Precision of 30 guided implants in complex tumour situations.

Implant born prosthetic rehabilitation of tumour patients can be difficult to perform. Challenges in treating such patients include disrupted anatomy with limited mouth opening due to previous ablative surgery as well as free-flaps or simple bone grafts, adjuvant therapy such as radiotherapy and, in general, poorer general health. Combining classical knowledge of ideal prosthesis placement and current virtual planning possibilities the positioning and in consequence the survival of dental implants can be optimised. Since prosthetic rehabilitation has a positive effect on the patients' quality of life and general health, we propose performing such surgeries as early as possible. All patients at our institution receiving pre-planned guided implant reconstruction and postoperative evaluation with Cone Beam Computed Tomography (CBCT) between 2015 and 2018 were evaluated for inclusion. Eight patients with a total of 30 implants met the inclusion criteria. The planned implant position was compared to the outcome position by fusing the two and deviations in entry-point position, apex-position, angular deviation and depth error were recorded. The mean (SD) discrepancy at entry-point was 2.28 (1.45) mm and 2.89 (1.53) mm at the apex, respectively. Mean (SD) angulation discrepancy was 9.5˚ (4.13˚) and the mean (SD) depth deviation was 1.52 (0.86) mm. Our results demonstrate the feasibility of pre-planned implant placement in challenging clinical situations and that only few concessions have to be made for precision.

The influence of lymph node ratio on survival and disease recurrence in squamous cell carcinoma of the tongue.

This study was performed to report the outcomes of patients with oral squamous cell carcinoma (OSCC) of the tongue over a 10-year period with the aim of testing the hypothesis that the lymph node ratio (LNR) has a significant influence on loco-regional recurrence. The charts of 227 patients with OSCC of the mobile tongue treated at the University Hospital of Zurich from 2003 to 2012 were screened. Following the application of the exclusion criteria (prior chemotherapy, radiotherapy, or surgery, perioperative death, N3 disease, unresectable disease, synchronous second primary, no signed informed consent, and follow-up <3years), prospective data were collected and a retrospective analysis performed for 88 of these patients who were treated with selective neck dissection. During a mean follow-up period of 78 months (standard deviation 37 months), loco-regional recurrence was diagnosed in 25 patients (28%). The overall and disease-specific survival rates for the study population were 72% and 80%, respectively. Perineural invasion was identified as an independent risk factor for decreased disease-specific survival, whereas LNR was not. LNR did not show an influence on disease recurrence. Thus, its prognostic value in patients with tongue cancer remains uncertain and the decision regarding adjuvant therapy should not be made solely on the basis of LNR.

Sentinel lymph node biopsy for early stage tongue cancer-a 14-year single-centre experience.

This study was performed to report the usage of sentinel lymph node biopsy (SLNB) in clinical stage I or II tongue cancer patients with cN0 necks seen over a 14-year period. Data were collected prospectively, and a retrospective analysis was performed of 41 patients with early stage oral squamous cell carcinoma of the tongue and a cN0 neck. Sentinel lymph node (SLN)-positive patients underwent elective neck dissection, whereas SLN-negative patients were kept under careful observation. Seven of the 41 (17%) patients enrolled in the study were found to have occult metastases. The patients were followed up for a mean duration of 92 months (range 60-144 months). The neck recurrence rate for SLN-positive patients was 0% and for SLN-negative patients was 3%. The authors recommend the routine use of SLNB in patients with early stage oral squamous cell carcinoma of the tongue and a cN0 neck. Furthermore, special focus should be placed on isolated tumour cells, as their presence is of high clinical relevance.

Total virtual workflow in CAD-CAM bony reconstruction with a single step free fibular graft and immediate dental implants.

The Surgical reconstruction of defects of the face is challenging. Local and regional flaps have an important part to play, but large defects of bone and soft tissue are a greater problem. Microvascular tissue transfer has become the standard for such patients, and preoperative planning of bony reconstructions is now common. To use these preplanning tools best the implants should be placed in the prosthetically ideal place, and the bone positioned to surround the implants - that is, truly backward planning of the position of the bone. The buccolingual angulation and the actual position of the implants during operation can be difficult to verify. Using commonly available software and 3-dimensional printing solutions, therefore, we have constructed an algorithm to optimise the position of these implants during the operation, and to get their position as close to the planned outcome as possible. This algorithm is adaptable to any implant system and is potentially possible in any implant or preplanning software unit.

Are open mandibular fractures still an emergency?

INTRODUCTION: Early surgical management is often advocated for fractures of the tooth-bearing portion of the mandible. A 6-hour delay has been mentioned for the fixation of these fractures. Our aim was to bring this paradigm into question. METHODS: All patients referred to our department from September 2012 to May 2014 for fractures of the tooth-bearing portion of the mandible were retrospectively included. For each patient, age, gender, aetiology of the fracture, and characteristics of the fractures were recorded. Tobacco and/or alcohol addictions, diabetes and mandibular dental condition were taken into account. We also noticed the preoperative delay and the occurrence of complications such as: haematoma, infection, wound dehiscence, osteosynthesis failure and pseudarthrosis. RESULTS: Among the 47 patients referred, 36 were treated with a delay of more than 6 hours (76.6%). In 88.8% of the cases, the reason for this delay was unavoidable. The mean delay time from trauma to surgery was 52 hours (range: 7-312). Forty-nine percent of the patients had comorbidities. Complications occurred in 6 patients leading to an overall complication rate of 16.67%. A statistically significant higher complication rate was observed among smokers (P=0.006). No statistical relationship was found between the delay and the occurrence of complications (P=0.994). This study suggests that fractures of the tooth-bearing portion of the mandible should no longer be considered as an emergency that must be treated within a 6-hour delay.

[3D planning in maxillofacial surgery]. / Planification 3D en chirurgie maxi to-faciale.

The development of new technologies such as three-dimensional (3D) planning has changed the everyday practice in maxillofacial surgery. Rapid prototyping associated with the 3D planning has also enabled the creation of patient specific surgical tools, such as cutting guides. As with all new technologies, uses, practicalities, cost effectiveness and especially benefits for the patients have to be carefully evaluated. In this paper, several examples of 3D planning that have been used in our institution are presented. The advantages such as the accuracy of the reconstructive surgery and decreased operating time, as well as the difficulties have also been addressed.

The use of 3D planning in facial surgery: preliminary observations.

Three-dimensional (3D) planning is becoming a more commonly used tool in maxillofacial surgery. At first used only virtually, 3D planning now also enables the creation of useful intraoperative aids such as cutting guides, which decrease the operative difficulty. In our center, we have used 3D planning in various domains of facial surgery and have investigated the advantages of this technique. We have also addressed the difficulties associated with its use. 3D planning increases the accuracy of reconstructive surgery, decreases operating time, whilst maintaining excellent esthetic results. However, its use is restricted to osseous reconstruction at this stage and once planning has been undertaken, it cannot be reversed or altered intraoperatively. Despite the attractive nature of this new tool, its uses and practicalities must be further evaluated. In particular, cost-effectiveness, hospital stay, and patient perceived benefits must be assessed.

[Bile ductule carcinoma in a cow]. / Gallengangskarzinom bei einer Kuh.

A 20-year-old cow was presented due to chronic diarrhea and weight loss. The clinical examination revealed a markedly enlarged left ovary. However, a cause of the diarrhea could not observe. The examination of the feces was negative for a parasites or bacteria causing diarrhea. The results of hematological and biochemical analyses revealed a mild leucocytosis, bilirubinaemia, higher activities of the enzymes aspartate transaminase, gamma-glutamyltransferase and creatine kinase. The plasma concentrations of estrogen and testosterone were below the detection limits, progesterone concentration was 2.7 ng/ml. The postmortem examination revealed a bile ductule carcinoma with metastases in the lung and in lung and mestenterial lymph nodes. The cause of the tumor remained unclear. Diarrhea might have been the consequence of a portal hypertension due to the tumor. The pathological examination confirmed the clinical diagnosis of the ovarian tumor. The genesis of the ovarian tumor may be independent of the genesis of the bile ductule carcinoma.