Biomedical subjects

G Lauer

Publications and source records attributed to G Lauer.

At least 19 recordsLinked to original sources

PubMed2006

[Transoral osteosynthesis of condylar neck fractures using a three-dimensional plate].

AIM: The transoral approach minimizes the risk of damaging the facial nerve. However, stable osteosynthesis with two miniplates at the proximal fragment is often not possible. To achieve a stable fixation also of condylar neck fractures a new delta-shaped plate was developed, which meets the biomechanical demands of this region. This plate was tested in a clinical study. PATIENTS AND METHODS: In total 11 patients suffering from 13 condyle fractures (Spiessl I: n=2, Spiessl II: n=10, Spiessl III: n=1, 3 bilateral fractures) were treated via a transoral approach and assessed clinically as well as radiologically in the follow-up period. Functional parameters and fracture alignment were assessed. RESULTS: After 6 months postoperative function had returned to normal with a mouth opening of 42 mm and pro- and laterotrusion of more than 5 mm. Postoperative radiographic controls showed a good fracture alignment in 7 of 8 patients respectively in 6 of 8 cases after 6 months. In 12 of 13 fractures directly postoperative and in 10 of 13 fractures 6 months postoperative, respectively, Towne's view radiographs showed an anatomical correct position. No plate fracture and no bending of plates were observed. Loosening of screws was found in 2 patients during plate removal. CONCLUSION: The newly developed three-dimensional plate was easy to handle, and a sufficiently stable osteosynthesis of condyle fractures was possible. This plate can be recommended for surgical fracture treatment via a transoral approach omitting extraoral scars and damage to the facial nerve.

Adolescent↗

PubMed2006

Do antiviral CD8+ T cells select hepatitis C virus escape mutants? Analysis in diverse epitopes targeted by human intrahepatic CD8+ T lymphocytes.

Hepatitis C virus (HCV) is a variable RNA virus that can readily establish persistent infection. Cellular immune responses are important in the early control of the virus. Evidence from animal models suggests that mutation in epitopes recognized by CD8+ T lymphocytes may play an important role in the establishment of persistence but in human persistent infection, equivalent evidence is lacking. We investigated this by analysing a unique resource: viruses from a set of chronically HCV-infected individuals in whom the CD8+ T-cell responses in liver had previously been accurately mapped. Virus was sequenced in seven individuals at 10 epitopes restricted by 10 human leucocyte antigen (HLA) molecules. Two main patterns emerged: in the majority of epitopes sequenced, no variation was seen. In three epitopes, mutations were identified which were compatible with immune escape as assessed using phylogenetic and/or functional studies. These data suggest that - even where specific intrahepatic T cells are detectable - many epitopes do not undergo mutation in chronic human infection. On the contrary, virus may escape from intrahepatic CD8+ T-cell responses in a 'patchy' manner in certain specific epitopes. Furthermore, longitudinal studies to identify the differences between 'selecting' and 'nonselecting' intrahepatic CD8+ T-cell responses are needed in HCV infection.

CD8-Positive T-Lymphocytes↗

PubMed2005

[Custom moldable hydroxyapatite collagen composite for repair of osseous defects].

AIM: In the following study we evaluated the biological response of a new freely moldable bone substitute in an animal model. MATERIAL AND METHODS: Critically sized defects were created surgically in the lower jaw of ten adult minipigs. The drill defects were filled with hydroxyapatite collagen paste. After observation periods of 1, 3, 6, 12, and 18 months the mandibles were harvested without wound healing defects for histological evaluation of resorption and bone ingrowth with a sawing and grinding technique. RESULTS: The result of the remodeling process was a complete degradation of hydroxyapatite collagen implants after 12-18 months with reorganization of vital trabeculae oriented in a mature pattern. CONCLUSION: The hydroxyapatite collagen cement works as an osteoconductor and shows signs of direct osseointegration and resorption.

Animals↗

PubMed2003

[Evidence of osteocalcin expression in osteoblast cells of mandibular origin growing on biomaterials with RT-PCR and SDS-PAGE/Western blotting].

A new approach to addressing difficult tissue reconstructive or replacement problems in the oral cavity is to engineer new tissue by using selective cell transplantation on polymer scaffolds. The current study characterized the osteoblastic nature of adherent mandibular cells on biomaterials, which could have a potential use as scaffolds for tissue engineering strategies. Cells of mandibular origin from one patient were cultivated on three different biomaterials (PepGen P-15 trade mark, Frios Algipore, and OsteoGraf/LD-700) for 7 and 14 days and osteocalcin expression was demonstrated by RT-PCR and SDS-PAGE/Western blotting. In order to explicitly characterize only the adherent cells on the biomaterials, we first separated the biomaterials with adherent cells from the culture plate before trypsinization. We could demonstrate that cell growth of adherent mandibular osteoblast-like cells was significantly higher on biomaterials with an organic component (PepGen P-15 trade mark ) in comparison to Frios Algipore and OsteoGraf/LD-700, respectively. In conclusion, only the explicit study of adherent cells at the gene and protein levels gives information about the osteoconductivity of biomaterials.

Alginates↗

PubMed2003

[DiGeorge syndrome/velcardiofacial syndrome: oral and maxillofacial surgery].

The DiGeorge syndrome/velocardiofacial syndrome is the most frequent chromosomal microdeletion syndrome. Partial deletion of chromosome 22q11 may lead to symptoms including facial dysmorphy, hypoparathyroidism, thymic aplasia, congenital heart disease, developmental retardation, and disturbance of speech development. According to the literature, 9% of patients have cleft palate, an additional 5% have a submucosal cleft, and a total of 32% show velopharyngeal insufficiency. We studied 64 children with a cleft, or with delayed speech development and a submucosal or occult cleft, for the presence of the 22q11deletion using fluorescent in situ hybridisation. Five patients had the 22q11 deletion. We conclude that patients presenting with nasal speech and additional anomalies should all be studied for the presence of submucosal or occult clefting and for the presence of the DiGeorge syndrome/velocardiofacial syndrome.

Adolescent↗

PubMed2003

Influence of donor age and culture conditions on tissue engineering of mucosa autografts.

In oral surgery the transplantation of tissue engineered mucosa is used more frequently. The conventional single cell suspension culture method (SCSM) involves murine feeder cells and foetal calf serum. The explant technique (ET) has been used as alternative culture procedure. Aim was to study the efficacy of the ET and the SCSM without feeder cells to grow primary cultures and to test the effects of donor age, of extracellular matrix proteins (ECMP), and of autogenous serum on cell growth in explant cultures. These factors were assessed in cultures of 58 patients overall. In 48 cultures of 12 patients primary cell growth was compared between the ET and the SCSM. Eighteen of 24 cultures were established with the ET whereas only 3 of 24 were established with the SCSM. To test the influence of donor age on cell multiplication, the proliferation rate (DNA synthesis measured by bromodeoxyuridine uptake) and the overall growth (DNA content) was determined in cultures of five young and five old donors. In cultures from old donors (mean age 56 years) proliferation was lower but more sustained relative to the cultures from the young donors (mean age 25 years). In old donors overall in vitro cell growth was only 2/3 of that in young donors. In cultures of 20 donors the influence on cell adhesion and growth of the ECMP fibronectin and laminin was assessed by planimetry. While ECMP augmented explant adhesion, these substances did not enhance keratinocyte growth significantly. Comparing the influence of autogenous and foetal calf serum on cell growth no differences were observed in all cultures of the six donors. In conclusion, the ET without additional ECMP coating and with autogenous instead of foetal calf serum are now used to culture gingival keratinocytes for tissue engineering mucosa grafts. Consequently xenogenous components are avoided, being a considerable advantage.

Adolescent↗

PubMed2002

[Clinical application of tissue-engineered autologous oral mucosa transplants].

BACKGROUND: Tissue engineering of autogenous oral mucosa is a significant enrichment for various indications in oral and maxillofacial surgery. Besides preprosthetic surgery and prelamination of microvascular fasciocutaneous flaps, interdisciplinary work such as reconstruction procedures in cases of hypospadias and epispadias are the main indications for tissue-engineered oral mucosa. RESULTS: One main advantage of this technique is the reduction of second surgical procedures. The morbidity is decreased and the quality of life may be significantly increased. The manufacture of tissue-engineered autogenous oral mucosa up to 15 cm(2) requires a small biopsy of oral mucosa (4-8 mm(3)) and 40 ml of autogenous serum. DISCUSSION: The clinical and morphological long-term follow-up after different surgical procedures with tissue-engineered oral mucosa establishes this technique as an excellent additional tool in oral and maxillofacial surgery.

Female↗

PubMed2002

How to optimize seeding and culturing of human osteoblast-like cells on various biomaterials.

The optimization of seeding and culturing of human osteoblast-like cells on three collagen-based biomaterials (bovine, equine and calf collagen membrane) was studied by cell proliferation and cell colonization (scanning electron microscopy) analysis. Osteoblasts of five patients were seeded onto the three biomaterials and two different parameters were varied: the time intervals between initial seeding and adding culture medium (2 h 6 h. 12 h, 24 h) and the seeding concentration (1 x 10(5), 1 x 10(6), 2 x 10(6)cells/ml) of cells onto biomaterials. The results of the study demonstrated that the time interval between seeding osteoblasts and adding culture medium as well as the seeding concentration effects the cell proliferation and the cell colonization. The best proliferation rate was achieved by adding the culture medium 2 h after initial seeding and with a seeding density of 1 x 10(5) cells/ml. Moreover, all three biomaterials resulted in different proliferation rates. The best proliferation rate resulted with the bovine collagen membrane. In conclusion, the examined parameters are very important for the development of the tissue engineering techniques and in a larger perspective also for reconstructive surgery.

Alkaline Phosphatase↗

PubMed2002

Cellular immune responses against hepatitis C virus: the evidence base 2002.

Hepatitis C virus (HCV) is an RNA virus which is estimated to persistently infect about 170 million people worldwide. After acute infection, there is an initial period during which long-term outcome is decided. There is strong evidence that the cellular immune responses, involving both CD4+ and CD8+ T lymphocytes, are involved at this stage and it is their effectiveness which determines outcome. What is not understood is what determines their effectiveness. The most important component of this is likely to be some aspect of epitope selection, itself dictated by host MHC. Thus, to understand host immunity to HCV, we need to have a detailed understanding of the peptides involved in T lymphocyte responses. In this review, we discuss the peptide epitopes that have been identified so far, and their potential significance. We relate this to a scheme of host defence which may be useful for understanding natural and vaccine-induced immunity.

CD4-Positive T-Lymphocytes↗

PubMed2001

The titanium surface texture effects adherence and growth of human gingival keratinocytes and human maxillar osteoblast-like cells in vitro.

The adhesion, orientation and proliferation of human gingival epithelial cells and human maxillar osteoblast-like cells in primary and secondary culture were studied on glossy polished, sandblasted and plasma-sprayed titanium surfaces by scanning electron microscopy and in thin sections. The primary cultured explants of human gingival epithelial cells attached, spread and proliferated on all titanium surfaces with the greatest extension on the polished and the smallest extension on plasma-sprayed surfaces. In secondary suspension cultures of gingival keratinocytes, attachment spreading and growth was only observed on polished and plasma-sprayed surfaces, but not on sandblasted surfaces. Moreover, the attachment of these cells depended on the seeding concentration as well as on the coating with fetal calf serum. Cells on polished surfaces developed an extremely flat cell shape, but on sandblasted and plasma-sprayed surfaces a more cuboidal shape. In contrast human maxillar osteoblasts seeded as secondary suspension cultures attached very well to all three differently textured titanium surfaces and showed identical growth patterns independent of the titanium surface structure. These findings suggest that cell morphology, orientation, proliferation and adhesion of human gingival epithelial cells in primary or secondary culture are dependent on the texture of the titanium surface whereas no such differences were observed for maxillar osteoblast-like cells. In conclusion, the soft tissue integration and response is more influenced by the surface texture than the process of osseointegration.

Alkaline Phosphatase↗

PubMed2001

Immunohistochemical study during healing of free palatal mucosa grafts on plastic-embedded samples.

This immunohistochemical study describes changes in the histology and in the distribution of the basement membrane components laminin and collagen IV as well as of the cytokeratins (CK)1/2/10/11, CK5/6, CK13, CK14, CK17, CK19 during the take of free split mucosa (epithelial and connective tissue) transplants in humans up to 36 months post-operative. Histology showed a flattening of the epithelial layer within the first 2 weeks after grafting, followed initially by an increase (25-30 layers, week 6) and later on by a decrease of cell layers in the epithelium (15-20 layers, week 20). From that time onwards, clear stratification and reteridges as signs of differentiation were present. Up to day 14 of graft take, the linear staining patterns for laminin and collagen IV were interrupted, which was not observed at any later stage. During this early interval CK5/6, CK1/2/10/11, CK14 and CK17 were expressed in all epithelial layers. The reactions for CK5/6 and CK1/2/10/11 were less intensive. At 6 weeks, CK1/2/10/11 stained the intermediate and superficial layers, being consistent with findings after longer graft take. CK5/6 reacted in the basal and intermediate cell layers, and CK13, CK14 and CK17 reacted in all layers. In the following period up to week 20, CK5/6 were found in the parabasal cells of the intermediate cell layers and the basal cells. CK14 staining was confined to these cell layers too, but also showed some reaction in the superficial layers. CK13 and CK17 were still bound to all layers. At 7 months post-operative, CK5/6 and CK14 were seen in their typical localisation in the basal cell layer and the parabasal cells of the intermediate layers, CK17 was seen mainly in the intermediate layer and CK13 was seen in focal areas of all layers. Anti-CK19 reacted only with single basal and parabasal cells up to week 20. These results suggest that during healing of mucosal autografts there is a sequence of changes in the expression of cell biological differentiation markers that may involve an epithelio-connective tissue interaction before the typical patterns for the donor side were observed again on the gingiva or mucosa of the hard palate.

Adult↗

PubMed2001

Tissue-engineered mucosa graft for reconstruction of the intraoral lining after freeing of the tongue: a clinical and immunohistologic study.

PURPOSE: This article describes the use of tissue-engineered mucosal grafts instead of split-thickness skin grafts after freeing of the tongue in patients who had previous resection of an oral squamous cell carcinoma and initial primary wound closure. PATIENTS AND METHODS: Tissue-engineered mucosal grafts, up to 75 cm2 in size, were cultured from biopsy specimens of the hard palate in 6 patients, starting 3 to 4 weeks before the operation. After freeing of the tongue, the engineered mucosa was implanted on the wound surface by using vaseline gauze as carrier and fixed with an intraoral gauze wound dressing. RESULTS: A good glossoalveolar sulcus was formed in 5 patients, resulting in good mobility of the tongue and a satisfactory denture-bearing surface. In 1 patient, there was a disturbance of wound healing, leading to severe shrinkage of the glossoalveolar sulcus and very limited improvement in tongue mobility. Preoperative bromodeoxyuridine (BrdU) labeling of the graft and postoperative immunohistochemical staining of biopsy specimens from the grafted areas with anti-BrdU showed that the cultured cells are integrated into the newly formed mucosal epithelium. Postoperative histologic investigations showed a differentiation process in the grafted mucosal epithelium, with a change in the expression of cytokeratins. At 6 months postoperatively, the typical pattern of normal nongrafted mucosa was regained. CONCLUSIONS: This investigation provides evidence that tissue-engineered mucosal cells can serve as a graft for large intraoral wounds. Complete intraoral lining is quickly reestablished, and normal epithelial differentiation is seen in the graft area within a 6-month postoperative period.

Adult↗

PubMed2001

A clinical audit on the effect of suction drainage on microvascular anastomosis.

INTRODUCTION: There are reports that thrombosis in microsurgically anastomosed vessels occurred after the vessels were drawn into the suction drains. AIM: To study the effects of suction drainage on microvascular anastomosis. PATIENTS AND METHODS: The authors compared the proportion of complications in 77 patients who had suction drainage (n=45) or no suction drainage (n=32) with microvascular free flap surgery in the head and neck region. Ultrasonography and Doppler flow ultrasonography were performed on five more patients 3 days after the operation. RESULTS: There were no significant differences between the two retrospectively evaluated groups for incidence of postoperative complications. Ultrasound in the prospective study group revealed that vessels were neither sucked into the suction drain nor displaced towards the drain. CONCLUSION: These findings contravened the reports of vessels being sucked into drains and therefore the clinical use of suction drainage in conjunction with microsurgery in the head and neck region is still advocated.

Anastomosis, Surgical↗

PubMed2001

Intraoral wound closure with tissue-engineered mucosa: new perspectives for urethra reconstruction with buccal mucosa grafts.

In urethra reconstruction, the creation of a new urethra from a free oral mucosa graft is an established surgical technique. The oral mucosa is removed at the same time that the urethra reconstruction procedure is performed. Depending on the size of graft required, the intraoral wound is closed primarily or left to heal secondarily. The latter method limits this technique by leading to scars or strictures, which have a negative impact on the condition of the intraoral soft tissue. Therefore, in this study, a pilot study involving 12 patients, tissue-engineered mucosa was tested for covering intraoral defects to avoid the drawbacks mentioned above. For mucosa tissue-graft engineering, a biopsy sample 2 to 4 mm in diameter was removed from the hard palate approximately 4 weeks before the urethra reconstruction procedure was to be performed. In addition, 30 ml of autogenous serum was extracted from a venous whole-blood sample. The primary cultures were incubated in Dulbecco modified Eagle's medium and nutrient factor F 12 (Gibco Co., Eggenstein, Germany), containing the usual additives and autogenous serum. After a period of 3 weeks, subcultivation was performed to engineer mucosa transplants consisting of several layers of keratinocytes on a support foil. After thorough intraoperative blood coagulation had occurred, the cultured mucosa graft on the carrier foil was applied on the wound surface and fixed by single sutures. Additionally, the cultured mucosa graft was covered for 8 to 10 days by an intraoral dressing, which was also fixed onto the wound surface by single suture loops. It is possible to perform primary intraoral wound closure with tissue-engineered mucosa to cover defect sizes as large as 11.0 x 4.0 cm. This new method provides a better prospect for both urethra reconstruction and the reconstruction of intraoral tissue defects. The number and size of intraoral scars and strictures are diminished. This is of special interest for the reconstruction of the functional unit oral cavity, including soft tissue and cosmetic conditions (e.g., in case of prosthetic rehabilitation). In comparison to primary wound closure with local tissue, the technique presented in this study reduces the severity of postoperative pain and allows faster rehabilitation in patients because of a better wound-healing process. Furthermore, better mobility of intraoral soft tissue structures is achieved.

Adolescent↗

PubMed2001

Prelaminating the fascial radial forearm flap by using tissue-engineered mucosa: improvement of donor and recipient sites.

In reconstructive surgery, prelamination of free flaps using split-thickness skin is an established technique to avoid the creation of a considerable defect at the donor site, for example, in the case of a radial forearm flap. For oral and maxillofacial surgery, this technique is less than optimal for the recipient site because the transferred skin is inadequate to form a lining in the oral cavity. To create mucosa-lined free flaps, prelamination using pieces of split-thickness mucosa has been performed. However, the availability of donor sites for harvesting mucosa is limited. The present study combines a tissue-engineering technique with free flap surgery to create mucosa-lined flaps with the intention of improving the tissue quality at the recipient site and decreasing donor-site morbidity. On five patients undergoing resection of squamous cell carcinoma of the oral cavity, the radial forearm flap was prelaminated with a tissue-engineered mucosa graft to reconstruct intraoral defects. Using 10 x 5 mm biopsies of healthy mucosa, keratinocytes were cultured for 12 days and seeded onto collagen membranes (4.5 x 9 cm). After 3 days, the mucosal keratinocyte collagen membrane was implanted subcutaneously at the left or right lower forearm to prelaminate the fascial radial forearm flap. One week later, resection of the squamous cell carcinoma was performed, and the free fascial radial forearm flap pre- laminated with tissue-engineered mucosa was transplanted into the defect and was microvascularly anastomosed. Resection defects up to a size of 5 x 8 cm were covered. In four patients, the graft healed without complications. In one patient, an abscess developed in the resection cavity without jeopardizing the flap. During the postoperative healing period, the membrane detached and a vulnerable pale-pink, glassy hyperproliferative wound surface was observed. This surface developed into normal-appearing healthy mucosa after 3 to 4 weeks. In the postoperative follow-up period, such functions as mouth opening and closing and speech attested to the success of the tissue-engineering technique for flap prelamination.

Aged↗

PubMed2001

Sustained dysfunction of antiviral CD8+ T lymphocytes after infection with hepatitis C virus.

Hepatitis C virus (HCV) sets up persistent infection in the majority of those exposed. It is likely that, as with other persistent viral infections, the efficacy of T-lymphocyte responses influences long-term outcome. However, little is known about the functional capacity of HCV-specific T-lymphocyte responses induced after acute infection. We investigated this by using major histocompatibility complex class I-peptide tetrameric complexes (tetramers), which allow direct detection of specific CD8+ T lymphocytes ex vivo, independently of function. Here we show that, early after infection, virus-specific CD8+ T lymphocytes detected with a panel of four such tetramers are abnormal in terms of their synthesis of antiviral cytokines and lytic activity. Furthermore, this phenotype is commonly maintained long term, since large sustained populations of HCV-specific CD8+ T lymphocytes were identified, which consistently had very poor antiviral cytokine responses as measured in vitro. Overall, HCV-specific CD8+ T lymphocytes show reduced synthesis of tumor necrosis factor alpha (TNF-alpha) and gamma interferon (IFN-gamma) after stimulation with either mitogens or peptides, compared to responses to Epstein-Barr virus and/or cytomegalovirus. This behavior of antiviral CD8+ T lymphocytes induced after HCV infection may contribute to viral persistence through failure to effectively suppress viral replication.

Acute Disease↗

PubMed2000

Expression and proteolysis of vascular endothelial growth factor is increased in chronic wounds.

Degradation of angiogenic mediators might be an underlying cause of chronic wounds. To test this hypothesis, we evaluated the expression and integrity of vascular endothelial growth factor, a potent angiogenic mediator, and its receptors, Flt-1 and KDR, in chronic venous leg ulcerations. Immunohisto- chemical, in situ hybridization, and semiquantitative reverse transcriptase polymerase chain reaction analyses all indicate that expression of vascular endothelial growth factor is elevated in ulcerative tissue, with vascular endothelial growth factor mRNA being especially pronounced in the hyperplastic epithelium of the wound margin. Flt-1 and KDR protein and mRNA were detected in the papillary vessels in close vicinity to the lesional epithelium of chronic wounds. Although increased expression of vascular endothelial growth factor protein was detected in the epidermis, the intensity of this staining was weak compared with the epidermal staining in psoriatic lesions and compared with the strong vascular endothelial growth factor mRNA signal in chronic wounds and psoriasis. To analyze whether this apparent decrease in immunoreactivity could be the result of degradation of vascular endothelial growth factor by proteolytic activities from the wound environment, we examined the stability of recombinant vascular endothelial growth factor in wound fluid from chronic leg ulcers. As demonstrated by sodium dodecyl sulfate polyacrylamide gel electrophoresis, incubation of rVEGF165 with chronic, but not acute, wound fluid resulted in rapid proteolytic degradation of rVEGF165. Protease inhibitor studies indicate that serine proteases, such as plasmin, are involved in this degradation. Together, our data show that, although vascular endothelial growth factor expression is elevated in chronic wounds, increased proteolytic activity in this environment results in its degradation, which may contribute to an impaired wound healing response.

Chronic Disease↗

PubMed2000

Computer-aided 3-D 99mTc-DPD-SPECT reconstruction to assess mandibular invasion by intraoral squamous cell carcinoma: diagnostic improvement or not?

OBJECTIVE: A prospective study was designed to compare computer-aided 3-D 99mTc-DPD-SPECT (Technetium-Dicarboxy propan-single photon emission CT) reconstruction with clinical examination, panoramic radiography, CT scan and conventional 99mTc-DPD-SPECT investigation in the assessment of mandibular bone invasion by squamous cell carcinoma. PATIENTS AND METHODS: Between October 1997 and December 1999, 88 patients with intraoral squamous cell carcinoma of the regions adjacent to the mandible were enrolled in this study. In 50 cases, mandibular resection (segmental or marginal) was performed based on the pre-treatment diagnostic results. Imaging studies were read independently by four experienced observers. RESULTS: No differences could be found between presurgical 3-D 99mTc-DPD-SPECT reconstruction and conventional 99mTc-DPD-SPECT investigation. Both techniques revealed a sensitivity of 100% whereas CT scan showed the greatest specificity (93.8%). SPECT investigation had a specificity of 91.6% and the greatest efficiency (95.4%). The greatest predictive positive value was found for CT scan (92.3%). Clinical examination and panoramic radiography displayed the lowest sensitivity, 82.5% vs. 85.0%, and specificity, 79.2% vs. 89.5% respectively. CONCLUSION: This investigation does not provide evidence that 3-D 99mTc-DPD-SPECT reconstruction has any advantages when compared to conventional 99mTc-DPD-ECT investigation in the assessment of mandibular invasion by squamous cell carcinoma. Despite a sensitivity of 100% the specificity is still in need of improvement. Until newer methods or techniques become available the combination of CT scanning and conventional 99mTc-DPD-SPECT investigation appears to be the best means of detecting tumour invasion preoperatively and is thus helpful in directing appropriate surgical procedure.

Adult↗