Risto Kontio

Novel maxillary reconstruction with ectopic bone formation by GMP adipose stem cells

Microvascular reconstruction is the state-of-the-art in many fields of defect surgery today. Currently, reconstruction of large bony defects involves harvesting of autologous bone causing donor site morbidity and risk of infection. Specifically, utilizing autologous adipose stem cells (autoASCs), large quantities of cells can be retrieved for cell therapy applications and the risk of tissue rejection is diminished. The authors describe the first case report of a microvascular custom-made ectopic bone flap employing good manufacturing practice (GMP) level ASCs. The patient underwent a hemimaxillectomy due to a large keratocyst. After 36 months of follow-up, the defect was reconstructed with a microvascular flap using autoASCs, beta-tricalcium phosphate and bone morphogenetic protein-2. ASCs were isolated and expanded in clean room facilities according to GMP standards and were characterized in vitro. After 8 months of follow-up, the flap had developed mature bone structures and vasculature and was transplanted into the defect area. Postoperative healing has been uneventful, and further rehabilitation with dental implants has been started. The in vitro characterization demonstrated multipotentiality and mesenchymal stem cell characteristics in ASCs. This is the first clinical case where ectopic bone was produced using autoASCs in microvascular reconstruction surgery and it will pave way for new clinical trials in the field.

Prevalence and physical status of human papillomavirus in squamous cell carcinomas of the head and neck

Fresh‐frozen biopsies were obtained from 61 patients at diagnosis of squamous cell carcinoma of the head and neck (HNSCC) for study of the prevalence and physical status of human papillomavirus (HPV) DNA. The frequency of HPV DNA and genotypes were determined by SPF10 PCR screening with a general probe hybridization and INNO‐LiPA HPV genotyping assay. In addition, a single‐phase PCR with primers FAP 59/64 and a nested PCR with primers CP 65/70 and CP 66/69 served to detect particularly cutaneous HPV types. By the sensitive SPF10 PCR and INNO‐LiPA assay, 37 of 61 (61%) samples were positive for HPV. HPV‐16 was the most frequently detected type (31 of 37, 84%). Multiple infections were found in 8 of 37 (22%) of the HPV‐positive samples, and co‐infection by HPV‐16 and HPV‐33 was predominant. No cutaneous HPV types were detected. Patients with HPV‐positive tumors had similar prognosis as those with HPV‐negative ones. Real‐time PCR analysis of the HPV‐16 positive samples indicated the presence of integrated (11 of 23, 48%), episomal (8 of 23, 35%) and mixed forms (4 of 23, 17%) of HPV DNA. The viral load of HPV DNA exhibited large variation. The median copy numbers of E6 DNA in tonsillar specimens were approximately 80,000 times higher than that in nontonsillar HNSCC ones. Patients with episomal viral DNA were more frequently found to have large (T3–T4) tumors at diagnosis than were those with integrated or mixed forms.

Patient‐specific reconstruction with 3D modeling and DMLS additive manufacturing

Purpose – The purpose of this paper is to develop a workflow for 3D modeling and additive manufacturing (AM) of patient‐specific medical implants. The comprehensive workflow consists of four steps: medical imaging; 3D modelling; additive manufacturing; and clinical application. Implants are used to reconstruct bone damage or defects caused by trauma or disease. Traditionally, implants have been manually bent and shaped, either preoperatively or intraoperatively, with the help of anatomic solid models. The proposed workflow obviates the manual procedure and may result in more accurate and cost‐effective implants.Design/methodology/approach – A patient‐specific implant was digitally designed to reconstruct a facial bone defect. Several test pieces were additive manufactured from stainless steel and titanium by direct metal laser sintering (DMLS) technology. An additive manufactured titanium EOS Titanium Ti64 ELI reconstruction plate was successfully implanted onto the patients injured orbital wall.Findings...

Reconstruction of internal orbital wall fracture with iliac crest free bone graft: clinical, computed tomography, and magnetic resonance imaging follow-up study.

Background: The purpose of this study was to clinically and radiologically assess the outcome of internal orbital reconstruction with an iliac bone graft. Methods: Twenty-four consecutive patients with unilateral orbital wall fractures were enrolled in this prospective study. A medial cortical wall from the anterior ilium was used for reconstruction. At each follow-up visit, globe posture, diplopia, and eye movements were assessed. Coronal and sagittal computed tomography and magnetic resonance imaging were used to observe graft posture, bone defects, and intraorbital soft-tissue changes. Results: Most fractures (46 percent) were pure orbital floor fractures. The mean follow-up was 7.8 months. One patient with medial wall and floor fractures required reoperation because of insufficient bone graft. At the last follow-up, this was the only patient (4 percent) with both enophthalmos (2 mm) and hypophthalmos (3 mm). Five patients (21 percent) had hypophthalmos (>1 mm) at the end of the study. Resorption and remodeling were detected in all grafts, but no grafts were totally resorbed. Sagittal or coronal bone graft postures were assessed as good in 18 orbits (75 percent). Bone defects (>10 mm) at reconstructed areas were detected in 13 orbits (54 percent). Scar tissue was observed only in three reconstructed orbits (13 percent). Diplopia in central field of vision was registered in seven patients preoperatively but in none at the end of the study. Conclusions: The resorption rate was high, but most of it was advantageous remodeling. Overall outcome was good. Secondary operations led to poor outcomes. Thin computed tomography and magnetic resonance imaging sections (≤2 mm) are needed to evaluate accurately bone graft placement and posture and orbital volume.

Sentinel lymph node biopsy in oral cavity squamous cell carcinoma without clinically evident metastasis

The clinically N0 neck in patients with oral SCC is commonly treated by neck dissection because the existence of metastases cannot be excluded. To determine whether unnecessary treatment could be avoided, we evaluated the feasibility of sentinel lymph node (SLN) biopsy.

Rigid internal fixation of mandibular fractures - An analysis of 45 patients treated according to the ASIF method

A report is given of 45 patients with fractures of the mandible treated by the method of rigid internal fixation. In a majority of cases, there were either absolute or relative contraindications for an IMF. Most of the fractures plated were body fractures of the mandible, followed by angular, and symphysis fractures. In 4 cases, the fractures, caused by gunshots, were compound ones. In these, extensive soft tissue reconstructions were also performed. In a majority of the patients, good primary healing was observed, and the mean hospitalization time was only 4.4 days. The infection rate of 13% was, however, relatively high, and a few disturbances were seen with respect to motor and sensory function of the lower lip. Slight occlusal dysharmonies were registered in 23%, on an average of 22 weeks postoperatively, but these could be adjusted with a minimum of grinding. It was concluded that bone plating is a useful method in the treatment of several different types of mandibular fractures including the severe compound ones. The method can be especially recommended in cases in which an IMF is contraindicated or should be avoided. The possibilities for decreasing the frequency of postoperative infections are discussed.

Rapid prototyped patient specific implants for reconstruction of orbital wall defects

Defects of orbital walls can be reconstructed using implants. The authors report a safe and accurate method to reconstruct bone defects in the orbital area using patient specific implants. A detailed process description of computer aided design (CAD) reconstructive surgery (CRS) is introduced in this prospective study. The 3D volumetric virtual implant was design using MSCT data and PTCProEngineer™ 3D software. The intact orbital cavity of twelve patients was mirrored to the injured side. Specific ledges steered the implant into correct place. Postoperatively the position was assessed using image fusion. One implant (8%) was rejected due to chemical impurities, two (16%) had a false shape due to incorrect CAD. Data of thin bone did not transfer correctly to CAD and resulted in error. One implant (8%) was placed incorrectly. Duration of the CRS was in average 1.17 h, correspondingly 1.57 h using intraoperative bending technique. The CRS process has several critical stages, which are related to converting data and to incompatibility between software. The CRS process has several steps that need further studies. The data of thin bone may be lost and disturb an otherwise very precise technique. The risk of incorporating impurities into the implant must be carefully controlled.

Management of Orbital Fractures

Trauma to the orbit is always complex, and adequate therapy requires that the surgeon be familiar with the detailed anatomy of the orbit and the pattern of injury of the soft and hard tissue components. Preoperative CT, MRI scans, or both are mandatory for diagnosis and proper planning of reconstruction. Although several autogenous and alloplastic materials are available, autogenous bone grafting seems to give the best results. Resorbable materials cannot be recommended for large defects. Instead, either bone or titanium must be considered to achieve a long-lasting, accurate restoration of bony orbital anatomy and dimension. Postoperative CT scan evaluation is of utmost importance regardless of the reconstruction method used.

Sports-related maxillofacial fractures in a hospital material

Sports-related maxillofacial fractures were analysed in 80 patients, accounting for 5.6% of all patients with facial bone fractures, treated during the 5-year period 1981-1985. 55% of the patients had 1 or more mandibular fractures and 45% had midface fractures. 6% of the patients had multiple injuries. The most common causes of injury were collision and fall. Soccer and ice hockey turned out to be the most hazardous sports, although sports-related maxillofacial fractures were less severe than those related to other causes. The need for oral and facial protection among athletes involved in contact sports is discussed.

Bioresorbable poly-L/DL-lactide [P(L/DL)LA 70/30] plates are reliable for repairing of large inferior orbital wall bony defects: A pilot study

PURPOSE The purpose of this study was to share our clinical experience on the use of bioresorbable poly-L/DL-lactide implants (P[L/DL]LA) 70/30 (PolyMax; Synthes, Oberdorf, Switzerland) to repair, large (> or =2 cm2), inferior orbital wall defects and to evaluate whether P(L/DL)LA 70/30 implants adequately support the orbital soft tissue contents. PATIENTS AND METHODS Thirteen patients who suffered orbital blowout fractures, with > or =2 cm2 bony defects in the inferior orbital wall, took part in the study. The inferior orbital wall was explored via subconjunctival approach. After repositioning of orbital content, each inferior orbital wall was reconstructed using a round plate of P(L/DL)LA 70/30. Computed tomography and magnetic resonance imaging coronal sections were undertaken before the operation and 2 and 36 weeks postoperatively. RESULTS The magnetic resonance imaging studies showed no abnormal tissue foreign body reactions in the orbital region. The material showed adequate strength to stabilize bone segments during the critical period of bone healing. The bone healing seems to take place along the bone fragments. The clinical outcome was excellent in 11 of the 13 cases (85%). At the end of the study, only one patient had mild enophthalmos. CONCLUSIONS Bioresorbable P(L/DL)LA 70/30 implants are safe and reliable for the repair of large defects (> or =2 cm2) in the inferior orbital wall. It seems that this is the first reported biodegradable material, in the literature, to promote bone healing along the bone fragments of the inferior orbital wall.