Evaluation of Minimum Axial Airway Area and Airway Volume in Orthognathic Surgery Patients: A Retrospective Study.

The aim of this study was to compare preoperative and postoperative linear, planar, and volumetric measurements in the pharyngeal airway in orthognathic surgery patients. Preoperative and postoperative cone beam computed tomography (CBCT) images of 60 patients, who underwent maxillary advancement with mandibular setback (Group I, n=25) and bimaxillary advancement (Group II, n=35), were compared. The airway was divided into 3 regions as nasopharynx, oropharynx, and hypopharynx. Linear and planar measurements were made on the reference sections of each region. The minimum axial airway area, the volume of 3 regions, and total airway volume were also measured. Regarding the linear, planar, and volumetric measurements, while there was a statistically significant increase in the measurements for all three regions in Group II, in Group I only the measurements in the nasopharyngeal region demonstrated a statistically significant increase postoperatively (P<0.05). There was an increase in minimum axial airway areas in both groups; however, it was only statistically significant in Group II (P<0.05). There was a statistically significant increase in total airway volumes in both groups (P<0.05). A positive and good correlation was found between the percent increase in the minimum axial area and the percent increase in the total volume (P<0.05). While bimaxillary advancement surgery results in a significant increase in the pharyngeal airway, mandibular setback with maxillary advancement caused an increase in the total airway. Changes that may occur in the airway should be considered while planning orthognathic surgery.

Evaluation of mandibular condyle position in Class III patients after bimaxillary orthognathic surgery: A cone-beam computed tomography study.

Objective: This retrospective study evaluated the mandibular condyle position before and after bimaxillary orthognathic surgery performed with the mandibular condyle positioned manually in patients with mandibular prognathism using cone-beam computed tomography. Methods: Overall, 88 mandibular condyles from 44 adult patients (20 female and 24 male) diagnosed with mandibular prognathism due to skeletal Class III malocclusion who underwent bilateral sagittal split ramus osteotomy (BSSRO) and Le Fort I performed using the manual condyle positioning method were included. Cone-beam computed tomography images obtained 1-2 weeks before (T0) and approximately 6 months after (T1) surgery were analyzed in three planes using 3D Slicer software. Statistical significance was set at P < 0.05 level. Results: Significant inward rotation of the left mandibular condyle and significant outward rotation of the right mandibular condyle were observed in the axial and coronal planes (P < 0.05). The positions of the right and left condyles in the sagittal plane and the distance between the most medial points of the condyles in the coronal plane did not differ significantly (P > 0.05). Conclusions: While the change in the sagittal plane can be maintained as before surgery with manual positioning during the BSSRO procedure, significant inward and outward rotation was observed in the axial and coronal planes, respectively, even in the absence of concomitant temporomandibular joint disorder before or after the operation. Further long-term studies are needed to correlate these findings with possible clinical consequences.

Evaluation of Clinical Success of the 3D-Printed Custom-Made Subperiosteal Implants.

OBJECTIVE: The authors aim to share their experiences in subperiosteal implant applications in atrophic jaws, which have been practiced in their clinic for about 2 years, and evaluate the complications and clinical success of the implants. MATERIAL AND METHOD: Clinical and radiologic data of 32 patients who underwent subperiosteal implantation for advanced alveolar bone loss were evaluated, but 1 patient was excluded as they smoked. Of the 31 patients included in the study, 27 were operated with the diagnosis of total tooth loss, 3 for maxillectomy and 1 for partial tooth loss. A total of 60 subperiosteal implants were placed in them. The mean follow-up period was 15 months. RESULTS: During the operation, implant-bone adaptation problems were encountered in 11 patients, implant skeletal fracture in 1 patient, and loss of primary stabilization during mini-screw fixation in 2. Although there were no complications in the early postoperative period, biological and prosthetic complications occurred in the late postoperative period. Soft tissue retraction at various levels in 12 patients (only keratinized tissue retraction in 6 and mucosal retraction exceeding keratinized tissue in 6), soft tissue infection in 5 and oroantral fistula development in 1, mini-screw loosening in 3 were the biological complications that occurred. CONCLUSIONS: Various complications may occur during or after the application of custom-made subperiosteal implants. However, these are manageable and can be reapplied in case of a possible implant loss, making it an important alternative, especially in atrophic jaws where endosseous dental implants cannot be applied.

Biomechanical comparison of implantation approaches for the treatment of mandibular total edentulism.

Applying four anterior implants placed vertically or tilted in the mandible is considered to provide clinically reasonable results in the treatment of mandibular posterior edentulism. It is also reported that a combination of four anterior and two short posterior implants can be an alternative approach for the rehabilitation of severe atrophy cases. In this study, we aimed to evaluate the biomechanical responses of three different implant placement configurations, which represent the clinical options for the treatment of mandibular edentulism. Three-dimensional models of the mandible, prosthetic bar, dental implant, abutment, and screw were created. Finite element models of the three implant configurations (Protocol 1: Four anterior implants, Protocol 2: Four anterior and two short posterior implants, Protocol 3: Two anterior and two tilted posterior implants: All-on-4™ concept) were generated for 10 patients and analyzed under different loading conditions including chewing, biting, and impact forces. Protocol 2 led to the lowest stress concentrations over the mandible among the three protocols (p < 0.016). Protocol 2 resulted in significantly lower stresses than Protocol 3 and Protocol 1 over prosthetic bars under chewing forces (p < 0.016). None of the implant placement protocols consistently exhibited the lowest stress distribution over abutments. The lowest stresses over dental implants under the chewing, biting, and impact forces were obtained in Protocol 1, Protocol 2, and Protocol 3, respectively (p < 0.016). Protocol 3 was the best option to obtain the lowest stress values over the screws under all types of loading conditions (p < 0.016). In conclusion, Protocol 2 was biomechanically more ideal than Protocol 1 and Protocol 3 to manage the posterior edentulism.

Closure of Orocutaneous Fistula Using Submandibular Gland as a Pedicled Flap.

Orocutaneous fistulas in the maxillofacial region may be due to tumor resection, osteoradionecrosis, or trauma, and these defects limit the function of the patients and effect aesthetic and also psychological condition. Articulation and nutrition are also affected by these fistulas. Local flaps can be used for the reconstruction of small- and medium-sized defects with ease. Submandibular gland with its rich blood supply from the facial artery is a practical and useful choice for the reconstruction of mandibular region defects.

Gait Analysis of Patients Subjected to the Atrophic Mandible Augmentation with Iliac Bone Graft.

In this study, we aimed to quantitatively monitor and describe the gait functions of patients, who underwent iliac crest bone grafting in atrophic jaw augmentation operation, by taking into account the alterations of gait parameters and muscle forces in the early recovery course. To do so, temporospatial and kinematic gait parameters of ten patients during pre- and postoperative periods were recorded, and forces of the gluteus medius, gluteus maximus, and iliacus muscles were calculated. Three postoperative periods were specified as one week (post-op1), two weeks (post-op2), and three weeks (post-op3) after the surgery. Restoring process of the gait patterns was comparatively evaluated by analyzing the gait parameters and muscle forces for pre- and postoperative periods. Temporospatial and kinematic parameters of post-op3 were closer to those obtained in pre-op than those in post-op1 and post-op2 (p < 0.05). Muscle forces calculated in post-op3 showed the best agreement with those in pre-op among the postoperative periods in terms of both magnitude and correlation (p < 0.05). In conclusion, the patients began to regain their preoperative gait characteristics from the second week after surgery, but complete recovery in gait was observed three weeks after the surgery.

Does intravenous tranexamic acid reduce blood loss during surgically assisted rapid palatal expansion?

PURPOSE: The purpose of this study was to evaluate the efficacy of tranexamic acid (TXA) in reducing blood loss during surgically assisted rapid palatal expansion (SARPE) procedure. SUBJECTS AND METHODS: A total of 34 patients (12 male, 22 female) who had been treated surgically under general anesthesia with SARPE including pterygoid disjunction for transverse maxillary deficiency (TMD) were included in this study. The study group (n=17) received intravenous (IV) TXA 10 mg/kg as a preoperative bolus; the control group (n=17) received normal saline solution. Preoperative and postoperative haemoglobin and haematocrit values, intraoperative blood loss, and any blood product transfusion were recorded. RESULTS: Blood loss during SARPE was statistically significantly less in the study group than the control group (p=0.0001). CONCLUSION: Preoperative IV administration of TXA can effectively control blood loss during when SARPE with pterygoid disjunction is performed.

Reconstruction of atrophic maxilla by anterior iliac crest bone grafting via neuroaxial blockade technique: a case report.

Anterior iliac crest bone grafting is a well-established modality in the treatment of alveolar bone deficiencies. However, this procedure may also have considerable postoperative morbidity which is mostly related to general anesthesia. Postoperative pain-related complications can be managed by neuroaxial blockade techniques which provide adequate surgical analgesia and reduce postoperative pain. This clinical report describes the reconstruction of a severely atrophic maxilla with anterior iliac crest bone grafting using combined spinal epidural anesthesia. Neuroaxial blockade techniques may be a useful alternative to eliminate general anesthesia related challenges of anterior iliac crest bone grafting procedures.

Clinical and 3-Dimensional Radiographic Evaluation of Autogenous Iliac Block Bone Grafting and Guided Bone Regeneration in Patients With Atrophic Maxilla.

PURPOSE: To evaluate the rate of graft resorption in autogenous iliac bone grafting (IBG) and guided bone regeneration (GBR) in patients with atrophic maxillae. MATERIALS AND METHODS: We performed a retrospective study involving patients requiring implant placement who underwent IBG or GBR. Volumetric changes of the graft sites were evaluated by imaging studies. The primary predictor and outcome variables were augmentation technique and rate of volumetric resorption, respectively. Secondary outcome variables included bone gain, success of grafting, insertion torque of implants, and requirement for vestibuloplasty. RESULTS: The sample comprised 39 patients (21 with GBR and 18 with IBG). One patient in the IBG group had temporary sensory disturbance at the donor site, and one patient in the GBR group had late exposure of the nonresorbable membrane. The average values of percent volume reduction in the GBR and IBG groups were 12.26% ± 2.35% and 35.94% ± 7.94%, respectively, after healing and 15.87% ± 1.99% and 41.62% ± 6.97%, respectively, at last follow-up. The IBG group exhibited a significantly higher reduction in bone volume than the GBR group at both time points (P = .001). The mean values of horizontal and vertical bone gain after healing in the IBG group were significantly higher than those in the GBR group (P = .006 and P = .001, respectively). The mean implant torque during implant placement in the GBR group was significantly higher than that in the IBG group (P = .024). There was no significant difference in the requirement for vestibuloplasty between the two groups (P > .05). CONCLUSIONS: Although both hard tissue augmentation approaches provide an adequate volume of bone graft for implant insertion, IBG results in greater graft resorption at maxillary augmented sites than GBR. Clinicians should consider the differences in the extent of graft resorption between the two methods while choosing the treatment approach.

Does Combined Spinal Epidural Anesthesia Decrease the Morbidity of Iliac Block Bone Grafting for Deficient Alveolar Ridges Compared With General Anesthesia?

PURPOSE: To evaluate the morbidity of iliac block bone grafting performed under general anesthesia (GA) or combined spinal epidural anesthesia (CSEA). MATERIALS AND METHODS: We implemented a retrospective study including patients who underwent anterior iliac block bone grafting for deficient maxillary alveolar ridges. The anesthetic technique (GA or CSEA) was the primary predictor variable. The outcome variables were pain, gait disturbance, neurosensory disturbance (0 to 5 weeks), vomiting tendency (0 to 7 days), and postoperative hospitalization period (0 to 2 days). RESULTS: The sample comprised 22 patients, with 10 in the GA group and 12 in the CSEA group. No surgical complications except sensory disturbance in 2 patients were observed during the study period. Pain during initial healing (P < .001), the gait disturbance rate at 3 weeks after surgery (P = .003), and the vomiting tendency on the day of surgery (P < .001) were significantly higher in the GA group than in the CSEA group; all variables showed significant improvement with time in both groups. The postoperative hospitalization period was also significantly longer for the GA group than for the CSEA group (P < .001). No significant difference was observed between groups with regard to neurosensory disturbance. CONCLUSIONS: Iliac block bone grafting for deficient maxillary ridges can be successful under both GA and CSEA, although CSEA results in less pain and vomiting and early recovery, thus increasing patient comfort.

Removal of Deeply Impacted Mandibular Molars by Sagittal Split Osteotomy.

Mandibular third molars are the most common impacted teeth. Mandibular first and second molars do not share the same frequency of occurrence. In rare cases the occlusal surfaces of impacted molars are united by the same follicular space and the roots pointing in opposite direction; these are called kissing molars. In some cases, a supernumerary fourth molar can be seen as unerupted and, in this case, such a supernumerary, deeply impacted fourth molar is seen neighboring kissing molars. The extraction of deeply impacted wisdom molars from the mandible may necessitate excessive bone removal and it causes complications such as damage to the inferior alveolar nerve and iatrogenic fractures of the mandible. This case report describes the use of the sagittal split osteotomy technique to avoid extensive bone removal and protect the inferior alveolar nerve during surgical extruction of multiple impacted teeth.

Evaluation of Volumetric Changes of Augmented Maxillary Sinus With Different Bone Grafting Biomaterials.

Extensive alveolar bone resorption because of pneumatized maxillary sinus is a common problem that limits dental implant placement. Maxillary sinus floor augmentation (MSFA) is an accepted treatment protocol that provides sufficient bone volume. The aim of this study was to evaluate the percentage of graft volume reduction following MSFA using cone beam computed tomography. In this retrospective study, cone beam computed tomography scans of MSFA were measured to evaluate the volume of the grafted sinus with deproteinized bovine bone (DBB), mineralized allograft (MA), or a mixture of MA and demineralized allograft as a composite. The volumetric changes in sinus augmentation between 2 weeks (T-I) and 6 months (T-II) after operation were analyzed. Thirty-nine patients were included in this study. The average percent volume reduction was 8.14 ±â€Š3.76%, 19.38 ±â€Š9.22%, and 24.66 ±â€Š4.68% for DBB, MA, and composite graft, respectively. A significant graft volume reduction was found between T-I and T-II for all groups (P < 0.01). The DBB group showed the least volume reduction (P < 0.01). Biomaterials can influence the bone graft volume change before implant placement. Deproteinized bovine bone may offer greater volume stability during healing than mineralized and composite allografts.

Aspergillosis associated with surgically assisted rapid maxillary expansion.

Surgically assisted rapid palatal expansion (SARPE) is one of the most common orthognathic surgery operations for the treatment of maxillary transverse deficiencies. Although this operation is considered technically simple and has low complication rate, predisposing factors can complicate the postoperative period. In this case report, fistula formation and aspergillosis after SARPE operation were presented.

The effect of irrigation temperature on bone healing.

OBJECTIVE: Osteotomies, performed by rotational instruments, can cause temperature rise on the bone and elevated temperature can disrupt the bone healing. When the osteotomies are performed for the insertion of miniscrews, the bone healing disruption may cause stability loosening or failures. Saline irrigation is mostly used for the prevention of the heat generation during osteotomy. PURPOSE: The purpose of this study was to evaluate the effect of the saline irrigation temperature on bone healing. MATERIAL AND METHOD: Standardized drilling and miniscrew placement was performed in the tibias of 18 Sprague Dawley rats with rotating bur uncooled, cooled with 25°C and 4°C saline irrigations. After the 21 days, the difference in healing was observed between the uncooled and cooled groups. RESULTS: Although there was no statistically significant difference between the group irrigated with 25°C and 4°C saline for newly bone formation, osteoblasts were seen more active and bone marrow was more dynamic in group 4°C than group 25°C. There is no disadvantage to use 25°C, but it may be better to use 4°C for rapid healing.