ABSTRACT
This study was performed to evaluate the compressive mechanical strength of rigid internal fixation (RIF) using 1.5-mm L-shaped plates fixed with monocortical screws in sagittal split osteotomy (SSO). Thirty synthetic hemimandibles, which had all undergone a 5-mm advancement, were divided into three groups: three 12-mm bicortical titanium screws were placed in an inverted L pattern in group A; one straight 2.0-mm system spaced titanium plate fixed with four 5-mm monocortical screws was used in group B; two 1.5-mm system L-shaped titanium plates, each fixed with four 5-mm monocortical screws, were used in group C. The models were subjected to compressive and progressive mechanical tests with forces applied in the area between the second premolar and first molar to verify resistance in Newtons (N). A displacement speed of 1mm/min was applied, with a maximum 10mm displacement of the distal segment or until disruption of the fixation. The deformity and/or eventual rupture of the plates were evaluated, and consequently their technical stability was determined. The results showed that the modified fixation technique tested in this study on synthetic mandibles resulted in adequate stability and superior mechanical behaviour compared to simulated osteosynthesis with the use of a straight 2.0-mm titanium plate.
Subject(s)
Fracture Fixation, Internal/methods , Mandibular Fractures/physiopathology , Mandibular Fractures/surgery , Osteotomy, Sagittal Split Ramus/methods , Bicuspid , Biomechanical Phenomena , Bone Plates , Bone Screws , Compressive Strength , Equipment Failure Analysis , Humans , In Vitro Techniques , Jaw Fixation Techniques , Molar , Stress, Mechanical , TitaniumABSTRACT
Inferior alveolar nerve (IAN) repositioning has been used widely in recent years as an alternative approach for dental implant placement in the atrophic posterior mandible. The aim of this study was to answer the question: What are the complications associated with IAN repositioning? A systematic literature review performed in accordance with the PRISMA statement, using the PubMed (MEDLINE), Cochrane Library, and Scopus databases, identified a total of 116 articles related to this technique. Of those articles, 24 were included in the final review. Lateralization was the chosen technique in seven studies, transposition in 15 studies, and two studies reported both techniques. The longest follow-up period was 49.1 months and the shortest 6 months. Of the patients who underwent lateralization, 95.9% initially showed a neurosensory disturbance, and the condition remained at the end of the study for 3.4% of those patients. With regard to the patients who underwent transposition, neurosensory alterations were observed in 58.9% of patients initially, and the condition remained for 22.1% of those affected at the end of the study. Only one study found no neurosensory disturbance at any time. More data consolidation is necessary to determine scientifically if, which, and when the IAN repositioning technique can be recommended.
