Bone Substitutes in Le Fort I Osteotomy to Promote Bone Union and Skeletal Stability

Applications of regenerative techniques in adult orthodontics

Management of the growing adult orthodontic patient population must contend with challenges particular to orthodontic treatment in adults. These include a limited rate of tooth movement, increased incidence of periodontal complications, higher risk of iatrogenic root resorption and pulp devitalisation, resorbed edentulous ridges, and lack of growth potential. The field of regenerative dentistry has evolved numerous methods of manipulating cellular and molecular processes to rebuild functional oral and dental tissues, and research continues to advance our understanding of stem cells, signalling factors that stimulate repair and extracellular scaffold interactions for the purposes of tissue engineering. We discuss recent findings in the literature to synthesise our understanding of current and prospective approaches based on biological repair that have the potential to improve orthodontic treatment outcomes in adult patients. Methods such as mesenchymal stem cell transplantation, biomimetic scaffold manipulation, and growth factor control may be employed to overcome the challenges described above, thereby reducing adverse sequelae and improving orthodontic treatment outcomes in adult patients. The overarching goal of such research is to eventually translate these regenerative techniques into clinical practice, and establish a new gold standard of safe, effective, autologous therapies.

Bioactive glass granules S53P4 in osteotomy Le Fort I

We evaluated bioactive glass graft (S53P4) in patients undergoing Le Fort I osteotomy, with non-grafted patients as controls. Computed tomography facial scans of the 25 patients submitted for Le Fort I were divided into two groups: Group 1-S53P4 group and Group 2-without grafting. CT scans were analyzed in the immediate postoperative period (T1) and 6 months later (T2), for linear bone gap measurements, tomographic radiodensity and behavior of the maxillary sinus. A Kruskal-Wallis test on bone gap data adopted α significance levels (p ≤ 0.05). The Friedman test (p ≤ 0.05) was used to evaluate sinus reaction cores. For gap measurements, we observed a decrease in median data between T1 and T2 in both groups, with statistical significances observed between groups in T0; G1 presented statistical difference in its two studied times (p ≤ 0.0001). For bone density, the studied data behaved inversely. G1's bone density decreased from T1 to T2, whereas in G2 there was an increase from T1 to T2. S53P4 did not elicit increased reactions and/or sinus infections in the G1 group (p ≥ 1.00). S53P4 did not impact on Le Fort I osteotomies as a coadjuvant and a favorable factor in bone formation, and appeared innocuous in the maxillary sinus.

Maxillomandibular Advancement for Obstructive Sleep Apnea Produces Long-Term Horizontal Advancement of the Maxilla and Mandible

PURPOSE

Because limited data have been reported, the purpose of the present study was to evaluate the long-term craniofacial cephalometric skeletal changes associated with maxillomandibular advancement (MMA) for obstructive sleep apnea (OSA).

MATERIALS AND METHODS

We performed a retrospective cephalometric cohort study of craniofacial skeletal changes in patients who had undergone MMA for OSA. The primary predictor and outcome variables were time and the change in SNB over time, respectively. Digitized cephalometric radiographs were analyzed by an independent third-party cloud-based tracing software for 6 skeletal landmarks at 3 points-preoperatively, within 1 month postoperatively, and at the last follow-up evaluation. Post hoc stratification bidimensional analyses by gender and preoperative age and body mass index (BMI) were performed. Clinically significant results were determined as a greater than 2% change from baseline. Univariate and bivariate statistics were computed, and the statistical significance level was set at P < .05.

RESULTS

Thirty consecutive subjects with an even gender distribution were included in the present study. The average preoperative age, apnea hypopnea index, and BMI were 43.7 years, 59.8, and 39.3 kg/m². The average follow-up duration was 10.7 years (range, 5.6 to 18.8). Statistically and clinically significant long-term postoperative changes were found only for SNA (+4.9° or +6.0%; P < .001) and SNB (+3.8° or +4.9%; P < .001). Stratification by gender and median preoperative age and BMI did not find any statistically or clinically significant results.

CONCLUSIONS

Within the limitations of the present study, MMA for OSA produced statistically and clinically significant long-term cephalometric skeletal horizontal angular advancement of the maxilla and mandible of 6 and 4.9%, respectively, independently of gender, age, or BMI.

A prospective histomorphometric and cephalometric comparison of bovine bone substitute and autogenous bone grafting in Le Fort I osteotomies

PURPOSE

The aim of the present study was the histomorphometric and cephalometric comparison of autogenous bone grafting of the anterior iliac crest and the application of bovine bone substitute concerning new bone formation and postoperative stability in patients undergoing orthognathic Le Fort I osteotomy.

PATIENTS AND METHODS

Twenty-five patients requiring orthognathic surgery with Le Fort I osteotomy were included in this study. Patients were randomly divided into three groups receiving either autogenous iliac crest BONE grafting (BONE; n = 8) or xenogenic bovine bone grafting (Bio-Oss^®) in INTER (n = 12) or in ONLAY (n = 5) position. Histomorphometric analysis was performed using trephine bone biopsies from the autogenous, respectively xenogenic bone grafting region. Postoperative stability was evaluated using teleradiographies of three different timepoints.

RESULTS

All groups showed comparable mineralized fractions in bone biopsies of 50.2% (±13.2%) INTER, 46.48% (±12.3%) ONLAY and 57.1% (±20.6%) BONE as well as comparable percentage of connective tissue. Patients in the INTER-group revealed the lowest relapse rate of 20.5% (INTER) compared to 30.3% (ONLAY) and 33.0% (BONE). All groups underwent comparable maxillary advancement and healing time.

CONCLUSIONS

Present results indicate that block shaped bovine bone substitute is a promising alternative to autogenous bone grafting to bridge the Le Fort I osteotomy gap in orthognathic surgery.

Therapeutic Protocol for Orthosurgical Management of Class III Malocclusion in Patients With Cleidocranial Dysostosis

Cleidocranial dysostosis (CCD) is a congenital skeletal disorder with significant manifestations in facial and dental development. Patients are affected with CCD present maxillary deficiency, late dental eruption, and supernumerary teeth. Early and multidisciplinary approach is necessary to treat CCD patients, especially to manage dental eruption and Class III malocclusion with maxillary deficiency. Several orthodontic and surgical interventions are performed to enable traction and extraction of teeth. Yet the maxillary deficiency may be protracted followed by orthodontic dental compensation. On the other hand, it is important to note that CCD patients' treatment is closely related to the severity of transversal and sagittal deformities, as well as the discrepancies in the lower third of the face. In this context, patients with facial impairment highly affected by CCD may need ortho-surgical decompensation to reach more aesthetic outcomes. The present study reports a case of a 14-year-old young patient affected by CCD. Clinically, the patient presented Class III malocclusion, maxillary deficiency, short lower facial third, posterior crossbite, and anterior open bite leading to facial disharmony. The patient underwent treatment in 2 stages: the interceptive approach aimed to transversally expand the maxilla and promote its protraction; and the corrective phase combined with the orthognathic surgery treated the patients' main complains; the anterior open bite, unerupted teeth, and chin prominence. The treatment approach applied in the clinical report allowed the correction of the malocclusion and facial profile satisfying completely the patient's expectations.