Custom-made Subperiosteal Implants: A Finite Element Analysis on Monoblock and Dual Implant Systems in Atrophic Maxilla.

This study aims to investigate and compare the stress distribution, displacement, and bone loading of monoblock and dual custom-made subperiosteal implant systems in atrophic maxilla using finite element analysis (FEA). A total of 11 patients with insufficient bone tissue for conventional implant treatment were included in the study. Customized subperiosteal implant designs were generated using the 3D average models obtained from patients' computed tomography (CT) scans. Two different models were produced: a monoblock that covered the entire maxillary bone and a dual implant system where two mirror-imaged implants covered the left and right halves of the maxillary bone separately. We have calculated residual stress values formed on the implant models and jaw bone models separately. In addition, the highest displacement values formed on the implants and the highest stress values formed on abutment parts have also been observed in this study. Results showed that the stresses formed on implants that are under the mastication forces were significantly lower than the yield strength of the selected material, indicating that plastic deformation would not occur under static load. The dual implant geometry demonstrated a substantial reduction in stress compared to the monoblock structure. The highest von Mises stress values for the monoblock implants ranged from 131 MPa to 206 MPa, while those for the dual structure ranged from 124 MPa to 178 MPa. The highest residual stress values on the upper jawbone were observed in the M6 implant model, and the lowest was seen in the M1 and M3 models at 12 MPa. Displacement values under static load showed that loads on the implant would be below 0.21 mm. In conclusion, custom subperiosteal implants are a viable treatment option for patients with insufficient bone tissue for conventional implants. Dual implant systems were found to have lower stress and displacement values compared to monoblock structures, indicating a potential advantage in clinical use. However, mono implants may have benefits in cases of immediate teeth loading due to their ability to absorb and distribute occlusal forces better.

Effects of polymethylmethacrylate on the stability of screw fixation in mandibular angle fractures: A study on sheep mandibles.

Aim: Malfixed miniplates can impair fracture healing, and the screw pilot holes may widen during repeated fixation trials. This in vitro study explored the extent to which screw fixation of mandibular angle fractures could be improved by augmenting the drilling holes with polymethylmethacrylate (PMMA). Materials and Methods: We measured stabilization by recording specimen displacement under a vertical force of 50 N applied using a hydraulic tester. We included 20 hemimandibles from sheep (average weight 40 kg). The specimens were randomly divided into two groups of 10 and pilot holes were created in the angulus region using a drill 1.2 mm in diameter. Next, we performed osteotomies simulating angulus fracture repair. In group 1, the fracture site was fixed using non-compression miniplates and four screws were inserted to the maximal possible extent employing a mechanical screwdriver. In group 2, the pilot drill holes were filled with PMMA prior to miniplate fixation. Then vertical forces of 50 N were applied to the molar region and the displacements were measured. The Shapiro-Wilks test was used to compare the two groups. Result: The maximum average displacement in the experimental group was significantly lower than that in the control group (p=0.026). Thus, PMMA-augmented screws better stabilized bone, affording reliable fixation.

Oral surgical procedures under local anaesthesia in day surgery.

BACKGROUND: The objective of this study was to analyze gender-stratified data of patients who underwent day surgery in a hospital based on the type of treatment, type of local anaesthesia, and local anaesthesia complications. By learning all these parameters, it is our main goal to find answers to questions such as what we can do in hospital conditions, what we can win, and what operations we can treat. METHODS: A retrospective review was performed to assess hospital records of 10,750 dental patients who received oral surgery under local anaesthesia at the Istanbul University Department of Oral and Maxillofacial Surgery from August 2013 through June 2016. RESULTS: Patients mostly received surgery for wisdom teeth, dental implants, or odontogenic cysts or tumours. Men aged 31-40 years (23.66%) and women aged 21-30 years (30.73%) were the largest groups undergoing operations. Surgery for an impacted tooth was the most common ambulatory procedure, accounting for 54.2% of operations. The second most common ambulatory procedure was dental implant surgery (10.2%), followed by root (7.4%), odontogenic cyst (7.2%), and impacted canine surgeries (6.4%). The most common age group receiving surgery was 21-30 years old (3304 patients, 60.75%). Twice as many women as men underwent surgery. CONCLUSIONS: Day case surgery is an expanding area of health care and a valuable method of treating patients in many aspects of oral surgical practice. Different medical and dental specialties can benefit from this ambulatory approach to treatment, which also reduces treatment costs.

The histopathological effects of calcium triglyceride bone cement and chitosan on the healing of experimental bone defects

Background/aim: This study evaluated the histopathological effects of two different bone grafts, calcium triglyceride bone cement (CTBC) and chitosan, on the healing of experimental bone defects. Materials and methods: Ninety-two Sprague Dawley male rats, with a weight of 240 ± 20 g, were used. Two experimental groups that consisted of 64 rats were divided into four subgroups due to the sacrification days, which were 7, 14, 30, and 60. After creating an 8-mm- long and 1-mm-wide cortico-cancellous bone defect in the right tibia of each rat, CTBC and chitosan were applied to the bone defects. In the main group, after creating the bone defects in the right tibias, we kept those empty to serve as the control group. We evaluated inflammation, foreign body reaction, necrosis, fibrosis, new bone formation, and the residual graft material at 7, 14, 30, and 60 days. Results: In both the CTBC and chitosan groups, the new bone formation was higher than that in the control group, whereas foreign body reaction and residual graft material in the CTBC group and fibrosis in the chitosan group were significantly higher. After evaluating the results, both materials were found not to be very useful in the bone healing process. Conclusion: CTBC remained for a long time without being resorbed; it can be used as a placeholder in large bone defects, whereas the gel form of chitosan cannot be utilized for this purpose because it was resorbed in the first 7 days.

Oral and maxillofacial considerations in Gardner's Syndrome.

Gardner's Syndrome is a variant of familial adenomatosis polyposis (FAP) with a triad consisting of polyps of the colon, multiple osteomas and surface tumors of soft and hard tissue. The intestinal polyps have a %100 risk of undergoing malignant transformation, therefore early identification of this disease is very important. There are several symptoms of Gardner's syndrome in the oral and maxillofacial surgery, which can be discovered during routine dental examination. We report a case of a 25-year old male patient with Gardner's syndrome who has not any intestinal polyps but osteomas in the mandible and jaw deformalities.

Iatrogenic mandibular fracture associated with third molar removal.

Third molar extraction is one of the most common procedures performed in oral and maxillofacial surgery units. It is sometimes accompanied by complications such as alveolar osteitis, secondary infection, hemorrhage, dysesthesia and, most severely, iatrogenic fracture. This article describes two mandibular angle fractures that occurred in two patients during the surgical extraction of one erupted and one unerupted third molar, including a brief review of the literature.

Evaluation of light-emitting diode (LED-660 nm) application over primary osteoblast-like cells on titanium surfaces: an in vitro study.

BACKGROUND: The goal of this study was to evaluate the behavior of neonatal rat calvarial osteoblast-like cells cultured on different implant surfaces and exposed once or three times to a 660-nm light-emitting diode (LED). METHODS: An LED with a 660-nm wavelength was applied once or three times to cultured cells on standard and modified sandblasted acid-etched surfaces (SLA and SLActive; Straumann, Basel, Switzerland). To analyze the effect of the LED on cell proliferation, numbers, and viability, cells were cultured on titanium discs, and measurements were taken after 72 h. Cell proliferation rates were assessed using a bromodeoxyuridine immunohistochemical technique. Cell morphologies were evaluated by scanning electron microscopy (SEM). RESULTS: Osteoblast-like cells proliferated on all tested surfaces, with differences among groups in cell counts and DNA synthesis values. The application of one LED treatment caused a significant increase in cell count in the SLActive group in comparison with the SLA group (p = 0.001), whereas the application of three LED treatments caused a significant decrease in cell count in the SLA group compared with the SLActive group (p < 0.001). After 72 h, the number of cells was highest in the SLActive group exposed once to the LED. CONCLUSIONS: One LED application in the SLActive group resulted in significantly increased cell numbers. However, these findings were not exactly compatible with the SEM findings, which demonstrated fewer cells and weak attachments between cells and to the surface. Thus, further studies using different LED application times are needed to clarify the reason for the increased number of cells that are apparently incapable of attaching to the titanium surfaces after 72 h.

Use of cone-beam computerized tomography for evaluation of bisphosphonate-associated osteonecrosis of the jaws in an experimental rat model.

BACKGROUND: Bisphosphonate-induced osteonecrosis of the jaw (BONJ) is a frequently reported complication. The aim of this study was to investigate the clinical and histopathological presentation of BONJ with the Hounsfield score and to evaluate the reliability of the score for determining necrosis in an animal model. MATERIAL/METHODS: Eighty rats were prospectively and randomly divided into two groups of 40 each: a control group and an experimental group. Half of the animals from each group underwent extraction of the left mandibular molars, and the other half underwent extraction of the left maxillary molars under pentobarbital-induced general anesthesia. All animals were euthanized 28 days after tooth extraction. Maxillae and mandibles were extracted, cone beam computed tomography (CBCT) was performed, and Hounsfield scores were evaluated. RESULTS: The Hounsfield scores of the experimental group were found to be compatible with chronic osteomyelitis and periosteal reactions. The Hounsfield scores of the control group were compatible with a healthy healing period. CONCLUSION: In light of these results, both cone beam computed tomography (CBCT) and the Hounsfield Units (HU) evaluations together are thought to be efficient in the diagnosis of BONJ.

Pleomorphic adenoma of the palate.

Pleomorphic adenoma is the most common mixed benign tumor of major salivary glands. Approximately 80% of these tumors arise in the parotid gland, whereas 7% arise in the minor salivary glands. The most common sites for minor salivary gland where pleomorphic adenoma arises are the palates followed by lips and cheek. We report a palate mass in a 46-year-old male patient. The initial cytologic diagnosis by fine-needle aspiration biopsy was pleomorphic adenoma. This report describes a case of pleomorphic adenoma regarding all distinctive diagnoses with the review of the literature.

Comparison of the efficiency of alveolar decortication and low level laser therapy on orthodontic tooth movement and alveolar metabolism in rats.

BACKGROUND/PURPOSE: Reducing orthodontic treatment duration has many advantages for both clinicians and patients. This study was designed to compare the effects of alveolar decortication and low level laser therapy methods on tooth movement rate and alveolar bone metabolism. MATERIALS AND METHODS: A total of 42 Wistar albino rats were divided into three main groups as: Alveolar decortication (AD), low level laser therapy (LLLT) and only orthodontic force (F). The groups were evaluated at 7 and 14 day time points. Tooth movement rates were calculated by measuring the space between the contact points of the first and second molars. Comparisons regarding the alveolar bone metabolism were accomplished by evaluating osteoclast counts and RANKL - OPG expressions. RESULTS: The rate of tooth movement, at all time points, was significantly higher for the AD group than the other groups and was significantly higher in the LLLT group than the F group. At both time points, the RANKL and OPG expression in the AD group was significantly higher than the other groups and these parameters in the LLLT group was significantly higher than the F group. The osteoclast count values in the AD and LLLT groups were significantly higher than the F group and there were no significant differences between these two groups at all time points. CONCLUSION: This study shows that, to be more effective at AD, both AD and LLLT therapy significantly increases the level of tooth movement in the early period through their stimulating effects on the alveolar bone metabolism.

Healing of Oral Lichenoid Lesions following Replacement of Dental Amalgam Restorations with Feldspathic Ceramic Inlay-Onlay Restorations: Clinical Results of a Follow-Up Period Varied from Three Months up to Five Years.

OBJECTIVE: Previous studies have shown the effect of amalgam removal on the healing of oral lichenoid lesions (OLLs); however, no specific replacement materials have been suggested. The present series evaluated long-term results following the complete replacement of amalgam restorations with feldspathic ceramic inlay-onlay restorations for a group of patients with OLLs whose lesions were suspected to be related to amalgam restorations. MATERIALS AND METHODS: Twenty-four patients who had OLLs suspected to be related to their amalgam restorations were initially recruited. The patients underwent patch tests for a series of dental materials, in addition to clinical and histopathological examination. Sixteen (67%) of the 24 patients had their amalgam replaced with feldspathic ceramic inlay-onlay restorations and were examined within a follow-up period of 3 months to 5 years. RESULTS: After 3 months of clinical follow-up, complete healing (63%) was noted in all patients with OLLs whose lesions were in only close contact with their amalgam restorations. Healing was significantly related to the combination of lesions with close contact with the amalgam restoration and a diagnosis of OLL (x2 test, P=0.02). CONCLUSION: Feldspathic ceramic can be safely used as a replacement material for patients with OLLs to diminish adverse reactions to amalgam restorations.

Myxofibroma of the maxilla, current concepts, and differential diagnosis.

Odontogenic myxomas represent a small portion of all odontogenic tumors. A myxoma of the bone is a rare lesion that occurs almost exclusively in the jaws. An odontogenic myxoma has a variable clinical and radiological appearance, and it should be considered in the differential diagnosis of radiolucent and mixed radiolucent-radiopaque lesions of both jaws in all age groups. Myxomas consist of an accumulation of mucoid ground substance with little collagen, the amount of which determines whether it is called a myxofibroma. This paper presents the case of a 39-year-old male with a solid whitish red, nonulcerative, nontender expansion of both the buccal and palatal sides of the right upper alveolar bone. Results of a radiological examination revealed a unilocular radiolucency with cortical expansion and displacement of both the right upper second premolar and the first molar. The lesion was totally excised, and the histopathological examination showed a myxofibroma. Healing was uneventful, and there was no recurrence 12 months after surgical excision. Complete removal of the tumor, leaving no remnants attached to the soft tissue or bone, should be considered because of the well-known potential of myxofibromas to recur.

In Vitro Evaluation of Manual Torque Values Applied to Implant-Abutment Complex by Different Clinicians and Abutment Screw Loosening.

Preload is applied to screws manually or using a torque wrench in dental implant systems, and the preload applied must be appropriate for the purpose. The aim of this study was to assess screw loosening and bending/torsional moments applied by clinicians of various specialties following application of manual tightening torque to combinations of implants and abutments. Ten-millimeter implants of 3.7 and 4.1 mm diameters and standard or solid abutments were used. Each group contained five implant-abutment combinations. The control and experimental groups comprised 20 and 160 specimens, respectively. Implants in the experimental group were tightened by dentists of different specialties. Torsional and bending moments during tightening were measured using a strain gauge. Control group and implants with preload values close to the ideal preload were subjected to a dynamic loading test at 150 N, 15 Hz, and 85,000 cycles. The implants that deformed in this test were examined using an optical microscope to assess deformities. Manual tightening did not yield the manufacturer-recommended preload values. Dynamic loading testing suggested early screw loosening/fracture in samples with insufficient preload.

The Accuracy of New and Aged Mechanical Torque Devices Employed in Five Dental Implant Systems.

PURPOSE: Friction-style and spring-style torque wrenches are used to tighten implant abutments and prosthetic screws. The mechanical stability of these torque wrenches is crucial for the implant-abutment connection. The purposes of this study were to assess the performance of five brands (Straumann, Zimmer, Implant KA, Bredent, and Biohorizons) of wrench and to evaluate possible changes in applied torque values of aged wrenches. MATERIALS AND METHODS: Five new and aged wrenches that had been used approximately 250 times in a 1-year period were tested. The torque applied by friction- and spring-style wrenches was measured with a specially designed strain gauge indicator. Descriptive statistics, the one-sample t-test, and the independent-samples t-test were used to analyze values obtained from all torque wrenches. RESULTS: The accuracy of new and aged torque devices of all brands except Bredent differed significantly from the target values, but the mean values for aged and new wrenches did not differ significantly from each other (p > 0.05). Values for the spring- and friction-type torque wrenches deviated from the target values by 11.6% and 10.2%, respectively. CONCLUSION: The accuracy of aged torque wrenches is adequate for prosthetic screw tightening, but that of new torque wrenches is unsatisfactory and must be examined carefully before delivery.

Is immediate implant placement possible in the maxillary molar area? An anatomical study.

The dimensions of maxillary first molars were investigated and measured using cone beam computed tomography (CBCT) to examine the effectiveness of immediate placement of implants in the maxillary molar area. The CBCT images of 68 patients were collected. The dimensions of the maxillary first molar sockets were measured in both sagittal and coronal aspects, as well as the height of the alveolar bone crest (ABC) to the sinus membrane (SM) at optimal implant position. Sinus membrane and maxillary first molar relationships were analyzed sagittally and coronally. Interradicular bone presence and root intrusion into the sinus (IRS) were also noted. No statistically significant relationship was observed between IRS and age or sex. However, IRS was significantly related to sagittal type, as a type 1 sagittal relationship was characterized by greater root intrusion. The socket dimensions of male subjects were statistically significantly greater than those of female subjects, both coronally and sagittally. Changes in the socket dimensions were not significantly related to age in the sagittal plane. However, coronal plane measurements did increase with age. ABC-SM measurements decreased with age, but these changes were not statistically significant. These results showed that the socket dimensions in the maxillary first molar area are adequate for wider implant placement, but an implant longer than 8 mm increased the risk of perforation. All oral surgeons should be familiar with these anatomical variations so they can adopt appropriate additional practices and inform patients about the risks before operating.

Tooth extraction from a patient with cavernous hemangioma in maxillofacial region: case report.

Hemangiomas are benign vascular tumors which represent a rapid growth pattern followed by the involution phase. Generally, they are located in the soft tissues and are usually diagnosed in the first decade of life. Hemangiomas are mostly asymptomatic and rarely affect jaw bones. Mandible is affected more often than maxilla. If there is no complication present, treatment may not be necessary. Treatment planning of hemangiomas should be done by considering the location and the size of the lesion as well as the proximity to vital anatomical structures. The aim of this case report is to describe the procedures of tooth extraction in a patient who had been diagnosed as having maxillary cavernous hemangioma.

Monostotic fibrous dysplasia presenting in maxilla: a case report.

Fibrous dysplasia (FD) is a bone disorder in which fibrous tissue replaces normal bone. FD can be monostotic (10%-25%) or polyostotic (50-90%) and is typically diagnosed accidentally on radiographs. Craniofacial lesions are typically unilateral and are diagnosed by clinical assessment and radiographic evaluation. This report describes the case of a 50-yearold female patient who had presented with painless swelling of the right maxilla and was diagnosed with FD. Subsequent bone scintigraphy identified the lesion as monostotic. Based on the patient's age and the radiographic data, contour correction was performed. However, 1 year after surgery, the lesion regrew and the treatment was repeated.

A Complex Facial Trauma Case with Multiple Mandibular Fractures and Dentoalveolar Injuries.

The principles of management of mandibular fractures differ in children when compared to adults and depend on the specific age-related status of the growing mandible and the developing dentition. This paper presents a case report with a complex facial trauma affecting the mandibular body and condyle region and dentoalveolar complex. Clinical examination revealed soft tissue injuries, limited mouth opening, lateral deviation of the mandible, an avulsed incisor, a subluxated incisor, and a fractured crown. CBCT examination revealed a nondisplaced fracture and an oblique greenstick fracture of the mandibular body and unilateral fracture of the condyle. Closed reduction technique was chosen to manage fractures of the mandible. Favorable healing outcomes on multiple fractures of the mandible throughout the 6-year follow-up period proved the success of the conservative treatment. This case report is important since it presents a variety of pathological sequelae to trauma within one case.

Large rhinolith causing nasal obstruction.

Rhinoliths are calcified masses located in the nasal cavity and may cause symptoms such as nasal obstruction, fetid odour and facial pain. They are usually diagnosed incidentally on radiographic examinations or depending on the symptoms. In this paper we report a 27-year-old Caucasian woman with a calcified mass in the right nasal cavity causing nasal obstruction, anosmia and facial pain. The calcified mass was removed by endonasal approach.

Preservation of Involved Teeth Associated with Large Dentigerous Cysts.

Dentigerous cysts (DCs) are benign odontogenic cysts that are associated with the crowns of permanent teeth. The purpose of this study is to describe the management of DCs in four children. Four boys aged between 7 and 9 years were referred to our clinics with the complaints of intraoral alveolar swelling or facial asymmetry on the affected area. The panoramic radiographies showed large, well-defined radiolucent lesions associated with the deciduous teeth and displaced tooth buds. The treatment consisted of the extraction of the involved deciduous tooth and marsupialization of the cyst to allow eruption of the permanent tooth. Permanent teeth displaced by the DCs in three cases erupted spontaneously within one-year period. The case with horizontally displaced permanent tooth was managed by replantation. This is the first time that underlying permanent tooth in a DC case was intentionally replanted.