Comperative evaluation of the current and new design miniplate fixation techniques of the advanced sagittal split ramus osteotomy using three-dimensional finite element analysis

Background: The aim of this study was to evaluate the stress occurring in the fixation systems both developed in various geometric designs for this study and currently used in sagittal split ramus advancement osteotomy using finite element analysis. Material and Methods: The finite element model that imitates three-dimensional sagittal split advancement osteotomy was fixed in 10 different miniplate fixation methods: one miniplate fixed with four monocortical screws in a horizontal and oblique pattern; four-hole two miniplates with eight monocortical screws; five-hole miniplate fixed with four monocortical and one bicortical screws; six-hole straight and curved miniplates fixed with six monocortical screws in different geometric designs. Unilateral masticatory muscle loads that have previously determined in the literature were applied to the model at the anatomical muscle attachment regions and the data obtained from finite element analysis and static linear analysis methods were recorded as Von mises, maximum principle and minimum principle stress values. Results: It was observed from the results that maximum stress occurred in Group 1, which consisted of double backward T-shaped miniplate with 6-holes and, minimum stress occured in group 10, which mimiced hybrid system with one miniplate and four monocortical and one bicortical screws. Conclusions: Based on our results, the stress on the miniplates changes according to the geometric designs and the stress on the miniplate decreases as the numbers of miniplates and bars increase. The hybrid miniplate may be preferred by the surgeon as it will be exposed to less stress in excessive mandibular advancements by using the advantages of both the miniplate and the bicortical screw. (AU)

Finite Element Evaluation of Different Osteosynthesis Variations That Used After Segmental Mandibular Resection.

PURPOSE: The purpose of this study was to evaluate the effect of different reconstruction plates and screw combinations on stress distribution of segmental resected mandibles using finite element analysis. METHODS: Lateral (L) and lateral-central (LC) defects were simulated by a computer aided design modeling. The straight (s) and angular (a) titanium locking reconstruction plates of 2.5 mm (12 holes for L defects and 16 holes for LC defects) were modeled. Each screw was 2.5 mm in diameter and 10 mm in length. A total of 20 different screw placement combinations were created. The bite force used in the present model was a unilateral molar clench. The data obtained from finite element analysis were recorded as von Mises, maximum principle and minimum principle stress values. RESULTS: It was observed that stress values on neck of screw were higher for screws close to the resection area. When the first screw was loosened, the stress on the plate body and the remaining screws increased. Principle stress values were within the tolerance limits of the bone. CONCLUSION: The highest stress is observed in the screws nearest to the resection edge. Therefore, it is very important to place a screw adjacent to the resection edge.

Could Calcified Triglyceride Bone Cement Be an Alternative Graft Material in Maxillary Sinus Augmentation?

The ideal graft material for maxillary sinus augmentation is still a matter of controversy and the search for a more appropriate bone substitute for use continues. The aim of this study was to evaluate bone formation as a sign of the regeneration following maxillary sinus augmentation in rabbits using 3 different biomaterials, one of which is a newly developed graft material; calcified triglyceride bone cement (CTBC).Twenty-one New Zealand rabbits were used and randomly divided into 3 groups. Bilateral maxillary sinus augmentation was carried out and autogenous bone (AB), bovine hydroxyapatite (BHA), and CTBC were administered. Maxillary sinuses were dissected after fourth and eighth weeks of the operation. The bone formation was evaluated by stereological and histopathological analysis and the data were analyzed statistically.When the volume of primary bone is compared, statistically significant differences were found among all groups at both of the fourth and eighth weeks. The highest value was obtained from AB applied group. In BHA and CTBC applied groups, active bone formation, osseointegration of graft materials were observed at both fourth and eighth weeks. In CTBC applied group, primary bone formation was only seen as linked to the continuation of parent sinus bony wall.The efficiency of primary bone formation of CTBC was found less than AB and BHA. Of the 3 graft materials tested, BHA is the strongest alternative to AB graft for maxillary sinus augmentation.

Arteriovenous malformations in the differential diagnosis of palatal swellings.

An arteriovenous malformation (AVM) is composed of abnormal communications between arteries and veins without the normal intervening capillary bed. AVM of the head and neck is a rare vascular anomaly. We present here an unusual case of AVM with the size of 4x3 cm at the left posterior palatal area. Incisionel biopsy revealed AVM. Resection of the lesion following angiography was suggested to the patient however, he refused the treatment. The patient was considered to be under control. AVM should always be kept in mind in the differential diagnosis of palatal swellings.

Herpes zoster ophthalmicus reactivation following maxillary sinus lift operation: A case report.

PURPOSE: To present a case of Herpes Zoster Ophtalmicus (HZO), which was reactivated postoperatively after a sinus lift operation. MATERIALS AND METHODS: A 39-year-old male was referred to our clinic for implant-supported dental rehabilitation. He had maxillary missing teeth in positions 13, 14, 15 and 16 and a pneumatised right maxillary sinus with a bone height of 2 mm. Lateral sinus lifting and bone block grafting was performed before implant insertion. Twelve days after the sinus lift, the patient complained of pain and itching at the infraorbital area extending to the forehead. Clinical examination revealed no signs of infection or allergy. The patient received consultation from a dermatologist in order to rule out a possible dermatological disorder. Finally he was diagnosed with HZO. RESULTS: HZO was managed with systemic acyclovir treatment. Vesicular rashes and ptosis was seen 3 days after the medical treatment. After 1 month no postoperative skin or orbital sequela was seen. Three implants were inserted at the right posterior maxilla 5 months after sinus lift. One-year followup was uneventful. CONCLUSIONS: Dermatological diseases should always be kept in mind during the differential diagnosis of orofacial pain. In this case the proximity of the operation site and affected area gave rise to the idea that surgical trauma had a possible role in the reactivation of the virus. However, the process of reactivation is not entirely understood and requires further investigations. Early diagnosis is essential for HZO in order to avoid debilitating complications such as postherpetic neuralgia and blindness.

Deep neck infection after third molar extraction.

Odontogenic and oropharyngeal infections are relatively common in the cervicofacial region. In rare cases, odontogenic or peritonsillar abscesses may spread through the deep fascial cervical spaces and cause life-threatening complications. Odontogenic infection is the most common cause of deep neck infections and it accounts for 43% of the cases. Early diagnosis, immediate antibiotic treatment, and surgical drainage are the basis of therapeutic success. Deep neck infections are potentially life threatening complications if they are not diagnosed in time and treated quickly. This case report presents clinical, radiological features and treatment of the spread of abscesses through cervical spaces of an unusual case of deep neck infection that was caused by the secondary infection of the root remnants after extraction.

Dentinal dysplasia type I: a case report with a 6-year followup.

Introduction. Dentin dysplasia is a rare disturbance of dentin formation characterized by normal enamel but atypical dentin formation with abnormal pulpal morphology that is inherited as an autosomal pulpal morphology. Case Presentation. A 7-year-old female who had problems in chewing function was referred to Oral and Maxillofacial Surgery Department at the Faculty of Dentistry in Ondokuz Mayis University. In the radiographic examination, it was determined that some of the unerupted permanent teeth of the patient had short, blunted, and malformed roots with obliterated pulp chambers, although the bone below the teeth showed well-defined margins. This unusual case of generalized short roots presents a case demonstrating both classic and atypical features of dentinal dysplasia type I (DDI) in the mixed and permanent dentitions. Conclusion. There are still many issues in the diagnosis and management of patients with dentin dysplasia. Early diagnosis, clinical and radiographic findings, as well as treatment of this condition and the initiation of effective preventive strategies may help prevent or delay loss of dentition.

Graft necrosis occurred after iliac crest reconstruction after mandibular segmental resection of ameloblastoma.

Ameloblastoma is an uncommon benign odontogenic neoplasm of the maxillofacial region constituting less than 1% of tumors of the oral cavity. Ameloblastomas have been categorized broadly into 3 biologic variants: cystic (unicystic), solid, and peripheral. Unicystic ameloblastoma is a rare and less aggressive variant of ameloblastoma. The aim of this report is to describe a case of cystic ameloblastoma treated with segmental resection and iliac graft reconstruction. The possible reasons of graft failure seen in our patient at the early stage of the healing were also discussed.

Descending necrotizing mediastinitis associated with an infected dentigerous cyst.

Descending necrotizing mediastinitis (DNM) is a rare condition in which an infection from the head and neck propagates into the mediastinum. The most common cause of DNM is odontogenic infection. DNM is spread by the fascial planes from the neck into the mediastinum and requires an aggressive surgical drainage through cervical and thoracic approaches. We report on a 67-year-old male patient, who had acute mediastinitis related to an infected dentigerous cyst in the left parasymphyseal region. A multidisciplinary team approach was used to treat the patient. The team consisted of thoracic surgeons, maxillofacial surgeons, and a radiologist. After the drainage of the mediastinum and pleural cavity, the cyst was enucleated. The patient was discharged at the 42nd day of hospitalization. The aim of this article is to present diagnosis, management, and follow-up of an infected dentigerous cyst that caused DNM.

Prevalence and distribution of odontogenic and nonodontogenic cysts in a Turkish Population

Objective : To determine the relative frequency and distribution of odontogenic and nonodontogenic cysts in alarge Turkish population. Study Design A retrospective survey of jaw cysts was undertaken at the Oral Diagnosis and Radiology and Oral and Maxillofacial Surgery Department, Ondokuz Mayýs University Dental School, Samsun, Turkey . Data were retrieved from clinical files, imaging, and histopathology reports from 2000 to 2008; a total of 12,350 patients were included . In each case, we analyzed age, gender, type and number of cysts, and cyst location . Imaging pat -terns and pathologies associated with cystic lesions were also determined .Results : The prevalence of odontogenic and nonodontogenic cysts was 3.51%; males were affected more frequently than females . There were 452 odontogenic cysts (98.5%) and seven nonodontogenic cysts (1.5%). The most frequent odontogenic cyst was radicular (54.7%), followed by dentigerous (26.6%), residual (13.7%), odontogenic keratocyst (3.3%), and lateral periodontal cyst (0.2%). Nasopalatine duct cyst (1.5%) was the only nonodontogenic cyst . By age, cysts peaked in the third decade (24.2%). Concerning location, no statistically significant difference was found between the maxilla and mandible (p>0.05). The most frequent radiological feature of these lesions was unilocular cyst (93.7%). Pathologies associated with cystic lesions occurred in 14.7%.Conclusion : The prevalence of both odontogenic and nonodontogenic cysts were lower than that reported in many other studies . In our study population, cysts were mainly inflammatory in origin (AU)

Use of artificial neural network in differentiation of subgroups of temporomandibular internal derangements: a preliminary study.

PURPOSE: Artificial neural networks (ANNs) have been developed in the past few decades for many different applications in medical science and in biomedical research. The use of neural networks in oral and maxillofacial surgery is limited. The aim of this study was to determine the use of ANNs for the prediction of 2 subgroups of temporomandibular joint (TMJ) internal derangements (IDs) and normal joints using characteristic clinical signs and symptoms of the diseases. MATERIALS AND METHODS: Clinical symptoms and diagnoses of 161 patients with TMJ ID were considered the gold standard and were employed to train a neural network. After the training process, the symptoms and diagnoses of 58 new patients were used to verify the network's ability to diagnose. The diagnoses obtained from ANNs were compared with diagnoses of a surgeon experienced in temporomandibular disorders. The sensitivity and specificity of ANNs in predicting subtypes of TMJ ID were evaluated using clinical diagnosis as the gold standard. RESULTS: Eight cases evaluated as bilaterally normal in clinical examination were evaluated as normal by ANN. In detecting unilateral anterior disc displacement with reduction (ADDwR; clicking), the sensitivity and specificity of ANN were 80% and 95%, respectively. In detecting unilateral anterior disc displacement without reduction (ADDwoR; locking), the sensitivity and specificity of ANN were 69% and 91%, respectively. In detecting bilateral ADDwoR, the sensitivity and specificity of ANN were 37% and 100%, respectively. In detecting bilateral ADDwR, the sensitivity and specificity of ANN were 100% and 89%, respectively. In detecting cases of ADDwR at 1 side and ADDwoR at the other side, the sensitivity and specificity of ANN were 44% and 93%, respectively. CONCLUSION: The application of ANNs for diagnosis of subtypes of TMJ IDs may be a useful supportive diagnostic method, especially for dental practitioners. Further research, including advanced network models that use clinical data and radiographic images, is recommended.

Prevalence and distribution of odontogenic and nonodontogenic cysts in a Turkish population.

OBJECTIVE: To determine the relative frequency and distribution of odontogenic and nonodontogenic cysts in a large Turkish population. STUDY DESIGN: A retrospective survey of jaw cysts was undertaken at the Oral Diagnosis and Radiology and Oral and Maxillofacial Surgery Department, Ondokuz Mayis University Dental School, Samsun, Turkey. Data were retrieved from clinical files, imaging, and histopathology reports from 2000 to 2008; a total of 12,350 patients were included. In each case, we analyzed age, gender, type and number of cysts, and cyst location. Imaging patterns and pathologies associated with cystic lesions were also determined. RESULTS: The prevalence of odontogenic and nonodontogenic cysts was 3.51%; males were affected more frequently than females. There were 452 odontogenic cysts (98.5%) and seven nonodontogenic cysts (1.5%). The most frequent odontogenic cyst was radicular (54.7%), followed by dentigerous (26.6%), residual (13.7%), odontogenic keratocyst (3.3%), and lateral periodontal cyst (0.2%). Nasopalatine duct cyst (1.5%) was the only nonodontogenic cyst. By age, cysts peaked in the third decade (24.2%). Concerning location, no statistically significant difference was found between the maxilla and mandible (p>0.05). The most frequent radiological feature of these lesions was unilocular cyst (93.7%). Pathologies associated with cystic lesions occurred in 14.7%. CONCLUSION: The prevalence of both odontogenic and nonodontogenic cysts were lower than that reported in many other studies. In our study population, cysts were mainly inflammatory in origin.

Oral and dental manifestations of diamond-blackfan anemia: case reports.

Diamond-Blackfan Anemia (DBA) is a red cell aplasia characterized with physical abnormalities. The incidence of the disease is reported to be five to seven (5-7) cases per million births in Europe and 4-5 per million live births in the UK and Netherlands with equal sex ratio. It was first recognized in 1938 but an exact pathophysiology of the disease has not been described yet. These abnormalities are well known, however, detailed oral and dental conditions related with the disease have not been described previously. We herein presented two cases of DBA together with oral and dental findings. Our study is first to report the gingival status of the patients with a complete investigation of any orthodontic or dental abnormalities in these kind of patients. A careful follow up and preventive therapies should not be missed in these kind of patients.

A Case Report of Focal Epithelial Hyperplasia (Heck's disease) with PCR Detection of Human Papillomavirus.

Focal epithelial hyperplasia or Heck's disease, is a rare viral infection of the oral mucosa caused by human papillomavirus. The frequency of this disease varies widely from one geographic region to another. In Caucasians there have been only few cases reported. This paper reports a case of focal epithelial hyperplasia and demonstrates the association with HPV subtype 32 through polymerase chain reaction (PCR) and sequencing of PCR products. A 7-year-old Caucasian girl was admitted to our clinic for investigation of multiple oral mucosal lesions in the mouth. Lesion was excised under local anesthesia without any complication. The lesion was diagnosed as focal epithelial hyperplasia according to both clinical and histopathological features. Dental staff should be aware of these kind of lesions and histopathological examination together with a careful clinical observation should be carried out for a definitive diagnosis.

Oral verrucous carcinoma: a study of 12 cases.

OBJECTIVES: The purpose of this clinical study was to identify a clinical and histopathological relationship between verrucous hyperplasia, verrucous keratosis, and verrucous carcinoma. METHODS: We evaluated 12 patients who had developed oral verrucous carcinoma in the past 10 years in a follow-up study. In this study, the diagnostic criteria included clinical and histopathological features of the lesions. Each lesion was examined by a single oral pathologist. RESULTS: All the patients were diagnosed with verrucous carcinoma following excisional biopsy. One patient was diagnosed with verrucous hyperplasia and another with verrucous keratosis in their initial histological findings. Mandibular, posterior alveolar crest, and retromolar trigone were the most affected sites (41.6%), followed by the buccal mucosa (16.6%), the palate (16.6%), the floor of the mouth (16.6%), and the lip (8.3%). No patients had evidence of recurrence after treatment. CONCLUSIONS: Verrucous hyperplasia, verrucous keratosis, and verrucous carcinoma may not be distinguished clinically or may coexist, resulting in diagnostic difficulties. It should be kept in mind that verrucous hyperplasia may also develop from leukoplakic lesions, and it may transform into verrucous carcinoma or squamous-cell carcinoma, acting as a potential precancerous lesion.

Intractable bimaxillary osteomyelitis in osteopetrosis: review of the literature and current therapy.

PURPOSE: Osteopetrosis (OP), also known as Albers-Schönberg disease, is a rare metabolic bone disease caused by a congenital defect in the development or function of the osteoclasts resulting in generalized increase in skeletal mass. Osteomyelitis is a recognized complication, and prevention of dental infections can be difficult. The locations of osteomyelitis in the jawbones have been either in the mandible or maxilla. In this article, a case of OP complicated with osteomyelitis of the mandible and the maxilla is presented, and types of OP and treatment options are discussed with a literature review. MATERIALS AND METHODS: The 18-year-old blind female patient had been diagnosed with OP in the past. She had a purulent discharge at the medial canthus of the left eye, in addition to another discharge of pus in the infraorbital and upper left molar region, and multiple malformed and partially impacted teeth, and there were sequestrum formations in the maxilla and mandible. For the treatment of osteomyelitis, systemic combined antibiotics of sultamicillin 750 mg and ornidazole 500 mg twice daily, were given orally for 5 weeks followed by surgical removal of small sequestra in the jaws. Persistent osteomyelitic bones were removed by saucerization in the mandibular anterior and right premolar region and the left posterior maxilla under the same antibiotic regimen. After wound healing was completely achieved in both jaws, the oroantral opening in the left posterior maxilla was successfully closed with a buccal flap under antibiotic coverage. RESULTS: The purulent discharge at the medial canthus of her left eye subsided and she had no recurrent infections during the long-term follow-up of 2 years. CONCLUSION: The case reported shows that osteomyelitis is difficult to treat in subjects suffering from OP. Therefore, it is necessary to be very cautious against infections in even minor surgical interventions such as simple dental extractions in patients with OP, regardless of the location of the teeth. When considering removal of impacted teeth in the posterior maxilla, resultant oroantral communication from osteomyelitis of the extraction site should be regarded as a potential complication.

Peripheral giant cell granuloma associated with dental implants: a rare case report.

The peripheral giant cell granuloma is a benign reactive exophytic lesion of unknown etiology occurring on the gingiva and alveolar ridge. Different local causal factors have been associated with this type of lesion. Although peripheral giant cell granuloma is the most common giant cell lesion of the jaws, it is rarely seen in association with implants. This report discusses the etiology and management of a peripheral giant cell granuloma around dental implants in a 60-year-old woman. A new implant-supported prosthesis with adequate marginal adaptation between the restoration and abutments was made. There were no complications during 1 year of clinical and radiologic follow-up.

Regional odontodysplasia of the deciduous and permanent teeth associated with eruption disorders: A case report.

Regional odontodysplasia (RO) is an unusual, non-hereditary anomaly of the dental hard tissues with characteristic clinical, radiographic and histological findings. Clinically, RO affects the primary and permanent dentition in the maxilla and mandible or both jaws. Radiographically, there is a lack of contrast between the enamel dentin, both of which are less radiopaque than unaffected counterparts. Additionally, enamel and dentin layers are thin, giving the teeth a "ghost-like" appearance. Histologically, areas of hypocalcified enamel are visible and enamel prisms appear irregular in direction. Coronal dentin is fibrous, consisting of clefts and a reduced number of dentinal tubules; radicular dentin is generally more normal in structure and calcification. The RO etiology is uncertain; numerous factors have been suggested and considered as local trauma, irradiation, hypophosphatasia, hypocalcemia, hyperpyrexia. The treatment of RO has given rise to controversy. These cases require a continuous and multidisciplinary approach. Most clinicians advocate extracting the affected teeth as soon as possible and inserting a prosthetic replacement. Other clinicians prefer restorative procedures, if possible, to protect the affected erupted teeth. A case of RO in an 8 year-old male whose chief complaint was the absence of eruption of permanent teeth is presented. Clinical, radiographic and histological findings are described.

Regional odontodysplasia of the deciduous and permanent teeth associated with eruption disorders: A case report

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Regional odontodysplasia (RO) is an unusual, non-hereditary anomaly of the dental hard tissues with characteristic clinical, radiographic and histological findings. Clinically, RO affects the primary and permanent dentition in the maxilla and mandible or both jaws. Radiographically, there is a lack of contrast between the enamel dentin, both of which are less radiopaque than unaffected counterparts. Additionally, enamel and dentin layers are thin, giving theteeth a “ghost-like” appearance. Histologically, areas of hypocalcified enamel are visible and enamel prisms appear irregular in direction. Coronal dentin is fibrous, consisting of clefts and a reduced number of dentinal tubules; radicular dentin is generally more normal in structure and calcification.The RO etiology is uncertain; numerous factors have been suggested and considered as local trauma, irradiation,hypophosphatasia, hypocalcemia, hyperpyrexia. The treatment of RO has given rise to controversy. These cases require a continuous and multidisciplinary approach. Most clinicians advocate extracting the affected teeth as soon as possible and inserting a prosthetic replacement. Other clinicians prefer restorative procedures, if possible, to protectthe affected erupted teeth.A case of RO in an 8 year-old male whose chief complaint was the absence of eruption of permanent teeth is presented. Clinical, radiographic and histological findings are described (AU)

Biomechanical comparison of different plating techniques in repair of mandibular angle fractures.

OBJECTIVE: The purpose of this study was to evaluate the biomechanical behaviors of different miniplate fixation techniques for treatment of fractures of the mandibular angle. STUDY DESIGN: Twenty sheep hemimandibles were used to evaluate 4 different plating techniques. The groups were fixated with Champy technique, biplanar plate placement, monoplanar plate placement, and 3-dimensional (3D) curved angle strut plate. A custom-made 3-point biomechanical test model was used for the samples. Each group was tested with compression forces by an Instron Lloyd LRX machine. The biomechanical behavior of the groups for the forces (N) that caused displacement of 1.75 mm were compared using the Instron software program and displacement graphics. RESULTS: The variance analyses showed that biplanar plate placement had more favorable biomechanical behavior than Champy technique and monoplanar plate placement (P < .05). In addition, the 3D curved angle strut plate technique had more favorable biomechanical behavior than the Champy technique (P < .05) but was not significantly different from biplanar or monoplanar plate placement techniques (P > .05). CONCLUSION: The study demonstrated that 3D strut plates or dual miniplate techniques had greater resistance to compression loads than the Champy technique. In addition, biplanar plate orientation may provide a more favorable biomechanical behavior than monoplanar plate placement.