Survival of retained permanent canines after autotransplantation: A retrospective cohort study.

INTRODUCTION: After third molars, canines are the teeth most commonly affected by displacement and impaction. Although orthodontic surgical treatment represents the standard method for realignment of canines, autotransplantation (autoTX) functions as the second-line therapy if orthodontic alignment does not succeed in treating impaction and severe displacement. This retrospective cohort study aimed to identify clinical predictors for postoperative survival and endodontic treatment needs after autoTX of severely displaced and impacted canines. METHODS: The study cohort comprised patients who received canine autoTX in a single surgical center between 2006 and 2018. Canines with severe displacement and retention were surgically treated using a standardized protocol. Statistical analysis of survival probability was performed with the Kaplan-Meier method, and bivariate data were analyzed using logistic regression and the Pearson chi-square test. Nonparametric continuous variables were analyzed using the Mann-Whitney U test. RESULTS: Data from 319 patients with 378 canine grafts were available for analysis after a mean follow-up of 54.7 ± 36.5 months on the patient level (range, 0.3-181.8 months). With 25 lost autotransplants, the cumulative survival rate was 93.4%. Patient age at surgery, the state of the apical foramen, endodontic treatment need, and persistence of deciduous teeth at the implantation site had a significant negative impact on autotransplant survival (P <0.05). Endodontic treatment need was significantly related to the patient's age at surgery, the state of the apical foramen, and preoperative orthodontic traction (P <0.05). Thus, these independent variables were identified as clinical predictors for the survival of both the autotransplant and the dental pulp. Gender, ischemia time, postoperative ankylosis, or site of autoTX did not influence any of the outcome variables. CONCLUSIONS: The high survival rates of autotransplanted permanent canines make this treatment a promising option, especially in patients with severe tooth displacement, in which orthodontic treatment alone cannot provide predictable alignment, irrespective of the patient's age. Interpreting age and preoperative orthodontic traction as delaying the onset of autoTX and state of apex, time-dependent aspects seem to be of great importance for postoperative complications leading to endodontic treatment or graft loss. Therefore, early implementation of autoTX as a treatment modality for impacted, severely displaced, and vain exposed canines in daily surgical practice should be encouraged.

Traumatized teeth: clinical practice guideline for the interim management of teeth with various poor prognosis scenarios in growing patients.

OBJECTIVES: Many treatment options accepted for unsalvageable traumatized teeth in adults would seem contraindicated in children and adolescents. Instead, growing patients need interim restorative measures, thus extensively preserving their local bone and soft tissue structures and, ideally, preparing the involved site for later definitive restoration while they transform to skeletal maturity. This narrative topic review addresses the interim management in case of very deep intra-extra-alveolar fractures, extensive infection-related root resorption, tooth ankylosis, and anterior tooth loss in growing patients, and seeks to empower the clinician to select the appropriate treatment approach. DATA SOURCES: The literature up to 2021 was reviewed based on several scoping searches on PubMed and the Cochrane Library using relevant terms. Due to the complexity of the topic (with various poor prognosis scenarios and the differing therapeutic options), a systematic review was deemed inappropriate. CONCLUSION: Suitable interim treatment options include extrusion of teeth showing deep intra-extra-alveolar fractures, and decoronation of ankylosed teeth as well as resin-bonded fixed dental prostheses, natural tooth pontics, and primary tooth autotransplantations after tooth loss. The interim management options described in this article represent compromises chosen in the absence of better alternatives after a careful risk-benefit analysis. However, if adequately performed, the presented treatment options have the potential to achieve the temporary restoration of function and esthetics in growing patients. Close clinical and (if appropriate) radiologic monitoring of these patients is considered mandatory to ensure early detection of possible complications that might jeopardize or could render impossible subsequent therapeutic measures. (Quintessence Int 2022;53:722-731; doi: 10.3290/j.qi.b3236409; Modified from a previously published article (in German) Quintessenz 2022;73(2):162-169).

Implant-prosthetic rehabilitation of patients with severe horizontal bone deficit on mini-implants with two-piece design-retrospective analysis after a mean follow-up of 5 years.

BACKGROUND: As a consequence of tooth loss due to trauma or extraction, a reduced alveolar crest volume limits the deployment of standard implants in certain patient cases. For this reason, minimal-invasive treatment with mini-dental implants (MDI) might be an option to allow implant treatment even in cases with severe horizontal bone loss without augmentation measures. The aim of this retrospective cohort study was to investigate clinical and radiological implant, as well as patient-related parameters after treatment with MDI. RESULTS: Clinical and radiological records of 19 female (82.6%) and 4 male patients (17.4%) (N = 23), who received 52 mini-dental implants with a two-piece design in a single surgical center between November 2011 and October 2018, were retrospectively analyzed. Implants were submitted to conventional loading on different types of screwed superstructures. Crestal bone loss was measured on standardized periapical radiographs. Patient-related outcome parameters (PROMs) were recorded during follow-up period. Mean clinical and radiological follow-up was 69.6 months (5.8 years) and 51.6 months (4.3 years), respectively. Three implants were lost in two patients, leading to an implant survival rate of 94.2%. Mean radiological crestal bone loss was 1.6 mm. Both amount of peri-implant recession and crestal bone loss were significantly correlated (r = 0.65; p < 0.001). Likewise, a significant correlation was observed between deeper probing depths and increased peri-implant bone loss (r = 0.41; p = 0.012). Alveolar ridges with a reduced alveolar crest width were significantly correlated with higher peri-implant bone loss as well (r = - 0.33; p = 0.011). No prosthetic complications were reported during follow-up. Extent of midfacial recession and papilla height loss had a significant negative impact on most of the PROMs. CONCLUSIONS: Treatment with MDI seems to be a successful alternative treatment option, especially for elderly patients with reduced crest width at implant sites. Due to the good clinical results and high survival and success rates, this treatment option was associated with high patient satisfaction. Despite the promising results, particular consideration should be given to appropriate treatment planning in these patients due to the strong correlation between peri-implant soft-tissue parameters, crestal bone loss, and reduced alveolar crest width.

Primary tooth autotransplantation: update and retrospective clinical study.

OBJECTIVE: A new technique of primary tooth autotransplantation has recently been published demonstrating reliable replacement of missing permanent incisors in young children due to trauma or agenesis. This retrospective clinical study reports on the longterm success of this new technique in a larger patient group regarding its potential to support bone and soft tissue growth. STUDY DESIGN: 40 children (age range: 2.7-17.6 years) received 53 primary tooth autotransplants (49 canines and 4 incisors) due to traumatic tooth loss (73%), agenesis (19%) or dysplasia/displacement (8%). Clinical and radiological follow-up examinations were performed to check up on root resorption, bone and soft tissue growth, survival and success. RESULTS: 22 transplants still present in the oral cavity of 18 patients yielded a success rate of 77%. The Kaplan-Meier estimator measured a median survival time of 86 months (7.2 years) for all 53 grafts. In all cases, increasing soft tissue and bone development enabled a successful prosthetic rehabilitation regarding aesthetics and function. CONCLUSIONS: Primary tooth autotransplantation reliably restores edentulous anterior space in children experiencing traumatic tooth loss or agenesis and acts as an immediate therapy before other therapies such as premolar transplantation or orthodontic space closure can be carried out at a later time. It guarantees the co-development of soft tissue and bone in the teenage jaw which is associated with high patient satisfaction and acceptance of this method.

The influence of storage temperature on fracture behavior of cryopreserved teeth-An in vitro study.

OBJECTIVES: Cryopreservation is discussed as a viable method of preserving teeth for determined autogenous tooth transplantation. Unchanged physical properties of hard tooth tissues are crucial for functional healing. Due to different thermal expansion coefficients of enamel and dentin or the crystallization process, the freezing process may lead to crack formation, which could adversely impact the long-term prognosis of the teeth. MATERIAL AND METHODS: Twenty third molars (n = 20) were frozen slowly using a conservative cryopreservation protocol and stored at -80°C (group 1) and -196°C (group 2). After a storage time of 2 weeks, the samples were thawed to a temperature of +36°C and embedded in polymethyl methacrylate blocks. Cyclic loading was carried out using a spherical steel test specimen with 50,000 mechanical load cycles, followed by load to failure testing for determination of critical load. RESULTS: No significant difference in the first load drop could be detected during the load to failure test under different storage conditions. The values until fracture correlated very closely in contralateral tooth pairs, which emphasizes the importance of crown geometry in load to failure tests. CONCLUSIONS: Conclusions: Cryopreservation, specifically the storage temperature, does not appear to have a significant effect on the physical properties of tooth transplants.

Premolar autotransplantation in juvenile dentition: quantitative assessment of vertical bone and soft tissue growth.

OBJECTIVE: Premolar autotransplantation represents an effective therapeutic option for the treatment of juvenile dentition with either aquired or congenital hypodontia. The objective of this prospective clinical study was to quantitatively assess bone and soft tissue levels after autogenous premolar transplantation by clinical and radiographic parameters. STUDY DESIGN: In the study, 26 premolars were transplanted in 20 patients after traumatic tooth loss (n = 16) or congenital aplasia (n = 10) in the anterior maxilla. Based on standardized photographic documentation, the relative soft tissue level was measured compared to the healthy adjacent teeth. Radiographic findings included evaluation of root resorption, pulp canal obliteration, and relative bone height. RESULTS: Average survival rate of transplanted premolars (n = 26) was 100% over a follow-up period of 29 months (range 10-60 months). The relative soft tissue level significantly increased by +1.1 mm (P < .01). Radiographs showed a tendency toward vertical bone growth. Continuous root development and signs of pulpal healing were observed postoperatively in 18 transplants (69.2%). CONCLUSIONS: Autogenous premolar transplantation represents a safe method to ensure functional and aesthetic rehabilitation in the anterior maxilla irrespective of the nature of tooth loss.

Laser therapy of a dermal nevus in the esthetic zone of the nasal tip: A case report and comprehensive literature review.

This case report demonstrates the ablation of a dermal nevus using a diode laser in the esthetically very demanding facial area of the nasal tip. The clinical outcome shows good results and a high level of patient satisfaction. Due to effective wound granulation and healing, elaborate skin grafts could be avoided. The application of the contact laser ensures safe treatment in highly perfused areas thanks to haptic feedback and good coagulative effect. The method should therefore be considered as an alternative to other ablative procedures for benign lesions in the facial area.

Primary canine auto-transplantation: a new surgical technique.

OBJECTIVE: The aim of this study was to investigate whether the growth of soft tissue and bone in children with traumatic tooth loss or agenesis of teeth can be developed reliably, using a new technique of autogenous primary canine transplant. STUDY DESIGN: A total of 10 patients (age range, 7-13 years) were treated either for trauma or for agenesis (n = 14 primary canine transplants). In addition to the clinical examination, patients were subjected to radiologic examinations with regard to root resorption, bone height, and soft tissue level. RESULTS: With an average survival rate of 87%, the average survival time of the transplants using the Kaplan-Meier estimator was 5.2 years. In all cases, soft tissue and bone growth was effectively developed. CONCLUSIONS: Autogenous primary canine transplant is a reliable surgical method for rehabilitating children in the early mixed dentition after traumatic tooth loss, enabling adequate soft tissue and bone growth.

Autotransplantation and surgical uprighting of impacted or retained teeth: A retrospective clinical study and evaluation of patient satisfaction.

OBJECTIVES: This retrospective clinical study aimed to determine the success rate of autotransplanted impacted or retained teeth along with a patient satisfaction survey and to analyze the influence of relevant clinical and radiographic parameters. SUBJECTS AND METHODS: Fifty-seven teeth (37 canines, 10 molars, seven premolars, three incisors) in 45 patients (median 15 years) were evaluated over a mean of 1.6 years. The success criteria were pocket probing depth ≤3.5 mm, mobility grade ≤ II, Periotest ≤30 and complete alveolar bone healing. The influencing parameters were oral hygiene, smoking, periodontal screening index, occlusal/proximal contacts, horizontal position, dental age, pulp obliteration and degree of displacement. Furthermore, bone height was measured. RESULTS: The overall success rate was 74%, along with a high patient satisfaction. The survival rate was 96% after a mean follow-up of 1.6 years. The favorable factors were proper oral hygiene, non-smoking, good general periodontal condition, proximal contacts and pulp obliteration. An increase in or maintenance of bone level was found in 96%. CONCLUSIONS: Autotransplantation of impacted or retained teeth is an appropriate treatment, if orthodontic alignment has failed, especially in growing patients.

Fiber optical spatial filter anemometry--intravital measurement of red blood flow velocity (RBCV) in the microcirculation.

The fiberoptical spatial filter anemometry (SFA) is a common technique based on an optical grid to measure the velocity of corpuscular components in a multiphase flow, e.g. in the microvessels. The technical innovation is the analysis of flow velocities using an optical grid sensor and frequency analysis by Fast Fourier Transformation (FFT). This study describes a non-invasive, on-line technique to measure RBCV in the microcirculation. The sensor's validity was proven by in vitro measurements using a rotation disk of an exactly defined velocity with a correlation coefficient of 0.99967. For validation of RBCV measurements in the microcirculation in vivo, the setup was adapted to an intravital microscope. RBCV was measured in arterioles, capillaries, and postcapillary venules ranging from 8-140 microm diameter. As reference method for velocity measurements a computer assisted imaging system was used to measure the RBC-velocity in the identical vessels by frame to frame analysis. Both methods revealed a high significant correlation using transillumination technique for capillaries (r=0.986, p<0.001) and venules (r=0.952, p<0.001) as well as epiillumination technique (capillaries r=0.939, venules r=0.975, p<0.001).

Atrophy of free fibular grafts after mandibular reconstruction.

BACKGROUND: In free fibular flap surgery, the graft's low vertical height and tendency to resorb over time have been considered potential drawbacks. This study investigated (1) short- and long-term bone resorption in free fibular grafts; (2) resorption behavior of fibular grafts versus dentulous and edentulous autochthonous mandibular bone; and (3) factors that potentially influence long-term bone atrophy, such as site of reconstruction, presence of osseointegrated dental implants, patient age, and adjuvant radiation therapy. METHODS: Between 1992 and 2004, 113 patients received free fibular grafts. Fifty-four of these patients were examined retrospectively. Postoperative Panorex examinations assessed loss of bone height per month. Standardized miniplate measurements served as a reference to prevent errors caused by projection on magnification. RESULTS: Follow-up ranged from 6 months to 12 years. According to Jewer's classification, the following defect types were found: L, 23 (42.6 percent); H, five (9.3 percent); C, two (3.7 percent); LC, 12 (22.2 percent); HC, nine (16.7 percent); and LCL, three (5.6 percent). Radiographic analysis revealed a monthly atrophy of 0.04 +/- 0.08 mm (mean +/- SD) for fibular bone, 0.14 +/- 0.11 mm for dentulous mandibula, and 0.20 +/- 0.17 mm for edentulous mandibula. The difference in bone loss between fibula and edentulous or dentulous bone was significant (Friedman's test and Wilcoxon paired-sample test, p < 0.0001 and p = 0.02, respectively). Investigated factors had no significant influence on bone resorption rate. CONCLUSIONS: Fibular grafts show short- and long-term stability. Their rate of atrophy is significantly lower than that of edentulous or dentulous mandibular bone. Thus, implants can be inserted into this bone graft just as successfully as they are inserted into adjacent mandibular bone when the same bone height is present.

Effects of Diaspirin Crosslinked Hemoglobin (DCLHb) on microcirculation and local tissue pO2 of striated skin muscle following resuscitation from hemorrhagic shock.

The hemoglobin based oxygen carrier (HBOC) Diaspirin Crosslinked Hemoglobin (DCLHb) has been developed to substitute not only the blood volume, but also to restore the oxygen-carrying properties of blood during hemorrhagic shock. However, it has been suggested that HBOCs may enhance the formation of free oxygen radicals through the release of free iron ions via the Haber-Weiss reaction. The aim of this study was to investigate the effects of DCLHb on the microcirculation, leukocyte-endothelial cell interaction and local tissue oxygenation in striated skin muscle of Syrian golden hamsters during and after resuscitation from hemorrhagic shock. In particular we focused on the local tissue oxygenation after resuscitation with DCLHb (hemoglobin content 10 g%) compared to resuscitation using autologous blood diluted to a hemoglobin content of 10 g%. Hemorrhagic shock was induced for 45 minutes by bleeding the animals at a rate of 33 ml/kg BW maintaining a mean arterial pressure of 30 +/- 5 mmHg. Animals were resuscitated either with 33 ml/kg BW 6% Dextran-60.000 or with 10 g% DCLHb. The control group received shed blood diluted with Ringers to a hemoglobin content of 10 g%. Intravital microscopy was used for investigation of the microcirculatory parameters and a multiwire platinum surface electrode for measurement of local tissue pO2 in striated skin muscle in the dorsal skinfold chamber of Syrian golden hamsters. Resuscitation from hemorrhagic shock with 10 g% AUB revealed significant increase of leukocytes rolling in postcapillary venules at 30 to 120 minutes after resuscitation compared to baseline values. DCLHb turned out to reduce the number of firmly adherent leukocytes after resuscitation compared to 10 g% AUB. Microvascular permeability as an indicator for functional endothelial integrity revealed no significant differences between the groups. DCLHb and 10 g% AUB led to a significant increase in local tissue oxygenation after resuscitation from hemorrhagic shock. However, 10 g% AUB turned out to be most effective to restore the local tissue pO2 compared to Dx-60. Our findings indicate that DCLHb restores microvascular perfusion after critical hemorrhagic shock as efficient as Dx-60 and 10 g% AUB. The absence of enhanced leukocyte-endothelium interaction after resuscitation with DCLHb implies that this HBOC does not exacerbate formation of oxygen free radicals during reperfusion. DCLHb effectively increases local tissue pO2 after resuscitation from hemorrhagic shock; however, not as effectively as 10 g% AUB.

Free flap monitoring using simultaneous non-invasive laser Doppler flowmetry and tissue spectrophotometry.

BACKGROUND: Early identification of flap failure is an indispensable prerequisite for flap salvage. Although many methods of free flap monitoring are available, there is still no single reliable non-invasive technique for early recognition of flap failure and for differentiation between arterial occlusion and venous congestion. The aim of this study was to investigate the benefits of the tissue oxygen analysis system O(2)C for monitoring patients undergoing maxillofacial reconstruction with fasciocutaneous radial forearm flaps. MATERIAL AND METHODS: In a prospective clinical study the microcirculatory parameters of blood flow, flow velocity, haemoglobin concentration (AU, Arbitrary Units) and oxygen saturation (%) were assessed by clinical means, by laser Doppler flowmetry and tissue spectrophotometry in 61 patients intraoperatively. Measurements were carried out before flap harvest, in the separated radial forearm flap, immediately after anastomoses and up to 14 days after reconstruction. RESULTS: Following anastomosis, blood flow and flow velocity exceeded the level before flap elevation and reached significant differences by the third postoperative day (p<0.05). Oxygen saturation decreased significantly by the third postoperative day and haemoglobin oxygenation showed stable values after performing anastomosis. Simultaneous, non-invasive laser-Doppler flowmetry and tissue spectrophotometry detected vascular complications in all cases with no false positive or false negative results and prior to clinical assessment. CONCLUSION: For the first time this new device allows reliable prediction of venous congestion by an increase of haemoglobin-concentration, and of arterial occlusion by a decrease in blood flow parameters and oxygen saturation. It can thus differentiate the mechanisms of flap failure before clinical assessment.

Bilateral synchronous submandibular lumps in a patient with gastric carcinoma.

This case report deals with a patient who was readmitted with a bilateral submandibular swelling after having received primary surgery due to gastric adenocarcinoma 6 months before. After bilateral submandibulectomy both glands were diagnosed histopathologically as metastasis of adenocarcinoma. This is the rare case of a submandibular gland metastasis and the first case of a bilateral synchronous submandibular gland metastasis from gastric carcinoma.

In vivo visualization of platelet/endothelium cell interaction in muscle flaps.

Increasing evidence underlines the substantial pathophysiological impact of platelets on the development of ischemia/reperfusion injury (I/R) in flaps. Methods for studying dynamic platelet mechanisms in flaps in vivo are not available. The aim of this study was to develop a model enabling quantitative analysis of platelet kinetics and platelet-endothelium cell interaction within the microcirculation of muscle flaps in vivo. Balb/c mice (n = 16) were anesthetized, and an epigastric muscle flap was prepared. Autologous platelets were separated from blood donor animals (n = 16) and labeled ex vivo by means of rhodamine-6-G. After I/R (90 minutes' clamping, 10 minutes' reperfusion), the platelets were administered intra-arterially (i.a.). Microhemodynamics and kinetics of platelets were investigated by intravital fluorescence microscopy. I/R of muscle flaps induced disturbances in microcirculation. The number of rolling platelets, as well as platelets adhering to the inner vessel wall of venules, was increased in the ischemia group. Using intravital fluorescence microscopy, platelet kinetics were analyzed directly in flap microcirculation in vivo for the first time. Since platelet/endothelial cell interaction is a key event in the pathophysiology after microsurgical procedures, this model will help to understand basic molecular mechanisms of platelet behavior during I/R.

Degradable injectable bone cement in maxillofacial surgery: indications and clinical experience in 27 patients.

BACKGROUND: A carbonated apatite cement (NORIAN SRS) was used as a bone mineral substitute for the calvaria or viscerocranium in 27 patients. It has the consistency of a paste and hardens at physiologic pH and body temperature due to dahllite crystallization, which has the stoichiometric formula Ca(8.8)(HPO(4))(0.7)(PO(4))(4.5)(CO(3))(0.7)(OH)(1.3). MATERIAL AND METHODS: The cement was used for posttraumatic bone defects in the orbital, periorbital or malar regions (nine patients), posttraumatic deformities of the frontal bone (six patients), tumour-dependent bony defects of the calvaria (two patients) and posttraumatic or cystic defects of the mandible (five patients). In another five patients, the material was used to augment the atrophic anterior mandible in combination with the insertion of dental implants. Follow-up varied between 6 and 40 months (mean: 29 months). RESULTS: There was no inflammatory reaction surrounding the implanted material. There was no sign of infection in any of the patients and only one case of partial wound dehiscence with superficially exposed material. The defect fillings and augmentations were successful in all patients. None of the 19 dental implants which were inserted in combination with the material showed any sign of infection or loosening. Also, there was no loosening of the implants after loading (mean follow-up: 15 months). From the check-up radiographs, the material could be seen as a dense, radio-opaque structure. There were no material fractures or dislocations. Radiologically, the material seemed to be completely replaced by bony tissue after 30 months. CONCLUSION: Our 5-year clinical experience suggests that the material is a suitable bone mineral substitute for cranio-maxillofacial surgery especially for moderate-sized defects of the calvaria and forehead bone. It has advantages over preformed, solid bone substitute materials, and, due to its initial plasticity and eventual great compressive strength, it can also stabilize dental endosseous implants in the atrophic mandible.

Long-term anaesthesia using inhalatory isoflurane in different strains of mice-the haemodynamic effects.

The aim of this study was to establish a simple and safe method of anaesthesia for intravital microcirculatory observations in small laboratory animals. The usefulness of isoflurane inhalation anaesthesia has been investigated in different strains of mice commonly used in experimental medicine. These were the hairless (hr/hr, n = 12), the BALB/c (n = 12) and the nude mouse (nu/nu, n = 3). Anaesthesia was maintained by mask inhalation of isoflurane vaporized at concentrations of up to 4% in the induction phase, at 1.5% during acute surgical procedures and at 0.8-1.3% during prolonged experimental observations. Isoflurane was vapoured in a N(2)O/O(2) mixture and saturated with 32-36% F(i)O(2). During observations the body temperature was kept constant at 37 degrees C. The tail artery was cannulated for monitoring of mean arterial blood pressure (MAP) and heart rate (HR). To maintain the body fluid balance, isotonic saline was administered at a constant rate of 0.2 ml/h. Arterial blood samples were drawn for blood-gas analysis at the end of the experiments. All animals survived the anaesthesia protocol lasting between 3 and 6.5 h. During isoflurane inhalation, no breathing complications or changes in systemic circulatory parameters were observed. Mean values of MAP and HR were 79+/- 3 mmHg and 486+/- 13 min(-1), respectively, over the entire observation period. A moderate acidosis was recorded in animals under isoflurane anaesthesia, with alterations of arterial blood pH, p(a)O(2) and pCO(2) values (7.29+/- 0.06, 130+/- 19 mmHg and 35.6+/- 4.7 mmHg, respectively). In conclusion, inhalation anaesthesia with isoflurane is useful for experimental studies in the mouse due to (1) the simplicity of administration of the anaesthetic, (2) the rapid induction of anaesthesia, (3) easy control of the depth of anaesthesia, (4) the low percentage of complications, and (5) stable MAP and HR during observations lasting several hours. The proposed technique is especially suitable for observations of the microcirculation under intravital fluorescence microscopy.

Perforator flaps from the lateral lower leg for intraoral reconstruction.

Perforator flaps are based on cutaneous, small-diameter vessels that originate from a main pedicle and perforate fascia or muscle to reach the skin. Although these flaps have recently become popular for soft-tissue reconstructions in nearly all regions of the body, the systematic application of perforator flaps with short, small-caliber pedicles for intraoral reconstruction has not been reported. Experience with the use of 10 consecutive perforator flaps from the lateral lower leg for intraoral defect coverage is reported. In 10 cases, a 4- to 6-cm-long septocutaneous or myocutaneous perforating vessel from the peroneal artery, with a diameter of 1 to 2 mm, could be identified in the proximal one-half of the lateral lower leg. The thin, pliable skin paddles, measuring up to 6 x 8 cm, were used for defect coverage after resection of squamous cell carcinomas of the floor of the mouth (five cases), soft palate (one case), tongue (two cases), or buccal mucosa (two cases). Anastomoses were performed to the lingual artery and concomitant vein. Except for one case, all perforator flaps healed without complications and the functional results were satisfying. At the donor site, which was always closed directly, an approximately 15-cm-long scar resulted, without functional impairments. The peroneal artery was regularly preserved. Perforator flaps from the lateral lower leg might have many applications for intraoral soft-tissue reconstruction, especially because of their minimal donor-site morbidity.

Nutritive perfusion at donor site after microvascular fibula transfer.

There are many reports on the versatility of the fibular flap, but only a few studies have reported on the morbidity, and none on the nutritive perfusion, of the donor site. This study describes for the first time the quantitative investigation of nutritive perfusion at the donor site after osteomyo-cutaneous fibula transfer. Tissue nutrition of the lower leg was measured in 25 patients by micro-lightguide spectrophotometry and laser Doppler flowmetry. In a standardized examination, hemoglobin oxygenation and blood flow of the donor leg and the contralateral leg (intraindividual control) were measured at the nutritive region of the peroneal artery (I), posterior tibial artery (II), and anterior tibial artery (III). In the operated leg, blood flow was significantly reduced in region I with the sacrificed peroneal artery, and significantly increased in region II and III, probably for compensation (P = 0.03). Decreased hemoglobin oxygenation and blood flow of the peroneal region at the donor site were without significance in comparison to the control leg (P = 0.55 and P = 0.35, respectively). Decreased nutritive perfusion at the donor site was below the threshold of clinical manifestation, and supports the low donor site morbidity following fibular grafting.

Effects of ultra-purified polymerized bovine hemoglobin on local tissue oxygen tension in striated skin muscle -- an efficacy study in the hamster.

The development of hemoglobin-based oxygen carriers has been propagated for replacement of the oxygen carrying properties of red blood cells for almost one century. Using a Clark-type multi-wire oxygen surface electrode and the dorsal skin fold chamber model of the awake Syrian golden hamster, local tissue pO(2) was analyzed in the thin striated skin muscle before and after administration of an ultra-purified polymerized bovine hemoglobin solution (U-PBHb, Biopure Corp., Boston, Mass., USA) under the following experimental conditions: (a) hypervolemic infusion with U-PBHb at approximately 10% of calculated blood volume, and (b) isovolemic exchange transfusion with U-PBHb by replacing approximately 50% of calculated blood volume. Control animals of group a received equivalent treatment with either isotonic saline or dextran 60, control animals of group b received dextran 60. Local tissue pO(2) was found slightly decreased after both hypervolemic infusion and isovolemic exchange transfusion with U-PBHb, while frequency distribution curves of local tissue pO(2) were found more narrow (less values <10 mm Hg and >25 mm Hg), suggesting a more homogeneous tissue pO(2) distribution. The data thus indicate that U-PBHb slightly decreases mean tissue pO(2) after both hypervolemic infusion and isovolemic exchange transfusion which is accompanied by an effective homogenization of local tissue pO(2) distribution as compared to dextran 60.