Felix Blake

Outcome and complications of 540 microvascular free flaps: the Hamburg experience.

The aim of this study was to retrospectively analyze surgical outcome and complications of 540 free flap procedures performed at the Department of Oral and Maxillofacial Surgery of the University Medical Center Hamburg-Eppendorf during 1987–2005. A total of 532 patients were reconstructed with 540 flaps: 32% were latissimus dorsi flaps, 23% were radial forearm flaps, 21% were iliac crest flaps, 10% were fibula flaps, 6% were jejunal flaps, and 8% were other flaps. Thrombosis of one of the vessels and hematoma were the most frequent causes of failure in microvascular free tissue transfer. A total free flap failure occurred in 34 (6.2%) and a partial flap failure in 42 (7.7%) patients. The most reliable flap in regard to survival was the radial forearm flap. The present study confirms that free flaps are extremely reliable in achieving successful reconstruction of the head and neck.

The biosurgical wound debridement: Experimental investigation of efficiency and practicability

The use of maggot therapy is experiencing a revival in the treatment of problem wounds. Although this alternative therapy is ancient, little scientific research has been aimed at standardizing this therapy. The purpose of our investigation was to determine the debridement efficiency of this therapy, i.e., to compare the use of freely crawling maggots with maggots in a Biobag and to estimate the amount of maggots needed for debridement. We designed an artificial wound model and investigated the rate of decomposition of porcine tissue. Two application alternatives were compared, each being carried out either for 3 or for 4 days, (1) maggots that were allowed to crawl freely over the substrate and (2) maggots confined to a Biobag with no direct contact with the wound. We found that a single maggot was capable of debriding approximately 0.15 g of dead tissue per day. Assuming an absolute difference of <0.05 g per day and maggot as clinically irrelevant, the debridement efficiency of free maggots appears to be similar to those in a Biobag. We were able to determine for the first time the average debriding ability of maggots and thus provide the clinician with data that may help to optimize the maggot therapy by facilitating more exact approximations of the number of maggots needed. Furthermore, the result that the maggots in the Biobag are equal to free maggots in their debriding efficiency will promote its use, especially with respect to the time saved for changing of the dressings. Also, we were able to show that no direct contact is necessary between the maggots and the wound surface, proving that the mechanical crawling effect appears to be neglectable. Because significantly more tissue was metabolized after 4 than after 3 days, application intervals of 4 days appear more appropriate than those of 3 days.

Intraoperative Cone-Beam Computed Tomography in Oral and Maxillofacial Surgery Using a C-Arm Prototype : First Clinical Experiences After Treatment of Zygomaticomaxillary Complex Fractures

PURPOSE To describe the first clinical applications of intraoperative cone-beam computed tomography with an integrated flat-panel detector in oral and maxillofacial surgery after surgical treatment of zygomaticomaxillary complex fractures PATIENTS AND METHODS Nine cone-beam computed tomography datasets of patients with zygomaticomaxillary complex fractures were intraoperatively acquired using a mobile isocentric C-arm (PowerMobil; Siemens Medical Solutions, Erlangen, Germany), including a flat-panel detector. Datasets based on 400, 200, and 100 fluoroscopic images were performed with different tube currents (4.6 mA, 3.3 mA, 2.3 mA, 1.2 mA, and 0.5 mA) and a current tube voltage of 100 kV. Postprocessing resulted in 15 different datasets available for comparison with corresponding preoperative computed tomography datasets. Four oral and maxillofacial surgeons and 2 experienced radiologists evaluated each dataset regarding noise, transition, and the delimitation of landmarks. RESULTS All examinations were successfully performed. Reconstructed datasets showed high-resolution images of all midfacial osseous structures in near-computed tomography quality. Regarding high-contrast structures, detailed analyses of datasets acquired in this study suggest that the parameters 400 projections, 1.2 mA, and 100 kV are sufficient. In terms of soft-tissue visualization, a higher level of mA seems preferable. CONCLUSIONS The tested prototype predicts a new era in cone-beam computed tomography imaging. The integration of a flat-panel detector will overcome the limitations of current available systems. The size of the field of view is increased allowing regularly the visualization of the whole facial skeleton. Particularly in cases of open reduction of unilateral fractures, the assessment of symmetry is of clinical value.

Clinical follow-up examination of surgically treated fractures of the condylar process using the transparotid approach.

PURPOSE The surgical approaches for the open treatment of condylar process fractures have been controversial. In our study, we evaluated the morbidity of the transparotid approach during 2 years of follow-up. PATIENTS AND METHODS A total of 48 patients with condylar process Class II and IV fractures according to classification of Spiessl and Schroll, were included in the present study. Of the 48 patients, 16 were female and 32 male. The patient age range was 16 to 79 years (average 36.52). All patients were treated using the transparotid approach, with rigid internal fixation using miniplates. Follow-up examinations were performed for a minimum of 6.5 months and a maximum of 25 months (average 12.16) after surgical treatment. At the follow-up examination, the patients completed the Mandibular Function Impairment Questionnaire, and the examiner completed the Helkimo index. X-rays taken before, directly after, and 6 months after surgery were compared. RESULTS None of our patients had problems with wound healing; 2 patients developed a fistula of the parotid gland; and 4 patients developed palsy of the facial nerve that was completely reversible after 6 weeks. The results of the Mandibular Function Impairment Questionnaire and the Helkimo index revealed only a few subjective and objective problems after 6 months. CONCLUSIONS The transparotid approach to condylar process fractures is most appropriate for strongly displaced Class II fractures. Especially for very old patients with dementia, for whom maxillomandibular fixation is contraindicated, this approach is very appropriate. Another benefit to this type of patient is the short operating time, with an average of 45 minutes.

Major Mandibular Surgical Procedures as an Indication for Intraoperative Imaging

PURPOSE This study investigated 3-dimensional (3D) imaging with intraoperative cone beam computed tomography (CBCT) in major mandibular reconstruction procedures. PATIENTS AND METHODS The study group was comprised of 125 patients (83 males, 42 females) admitted for surgical treatment of the mandible. The patients ranged in age from 3 months to 91 years (average age, 40.72 +/- 22.843 years). Surgical procedures of the mandible were subdivided into repair of body fractures (17 patients), angle fractures (21 patients), condylar fractures (14 patients), and multiple fractures (30 patient). In addition, the study group included 21 patients undergoing orthognatic surgery and 22 undergoing reconstructive surgery on the mandible. Intraoperatively, 3D images were generated with a mobile CBCT scanner (Arcadis Orbic 3D; Siemens Medical Solutions, Erlangen, Germany). RESULTS During open reduction of mandibular fractures, not all fracture sites can be readily exposed for direct visual control. For example, the lingual cortical bone of the mandible is difficult to assess intraoperatively. This structure and others can be effectively visualized using the 3D mode of CBCT. Furthermore, screw placement can be evaluated, specifically in insertions near the alveolar nerve. The intraoperative acquisition of the data sets is uncomplicated, and the image quality is sufficient to allow evaluation of the postoperative result in all cases. CONCLUSION Intraoperative CBCT has proven to be a reliable imaging technique for providing visual control during major mandibular procedures.

Impact of rhBMP-2 on regeneration of buccal alveolar defects during the osseointegration of transgingival inserted implants

OBJECTIVE New approaches to enhance vertical bone regeneration in clinically relevant implant models are needed. Therefore, we analyzed the impact of recombinant human bone morphogenic protein 2 (rhBMP-2) on the healing of large buccal alveolar defects during osseointegration of transgingivally inserted implants. STUDY DESIGN Twenty-four dental implants were inserted transgingivally in the mandibles of 6 labrador/golden retriever cross-bred dogs. Before implantation, a standardized buccal bone defect was created and refilled with either calcium phosphate as a carrier containing rhBMP-2 or calcium phosphate alone. Either ceramic abutments that enabled immediate implant loading or healing distance collars to prevent loading were mounted. Sixteen weeks after intervention, bone implant units were analyzed by radiofrequency analysis and histomorphometry. RESULTS In total, 14 implants (58.3%) were available for further analysis. The mean depth of the bone defects, the gain of regenerated bone, the vertical osseointegration of the implants, and the bone-to-implant contact in the newly formed bone were slightly greater in the rhBMP-2-containing samples. In contrast, the osseointegration in the preexisting bone was even superior within the non-rhBMP-2-treated specimen. However no differences were statistically significant. CONCLUSIONS When rhBMP-2-conducted bone regeneration was compared with control samples, no significant differences of newly formed bone were found at the bone-implant interface. The amounts of rhBMP-2 applied do not seem suitable to enhance implant osseointegration in large buccal defects.

Intraoral osteotomies using piezosurgery for distraction in an infant with Pierre–Robin sequence

Airway management in infants with Pierre Robin sequence (PRS) is often challenging. Advancement of the tongue base using mandibular distraction in neonates can avoid tracheotomy and is increasingly propagated. The osteotomies can be performed via intra- and extraoral approaches. Nowadays, for precise bone cutting, piezosurgical devices have been introduced in maxillofacial surgery, which we used for osteotomies via the intraoral approach in the 7-week-old patient presented in this study. Instead of a preoperative CT scan, a 3D data set was generated preoperatively in the operating theatre using a 3D C-arm system. After bilateral transcutaneous pin placement and osteotomies, a second 3D data set was acquired. Primary and secondary reconstructions clearly visualized the patient’s bone despite the low level of ossification in newborns and the presence of a large amount of metal implants. In view of the low level of radiation exposure going along with the 3D C-arm imaging, a follow-up examination after removal of the distractors was performed. With this report of a 7-week-old female infant with the diagnosis of PRS, we want to extend the surgical and diagnostic armamentarium for the treatment of infants with PRS.

Clinical indication for intraoperative 3D imaging during open reduction of fractures of the neck and head of the mandibular condyle.

PURPOSE This study aimed to evaluate the use of intraoperative cone-beam computed tomography (CBCT) in monitoring the results of repositioning and osteosynthesis of condylar process and head (capitulum) fractures of the mandible to see if CBCT is beneficial for these patients. PATIENTS AND METHODS Sixty patients (22 females and 38 males, age range 16-79 years, average 36.5 years) with condylar process and head fractures according to the classification of Spiessl and Schroll were treated during the study period. Thirty-four of the 60 patients received a CBCT scan immediately after surgical treatment under aseptic conditions. RESULTS In all 34 cases, intraoperative CBCT provided high-quality imaging of the condylar process in all three planes. In four patients (11.8%), unsatisfactory reposition or unexpected complications were detected which could immediately be corrected with a surgical revision. CONCLUSION Intraoperative use of CBCT enables optimization of the surgical outcome for fractures of the condylar process and head of the mandible, reduces postoperative complications, and spares patients from repeated intervention. In addition, intraoperative CBCT enables safer treatment with minimally invasive approaches.

Distraction osteogenesis in secondary microsurgical mandible reconstruction : Report of seven cases

INTRODUCTION Fibula, ilium and scapula are the preferred donor areas for vascularised bone grafts. For secondary mandibular reconstruction, however, compromises often have to be made as a result of the poor quality of the covering soft tissue and recipient vessels especially in irradiated patients. Callus distraction osteogenesis is a complementary method for optimising the intermaxillary relationship and the facial profile from an aesthetic point of view. MATERIALS AND METHODS Thirteen distractions were performed in seven patients following microsurgical mandibular reconstruction over a period of 4 years, all by the same surgeon. Intra-oral distraction devices were predominantly applied. After a 7-day healing period, the callus distraction was begun, involving two advisements per day of 0.5mm each. The distraction devices were removed after a consolidation phase of 4-5 months. RESULTS Ten of the 13 distractions were uneventful with an average bone lengthening of 20mm, retained after a follow-up time of 6-47 months (average 27 months). The intermaxillary relationship and the facial profile were improved in all cases. Distraction plate fractures, screw loosening or absence of new bone formation were the complications encountered in the other three patients. CONCLUSION Regarding the high complication rate, a successful outcome cannot be expected with greater certainty. Thus the indication should be stringent when including this procedure within the possible treatment alternatives available to the clinician.

Primary osteoplasty using calvarian bone in patients with cleft lip, alveolus and palate

PURPOSE The results of primary bone grafting in terms of initial cleft width, existence or absence of a lateral incisor and scar formation in the donor area are compared. METHODS After primary osteoplasty with calvarian bone at an average age of 24 months (4-56 months) radiographic assessment was carried out in 31 patients with 40 alveolar clefts. The bone formation in the grafted area was assessed using dental radiographs taken at 66 months on average (13-114 months) after primary bone grafting. According to the Abyholm classification patients were assigned to 4 groups (indices I-IV) with indices I and II being rated as a success. RESULTS We observed success (indices I and II) in 76% and poor results (index IV) in 14%. The causes for the poor results were an alveolar cleft width of 11-12 mm in three cases, an extraction of a decayed deciduous tooth 17 months after bone grafting in one case and a traumatic transplant loss in another case. The non-existence of a lateral incisor and a broad cleft are related to poor results. CONCLUSION Based on the results presented, primary bone grafting using calvarial bone seems to be a promising alternative in bridging narrow alveolar defects. This method allows early intervention at an age in which children do not recognize themselves as cleft patients. The preservation of the deciduous teeth is equally important regarding their functional stimulus for bone development.