Diş Hekimliği Fakültesi / Faculty of Dentistry

Permanent URI for this collectionhttps://hdl.handle.net/11727/2120

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    In Vitro Biomechanical Comparison of Six Different Fixation Methods Following 5-mm Sagittal Split Advancement Osteotomies
    (2015) Oguz, Y.; Watanabe, E. R.; Reis, J. M.; Spin-Neto, R.; Gabrielli, M. A.; Pereira-Filho, V. A.; 0000-0002-0287-0400; 25840861; M-4178-2017
    The sagittal split ramus osteotomy (SSRO) is a surgical technique used widely to treat many congenital and acquired mandibular discrepancies. Stabilization of the osteotomy site and the potential for skeletal relapse after the procedure are still major problems. The aim of this study was to compare the mechanical stability of six methods of rigid fixation in SSRO using a biomechanical test model. Sixty polyurethane replicas of human hemimandibles were divided into six groups. In group I, the osteotomies were fixed with two four-hole titanium miniplates; in group II, with one four-hole miniplate; in group III, with one four-hole miniplate + a bicortical screw; in group IV, with a grid miniplate; in group V, with a four-hole locking miniplate; and in group VI, with a six-hole miniplate. A linear load in the premolar region was applied to the hemimandibles. The resistance forces (N) needed to displace the distal segment by 1, 3, and 5 mm were recorded and the data transmitted from the load cell to a computer. One-way analysis of variance with Tukey's post hoc test was performed to compare the means between groups. For the three displacement conditions, there was a strong tendency for the 2.0-mm plate + screw and the grid plate to have higher values.
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    The Influence of Bilateral Sagittal Split Ramus Osteotomy on Submental-Cervical Aesthetics
    (2014) Soydan, S. S.; Uckan, S.; Ustdal, A.; Bayram, B.; Bayrak, B.; 24946129; K-2259-2018
    The effect of orthodontic-surgical treatment on submental-cervical region was evaluated in a very limited number of studies. The aim of this study was to evaluate submental-cervical soft tissue contour changes following mandibular advancement and set-back procedures via bilateral sagittal split ramus osteotomy. Sixty-seven patients were included in this study. Group 1 consisted of 27 skeletal Class II patients who underwent mandibular advancement surgery, whereas Group 2 consisted of 40 skeletal Class III patients who underwent mandibular set-back surgery. Various linear and angular measurements were performed on pre-operative and sixth month post-operative cephalometric radiographs. A new method was used to evaluate the amount of sagging at submental region. The submental length did not change in Group 1; however, it decreased significantly in Group 2 (P<005). The angle between submental plane and facial plane decreased to 959 degrees from 988 degrees in Group 1(P<005), whereas it increased to 931 degrees from 882 degrees in Group2 (P<005). The change of submental soft tissue sag was almost stable in Group 1, while 034mm increase of sag was observed in Group 2. This increase was not statistically significant (P>005). Mandibular set-back and advancement procedures do not remarkably change the submental sag following approximately 6mm jaw movement. Although mandibular advancement did not significantly effect submental length, soft tissue followed mandibular set-back with a ratio of 1:1 at C-point to projection of soft tissue pogonion and 1:07 at C-point to soft tissue menton distances.
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    Changes in Difficult Airway Predictors Following Mandibular Setback Surgery
    (2015) Soydan, S. S.; Bayram, B.; Akdeniz, B. S.; Kayhan, Z.; Uckan, S.; 0000-0003-0579-1115; 0000-0002-1988-3195; 26206397; AAJ-4623-2021; N-1121-2014
    The aim of this study was to determine the effect of surgical mandibular backward movements on the predictors of a difficult airway. Thirty-seven skeletal class III patients were included in this study. The Mallampati score, body mass index (BMI), maximal inter-incisal distance, and thyromental and sternomental distances of these patients were evaluated preoperatively and at 6 months and 2 years postoperatively. A sagittal split ramus osteotomy (SSRO) without genioplasty was performed in all patients by the same surgical team, and anaesthesia was provided by the same anaesthesiologist using nasotracheal intubation. The paired samples t-test and Wilcoxon signed-rank test were used for statistical comparisons of the data. There were no statistically significant changes in BMI or sternomental and thyromental distances after SSRO. The maximal inter-incisal distance was significantly reduced at 6 months postoperatively (P < 0.05), but no statistical difference was found between the values obtained preoperatively and at 2 years postoperative. A statistically significant increase in Mallampati score was observed postoperatively (P < 0.05). Both the patient and practitioner should be aware of the risks associated with an increased postoperative Mallampati score in mandibular setback patients. The amount of mandibular setback in skeletal class III patients with a high preoperative Mallampati score should be limited to prevent potential postoperative airway problems.