Halil Ibrahim Canter

Use of three-dimensional medical modeling methods for precise planning of orthognathic surgery.

Stereolithographic (medical rapid prototyping) biomodeling allows three-dimensional computed tomography to be used to generate solid plastic replicas of anatomic structures. Reports in the literature suggest that such biomodels may have a use in maxillofacial surgery, craniofacial surgery, orthopedics, neurosurgery, otology, vascular, and nasal research. A prospective trial to assess the usefulness of biomodeling in orthognathic surgery has been performed. In 12 patients with mandibular prognathism and/or maxillary retrusion, in addition to routine preoperative cephalometric analysis, preoperative high-resolution (cutting slice thickness of 1 mm) three-dimensional computed tomography scan of the patients was obtained. Raw data obtained from computed tomography scanning was processed with a Mimics 9.22 Software (Materialises Interactive Medical Image Control System, Belgium). Fabrication of three-dimensional medical models was obtained through a process called powder depositional modeling by use of a Spectrum Z 510 3D Color Printer (Z Corporation, Burlington, MA). Alveolar arches of the maxilla and mandibula of the models were replaced with orthodontic dental cast models. Temporomandibular joints of the models were fixed with Kirschner wire. Maxillary and mandibular bony segments were mobilized according to preoperative orthodontic planning done by analysis of cephalometric plain radiographs. The relation between proximal and distal mandibular segments after bilateral sagittal split osteotomies were evaluated on models preoperatively. The same surgeon had a role in both model cutting preoperatively and as an instructor preoperatively. The same bony relation was observed both in preoperative modelsand in the perioperative surgical field in all patients. Condylar malpositioning was not observed in any of the patients. Studying preoperative planned movements of osteotomized bone segments and observing relations of osteotomized segments of mandibula and maxilla in orthognathic surgery increased the intraoperative accuracy. Limitations of this technology were manufacturing time and cost.

Comparison of Facial Soft Tissue Measurements on Three-dimensional Images and Models Obtained With Different Methods

Aim:The aim of this study was to compare the clinical facial soft tissue measurements with the measurements of facial plaster cast, three-dimensional scanned facial plaster cast, 3-dimensional digital photogrammetrical images, and three-dimensional laser scanner images. Materials and Methods:Three-dimensional facial images of 15 adults were obtained with stereophotogrammetry and a three-dimensional laser scanner. Facial models of subjects were obtained using silicone impression and were scanned. Landmarks were marked on the subjects and plaster casts, digitized on three-dimensional models, and measured in Mimics 12.0 software (Materialises Interactive Medical Image Control System, Leuven, Belgium). Results:No statistically significant differences were found between all three-dimensional measurement methods in mouth width, philtrum median height, and nasal width. Comparison of clinical measurements with facial plaster cast measurements revealed that philtral width, nasal tip protrusion, and right lip and nostril heights were wider and longer in clinical measurements than in facial plaster cast measurements. Comparison of clinical measurements to the laser scanned and stereophotogrammetric model measurements revealed that philtrum lateral and lip heights and philtral width were significantly different between methods. When laser scanned and stereophotogrammetric measurements were compared, significant differences were observed in lip and nostril heights. Conclusions:Facial impression may be problematic owing to the depression caused by the impression material especially on the tip of the nose. Laser scanning is not sensitive enough to visualize the deeper indentations such as nostrils. Stereophotogrammetry is promising for three-dimensional facial measurements and even will be better when color identification between mucocutaneous junctions of the lip region is achieved.

Semirigid fixation of mandible and maxilla in orthognathic surgery: stability and advantages.

Although the use of rigid fixation of bony segments in orthognathic surgery has become a standard of care, the question remains, ‘With use of rigid fixation has stability of common orthognathic surgical procedures improved?’ Because of the problems with various methods of osteosynthesis for the osteotomies commonly used in orthognathic surgery, we have developed our own way of semirigid fixation method to stabilize the osteotomized fragments for bone healing with enough flexibility to avoid the problems arising from absolute rigid fixation. The purpose of this article is to review the existing data to determine whether our method of semirigid fixation yields enough short-term and long-term stability after orthognathic surgery procedures.The study was designed as a retrospective trial. A total of 23 patients with double jaw surgery and 12 patients with mandibular set back surgery were reviewed. Preoperative lateral cephalometric radiographs obtained 1 month before the surgery, early postoperative cephalometric radiographs obtained after intermaxillary fixation was opened and late postoperative cephalometric radiographs were evaluated. Pog-McNamara vertical (mm) was used to measure the anteroposterior movement of mandible. Facial axis (°) was used to measure the vertical movement of the anterior part of the mandible. A-McNamara vertical (mm) was used to measure the anteroposterior movement of maxilla. Maxillary height (°) was used to measure rotational movement of the osteotomized maxillary segment in vertical dimension. The raw data obtained from cephalometric analysis were evaluated by using the computerized statistical program SPSS version 11.5 for Windows. The differences in linear and angular measurements between time intervals were tested for statistical significance, using repeated measures analysis of variance. A value of P < 0.05 was considered significant.None of the patients had infection at maxillary osteotomy side. Unilateral local infection at osteotomy side was seen in only one patient after double jaw surgery. Condylar malpositioning was not observed in any of the patients. Although postoperative maxillaomandibular fixation with elastics was applied routinely to all patients for 15 days, none of the patients had complaint related with temporomandibular joint discomfort, such as pain, restricted joint motion, etc. There is significant difference in anteroposterior movement of mandible in all time intervals. In terms of facial axis, the differences at T1 and T2 and at T2 and T3 are significant, while the difference at T1 and T3 is not significant. There is significant difference in anteroposterior movement of maxilla in all time intervals. In terms of maxillary height, the differences at T1 and T2 and at T2 and T3 are significant, while the difference at T1 and T3 is not significant.Method of semirigid fixation with 2 plates for maxillary fixation and 2 screws for mandibular fixation provide enough stability after LeFort I and bilateral sagittal split osteotomy procedures where mainly anteroposterior linear displacements were performed. There was no significant clinical short-term or long-term relapse. Stability in rotational movements needs to be further evaluated.

Effect of use of slow release of bone morphogenetic protein-2 and transforming growth factor-Beta-2 in a chitosan gel matrix on cranial bone graft survival in experimental cranial critical size defect model.

Bone grafts, used for providing structural integrity of cranial vault remodeling, could not always integrate with the remaining bone structures. All efforts are focused on increasing incorporation of the applied bone grafts. Allografts were covered by chitosan so that slow release of bone morphogenetic protein-2 (BMP-2) and Transforming growth factor-beta-2 (TGF-beta-2) was achieved. Two hundred forty Wistar-Albino rats were distributed equally in 8 study groups. Study groups were designed as; defect group, autograft group, allograft group, chitosan group, allograft + chitosan, TGF-beta-2 group, BMP-2 group, and TGF-Beta-2 +BMP-2 group. Bone biopsies were obtained at second, eight, and 14th weeks. Bone regeneration was evaluated by morphologic studies detecting histologic bone healing and radiologic studies detecting bone density. Histologic findings were evaluated in 2 categories; tissue response to the implant and defect healing. Additionally, scanning electron microscopy for detailed morphologic evaluation was done. Bone density of the applied scaffold and the parietal bone at the same computed tomography section were measured in Hounsfield scale and this ratio was used for densitometry evaluations. Kruskal-Wallis test was used to analyze difference among groups according to the histologic and radiologic data. Pairwise comparisons were done using Mann-Whitney U test with Bonferroni correction. P < 0.05 was considered significant. In the morphologic studies, bone regeneration in BMP-2 group was found to be compatible with bone regeneration in gold standard autograft group and even better than it within 15 days. Chitosan is a biocompatible material. TGF-Beta-2 alone is not effective enough in bone regeneration; BMP-2 alone has a positive effect in every step of bone regeneration. Combining TGF-Beta-2 with BMP-2 does not lead to a better bone regeneration than using BMP-2 alone. A synergistic effect is not obtained by using these 2 factors together.

Botulinum toxin in closed treatment of mandibular condylar fracture.

Background:The topic of condylar injury in adults has generated more discussion and controversy than any other in the field of maxillofacial trauma. The treatment of condylar fractures in adults is still a highly debated theme. Methods:Patients with unilateral subcondylar or condylar neck fractures of the mandibula without any significant angulation of the condylar head were managed with closed-treatment protocol. Closed treatment was applied through the injection of 100 units of botulinum toxin A, diluted to a concentration of 20 IU/mL, into the muscles of mastication of the fractured side. Masseter and anterior fibers of temporalis muscles were reached through percutaneous extraoral route and 30 IU of the toxin was injected to each muscle. Additional 40 IU of the toxin was injected around the fractured bone fragments through transmucosal intraoral route to paralyze medial and lateral pterygoid muscles as much as possible. An asymmetric occlusal splint was applied for maxillomandibular fixation to restore the vertical height for 10 days. Functional therapy with intermaxillary guiding elastics was advocated for 2 months. Results:There were no complications related to either toxin injections or splint application procedures. The toxin was effective on all occasions. Fractured condylar process and ramus of the mandibula were in good approximation and remained in reduced positions. None of the patients had any occlusal disturbance, mandibular asymmetry, or joint dysfunction in the follow-up period. Conclusions:We believe that modification of treatment options concerning the clinical situation of the patients is the best method for condylar injury. The purpose of this study is to present and discuss the results achieved in closed treatment of a selected group of patients with mandibular condylar fractures to whom botulinum toxin A was injected to relieve the spasm of muscles of mastication, along with special splint application.

Treatment of Noncomminuted Zygomatic Fractures With Percutaneous Screw Reduction and Fixation

The standard treatment modality of zygomatic fractures is open reduction and rigid fixation of the fractured segments. Although most of the zygomatic fractures deserve this attentive surgical manipulation to prevent late residual asymmetry, minimally depressed noncomminuted zygomatic fractures can be reduced and fixed percutaneously. Percutaneous intervention causes minimal scarring and morbidity than open techniques and it is possible to align fragments precisely by using high-quality three-dimensional computed tomography (3-D CT) imaging. Six patients with noncomminuted fractures of the zygomaticomaxillary skeleton were evaluated with plain radiographs of facial bones, axial, coronal and 3-D CT. Reduction of the displaced bone segments were achieved by traction of percutaneously applied screw. Either reduced segments were not fixated at all or one of the two new fixation techniques, described in detail in the article, were used for stabilization of reduced segments. In all patients, accurate reduction was obtained. None of the patients showed any recurrent displacement or infection during the follow-up period of six months. The screws were removed in the clinical settings without difficulty. Although percutaneous reduction and external fixation of noncomminuted zygomatic fractures has limited indications, it has its own advantages over open techniques. This method is a less invasive technique and can be performed without any problem in selected cases. Our technique is not suitable for complex zygomatic and periorbital fractures.

Results of botulinum toxin: an application to blepharospasm Schwartz-Jampel syndrome.

Schwartz-Jampel syndrome (SJS) is a rare congenital disorder of continuous myotonia, causing visual and eyelid problems such as blepharospasm, acquired ptosis, and blepharophimosis. We report the management of blepharospasm in two sisters with Schwartz-Jampel syndrome with application of botilinum toxin type A (BTX-A), as an alternative to the surgical treatments, such as orbicularis oculi myectomy, levator aponeurosis resection, and lateral canthopexy as described in the literature. Three consequent doses of commercially available BTX-A (Botox®-Allergan, Inc. 100 u/via) were injected to orbicularis oculi muscle in two sisters with Schwartz-Jampel syndrome. At the least, the authors waited for a six-month interval to prevent development of sensitivity to BTX-A in patients. No significant improvement was observed after the injection of first dose of BTX-A, with the total dose of 25 units of BTX-A to each orbicularis oculi muscle of the eyes. The muscle tone weakened after the second dose, which was the twice as such of the first applied total dose (50 units of BTX-A to each orbicularis oculi muscle of the eyes) and significant functional and cosmetic improvements were achieved after injection of the third dose, in which the total applied dose was the same as the one applied in second dose. The blepharospasm and eyelid alterations caused by Schwartz-Jampel syndrome should be treated to provide functional and cosmetic improvements. Application of BTX-A to orbicularis oculi muscle for the treatment of blepharospasm could be considered as an alternative to levator resection, and lateral canthopexy in Schwartz-Jampel syndrome.

Closed treatment of frontal sinus fracture with percutaneous screw reduction.

Fractures of the frontal sinus are a relatively common injury presenting to trauma units that deal with craniofacial injuries. Approximately one third of frontal sinus fractures affect the anterior wall alone, with two thirds involving the anterior wall, posterior wall, or frontonasal duct. Isolated posterior wall defects are exceedingly rare. Frontal sinus fracture management is still controversial and involves preserving function when feasible or obliterating the sinus and duct, depending on the fracture pattern. In the standard treatment modality of frontal sinus fractures, repair is best performed by way of a coronal approach, which offers excellent access. Most of the frontal sinus fractures deserve this attentive surgical manipulation to prevent late sequelae of infection or mucocele formation. In this article, we present a case of isolated depressed anterior wall fracture of the frontal sinus that was treated by closed reduction to avoid coronal incision. Anterior wall fracture of the right frontal sinus was diagnosed with preoperative evaluation of three-dimensional CT of a 34-year-old male patient with maxillofacial trauma. The anterior wall fracture was reduced by traction of two percutaneously applied screws to the depressed fragments. Accurate reduction was obtained, and neither recurrent displacement nor infection was observed during the follow-up period of 3 months. The screws were removed in the clinical setting without difficulty. Although percutaneous reduction of noncomminuted anterior wall frontal sinus fractures has limited indications, it has its own advantages over open techniques. This method is a less-invasive technique and can be performed without problem in selected cases. Our technique is not suitable for complex fractures of the frontal sinus.

Tridimensional evaluation of maxillary and mandibular movements in orthognathic surgery.

For better evaluation of long-term results of orthognathic surgery, movements of osteotomized maxillary and mandibular segments should be documented both in x-, y-, and z-axes and in terms of kind of movement (either linear or rotational movements). Lateral cephalometric, anteroposterior cephalometric, and submentovertex radiographs of 14 patients, treated with combined orthodontic and surgical treatment for skeletal class III malocclusion, were reevaluated retrospectively to demonstrate the applicability and usefulness of defined parameters in four maxillary and five mandibular movements. There was no clinically significant relapse in the follow-up period of 6 months in any of the patients. Differences between preoperative and postoperative measurements to demonstrate the linear movement in the z-axis, rotational movements in the x-axis and y-axis of the maxilla, and the linear movement in the z-axis of the mandibula were found to be statistically significant. Differences between early postoperative and late postoperative measurements to demonstrate rotational movement in the y-axis of the maxilla and rotational movement in the y-axis of the mandibula were found to be statistically significant. In this article, the possible tridimensional movements and cephalometric measurements of osteotomized bony segments after LeFort I and sagittal split osteotomy surgery were defined for better evaluation and follow up of the postoperative results.

Nicolau syndrome and perforator vessels: a new viewpoint for an old problem

Nicolau syndrome is rare cutaneous adverse reaction following injection of various drugs. The disease has been associated with almost all classes of medications, such as nonsteroidal anti-inflammatory drugs, local anesthetics, corticosteroids, antibiotics, vitamin B complexes, antihistamines, and vaccines. The most severe cases of this complication occur after injection of nonsteroidal anti-inflammatory drugs. Subcutaneous injection is an important factor in the pathogenesis of the syndrome. We report a case of Nicolau syndrome resulting from intramuscular injection of diclofenac and discuss some precautions to prevent this complication.