TMJ related short-term outcomes comparing two different osteosynthesis techniques for bilateral sagittal split osteotomy

OBJECTIVES

Bilateral sagittal split osteotomy (BSSO) is a morpho-functional surgery and post-surgical osteosynthesis may influence temporomandibular joint (TMJ) health. Our objective was to evaluate temporomandibular disorders (TMD) and TMJ symptoms after orthognathic surgery according to the type of osteosynthesis used in a population of patients with dentofacial deformities.

MATERIALS AND METHODS

One hundred and eighty-three consecutive patients undergoing orthodontic and maxillofacial surgery treatment for correction of their malocclusion were recruited for a two-year period at Lille University Hospital. All patients had at least a mandibular BSSO using Epker's technique. Each patient was examined before and one year after orthognathic surgery. We compared osteosynthesis by miniplates fixed with monocortical screws (n=42) and the hybrid fixation with bicortical retro-molar screws used with miniplates (n=141). TMJ health was assessed by monitoring TMD signs and symptoms according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) and scores obtained from the "Jaw Pain Function" questionnaire.

RESULTS

There was no significant difference in pre-operative and one year post-operative RDC/TMD assessments (p≥0.91) or JPF score (p≥0.29) between the two types of osteosynthesis.

CONCLUSION

There was no difference in TMJ health between the two techniques of osteosynthesis after BSSO.

CLINICAL RELEVANCE

In our experience the hybrid technique fixation affords many advantages and does not influence postoperative TMD compared with osteosynthesis by miniplates.

Temporomandibular disorders in head and neck cancers: Overview of specific mechanisms and management

Diagnosis classification system of Temporomandibular disorders (TMD) is based on the biopsychosocial model of pain. The pathogenesis is poorly understood, leading to difficulties in treating these multifactorial conditions. The predisposing factors are pathophysiological, psychological or structural processes that alter the masticatory system and lead to an increase in the risk of development of TMD. The purpose of this integrative review was then to point out the specific mechanisms of TMD in the oral oncologic context to optimize the TMJ functional results in the management of patients with oral oncologic conditions. We explored in this paper the role of Axis II assessment of the biopsychosocial model of pain, the involvement of mechanical concepts such as dental occlusion, mandibular condyle positioning and related-structures reconstruction, and the stomatognathic changes induced by radiation.

A modified method for a customized harvest of fibula free flap in maxillofacial reconstruction

Mandibular reconstruction using computer-aided design/computer-aided manufacturing cutting guides is currently a common procedure. However, inaccurate positioning of the cutting guide onto the fibular bone may result in osteosynthesis difficulties or imprecision in the reconstruction. A novel way to improve the stability of the cutting guides may be to add pillars in order for them to be suspended from the fibula, avoiding soft tissues interactions. We present the case of a 39-year-old male who needed mandibular reconstruction after a self-inflicted ballistic injury. We designed a customized cutting guide which included a set of 8 pillars allowing a suspension of the cutting guide 8 millimeters above the bone level. The pillars were perpendicular to one another, and allowed the operator to screw the cutting guide to the bone. The orthogonal position of the pillars enabled real stability during the osteotomies. In the operator experience, the length of the pillars was too important, and led to incomplete osteotomies, and the whole device was too bulky. However, with adaptations in the size of the pillars and the size of the whole device, this solution could be useful in cutting guide design to avoid impairments due to the soft tissues surrounding the fibula.

The use of onlay bone grafting for implant restoration in the extremely atrophic anterior maxilla. A case series

Functional and aesthetic treatments are challenging when ensuring maintain long-term successful prosthetic rehabilitation after alveolar ridge resorption of the anterior maxilla. The goal of this case series was to evaluate implant success rate, prosthetic stability and patient satisfaction in patients treated by onlay bone grafting in atrophic premaxilla. Nineteen patients treated for severe atrophic anterior maxilla by reconstruction using onlay bone grafting and implant restoration between 2002 and 2012 were examined. The surgical procedure was designed to allow the insertion of 49 endosseous implants in the grafted anterior maxillae. Bone resorption and implant success rate were retrospectively evaluated after a follow-up period of 5 years (from 5 to 15 years) subsequent to reconstruction. A questionnaire was the medium used to evaluate patient satisfaction and highlight functional and aesthetic outcomes. The bone grafting success rate was 74%. None of the grafted bones were reported to be infected. Four implants were removed. Implant survival rate was 91.8% after 8.9 years. The permanent reconstruction was fixed in 74% of the cases and removable in 26%. The level of patient satisfaction reported was 6.5/7. In conclusion, his study suggests that onlay bone grafting can be considered a predictable technique for rehabilitation in atrophic premaxilla. The procedure has a high implant survival rate, acceptable bone resorption over time, and promotes graft stability for longterm prosthetic fixation, thereby increasing patient satisfaction.

Functional and morphologic outcomes of CAD/CAM-assisted versus conventional microvascular fibular free flap reconstruction of the mandible: A retrospective study of 25 cases

INTRODUCTION

Mandibular reconstruction using fibula free flap has been improved in the last decade with computer-aided design and computer-aided manufacturing (CAD/CAM) but any functional and aesthetic evaluation of their reattempts has been realized. Aim of this retrospective study is to compare functional and morphologic outcomes after mandibular reconstruction with fibula free flap using CAD/CAM or conventional peroperative shaping for mandible reconstruction. Moreover, we compared quality of life, patient and surgery characteristics in the two groups.

PATIENTS AND METHODS

We realized a monocentric retrospective analyzed of 25 cases of unilateral mandibular reconstruction divided in two groups, using CAD/CAM (12 patient) or conventional approach (13 patients) between April 2012 and March. Functional and aesthetic measurements were performed postoperatively.

RESULTS

Mouth opening, laterotrusion and protrusion of the mandible seemed to be improved in CAD/CAM group compared with conventional group but did not differ significantly. Quality of life, bite force, masticatory ability, eating and chewing satisfaction, appearance and social activity satisfaction did not differ significantly in the two groups.

CONCLUSION

Even if no superiority has been established for CAD/CAM group regarding functional and aesthetic outcomes, a prospective design of future studies and transdisciplinary approach should improve our data and their interpretations. Thus, the integration of virtual planning and guided surgery is definitely of significant value and must be considered in complex maxillofacial reconstructions.

Influence of preoperative imaging on fibula free flap harvesting

INTRODUCTION

The fibula free flap (FFF) is the gold standard for the reconstruction of large maxillofacial defects. Magnetic resonance angiography (MRA) seems to supersede digital subtraction angiography (DSA) as the reference in preoperative evaluation, being non-invasive and having equivalent diagnostic results. The aim of this study was to assess the impact of preoperative MRA versus DSA on the viability of FFF and its success rate.

MATERIAL AND METHODS

A total of 216 patients, who underwent mandibular or maxillary FFF reconstruction from January 1995 to January 2011, were retrospectively included in the study. Of them, 101 patients underwent preoperative DSA and 115 underwent MRA. Recorded criteria were as follows: age, sex, tobacco consumption, defect etiology, preoperative vascular assessment, donor-site choice and flap failure. The DSA group was compared to the MRA group.

RESULTS

The harvested side was switched in 15.7% of cases with preoperative MRA versus 4% with DSA. Our success rate was higher (96.1%) with MRA than with DSA (88.1%) (P<0.05). More atherosclerotic patients (P=0.004) were diagnosed through MRA. MRA and DSA showed similar results in anatomical variation detection.

CONCLUSION

MRA is less invasive and more effective in atherosclerosis detection than DSA. Therefore, donor-site switching was more frequent in the MRA group, which led to a better success rate. MRA should replace DSA as the reference in preoperative assessment.

Bone-borne distractor versus tooth-borne distractor for orthodontic distraction after surgical maxillary expansion: The patient's point of view

INTRODUCTION

Orthodontic distraction after surgical maxillary expansion is a mode of treatment regularly used in the context of transverse maxillary constriction. There is, however, no consensus in the literature as to the type of distractor (bone-borne or tooth-borne) that should be used.

PATIENTS AND METHOD

This retrospective study compared orthodontic distraction using a bone-borne or a tooth-borne distractor from the point of view of tolerance, ease of use and overall patient satisfaction, by means of a questionnaire completed by patients undergoing maxillary expansion surgery in the Stomatology and Maxillofacial Surgery Department of Lille University Hospital between January 2013 and March 2015. The efficacy of the two distractors was also assessed.

RESULTS

Thirty-two patients were included: 10 in the bone-borne distractor group and 22 in the tooth-borne group. Sixty percent of patients questioned found the bone-borne distractor easy to use compared with 32% for the tooth-borne distractor (P=0.167). Tolerance was noted to be comparable and acceptable by the two groups. The overall satisfaction rate was high for both groups at over 90%, and was correlated with ease of use and clear information. The average space gain between the first molars was 11.1mm with the bone-borne device and 10.7mm for the tooth-borne appliance.

CONCLUSION

The use of a bone-borne distractor for orthodontic distraction after maxillary expansion surgery appears to be an effective, simple and well-tolerated alternative to the use of a tooth-borne distractor. According to patients, this distractor also appears easier to use than the traditional Hyrax-type distractor. This ease of use is correlated with overall satisfaction.

[Anatomic study of the submental artery relationships for submental flap raising]

INTRODUCTION

Submental flap is useful for intra-oral reconstructions and reconstructions of the lower two thirds of the face. Dissection is delicate because of a difficult exposure under the lower rim of the mandible, numerous collateral arterial branches and the proximity of the marginal branch of the facial nerve. The aim of our work was to propose anatomical landmarks in order to facilitate the submental flap raising.

MATERIAL AND METHOD

Ten bodies preserved in Biomet liquid were dissected bilaterally. The anatomic relationships between the marginal branch of the facial nerve and the mandible, the relationships of the submental artery, the amount and the location of its collateral branches were measured by means of a caliper.

RESULTS

The highest marginal branch observed was located 0.5 cm above the mandibular lower rim, while the lower one was located 0.6cm below this rim. The mean length measured between the facial artery at its crossing over the mandibular rim at the level of the pre-angular notch and the origin of the submental artery was 1.5cm. The average number of collateral branches was 3.6.

DISCUSSION

A skin incision made directly under the mandibular lower rim, as mentioned by some authors, may endanger the mandibular marginal branch of the facial nerve. Three positions of the submental artery in relation to the sub-maxillary gland are reported. The collateral branches are intended for gland, muscle, skin and bone. It is necessary to pay particular attention to the sub-lingual artery, an artery of big diameter that arises at 2.8cm on average from its origin and plunges towards the mouth's floor. It must not be followed at risk of clamping the thin pedicle destined to the digastric muscle. It is important to preserve the fat tissue around the submental pedicle in order to avoid venous congestion of the flap.

[Labial recurrent swelling revealing median congenital upper-lip fistula]

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.

Symphyseal distraction in the context of orthodontic treatment: a series of 35 cases

INTRODUCTION

Use of symphyseal distraction osteogenesis to treat a mandibular bone deficit with tooth-jaw discrepancy due to lack of space makes it possible to avoid the risks associated with the techniques usually envisaged (stripping, labioversion of incisors, extractions).

PATIENTS AND METHOD

This retrospective study presents the symphyseal distraction technique used in the maxillofacial surgery department of Lille University Hospital between January 1998 and March 2013. Treatment efficacy, complications and the stability of results were all evaluated.

RESULTS

Thirty-five patients were included in the study. The gain of inter-mental-foramen space was on average 7 mm (3-12, standard deviation 1.8 mm). A good occlusal result with dental Class I and no labioversion of the lower incisors was obtained in 27 of the 35 patients (77%).

CONCLUSION

Mandibular distraction by symphyseal osteotomy seems to be a quick, safe treatment for an anterior transversal mandibular deficit giving results that are stable over time. Its success depends on good collaboration between the orthodontist and the surgeon, and on strict patient selection.

[Patient treated with sub-mental intubation for maxillofacial trauma]

Maxillo-facial traumas are frequent and most often occur in young patients. Naso-tracheal or orotracheal intubation may be contraindicated in case of combined occlusal fracture and nasal or ethmoido-nasal fracture. This study was carried out a clinical case of a patient treated at the Lille University Hospital for a maxillofacial trauma associating fracture of nose and maxilla. The purpose was to assess the reliability of submental intubation as an alternative to tracheotomy. Submental intubation is a reliable single and safe technique allowing an one-stage surgical treatment in case of complex association of fractures without using tracheotomy. Its use should be implemented on a larger scale.

[Comparative effectiveness of maxillomandibular advancement surgery versus mandibular advancement device for patients with moderate or severe obstructive sleep area]

INTRODUCTION

Currently, positive airway pressure is the gold standard treatment of obstructive sleep apnea (OSA). Unfortunely, adherence rates are poor. Alternative therapies are mandibular advancement device (MAD) and maxillomandibular advancement (MMA).

PATIENTS

This retrospective study compared both treatment effectiveness on patients with moderate and severe OSA from January 2005 to September 2012, and carried out predictive factor of effectiveness. We defined therapeutic success as an apnea hypopnea index (AHI) less than 15 per hour and at least a 50% reduction of the initial index. The difference in effectiveness has been studied using regression logistic adjusted on MAD versus MMA propensity score.

RESULTS

This study included 198 patients. 37 were treated by MMA, and 161 with MAD. MMA treatment was significantly more efficient than MAD treatment with an odds ratio of 3.22; CI95% 1.31Γ7.82 (p = 0.011). Younger age and lower initial AHI were predictive of increased success. There was no significant interaction between the treatment and morphologic patient factors.

CONCLUSION

In our sample of patients, MMA surgery was significantly more efficient than MAD treatment for the patients with moderate or severe OSA. No morphologic characteristic was identified to determine which patients would benefit most from MAD versus MMA surgery.

[Pneumoparotid: a rare cause of recurrent parotid swelling]

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.

[Naso-ethmoido-maxillary protrusion (NEMP): a specific dysmorphosis]

Naso-ethmoido-maxillary protrusion (NEMP) is a rare dental and facial dysmorphosis, with excessive growth of basicranium, ethmoid, maxillary, and nasal bones. The clinical presentation includes nasal and upper lip protrusion, telecanthus, a class 2 malocclusion with maxillary protrusion and exoclusion. The craniofacial field is increased in Delaire's analysis. Contrary to isolated maxillary protrusion secondary to membranous ossification dysfunction, NEMP is a constitutional anomaly resulting from an excessive primary growth of the chondrocranium. The therapeutic management of NEMP should take into account these specificities.

[Surgical treatment of Obstructive Sleep Apnea Syndrome. Functional assessment]

INTRODUCTION

Obstructive Sleep Apnea Syndrome (OSAS), when associated with adverse skeletal dysmorphia, can be managed by curative surgery i.e. advanced maxillomandibular associated with genioplasty and uvulopalatoglossoplasty ("6 in 1"). The purpose of this study was to assess the functional impact of this procedure.

MATERIALS AND METHODS

This retrospective study was made on 27 patients with OSAS surgically treated between 1998 and 2009. The functional results were considered satisfactory when postoperative apnea/hypopnea index (AHI) was <15/h and/or at least decreased by 50%.

RESULTS

After surgical treatment, the AHI dropped below 15/h for 70.4%, and for 92.6% it was at least decreased by 50%, one year after surgery. A significant concomitant decrease of the body mass index (BMI) was also observed.

DISCUSSION

This "6 in 1" surgical management seemed to effectively treat OSAS in the selected cases.

[Do anti-inflammatory drugs worsen odontogenic cervico-facial cellulitis?]

OBJECTIVE

The aim of this prospective study was to determine the influence of anti-inflammatory drugs on the severity of odontogenic cellulitis in patients admitted to our hospital emergency unit.

STUDY DESIGN

The study was made from April 30 to October 31 2006. The clinical and pharmacological data was prospectively collected at admission, during hospitalization, and during systematic follow-up. We first studied the whole population and then compared the two groups: patients having received anti-inflammatory drugs before admission or not.

RESULTS

Two hundred and sixty-seven patients were included. The only severity criterion significantly different between the two groups was spreading of cervical lymphangitis (P = 0.028). None of the four studied parameters was identified as a risk factor for spreading of cervical lymphangitis in multivariate analysis: anti-inflammatory use (OR = 5.99, 95%CI [0.71-50.88]), alcohol abuse (OR = 4.00, 95%CI [0.66-24.12]), dental hygiene (OR = 1.53, 95%CI [0.36-6.56]), and tobacco use (OR = 0.27, 95%CI [0.57-1.28]).

DISCUSSION

The use of anti-inflammatory drugs during the initial phase of an odontogenic infection was not related to the severity of infection.

[Extended resection and radiotherapy for primary intraosseous maxillary carcinoma]

INTRODUCTION

Primary intraosseous maxillary carcinoma is a rare squamous cell carcinoma developing from remnants of the odontogenic epithelium. Risk factors are unknown and it may occur at any age. Little epidemiological data is available and few series include a sufficient number of patients. We assessed the prognosis of these tumors after wide exeresis (margin of 2 cm) followed by adjuvant radiotherapy.

METHODS

We reviewed the treatment and outcome data in nine cases of primary intraosseous maxillary carcinoma from 1995 to 2010. The WHO diagnostic criteria were used. We analyzed the demographic, clinical, and radiological data, as well as the type of treatment and the outcome of patients.

RESULTS

The gender ratio was 3.5/1, and the mean age 40.2 years. The most frequent presentation was a unilocular osteolytic lesion with an irregular contour, between 24 and 60 mm, in the mandibular angle. Extended tumor resection was performed in all patients. Reconstruction was performed with a fibula flap in seven patients. Five patients underwent adjuvant radiotherapy. The survival rate at 2 years was 100%. The mean follow-up was 6.9 years (2-14 years) at the end of the study. Two patients were treated for a relapse and one died after 3 years of follow-up.

DISCUSSION

The combined treatment was efficient on primary intraosseous maxillary carcinoma. The diagnosis is made with strict clinical, radiological, and histological criteria. The intraosseous location of these tumors requires an early diagnosis and aggressive treatment combining broad exeresis followed by adjuvant radiotherapy to avoid recurrence and have an optimal survival rate.

[Head and neck cellulitis caused by a broken anesthesia needle]

INTRODUCTION

Third molar extraction is one of the most common surgical procedures in oral and maxillofacial surgery. Infectious complications can be estimated at 3.6% after local anesthesia.

OBSERVATION

A 39-year-old female patient, presenting with important swelling of the face and neck after extraction of teeth 28 and 38 after local anesthesia. Clinical and radiographic data led to the diagnosis of facial cellulitis due to a foreign body on the sub angulo-mandibular region. Drainage under general anesthesia was performed and a fragment of anesthesia needle was removed. One month after surgery, the patient was considered cured.

DISCUSSION

Breaking an anesthesia needle is a rare accident, which can occur during oral surgery under local anesthesia. Respecting the rules of good practice is essential in preventing this type of complication, especially since forensic rules for dental and oral surgery are becoming stricter.

Masseter function and skeletal malocclusion

The aim of this work is to review the relationship between the function of the masseter muscle and the occurrence of malocclusions. An analysis was made of the masseter muscle samples from subjects who underwent mandibular osteotomies. The size and proportion of type-II fibers (fast) decreases as facial height increases. Patients with mandibular asymmetry have more type-II fibers on the side of their deviation. The insulin-like growth factor and myostatin are expressed differently depending on the sex and fiber diameter. These differences in the distribution of fiber types and gene expression of this growth factor may be involved in long-term postoperative stability and require additional investigations. Muscle strength and bone length are two genetically determined factors in facial growth. Myosin 1H (MYOH1) is associated with prognathia in Caucasians. As future objectives, we propose to characterize genetic variations using "Genome Wide Association Studies" data and their relationships with malocclusions.

[Congenital piriform aperture stenosis and odontogenic disorders]

PURPOSE

We had for objective to assess odontogenic disorders associated to a congenital piriform aperture stenosis and to study their various presentations.

METHODS

Twelve patients presenting with a congenital piriform aperture stenosis, 1 week to 3 months of age, were retrospectively included from 1998 to 2008. All patients underwent an initial CT scan to evaluate the temporary dental germs.

RESULTS

Deciduous dental germs were abnormal in 75% of the cases. Thirty-three percent had a single median maxillary central incisor.

DISCUSSION

The concept of solitary median maxillary central incisor syndrome makes for a more pathophysiological approach of this type of disease, with various clinical presentations, corresponding to various levels of severity of a same pathological process.

Initial staging for squamous cell carcinoma of the mouth, larynx and pharynx (except nasopharynx). Part 3: general assessment. 2012 SFORL recommendations

OBJECTIVES

The French Society of Otorhinolaryngology (SFORL) set up a work group to draw up guidelines for initial staging of head and neck squamous cell carcinoma. Locoregional and remote extension assessment are dealt with in two separate reports. The present part 3 deals with the assessment of frequent associated symptoms and pathologies, requiring early treatment and the collection of data on a certain number of clinical and paraclinical parameters for therapeutic decision-making in the multidisciplinary team meeting.

MATERIALS AND METHODS

A multidisciplinary critical analysis of the literature was conducted. General assessment here covers screening, assessment and initial management of the following: usual risk factors (smoking, alcohol, HPV), the most frequent medical comorbidities, nutritional status, social and psychological status, dental status, pain and possible anemia. As oncologic management frequently associates surgery, radiation therapy and chemotherapy, the underlying examinations should be early, as part of initial staging. The levels of evidence for the examinations were estimated so as to grade guidelines, failing which expert consensuses were established.

RESULTS

The high rates of pain, malnutrition and anemia call for systematic screening and early management, especially as rapidly effective treatments exist. Assessing comorbidity and social and psychological status enables general health status to be assessed, along with possible contraindications to the usual treatments. Tracheal intubation problems may require intubation under flexible endoscopy or jet-ventilation by inter-cricothyroid catheterization from the diagnostic endoscopy stage. Assessment and adapted dental care should be conducted if radiation therapy is likely or certain.

CONCLUSION

Early management of symptoms and comorbidity and anticipation of subsequent treatment are intended to shorten initial staging time and to collate the data needed for therapeutic decision-making. This assessment should be performed at the same time as the locoregional and remote extension assessment, and is obviously to be adapted according to tumoral extension stage and the possible treatment options.

[Engineering a bone free flap for maxillofacial reconstruction: technical restrictions]

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.

[Autologous tissue engineering by means of distraction osteogenesis: Biomechanical considerations]

Tissue engineering consists in producing functional replacement tissue. Distraction osteogenesis is a tissue engineering technique that uses the mechanical environment of cells to induce tissue regeneration, without need for exogenous biochemical factors. A better understanding of the optimal mechanical conditions of distraction callus stretching may reduce the duration, discomfort, and even social impact of distraction protocols, and complications and failures. We present the current state of knowledge in this field by addressing the fundamentals of elongating bone tissue biomechanics, the influence of rhythm and rate of distraction, and that of vectors and stability. Finally, we present the innovations currently studied, which may modify our clinical protocol in the short term.

[Oro-maxillofacial bone tissue engineering combining biomaterials, stem cells, and gene therapy]

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.

[Bone substitutes: Classification and concerns]

Autograft is considered as the "gold standard" for bone reconstruction. It provides osteoinductive factors, osteogenic cells, and appropriate osteoconductive scaffold. Donor site morbidity is the main limitation of autograft. Donor disease transmission limits the use of allograft. Synthetic bone substitutes still lack osteoinductive or osteogenic properties. Composite bone substitutes combining synthetic scaffold and biochemical substances initiating proliferation and cell differentiation, and possibly osteogenesis. Bone substitutes and grafts intended for clinical use are listed.

[A classification of cranio-facial syndromes]

How to manage craniofacial malformative cases? It seems to be very difficult, especially in orthodontics because of the lack of consensus. The authors' aim is to propose a physiopathologic classification of these craniofacial syndromes in order to simplify the medical practice when we meet these patients. More than fifty cases are actually treated and followed in our hospital; we have described all of these cases before to choose the most representative in each category. These syndromes are classified in four categories, organ abnormalities of one or many functional matrix, localized abnormalities of the anatomical structures, general abnormalities of the connective tissue, mixed syndromes.

Particularités de la réhabilitation dentaire prothétique dans les séquelles de fentes

The same techniques are used for dental rehabilitation in cleft patients and non-cleft patients. The clinical state for cleft edentulous patients ranges from one missing tooth to maxillary loss. For cleft patients, several surgical procedures may have been performed to close the cleft lip and/or palate, so the patient will not always agree to a new surgical procedure for preprosthetic management. The main difference to take into account is the dental occlusion stability. If previous management of the cleft patient did not provide normal occlusion, dental rehabilitation is the alternative. We describe implant-supported prosthesis; implant stabilized prosthesis, bridge, and maxillofacial prosthesis.

[Oronasal fistula in sequels of labialalveolarvelopalatine clefts]

Labial and palatine maxillary clefts are treated by surgery, as for oronasal fistula. One of the most important parts of management is the timing of primary surgery in order to avoid growth disturbance. The authors describe the various possibilities to close secondary oronasal fistula. The timing and choice of surgical techniques are still debated and being improved. Various surgical techniques are available, from mucoperiosteal palatal flap to a free flap. Nevertheless, the mucoperiosteal palatal flap is the most commonly used. In some cases mucoperiosteal flaps are impossible to perform, so other options for extreme cases are discussed.

Aggressive maxillary squamous odontogenic tumour in a child: histological dilemma and adaptative surgical behaviour

A case of a maxillary osteolytic tumour is described in a 9-year-old boy. Histological analysis led to an initial diagnosis of benign squamous odontogenic tumour, although this was not straightforward due to swelling, and cellular pseudo-malignant and non-specific signs. Because of the young age of the patient, a local surgical tumourectomy was first chosen with respect to the mixed dentition. For 10 months, the evolution was satisfactory. Then, a very aggressive tumoural recurrence with lip and palate infiltration led to doubts as to the histologic nature of the tumour. Efficient collaboration between several specialized pathologist teams finally confirmed that this was a squamous odontogenic tumour but in a very aggressive form. Radical surgery was then carried out.