Gwenael Raoul

Microsurgical reconstruction of the jaw with fibular grafts and implants.

Reconstructive treatments for jaw defects are complex procedures that can combine multiple techniques including fibula free flap (FFF) grafting. The purpose of this retrospective study was to document and share our experience on mandibular and maxillar reconstruction with FFF followed by secondary dental rehabilitation using implant insertion. We reviewed 198 patients treated by FFF grafting for mandibular and/or maxillary defects in our department during the past 11 years (1996-2007). A selection of 30 patients (18 males and 12 females, mean age of 46 y) with adequate criteria (hygiene, motivation, and prognosis) received secondary placement of osseointegrated implants. The implant success was clinically and radiographically evaluated. A total of 105 osseointegrated implants were placed in the grafted fibulas 5 months to 3 years after the reconstruction surgery. Only 4 implants were lost because of peri-implantitis (3 patients) and fibular fracture (1 patient); this corresponds to a 96.2% implant success rate. During the mean follow-up of 76 months, patients satisfaction and functional and aesthetic results were evaluated. Radiologic findings indicated a low crest resorption around the implants despite an unfavorable crown-to-root ratio. The main difficulties in the reconstructions were lack of FFF height, absence of a vestibular groove, limitation of mouth opening, skin paddle thickness, and the reconstruction of surrounding tissues including the lip. Our management strategy is discussed. Prosthetic choice is fundamental to achieving patient-specific solutions. The prostheses used included sealed or screwed bridge, resin-bonded bridge, tooled bar, implant-borne denture, or implant-stabilized dentures. Dental implants may be used even in situations involving an unfavorable crown-to-root ratio and implant position by using milled bar and overdenture. The FFF provides a consistent bone graft that allows a reliable and predictable restoration with dental implants, leading to a satisfactory functional and aesthetic restoration.

Maxillary reconstruction to enable implant insertion: a retrospective study of 181 patients

BackgroundThe purpose of the present study was to evaluate different types of maxillary pre-prosthetic surgery using autogenous bone graft and suggest a guideline for maxillary reconstruction to place implant.Methods181 patients (125 females and 56 males), age range from 16 to 76 years old, were operated at the Maxillo-Facial Service of the Lilles 2 Universitary Hospital Center (Chairman Pr Joël Ferri). Different techniques were used, but always with autogenous bone grafting. 21 patients underwent a Lefort 1 procedure, 139 underwent sinus graft with or without vestibular onlay graft and 21 underwent onlay graft. This surgical procedure was made to allow the insertion of 685 implants.ResultsThe patients were evaluated by clinical and radiological assessment. In the cases of Lefort 1, the rate of successful osteointegration was higher when the implants were placed in the second part of a two stages procedure: 92%, against 81% for one stage. In cases of sinus lift procedure, the rate of implant success was 98%. The infection rate was 3.5%. There was no significant resorption and the type of prosthesis used was a denture retained by a bar or fixed bridge. In cases of onlay graft, the implant insertion success was 97% and there was no infection. The amount of resorption was more significant in the pre-maxilla than in the other areas and the type of prosthesis used was fixed dentures.ConclusionThese observations demonstrate that: the aetiology of the bone defect indicate the type and number of the surgical procedures to re-established good jaws relationship and give the bone conditions to implant insertion successful.Clinical RelevanceA guideline for surgical decision in the maxillary reconstruction for oral rehabilitation by implants may help to prevent failures of osseous resorption disorders and to foresee the investment of the bone in quality and necessary quantity.

Temporomandibular joint dysfunction and orthognathic surgery: a retrospective study

BackgroundRelations between maxillo-mandibular deformities and TMJ disorders have been the object of different studies in medical literature and there are various opinions concerning the alteration of TMJ dysfunction after orthognathic surgery. The purpose of the present study was to evaluate TMJ disorders changes before and after orthognathic surgery, and to assess the risk of creating new TMJ symptoms on asymptomatic patients.MethodsA questionnaire was sent to 176 patients operated at the Maxillo-Facial Service of the Lilles 2 Universitary Hospital Center (Chairman Pr Joël Ferri) from 01.01.2006 to 01.01.2008. 57 patients (35 females and 22 males), age range from 16 to 65 years old, filled the questionnaire. The prevalence and the results on pain, sounds, clicking, joint locking, limited mouth opening, and tenseness were evaluated comparing different subgroups of patients.ResultsTMJ symptoms were significantly reduced after treatment for patients with pre-operative symptoms. The overall subjective treatment outcome was: improvement for 80.0% of patients, no change for 16.4% of patients, and an increase of symptoms for 3.6% of them. Thus, most patients were very satisfied with the results. However the appearance of new onset of TMJ symptoms is common. There was no statistical difference in the prevalence of preoperative TMJ symptoms and on postoperative results in class II compared to class III patients.ConclusionsThese observations demonstrate that: there is a high prevalence of TMJ disorders in dysgnathic patients; most of patients with preoperative TMJ signs and symptoms can improve TMJ dysfunction and pain levels can be reduced by orthognathic treatment; a percentage of dysgnathic patients who were preoperatively asymptomatic can develop TMJ disorders after surgery but this risk is low.

Masseter myosin heavy chain composition varies with mandibular asymmetry.

Human jaw dysmorphologies are frequent and often affect young patients, resulting in malocclusion of teeth and inappropriate jaw relationships. Treatment is performed by means of orthodontics with orthognathic surgery as required. Mandibular asymmetry is one of the most frequent dysmorphologies, but in many cases, the specific cause is unknown. In healthy patients who were undergoing orthognathic surgery for correction of malocclusion, we tested the hypothesis that masseter muscle phenotype composition, which determines contractile properties, was different between sides in patients with mandibular asymmetry but not in those without mandibular asymmetry. After cephalometric analysis, 50 patients from whom we obtained samples of both right and left masseter muscles were separated into 2 groups: with or without mandibular lateral deviation. Samples were immunostained with myosin-isoform-specific antibodies to identify 4 skeletal muscle fiber types, and their fiber areas and proportions were measured. Two-tailed Wilcoxon test for paired samples was used to compare the 4 fiber-type compositions by means of percent occupancy and mean fiber area on both sides. Patients with mandibular asymmetry were associated with a significant increase of type II fiber occupancy (P = 0.0035) on the same side as the deviation. This finding that masseter muscle phenotype is significantly linked to mandibular asymmetry is of relevance to physiotherapeutic and surgical managements of jaw discrepancies and merits further investigation in the light of its possible role in the etiology of this condition.

Complications of calvarial bone harvesting for maxillofacial reconstructions.

Background:For almost a century, autologous bone grafts are the criterion standard for facial skeleton rehabilitations. Progressively, because of its various advantages, calvarial bone imposed as one of the most adapted for craniomaxillofacial reconstructions. Also, calvarial harvesting remains a controversial technique because of its potential complications described in the literature. The aim of this study was to report the precocious and late complications encountered in our practice and to compare them with the previous data of the literature. Methods:We decided to realize a retrospective study over 10 years and 511 cases of calvarial bone harvesting performed in our maxillofacial department. Results:Our results are very clear, reporting some annoying consequences and long-term aesthetic reattempts, but any serious complication. Discussion:According to our experience and previous data of the literature, we described some technical refinements that could improve our technique and reduce its potentials complications. Nevertheless, we think that nowadays calvarial harvesting is the criterion standard for maxillofacial bone grafts, and the complications described in the literature are negligible for experienced operators.

Condylar hyperplasia: correlation between clinical, radiological, scintigraphic, and histologic features.

PurposeThe objectives of this study were to compare demographic, clinical, radiographic, scintigraphic, and histologic differences between the 2 main types of condylar hyperplasia (CH) and to suggest a new therapeutic management based on such findings. MethodsThis was a retrospective study based on 28 patients who presented either vertical (group 1) or horizontal (group 2) forms of CH and underwent surgical treatment. Every patient had a complete preoperative clinical and radiological examination as well as a single-photon emission computed tomography scan. A histologic analysis of each resected condyle was performed. These various parameters were then compared in the 2 patient groups. ResultsThe mean age at time of the diagnosis was 25.8 years (range, 12–50 years), and there were 22 females and 6 males. Nineteen patients had the vertical form of CH, and 9 had the horizontal form. Scintigraphic analysis showed moderate to extensive radionucleotide uptake in cases with rapid growth. Four cases had negative single-photon emission computed tomography scan uptake, and all were vertical forms, but there was no statistically significant difference between the 2 groups. The histologic analysis showed both a global thickening of the cartilage cap and of the prechondroblastic cells layer with no statistically significant difference between the 2 groups. ConclusionsCondylar hyperplasia is a pathologic condition affecting mainly young females and whose origin remains unknown. Single-photon emission computed tomography scans as an indicator of the rapidity of the disease progress are essential in assessing the condylar hyperplasia and to guide the therapeutic approach.

Human Masseter Muscle Fiber Type Properties, Skeletal Malocclusions, and Muscle Growth Factor Expression

PURPOSE We identified masseter muscle fiber type property differences in subjects with dentofacial deformities. PATIENTS AND METHODS Samples of masseter muscle were collected from 139 young adults during mandibular osteotomy procedures to assess mean fiber areas and percent tissue occupancies for the 4 fiber types that comprise the muscle. Subjects were classified into 1 of 6 malocclusion groups based on the presence of a skeletal Class II or III sagittal dimension malocclusion and either a skeletal open, deep, or normal bite vertical dimension malocclusion. In a subpopulation, relative quantities of the muscle growth factors IGF-I and GDF-8 gene expression were quantified by real-time polymerase chain reaction. RESULTS Fiber properties were not different in the sagittal malocclusion groups, but were very different in the vertical malocclusion groups (P ≤ .0004). There were significant mean fiber area differences for type II (P ≤ .0004) and type neonatal-atrial (P = .001) fiber types and for fiber percent occupancy differences for both type I-II hybrid fibers and type II fibers (P ≤ .0004). Growth factor expression differed by gender for IGF-I (P = .02) and GDF-8 (P < .01). The ratio of IGF-I:GDF-8 expression associates with type I and II mean fiber areas. CONCLUSION Fiber type properties are very closely associated with variations in vertical growth of the face, with statistical significance for overall comparisons at P ≤ .0004. An increase in masseter muscle type II fiber mean fiber areas and percent tissue occupancies is inversely related to increases in vertical facial dimension.

Consequences of bony free flap's pedicle calcification after jaw reconstruction.

Introduction Most of the time, discovery of free flap pedicle calcification is fortuitous. We describe this phenomenon, try to elucidate its consequences, and discuss about prevention. We studied the effect of radiotherapy on the onset of calcification. We describe the first case of pedicle calcification with a scapula free flap. Materials and Methods We performed a retrospective study among the 162 bony free flaps harvested from 2003 to 2011. Follow-up included clinical examination, radiography, and head and neck computed tomography. We collected data including patients’ age during free flap surgery, genre, primary disease, disease location, connected artery, ossification delay, clinical signs, flap vitality, and, eventually, calcification removal. We tested the effect of radiotherapy on the onset of calcification using a log-rank test. Results We retrieved data of 15 patients with pedicle ossification after bony free flap (9.2%). Fibula free flap was present in 14 patients and scapula free flap was present in 1 patient. We noticed vascular pedicle ossification in 42% of our maxillary reconstructions and in 7% of our mandibular reconstructions. The maxillary-to-mandibular ratio is 5:10. Pedicle ossification was discovered between 92 and 366 days after surgery. We performed radiography for diagnosis. Clinical signs were reported in 6 patients. We removed ossified pedicle in 3 patients (20%) owing to pain, trismus, or hard cheek swelling. No free flap failure was noted among the 15 calcified pedicles. There was no statistically significant difference in the effect of radiotherapy on the onset of calcification (P = 0.126). Discussion Ossification of the vascular pedicle is uncommon and probably underdiagnosed. Complications are rare, and surgical ossification removal should be reserved for patients with symptoms.

Le Fort I osteotomy and calvarial bone grafting for dental implants

INTRODUCTION We present a reconstruction technique for atrophied maxilla which combines a Le Fort I osteotomy and calvarial bone grafting. This retrospective study was carried out to evaluate bone volume increase and the possibility to insert dental implants. PATIENTS AND METHODS Bone volume increase was assessed in 56 patients using preoperative and 6-month postoperative computed axial tomography (CAT). The implant rate success and the type of prosthesis were evaluated. RESULTS The average increase at the first molar level was 10.2mm vertically and 8.2mm transversally. No infection was reported. The implant success rate was 97.9% and a prosthetic rehabilitation was performed in all patients (55% with removable bar-supported prostheses, and 45% with fixed prostheses). DISCUSSION The technique is adapted to atrophied maxilla reconstruction for dental implant rehabilitation. The implant success rate was similar to that of other bone augmentation techniques.

Epigenetic influence of KAT6B and HDAC4 in the development of skeletal malocclusion.

INTRODUCTION Genetic influences on the development of malocclusion include heritable effects on both masticatory muscles and jaw skeletal morphology. Beyond genetic variations, however, the characteristics of muscle and bone are also influenced by epigenetic mechanisms that produce differences in gene expression. We studied 2 enzymes known to change gene expressions through histone modifications, chromatin-modifying histone acetyltransferase KAT6B and deacetylase HDAC4, to determine their associations with musculoskeletal variations in jaw deformation malocclusions. METHODS Samples of masseter muscle were obtained from subjects undergoing orthognathic surgery from 6 malocclusion classes based on skeletal sagittal and vertical dysplasia. The muscles were characterized for fiber type properties by immunohistochemistry, and their total RNA was isolated for gene expression studies by microarray analysis and quantitative real-time polymerase chain reaction. RESULTS Gene expressions for fast isoforms of myosins and contractile regulatory proteins and for KAT6B and HDAC4 were severalfold greater in masseter muscles from a patient with a deepbite compared with one with an open bite, and genes related to exercise and activity did not differ substantially. In the total population, expressions of HDAC4 (P = 0.03) and KAT6B (P = 0.004) were significantly greater in subjects with sagittal Class III than in Class II malocclusion, whereas HDAC4 tended to correlate negatively with slow myosin type I and positively with fast myosin gene, especially type IIX. CONCLUSIONS These data support other published reports of epigenetic regulation in the determination of skeletal muscle fiber phenotypes and bone growth. Further investigations are needed to elucidate how this regulatory model might apply to musculoskeletal development and malocclusion.