Comparative evaluation between the “All on Four” and “Four on Pillars” techniques in 3D virtual planning associated with guided surgery on atrophic jaws

Thorough technical knowledge and anatomical understanding are critical for optimal surgical results. The difficulty of complete maxillary surgery can vary significantly depending on the complexity of the anatomy or bone defect. In this work, we analyze and compare two methods of software-guided planning for the manipulation of dental implants, associated with the All on Four (ALL) and Four on pillars (FOUR) techniques used in patients with atrophic maxillae. Forty-two images of totally edentulous patients were analyzed, and surgical planning was performed using both methods. The average area of the Four on pillars technique is 4.9x (p<0.0001) greater than the average area of the All on four technique, this represents a difference of 489%. This means that, for the same force applied by the jaw, we will have a 4.9x smaller pressure, that is, a better distribution of forces on the jaws. It was not possible to notice a statistical difference between the success proportions (p=0.2542), this means that both techniques have a non-different (similar) success proportion. We conclude that the area of the polygon formed in the Four on pillars surgical plan is larger than in the All on four plan and this results in significantly less pressure on the implants. We also concluded that it was not possible to notice a statistical difference between the proportions of success, which shows that there is no technique with successful performance advantages over the other.

Assessement of the Nasal Shape after Orthognathic Maxillary Surgery

Background : Orthodontic and/or surgical modifications to the jawbone could undoubtedly have aesthetic effects on the shape or position of the nose.Aim : Cephalometric analysis was used to evaluate the aesthetic alterations (dimensional and positional) of the nose in this patients.he PIDAQ was cross-culturally adapted into Malay version by forward- and backward-translation processes, followed by psychometric validation.Methods : To compare cephalometric changes in the nose, a cross-sectional study was conducted from January to March 2019. A sample of 20 orthognathic patients was included in this study. Their mean age was 22.40 (+/-6.98 years). The amplitude of the surgical movements of all patients were measured, using measurements on profile teleradiographs and on photos of faces taken before and after surgery. The statestical analysis of cephalometric data before and after surgery was performed using the Wilcoxon test. The significance level was p≤0.05.Results : The results revealed that a significant reduction in the angular values of SNA (°) (p<0.001), GoGn/SN (°) (p=0.038), Occ/Sn (°) (p=0.007) and AoBo (mm) (p=0.025). No statistically significant differences were noted for specific cephamometric variables before and after surgery. For the comparison of facial photographs, all the values of the specific measurements before and after were significant with the exception of Prn - SN.Conclusion : The width of the base of the nasal wing increased, the displacement and the amount of rotation of the nasal tip also increased in most patients. In contrast, a drop in the X-axis to Prn distance was noted.

Secondary surgery in cleft lip and palate

Secondary surgery in patients with cleft lip and palate should be undertaken within a cleft multidisciplinary team where such expertise is available. A clinical psychologist can identify issues related (or unrelated) to the cleft and aid in establishing appropriate patient expectations if surgery is contemplated. The requirements of patients considering secondary cleft surgery are more similar to the needs of patients undergoing primary surgery than they are to other non-cleft facial surgery patients. Secondary surgical procedures appropriate to cleft lip and palate patients include revisional lip surgery, adjunctive alveolar or maxillary surgery, orthognathic surgery, revisional nasal surgery, and adjunctive facial procedures. These procedures tend to be performed once facial growth is complete and may need to be coordinated with other interventions, including orthodontics and speech assessment. Surgical procedures should be correctly sequenced and a long-term plan made in conjunction with the patient.

Analysis of the Complications in Patients Undergoing Orthognathic Surgery by Piezosurgery®: A 13 Years Retrospective Study

Orthognathic surgery is a branch of maxillo-facial surgery increasingly in demand, which deals with the correction of skeletal deformities. The aim of the present study is to identify the most common post-operative complications following orthognathic bimaxillary surgery performed by means of Piezosurgery®. Furthermore, through an examination of the available scientific literature, we wanted to establish whether the frequency of postoperative complications were consistent with those already reported. A retrospective study on 58 patients who underwent orthognathic surgery with a bilateral sagittal osteotomy (BSSO) of the mandibular bone branch, maxillary surgery with Le Fort I mono-segmented or multi-segmented approach, and genioplasty technique using Piezosurgery®. The complications taken into consideration were disorders of the temporomandibular joint (TMJ), paraesthesia and hypoesthesia, asymmetries, nose enlargement, nasal septum deviation, nasal obstruction, dental discolorations, pulpal necrosis, occlusion and masticatory efficiency, gingival recession, periodontal problems, dysgeusia, nausea and vomiting, weeping alterations, hearing problems, delayed healing, superinfection, removal of synthesis means, reoperation, cicatricial outcome, and bilateral pneumothorax. It has been highlighted that a number and type of postoperative complications matched those reported by the most recent literature reviews. Temporomandibular disorders and paraesthesia were the most common ones. The only complication rate that differed from the literature was nerve damage, which was significantly lower. Post-surgical complications depend on the used surgical techniques, clinical work, and treatment methods. The use of piezoelectric devices in orthognathic surgery operations provides an innovative, safe, and effective technique compared to traditional methods.

A Splint-to-CT Data Registration Strategy for Maxillary Navigation Surgery

Computer-assisted navigation plays an important role in modern craniomaxillofacial surgery. Although headpins and skull posts are widely used for the fixation of the reference frame, they require the use of invasive procedures. Headbands are easily displaced intraoperatively, thus reducing the accuracy of the surgical outcome. This study reported the utility of a novel splint integrated with a reference frame and registration markers for maxillary navigation surgery. A maxillary splint with a 10 cm resin handle was fabricated before surgery, to fix the reference frame to the splint. The splint was set after the incorporation of fiducial gutta-percha markers into both the splint and resin handle for marker-based pair-point registration. A computed tomography (CT) scan was acquired for preoperative CT-based planning. A marker-based pair-point registration procedure can be completed easily and noninvasively using this custom-made integrated splint, and maxillary navigation surgery can be performed with high accuracy. This method also provides maximum convenience for the surgeon, as the splint does not require reregistration, and can be removed temporarily when required. The splint-to-CT data registration strategy has potential applicability not only for maxillary surgery but also for otolaryngologic surgery, neurosurgery, and surgical repair after craniofacial trauma.