be different in composition and derivation. The bigger particles seem to consist of metallic titanium and sourced by working on the metallic implants during the implantation itself. On the other hand, the colloidal-like, small, rounded particles in tissue macrophages and outside the cells in the matrix of connective tissue are presumably of other origin; for example, they could be derived from biodegradation and chemical conversion of the metallic implants. The titanium miniplates were examined before and after implantation by using ESCA technique and revealed metallic titanium and different compositions with other elements. The amount of titanium load of the tissue was very low in most cases and presumably not of biomedical relevance.

Biocompatible Materials↗