[Labial recurrent swelling revealing median congenital upper-lip fistula]. / Tuméfaction labiale récidivante révélatrice d'une fistule congénitale médiane de la lèvre supérieure.

Midline upper-lip fistulas are an extremely rare variant of congenital facial malformations. Less than 30 cases have been reported in the literature since 1970. We report the case of a 2 and a half-year-old girl presenting with a median congenital blind fistula of the upper lip, without any relation with the oral cavity. A recurrent swelling of the upper lip was the main symptom. Complete surgical excision of the cyst or of the fistulous tract must be obtained to avoid recurrence.

[Pneumoparotid: a rare cause of recurrent parotid swelling]. / Pneumoparotide : une étiologie rare de tuméfaction parotidienne récidivante.

INTRODUCTION: Pneumoparotid is a rare cause of recurrent parotid swelling. It is often fortuitous, caused by an action inducing intraoral pressure, increased or self-induced. OBSERVATION: An 8-year-old boy presented with recurrent right unilateral parotid swelling for 2 years. A CT-scan was performed, outside of the acute phase, which revealed the presence of intraparotid air bubbles. DISCUSSION: Pneumoparotitis results from air flowing back into Stensen's duct, due to an anatomical abnormality and a significant increase of intraoral pressure. The diagnosis is made on clinical examination, often completed by a morphological examination (cervicofacial CT-scan or parotid ultrasound investigation). The outcome is most often favorable, with symptomatic treatment, and sometimes antibiotic prophylaxis. Patient education is the best means to prevent recurrence.

[Engineering a bone free flap for maxillofacial reconstruction: technical restrictions]. / Ingénierie d'un lambeau osseux vascularisé à destinée maxillofaciale : les limites techniques.

Vascularisation is a key for success in bone tissue engineering. Creating a functional vascular network is an important concern so as to ensure vitality in regenerated tissues. Many strategies were developed to achieve this goal. One of these is cellular growth technique by perfusion bioreactor chamber. These new technical requirements came along with improved media and chamber receptacles: bioreactors (chapter 2). Some bone tissue engineering processes already have clinical applications but for volumes limited by the lack of vascularisation. Resorbable or non-resorbable membranes are an example. They are used separately or in association with bone grafts and they protect the graft during the revascularization process. Potentiated osseous regeneration uses molecular or cellular adjuvants (BMPs and autologous stem cells) to improve osseous healing. Significant improvements were made: integration of specific sequences, which may guide and enhance cells differentiation in scaffold; nano- or micro-patterned cell containing scaffolds. Finally, some authors consider the patient body as an ideal bioreactor to induce vascularisation in large volumes of grafted tissues. "Endocultivation", i.e., cellular culture inside the human body was proven to be feasible and safe. The properties of regenerated bone in the long run remain to be assessed. The objective to reach remains the engineering of an "in vitro" osseous free flap without morbidity.

[Oro-maxillofacial bone tissue engineering combining biomaterials, stem cells, and gene therapy]. / Ingénierie du tissu osseux oro-maxillofacial par combinaison de biomatériaux, cellules souches, thérapie génique.

Improvements have been made in regenerative medicine, due to the development of tissue engineering and cellular therapy. Bone regeneration is an ambitious project, leading to many applications involving skull, maxillofacial, and orthopaedic surgery. Scaffolds, stem cells, and signals support bone tissue engineering. The scaffold physical and chemical properties promote cell invasion, guide their differentiation, and enable signal transmission. Scaffold may be inorganic or organic. Their conception was improved by the use of new techniques: self-assembled nanofibres, electrospinning, solution-phase separation, micropatterned hydrogels, bioprinting, and rapid prototyping. Cellular biology processes allow us to choose between embryonic stem cells or adult stem cells for regenerative medicine. Finally, communication between cells and their environment is essential; they use various signals to do so. The study of signals and their transmission led to the discovery and the use of Bone Morphogenetic Protein (BMP). The development of cellular therapy led to the emergence of a specific field: gene therapy. It relies on viral vectors, which include: retroviruses, adenoviruses and adeno-associated vectors (AAV). Non-viral vectors include plasmids and lipoplex. Some BMP genes have successfully been transfected. The ability to control transfected cells and the capacity to combine and transfect many genes involved in osseous healing will improve gene therapy.

[Palatal necrosis due to cocaine abuse]. / Nécrose palatine par consommation de cocaïne.

The easier access to cocaine allows chronic and intensive consumption. Nasally inhaled cocaine causes important midfacial lesions called: Cocaine Induced Midline Destructive Lesions. These lesions are due to several factors, the anesthetic, vasoconstrictive, locally prothrombotic properties of cocaine and its components combined with cytotoxic effects and traumatic nasal injuries related to consumption mode. Functional signs are: nasal regurgitation, rhinolalia, rhinorrhea, and midfacial pain. The morphological modifications of the nasal pyramid feature the destruction of bone and cartilage structures. Endo-buccal examination, anterior rhinoscopy, and TDM reveal palatine necrosis of variable extension. Nasal fossae superinfection is always present. Sinus superinfection is frequent. Management is multidisciplinary. Weaning must be achieved before surgery. It is necessary to rehabilitate speech and swallowing functions by the means of various local or free flaps.