Thomas Gander

Splintless orthognathic surgery: A novel technique using patient- specific implants (PSI)

In the past few years, advances in three-dimensional imaging have conducted to breakthrough in the diagnosis, treatment planning and result assessment in orthognathic surgery. Hereby error-prone and time-consuming planning steps, like model surgery and transfer of the face bow, can be eluded. Numerous positioning devices, in order to transfer the three-dimensional treatment plan to the intraoperative site, have been described. Nevertheless the use of positioning devices and intraoperative splints are failure-prone and time-consuming steps, which have to be performed during the operation and during general anesthesia of the patient. We describe a novel time-sparing and failsafe technique using patient-specific implants (PSI) as positioning guides and concurrently as rigid fixation of the maxilla in the planned position. This technique avoids elaborate positioning and removal of manufactured positioning devices and allows maxillary positioning without the use of occlusal splints.

Malignancy mimicking bisphosphonate-associated osteonecrosis of the jaw: a case series and literature review.

OBJECTIVE Bisphosphonate-related osteonecrosis of the jaw (BONJ) is a common complication of bisphosphonate treatment that has been well documented over the past decade. Nevertheless, its pathogenesis is poorly understood, and treatment guidelines are based mostly on expert recommendations. Clinicians must be aware of malignancy mimicking BONJ, of which a few cases have been documented in the literature. STUDY DESIGN Three patients undergoing long-term treatment with intravenous bisphosphonates for malignant disease demonstrated the distinct diagnostic signs of BONJ. Surgical treatment was performed by resecting the affected bone. In all cases, histologic specimens were taken for analysis. RESULTS Histologic analysis of the bone specimen with surrounding soft tissue revealed necrotic bone with signs of inflammation, but also with cells of the underlying malignant disease. CONCLUSIONS Clinical and radiographic diagnosis of BONJ should be confirmed by histologic analysis in patients with underlying malignant disease.

The 3dMD photogrammetric photo system in cranio-maxillofacial surgery: Validation of interexaminer variations and perceptions.

BACKGROUND Three-dimensional photography of the face is increasingly used to overcome the downsides of conventional photography or anthropometry regarding reliable evaluation. However, the precision of such a system has to be validated before it can be implemented for clinical use. MATERIAL AND METHODS Eight people were photographed with the 3dMDface system using lighting from sets of 2 × 4 compact fluorescent lights in a clinical photography room without natural light sources. Two different operators then individually, and without interaction, marked 27 different anatomical landmarks using the 3dMD Patient software. During this process, the operators were fully blinded against each other. The purpose of the study was to determine the repeatability and accuracy of the system when used by different operators and at different times. The 3D differentiation was analyzed using mixed ANOVA with person as the random factor, and operator, repetition, and landmark as the fixed factors. The ANOVA was followed by a Ryan-Einot-Gabriel-Welsch F post-hoc test for landmarks. RESULTS Statistical analysis grouped the landmarks into three subgroups: high precision, medium precision and low precision. CONCLUSIONS Virtual 3D models derived from the 3dMDface system not only provide a high level of technical precision but also of intra- and interobserver reliability regarding landmark identification. However, some of the classical landmarks are not reliable when it comes to virtual models; these are generally landmarks that examiners of real patients would tend to identify using palpation of underlying bony structures, such as the soft gonion.

Stafne bone cavities: systematic algorithm for diagnosis derived from retrospective data over a 5-year period

Stafne bone cavities are usually found in men 50-70 years old. Typically they appear as lingual, open, ovoid lesions of the molar region of the lower jaw, and most contain parts of the submandibular gland. We have retrospectively examined panoramic radiographs acquired over a 5-year period. All lesions suspected of being Stafne bone cavities were included and analysed further to retrieve statistical information and derive a systematic diagnostic algorithm. We identified 21 Stafne bone cavities among 2928 patients (0.7%). Four of these were confirmed on cone-beam computed tomography (CT). One patient had magnetic resonance imaging (MRI) to confirm the diagnosis. The M:F ratio was 14:7 and the mean age 53 years (range 22-82). All cavities were located in the posterior mandible, 9 on the right and 12 on the left. The mean length was 10.9 (range 4.5-23) mm and height 5.7 (range 3.3-17.3) mm. All cavities were located in the posterior mandible. Sixteen panoramic radiographs (0.6%) were classified as possibly having a Stafne bone cavity but did not fulfil enough criteria to confirm the diagnosis. These 16 were not further analysed. It is rare to diagnose a Stafne bone cavity on a panoramic radiograph. Thorough investigation is essential to exclude differential diagnoses such as keratocystic odontogenic tumour, ameloblastoma, or a metastasis. In atypical presentations 3-dimensional cone-beam CT is helpful to verify the lingual opening. If the diagnosis is still not clear, it can be confirmed by MRI.

Closed versus open treatment of mandibular condylar process fractures: A meta-analysis of retrospective and prospective studies

INTRODUCTION The treatment of fractures of the mandibular process remains controversial, although there is a trend towards open reduction and internal fixation. This study compared open and closed treatments and assessed the results with a meta-analysis. MATERIALS AND METHODS A literature search of PubMed found eight studies that met the search criteria and were included in the meta-analysis. RESULTS The studies increasingly suggest better results for open treatment, in terms of mouth opening, protrusion, laterotrusion, pain, and malocclusion. In the meta-analysis, the outcome was significantly better for laterotrusion and protrusion in patients treated by open reduction and internal fixation. CONCLUSION Due to the different study protocols and lack of information on classification, follow-up time, and inclusion criteria, comparison of the studies remains difficult and further prospective, randomized studies should examine these issues.

Preservation of ipsilateral submandibular gland is Ill advised in cancer of the floor of the mouth or tongue

Preservation of the submandibular gland (SMG) during a neck dissection is gaining popularity and is showing an increasing tendency. The potential benefit, if the SMG is preserved, can be manifold. The aim of this study was to assess the benefit of the preservation of the SMG and the associated risk of recurrent disease in patients with oropharyngeal or oral cavity squamous cell carcinoma.

Patient-specific biodegradable implant in pediatric craniofacial surgery

Surgical correction of premature fusion of calvarial sutures involving the fronto-orbital region can be challenging due to the demanding three-dimensional (3D) anatomy. If fronto-orbital advancement (FOA) is necessary, surgery is typically performed using resorbable plates and screws that are bent manually intraoperatively. A new approach using individually manufactured resorbable implants (KLS Martin Group, Tuttlingen, Germany) is presented in the current paper. Preoperative CT scan data were processed in iPlan (ver. 3.0.5; Brainlab, Feldkirchen, Germany) to generate a 3D reconstruction. Virtual osteotomies and simulation of the ideal outer contour with reassembled bony segments were performed. Digital planning was transferred with a cutting guide, and an individually manufactured resorbable implant was used for rigid fixation. A resorbable patient-specific implant (Resorb X-PSI) allows precise surgery for FOA in craniosynostosis using a complete digital workflow and should be considered superior to manually bent resorbable plates.

Influence of histopathologic factors on pattern of metastasis in squamous cell carcinoma of the head and neck

Knowledge of histopathological factors, such as perineural invasion (PNI), extracapsular spread (ECS), angiolymphatic vessel invasion, and conglomerate lymph nodes, in patients with head and neck squamous cell carcinoma is important for appropriate treatment decisions. Given the availability of aggressive therapeutic options with known side effects and burdens for the patient, choosing the correct treatment option is vital.

Medium-term outcome of Astra Tech implants in head and neck oncology patients.

Rehabilitation with implant-retained prostheses is a key step in the rehabilitation of patients after ablative head and neck surgery. Data of patients who underwent mandibular restoration with Astra Tech implants were gathered consecutively and analyzed retrospectively. Implant survival was calculated by Kaplan-Meier analysis, and Cox models were used to identify any association between implant failure and contributing factors. In total, 136 implants were placed in 33 patients. The main reason for ablative surgery was squamous cell carcinoma. Twenty-one patients received adjuvant radiotherapy with a cumulative radiation dose of 56-76Gy prior to implantation. Failure occurred in six patients, resulting in the loss of 17 implants. The cumulative implant survival rate was 92.7% after 1 year and 87.5% after 20 months. Smoking and alcohol consumption were associated with a significantly higher implant failure rate. Most patients had a stable implant status after 20 months.

Emergency decompression of tension retrobulbar emphysema secondary to orbital floor fracture

Orbital floor fractures are generally the result of blowout orbital and may be associated with orbital emphysema leading to proptosis and even to loss of vision. A 49-year-old woman fractured the orbital floor in a fall. After blowing her nose, she developed exophthalmos and severe reduction in vision. She consulted our department and underwent emergency surgical management with orbital drainage. Decompression led to immediate resolution of the exophthalmos and postoperative improvement in visual acuity. Urgent decompression is indicated by the presence of proptosis, elevated intraocular pressure, and progressive loss of vision in cases of orbital trauma with additional emphysema. Surgical treatment of tension emphysema includes lateral canthotomy or cantholysis, needle aspiration, transconjunctival, or lateral blepharoplasty approach, and bone decompression depending on the severity of the case. Sneezing or blowing the nose can lead to proptosis and decreased visual acuity secondary to trauma to the orbit. Under such circumstances, emergency decompression is essential.