Gurkan Bayar - Academia.edu (original) (raw)

Papers by Gurkan Bayar

Gulhane Medical Journal

Gülhane Tıp Dergisi.

... two basic components: a superficial portion or epidermis that contains keratinocytes and a de... more ... two basic components: a superficial portion or epidermis that contains keratinocytes and a deeper portion or der-mis [6]. Therefore, a ... 1 DDS, Ph.D. Oral and Maxillofacial Surgeon, Department of Oral and Maxillofacial Surgery, Gülhane Military Medical Academy, Ankara, Turkey ...

Introduction Condylar and subcondylar fractures account for 26-40% of all lower jaw fractures [1]... more Introduction Condylar and subcondylar fractures account for 26-40% of all lower jaw fractures [1]. Their treatment is therefore common in a maxillofacial department. Misdiagnosis or inappropriate treatment of condy-lar fractures can lead to anatomical and functional impairment and the ...

Journal of Oral and Maxillofacial Surgery, 2015

The aim of this study was to compare the efficacy of hyperbaric oxygen and systemic ozone, used s... more The aim of this study was to compare the efficacy of hyperbaric oxygen and systemic ozone, used separately and in combination, on the healing of bone defects. Sixty male Wistar rats were divided into 4 groups (n = 15) according to treatment (control, hyperbaric oxygen [HBO], ozone [O], and HBO plus O [HBO-O]) and divided further into 3 subgroups according to day of sacrifice (postsurgical days 5, 15, and 30). Surgery was performed under general anesthesia to create a critical-size bone defect (5 mm in diameter) in the cranium. After sacrifice, microtomographic images of all samples were recorded, and histomorphometric analysis was performed. Histologic and radiologic measurements showed that the values of all experimental groups were higher than those of the control group. Histologic scores for all experimental groups were statistically higher than those for the control group day 30 (O, P = .045; HBO, P = .049; HBO-O, P = .042). Histologic scores also were statistically higher for the HBO group on day 5 (P = .045) and day 15 (P = .009) compared with the control group. Microtomographic scores were higher for the experimental groups than for the control group, with statistically significant differences for group O on day 5 (P = .033) and day 30 (P = .0045) and for group HBO on day 15 (P = .005). Histologic and radiologic analyses showed positive correlations. Within the limitations of this study, the use of hyperbaric oxygen and ozone, separately and in combination, were shown to be effective in increasing bone healing. Combined usage was no more effective in stimulating bone healing than separate usage.

Cumhuriyet Dental Journal, 2014

ABSTRACT A B S T R A C T Extraoral sinus tracts of dental origin often are a diagnostic challenge... more ABSTRACT A B S T R A C T Extraoral sinus tracts of dental origin often are a diagnostic challenge. A delay in correctly diagnosing these types of lesions can result in ineffective and inappropriate treatment. A 64 year-old immunocompromised female with a huge cutaneous draining tract was referred to our clinic complaining of a purulent discharge from her skin on her right submandibular area. In clinical examination and radiographic assessment, periapical lesion associated with roots of lower right first molar was noticed. According to the patient history, she had kidney transplantation 17 years ago. Following the identification of the source of infection, it was surgically and medically resolved, and skin closure was performed. Her postoperative healing period was supported with hyperbaric oxygen therapy as well. Sinus tract was successfully treated.

Quintessence international (Berlin, Germany : 1985), 2015

The aim of the study was to compare the effect of submucosal injection of dexamethasone and triam... more The aim of the study was to compare the effect of submucosal injection of dexamethasone and triamcinolone acetonide on postoperative pain, swelling, and trismus occurring after impacted mandibular third molar surgery. A total of 78 patients (aged 18 to 35) with asymptomatic, unilateral, impacted mandibular third molar, and without any systemic disease were included in this study. Patients were divided into three groups randomly (control, dexamethasone, and triamcinolone acetonide). In the experimental groups, dexamethasone and triamcinolone acetonide were injected into submucosa at about 1 cm above the surgical area submucosally. The control group of patients did not take any drug submucosally but the same surgical procedure was applied. Pain evaluation was performed by visual analog scale (VAS). Swelling was measured using a flexible standard ruler measuring the dimensions of the axes between certain points on the face. For trismus evaluation, maximum mouth opening was measured. Me...

General dentistry

Cementoblastoma is a rare, benign, odontogenic neoplasm of ectomesenchymal origin, representing l... more Cementoblastoma is a rare, benign, odontogenic neoplasm of ectomesenchymal origin, representing less than 6% of all odontogenic tumors. Despite its well-known typical features, there are still controversies regarding the management of the condition. This article presents the case of a benign cementoblastoma in a 17-year-old girl. The lesion was typical and associated with the mandibular right first molar. Endodontic treatment of the involved tooth, enucleation of the cementoblastoma, and apicoectomy of the affected roots were performed. Removal of the tumor while preserving the associated tooth resulted in normal osseous healing and no evidence of recurrence after one year. Based on the findings of the current report, it can be suggested that, in properly selected cases, it is possible to remove cementoblastomas that affect molars without extracting the involved teeth.

Quintessence international (Berlin, Germany : 1985)

When a mandibular third molar is partially impacted in the soft tissue, it must be determined whe... more When a mandibular third molar is partially impacted in the soft tissue, it must be determined whether the extraction wound should be left partially open or completely closed. We hypothesize that a blood clot preserving a surgical wound with easily cleanable surfaces by primary closure and drain application would postoperatively minimize dry socket and/or alveolitis development. Twenty patients requiring bilateral extraction of partially soft tissue-impacted mandibular third molars in a vertical position were included in the study. The existence of dry sockets, alveolitis, pain, facial swelling, and trismus were evaluated on the second, fifth, and seventh days of the postoperative period. On the second day, pain, trismus, and swelling were higher in the drained group; however, pain reduced progressively in the drained group over time. There were no cases of dry sockets or alveolitis except for a single patient on the seventh day in the drained group over the 7-day study period. On th...

International journal of oral and maxillofacial surgery, 2013

The authors describe a simple and time saving technique for the ex-vivo production of oral mucosa... more The authors describe a simple and time saving technique for the ex-vivo production of oral mucosa keratinocytes by the direct explant method.

Oral health and dental management, 2012

The keratocystic odontogenic tumour (KCOT) is a relatively common oral and maxillofacial lesion t... more The keratocystic odontogenic tumour (KCOT) is a relatively common oral and maxillofacial lesion that derives from remnants of the dental lamina. It is aggressive, grows rapidly and invades the surrounding tissues. Various treatment modalities and differing recurrence rates have been reported for KCOT. In order to treat a 24-year-old male patient with KCOT the first stage was marsupialisation. This was followed six months later by enucleation with the application of Carnoy's solution. The defect was filled completely with newly formed bone tissue after two years. This case shows that a large KCOT can be treated with a combination of conservative and aggressive methods.

Cranio : the journal of craniomandibular practice, 2012

There are multiple theories as to the causes of coronoid process hyperplasia of the mandible, inc... more There are multiple theories as to the causes of coronoid process hyperplasia of the mandible, including trauma, temporalis muscle hyperactivity, hormonal stimulus, and genetic inheritance. The excess growth of the coronoid process can cause impingement on the zygomatic processes and may result in mandibular hypomobility. A case of an excessive unilateral coronoid hyperplasia with suspected traumatic etiology, which was successfully treated by coronoidectomy and postoperative physiotherapy, is presented. The patient was a 21-year-old man whose maximum mouth opening was 23 mm. The attachments of the temporalis muscle were stripped and the coronoid process was accessed using the Al-Kayat and Bramley approach. The coronoid process was then resected via an intraoral pathway. One week after surgery, physiotherapy was started and the maximum mouth opening had increased to 38 mm. In the case presented, a coronoidectomy with postoperative physiotherapy for treatment of coronoid process hyper...

International journal of oral and maxillofacial surgery, 2012

Neurosensory deficits are the most common complication following orthognathic surgery. Le Fort I ... more Neurosensory deficits are the most common complication following orthognathic surgery. Le Fort I and sagittal split ramus osteotomies have been widely studied but there is a lack of data about the neurosensory alterations resulting from anterior maxillary osteotomy (AMO). This paper evaluates the neurosensory alterations in cutaneous regions including lower eyelid, cheek, nose, upper lip and vestibular and palatal mucosal areas using simple clinical tests following AMO performed with Bell's incision so patients can be properly informed about the extent of sensory loss and its rate of recovery following AMO. Twenty-four sides of 12 patients (eight females; four males) with a mean age of 14.20 ± 1.86 years (range 12-17 years) were examined. Pin prick sensation, light touch sensation, static and dynamic two-point discrimination tests were used. Following AMO, vestibular mucosa, upper lip, nose and cheek were the most commonly affected sites. No alterations were detected in lower ey...

$Research paper thumbnail of An analysis of maxillofacial fractures: a 5-year survey of 157 patients$

Military medicine, 2004

The purpose of this study was to review retrospectively the outcomes for 157 patients treated for... more The purpose of this study was to review retrospectively the outcomes for 157 patients treated for maxillofacial fractures between 1994 and 1999 at one military hospital in Turkey. Significant data were collected according to age, gender, time of injury, type of facial injuries, cause of injury, treatment methods, and postinjury and postoperative complications. Fractures resulting from gunshot wounds were excluded in this study. Fractures were examined in two groups according to the type of fracture, i.e., isolated or combined. Methods of fixation with closed or open reduction were used to treat the fractures. Fixation was performed with miniplates, compression plates, microplates, reconstruction plates, and wires for open reduction, and stabilization was performed with arch bars for closed reduction. Complications were recorded in two groups, i.e., postinjury and postoperative complications. There were 151 male patients (96.18%) and 6 female patients (3.82%). The patients ranged in ...

Case Reports in Clinical Medicine, 2014

Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology, 2012

The aim of this study was to evaluate the effects of estrogen deficiency on newly formed bone obt... more The aim of this study was to evaluate the effects of estrogen deficiency on newly formed bone obtained by osteogenic periosteal distraction histomorphometrically. Thirty-six female rabbits were divided into 2 groups. The experimental group underwent a bilateral ovariectomy and a sham operation was applied to the control group to equalize the stress of ovariectomy surgery. Four weeks postoperatively, a gradual distraction of the mandibular corpus was performed. In the experimental group, callus formation was delayed and the new bone was less mineralized; conversely, when histomorphometric measurements were compared statistically, there were no significant differences between the ovariectomized and sham-operated subgroups in the mean extent of newly formed bone tissue. Although osteoporosis caused by the lack of estrogen has negative effects on osteogenic periosteal distraction (OPD), these negative effects do not appear to present a contraindication to OPD.

Journal of dental research, 2015

Real-time (RT) determination of the health of in vitro tissue-engineered constructs prior to graf... more Real-time (RT) determination of the health of in vitro tissue-engineered constructs prior to grafting is essential for prediction of success of the implanted tissue-engineered graft. In addition, the US Food and Drug Administration requires specific release criteria in RT prior to the release of tissue-engineered devices for human use. In principle, assessing the viability and functionality of the cellular component can be achieved by quantifying the secretion of growth factors and chemokines of tissue-engineered constructs. Ex vivo-produced oral mucosa equivalents (EVPOMEs) were fabricated under thermally stressed conditions at 43 °C for 24 h to create a functionally compromised EVPOME. We used microchannel enzyme-linked immunosorbent assay to evaluate the functionality of the cellular component, oral keratinocytes, of stressed and unstressed EVPOMEs by measuring the release of vascular endothelial growth factor (VEGF), interleukin-8 (IL-8), human β-defensin 1 (hBD-1), and tissue i...

Gulhane Medical Journal, 2012

According to the World Health Organization, it is proposed that benign fibro-osseous lesions be d... more According to the World Health Organization, it is proposed that benign fibro-osseous lesions be divided into 3 categories, including fibrous dysplasia, ossifying fibroma (OF), and osseous dysplasia. OF arises from the periodontal ligament, which contains multipotential cells. These benign tumors may become large and aggressive. Slow growth and lack of symptoms are the cardinal features. OF tends to occur in the second and third decades of life, with predilection for women and for the mandibular premolar-molar area. The method of treatment used for large or rapidly expanding lesions is surgical removal (enucleation). Rarely, OFs occur multifocally. We report a 20-year-old man with synchronous OFs of his maxilla and mandible and review other synchronous cases reported. Such lesions can be properly diagnosed and treated by correlating radiographic, clinical, surgical, and histopathologic findings.

Quintessence International, 2013

The residual alveolar bone height at the implant recipient site plays a key role in determination... more The residual alveolar bone height at the implant recipient site plays a key role in determination of the risk of sinus membrane perforation during crestal sinus elevation. In this study, we aimed to determine the correlation between residual ridge height and perforation limit of sinus membrane and to examine the safety range for the sinus membrane continuity in crestal sinus elevation. Formalin-fixed cadavers were used for the experiment to observe outcomes. Crestal sinus elevations were performed on 14 preserved human cadavers&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; heads. Residual ridge heights were measured using a bone caliper. The physiodispenser was preset to 30 Ncm and sinus floors were elevated by a concave sinus screw with diameter of 4 mm until sinus membrane perforation occurred. The perforations were identified either as Class I or Class II and the portion of the concave sinus screw in the sinus was measured each time using a ruler. Spearman&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s correlation coefficient was calculated to show the relation between the residual ridge heights and the membrane elevations at the time of perforation of the sinus membranes. In general, the perforation limit of sinus membrane after elevation was higher with greater residual ridge height. A statistically significant correlation was found between residual ridge heights and perforations of the sinus membrane (r = 0.620, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; .001). Although it is not always possible to extrapolate results from cadavers to an in vitro clinical setting, it could be considered to have clinical significance. Our findings suggest that higher subsinusoidal elevation may be achieved when the residual ridge bone height increases. The conclusions of this study should be verified with studies of more rigorous design.

Balkan Medical Journal, 2012

The aim of this study is the histological and immunohistochemical evaluation of ex vivo produced ... more The aim of this study is the histological and immunohistochemical evaluation of ex vivo produced oral mucosal equivalents using keratinocytes cultured by direct explant technique. Oral mucosa tissue samples were obtained from the keratinized gingival tissues of 14 healthy human subjects. Human oral mucosa keratinocytes from an oral mucosa biopsy specimen were dissociated by the explant technique. Once a sufficient population of keratinocytes was reached, they were seeded onto the type IV collagen coated &amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;AlloDerm&amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; and taken for histological and immunohistochemical examinations at 11 days postseeding of the keratinocytes on the cadaveric human dermal matrix. Histopathologically and immunohistochemically, 12 out of 14 successful ex vivo produced oral mucosa equivalents (EVPOME) that consisted of a stratified epidermis on a dermal matrix have been developed with keratinocytes cultured by the explant technique. The technical handling involved in the direct explant method at the beginning of the process has fewer steps than the enzymatic method and use of the direct explant technique protocol for culturing of human oral mucosa keratinocyte may be more adequate for EVPOME production.