Arterial vascularization of the mandible and soft tissues. Anatomic study.

PURPOSE: The literature has for too long described the arterial supply of the mandible as coming from a single artery, the inferior alveolar artery, and being of the terminal type. Rather, it appears to come from an extensive and complex arterial network dependent on the lingual, facial, and maxillary arteries and their collateral branches. Our study aims to confirm and demonstrate the arterial vascular richness of the mandible and to establish arterial mapping. METHODS: The arterial vascularization of the mandible was revealed in six anatomic specimens after performing selective injections of the lingual, facial, and maxillary arteries with different dyes. A specimen was injected intra-arterially with colored latex at the level of the maxillary artery for a morphometric study. RESULTS: Eighteen selective arterial injections were performed on six anatomic specimens. The mucocutaneous, musculoperiosteal, and intramedullary vascularizations were analyzed. Each of the arteries has a defined and delimited cutaneo-mucous vascular territory. The facial and maxillary arteries supply the musculoperiosteal vascularization of the mandible from the condyle to the symphysis. The lingual artery supplies only the inner cortex of the parasymphyseal and symphyseal regions. The facial and maxillary arteries provide intramedullary vascularization from the angle of the mandible to the parasymphysis. The vascularization of the symphysis depends on the facial artery. No staining was found in the condyle region. Neoprene latex injection was performed on an anatomic specimen, revealing a permeable anastomosis between the inferior alveolar and facial arteries. CONCLUSION: The arterial vascularization of the mandible is dependent on the maxillary, facial, and lingual arteries. This is a network vasculature. This study makes it possible to establish an arterial map of the mandible. The presence of an anastomosis between the inferior alveolar artery and the facial artery confirms the existence of dynamic and borrowed vascularization. Knowledge of this arterial system makes it possible to adapt maxillofacial surgical care and to anticipate possible intraoperative complications.

The external jugular vein axis: a new anatomical landmark for pre-operative prediction of the location of parotid gland tumours.

The relationships between parotid tumours and the facial nerve determine duration of surgical procedure and risks involved. As the division of the facial nerve is not visible using standard imaging techniques, other anatomical landmarks are used to determine the pre-operative location of tumours. This retrospective study aimed to evaluate reliability of the 'external jugular vein axis' compared with other landmarks generally used in imaging, such as the retromandibular vein, Conn's arc, the facial nerve line and the Utrecht line. Forty-eight pre-operative imaging exams of patients who underwent parotid benign tumour surgery between 2010 and 2016 were examined. We determined the location of tumour using the five markers. A pre-operative simulation was compared with the description given by the surgeon intraoperatively, in terms of sensitivity and specificity for each marker. External jugular vein axis and retromandibular vein are the most sensitive markers for locating suprafacial tumours (Se = 1). External jugular vein axis and Conn's arc are the most specific markers for locating suprafacial tumours (Spe = 0.92). External jugular vein axis is reproducible and present on all radiological sections, thereby overcoming any anatomical and nomenclature variations. This landmark appears to be the most representative marker of the dividing branches of the facial nerve.

Outcomes of orbital decompression using surgical navigation in thyroid-associated ophthalmopathy.

Thyroid-associated ophthalmopathy can result in proptosis. In such cases, orbital decompression surgery is often warranted to reduce the adverse impact on patient quality of life. Due to the anatomical complexity of the orbit, navigation can be of considerable assistance during orbital decompression. The objective of this study was to evaluate the benefits of using a surgical navigation device in orbital decompression surgery. A retrospective study was performed based on patients who underwent decompression surgery with (N+) or without (N-) a navigation device between 1997 and 2017. Included patients had undergone unilateral or bilateral orbital decompression by resection of the orbital floor and medial wall of the orbit. Criteria assessed were the presence of debilitating postoperative diplopia, postoperative proptosis reduction, symmetry of protrusion of the eyeballs, and the duration of surgery. Three hundred and fifty eyes were analysed (191 patients): 205 in the N+ group and 145 in the N- group. Use of the surgical navigation system resulted in a greater proptosis reduction, and this result was statistically significant for the right eyeball (P=0.03). The surgical navigation system had no effect on symmetry of protrusion of the eyeballs or on postoperative diplopia. Setting up the navigation device increased the duration of surgery by 40 minutes on average.

Temporomandibular joint arthroplasty for osteoarthrosis: A series of 24 patients that received a uni- or bilateral inter-positional silicone sheet.

PURPOSE: To evaluate mid-term results from using a silicone sheet for inter-positional arthroplasty in moderate or severe cases of osteoarthrosis of the temporo-mandibular joint (TMJ). To also determine any remaining indications from this method. PATIENTS AND METHODS: This retrospective study included patients that underwent surgery between 2008 and 2016. Pre- and post-operative mouth opening (MO), according to inter-incisal distance (mm) and pain score (PS: 0=no pain to 4=very severe pain) were recorded for 24 patients. Patients were divided according to thickness of the silicone sheet (group A: 1.0 mm, group B: 1.5 mm). RESULTS: The cohort included 22 females (92%). Mean age at surgery was 55 years±13 (26-80). Mean length of follow-up was 26 months±24 (6-80). Mean improvement in MO was 8.2 mm (+33%) and of PS was 1.7 (-68%). MO was not improved for two patients and worsened for one. PS score improved for all patients. No statistical difference was found between groups A and B. There was also a tendency for degradation of outcomes over time. CONCLUSION: The poor reputation of prosthetic discoplasty was not as evident in our series, even though anatomical and functional status seemed to deteriorate over time. This is because total-joint prosthetic replacement is often proposed instead. However, for elderly or fragile patients that have severe pain, and regarding cost-benefit aspects, conventional arthroplasty can still be discussed, especially since French national health-care insurance does not yet support TMJ prosthetic replacement for osteoarthrosis.