Distraction histogenesis of the maxillofacial region

A Novel Interdisciplinary Approach for the Management of Micrognathia (Brodie Syndrome)

This study describes a multidisciplinary approach for correcting a severe Class II malocclusion with reduced mandibular transverse dimension. A 35-year-old woman presented with an increased overjet, complaining chiefly of forwardly placed upper front teeth and unpleasant smile esthetics. The patient had a convex profile with severe mentalis strain on lip closure. Intraoral examination indicated a bilateral Class II canine relationship, scissor bite, and narrow lower arch. The skull lateral view assessment revealed a skeletal Class II relationship with reduced lower facial height. According to the diagnostic records and after consultation with the patient, surgically assisted expansion of the mandibular symphysis with a bone distractor, comprehensive orthodontic treatment, and combined jaw surgery were planned, followed by dental implant placement and prosthetic full-mouth rehabilitation. Restorative dentistry, orthodontics, and orthognathic surgery were the 3 disciplines that helped in achieving the best esthetic and functional results in this patient.

A Comparative Study of Skeletal and Dental Outcome between Transcutaneous External Maxillary Distraction Osteogenesis and Conventional Rigid External Device in Treating Cleft Lip and Palate Patients

Background: Traditional distraction osteogenesis (DO) with the tooth-borne rigid external device (RED) system was regularly used in treating patients with cleft-related maxillary hypoplasia. However, the bone-borne RED system with miniplates and bone screws has currently become an effective treatment. This retrospective study was to compare bone-borne RED with traditional tooth-borne RED in distraction effectiveness, blood loss, operative time, and long-term stability. Methods: Twenty-two growing patients who underwent RED therapy were divided into two groups: eleven patients utilizing the bone-borne RED system with the transcutaneous wire attached with skeletal anchorage; another eleven patients using the traditional tooth-borne RED system with the intra-oral device attached with dental anchorage. Serial lateral cephalograms were analyzed for comparing treatment outcomes and stability in 1 month, 6 months, and 1.5 years after distraction. Results: In bone-borne RED group, the maxilla was advanced by 19.98 mm with slight clockwise rotation of 0.40° and minimal palatal inclination change of incisor by −3.94°. In traditional tooth-borne RED group, the maxilla showed less advancement by 14.52 mm, with significant counter-clockwise rotation of −11.23° and excessive palatal inclination change of incisor by −10.86°. Although operative time was longer in the bone-borne RED group by 38.4 min, this did not bring about greater blood loss. Conclusions: the bone-borne RED via transcutaneous wire system provides an easy, simple, and comfortable procedure as well as favorable long-term stability in maxillary distraction.

Panax notoginseng Saponin Promotes Bone Regeneration in Distraction Osteogenesis via the TGF-β1 Signaling Pathway

Distraction osteogenesis (DO) is an efficient strategy that is employed for the treatment of large bone defects in craniomaxillofacial surgery. Despite its utility, however, DO is associated with a prolonged consolidation phase and a high complication rate that hinder its more widespread utilization. Panax notoginseng saponin (PNS) is a traditional Chinese medicine that is frequently administered for the treatment of a range of conditions. Herein, we explored the ability of PNS treatment to influence osteogenic differentiation using both rabbit bone marrow mesenchymal cells (BMSCs) and a model of mandibular DO. BMSC proliferation was assessed via CCK-8 assay, while osteogenic differentiation was monitored through ALP and alizarin red S staining. A PCR approach was used to evaluate the expression of genes associated with osteogenesis (ALP, Runx2, and OCN) and genes linked to the TGF pathway (TβR-II, SMAD2, SMAD3, and PPM1A). For in vivo experiments, treated BMSCs were locally injected into the DO gap, with PNS being injected into treated rabbits every other day throughout the experimental period. The quality of the regenerative process was assessed via scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray imaging, and hematoxylin and eosin (H&E) staining. These analyses revealed that PNS was able to promote BMSC osteogenesis and mandibular generation, driving the upregulation of osteogenesis-related genes at the mRNA levels through the modulation of the TGF-β1/Smad pathway. Consistently, the overexpression or silencing of TβR-II in PNS-treated BMSCs was sufficient to modulate their osteogenic potential. Analyses of in vivo mandibular DO outcomes revealed significantly augmented new bone growth in the PNS-treated group relative to control animals, with maximal osteogenesis in the group overexpressing rabbit TβR-II. Together, these results highlight the PNS as a promising and cost-effective therapeutic tool with the potential to enhance bone regeneration in clinical contexts through the modulation of the TGF-β1/Smad pathway.

Mandibular distraction of free iliac crest bone graft as treatment in a patient with a history of gunshot wound. Case Report

Introduction: The combination of non-vascularized iliac crest bone graft and distraction osteogenesis in a second surgical intervention has only been described to achieve alveolar ridge augmentation. This technique is not recommended to treat bone defects of the jaws caused by firearm projectile. Case presentation: 40-year-old woman with a segmental mandibular defect in the mandible body caused by the impact of a firearm projectile at the age of 1 year. The patient developed a severe Class II dentofacial anomaly that required a two-stage treatment; she underwent mandibular reconstruction with free iliac crest bone graft followed by a bilateral mandibular distraction at the level of the iliac crest bone graft. With these interventions, a remarkable improvement of the patient's malformation was achieved. Conclusion: Horizontal distraction of the free iliac crest bone graft is a safe and predictable procedure to treat dentolabial anomalies requiring mandibular reconstruction. This procedure was performed in the patient without complications. Further studies on the effectiveness of this technique are required.

Alveolar distraction osteogenesis of a fibula free flap in maxillary reconstruction

In maxillary reconstruction, it is challenging to obtain satisfactory maxillary projection and to optimizate the dental implant-prosthetic rehabilitation. We report a case of sagittal distraction of a fibula free flap used to reconstruct maxilla after a ballistic trauma. Distraction began seven days after implantation of the device. The distraction protocol was 0.9mm per day during a total period of 2 months. Cone beam computed tomography acquisitions were performed at 3 months after the end of the distraction. The distractor device was removed 5 months after the end of the distraction protocol to allow bone consolidation. A satisfactory total distraction of 7mm was obtained with an esthetic variation of the projection of the upper lip and closure of the nasolabial angle.

Alar width changes due to surgically-assisted rapid palatal expansion: A meta-analysis

A major objective of orthognatic surgery is the aesthetic outcome. Treatments only correcting for dentoskeletal deformities are not sufficient for optimal facial results because undesirable soft tissue changes may accompany skeletal manipulations. The primary objective of this study was to investigate alar base width (ABW) changes a minimum of 6 months following surgically-assisted rapid palatal expansion (SARPE). The following electronic databases and citation indices were searched: PubMed, Cochrane Library, Scopus, Web of Science, Embase, and Virtual Health Library. The search included articles published until September 2015 without language restriction. The intervention was SARPE with maxillary vestibular incision from first molar to contralateral first molar, a modified LeFort I osteotomy with or without pterygomaxillary disjunction, and a V-Y closure. The primary outcome was the unstandardized mean difference between pre and postoperative ABW. A random effects meta-analysis was performed to combine study results, and included studies that were assessed for statistical heterogeneity using a Chi-square test for independence. The results of this meta-analysis (N = 41) showed a significant + 1.74 mm, 95% CI [0.14, 3.34] ABW increase in patients submitted to SARPE. There was no statistical heterogeneity among included studies (χ² = 0.03; df = 2; P = 0.98). ABW increases were observed despite including cinched patients in the analysis. None of the three included studies were completely free of bias. The most prominent flaws were measurement bias, limited sample size, and patient recruitment.

[Rational use of distraction osteogenesis in craniofacial surgery]

Distraction osteogenesis, initially developed by Ilizarov for limb, is the tissular extension caused by the progressive space of the osseous pieces following an osteotomy. Distraction is osteogenesic and histogenic. Twenty-five years ago, at the instigation of McCarthy, this technique was used to handle the craniofacial malformations in the various floors of the face : mandibular, mediofacial and cranial. The most wide-spread protocols respect a latency period from 0 to 7 days, a rhythm of distraction from 1 to 2mm a day in 2 at 4 times and a period of consolidation from 4 to 8 weeks. Distraction is the result of the inventiveness of the pioneers then the work to always adapt to the multiple complex clinical situations. The surgeon has to choose between internal or external materials allowing a mono- or multi-vectorial extension, in osseous and/or dental anchoring. The mandibular distraction is very effective for the treatment of the secondary obstructive syndromes in the unilateral or bilateral severe hypomandibular malformations. She also allows desobstruction of the superior airways within the framework of the mediofacial hypoplasies as well as the secondary treatment of the growth defects in cleft lips and palates. Finally, the distraction osteogenesis enhanced reliability of the fronto-facial advancement in early and secondary treatment of craniofaciosynostosis. This is a real support of the facial growth, which has to be included in a plan of global treatment.