Area Of Mandible Research Articles

IMPACT OF NF-κB AND NRF2 TRANSCRIPTION FACTOR MODULATORS ON METABOLIC CHARACTERISTICS IN MANDIBLE BONES OF RATS DURING RECOVERY FROM INCOMPLETE FRACTURE UNDER CHRONIC ALCOHOL INTOXICATION

This study aims at investigating the influence of specific modulators of NF-κB and Nrf2 transcription factors on oxidative-nitrosative stress indicators and bone biopolymer depolymerization in mandibular bone following incomplete fracture under chronic alcohol intoxication (CAI). Twenty-eight white male Wistar rats were divided into five groups: Group 1 comprised "falsely injured" rats, while Group 2 underwent incomplete mandibular fracture (IMF) under CAI exposure. Rats in groups 3 and 4 received intraperitoneal injections of ammonium pyrrolidinium dithiocarbamate, an inhibitor of NF-κB activation, in a dose of 76 mg/kg, and dimethyl fumarate, an Nrf2 inducer, in a dose of 15 mg/kg three times a week for 14 days following the modeling of IMF under CAI exposure. The activity of total NO synthase, including its constitutive and inducible isoforms, along with ornithine decarboxylase, and concentrations of peroxynitrites of alkaline and alkaline-earth metals, free hydroxyproline, N-acetylneuraminic, and hexuronic acids were assessed in the homogenate of the standard mandible area using a spectrophotometric method. The findings have demonstrated that the administration of ammonium pyrrolidine dithiocarbamate and dimethyl fumarate notably decreased the activity of NO synthase (primarily its inducible isoform) and the concentration of peroxynitrite in the mandibular bone homogenate, while increasing the activity of ornithine decarboxylase, a key enzyme in polyamine biosynthesis. Furthermore, under experimental conditions, the use of ammonium pyrrolidine dithiocarbamate and dimethyl fumarate limited the depolymerization of bone biopolymers (collagen, glycoproteins, and proteoglycans), thereby facilitating effective reparative osteogenesis.

Follicular Ameloblastoma of the Mandible in a Young Adult Patient: Case Report

Introduction: Ameloblastoma is a locally invasive tumor that grows slowly and attacks the maxillofacial area. There are various histological variants of ameloblastoma. The most common is follicular ameloblastoma. They are characterized by slow growth and are relatively aggressive locally, with the primary site of origin being the mandible. Late recurrence after surgical management is relatively common and is related to the histologic type, site of origin, and initial treatment modality. The mandibular bone is also a relatively common location for this tumor. Optimal surgical treatment of ameloblastoma should minimize recurrence, restore function and aesthetics, and minimize morbidity at the donor site. Segmental mandibular resection surgery is tumour surgery by removing part of the mandible. Case report: A 15-year-old female patient came with complaints of a mass in the mandible area. The mass infiltrated the right mandible. The surgical intervention performed on this patient was a segmental resection operation. From the results of the Anatomic Pathology (AP) examination, follicular ameloblastoma was found in the right mandibular region. Conclusion: The patient's age and histopathological pattern of the tumor influence the treatment plan. Keywords: Follicular Ameloblastoma, Benign, Segmental resection surgery

Evaluation of the accuracy of the resection template and restorations of the bone structures in the mandible area manufactured using the additive technique

The article presents the current possibilities in the field of modeling and manufacturing models of anatomical structures, surgical templates, and implants in terms of planning surgical procedures in the area of ​​the mandible. In the first stage, the 3D reconstruction of the mandible geometry using the 3D-Slicer software was presented. The next step of the process consisted in modeling resection templates and supplementing the loss of the bone structure of the mandible. The last stage consisted of manufacturing models using the additive FDM method from PC-ISO material and performing an accuracy assessment. The models' accuracy using the additive FDM technique is within the tolerance range of +/- 0.2 mm. It is sufficient to use models when planning a procedure.

Response to Dabrafenib and Tramatenib in an Extra-Cranial Avm with BRAF V600E Mutation

Background: Arteriovenous malformations (AVMs) are blood vessel malformations characterized by shunting of blood through dilated veins and arteries. KRAS is an effector molecule in a MAPK pathway that mediates activation of downstream processes such as BRAF production related to known proliferative disorders such as AVMs. Similarly MAP2K1 mutations that encodes for MEK have recently been implicated in sporadic intracranial and extracranial AVMs. Inhibition of the RAS/MAPK pathway is of interest in treatment of vascular malformations. Objective: We report a case of treatment response of a BRAF mutated arteriovenous malformation with MEK and RAF inhibitors. Description of the case: A 22 year old male presented initially at 6 years of age with swelling of the left face involving the cheek and mandible area, the area continued to grow in size with associated pain and rarely intermittent bleeding from the left buccal mucosa. US and MRI showed evidence of an AVM. He underwent 2 embolizations followed by debulking with some improvement of the swelling. Pathology revealed a BRAF V600 mutation by molecular testing. He was treated with oral Dafrafenib 150 mg twice daily and Trametinib 2 mg daily, showing improvement of the swelling with a 3 month old follow up. Conclusion: AVMs continue to present treatment challenges for hematologists, surgeons and other care providers. Treatment with target directed therapies with inhibitors of the RAS-RAF-MEK-ERK pathway such as Trametinib and Dafrafenib have the potential to make a positive impact in the current management of these entities. Further studies are required to explore safety and impact of long term effects of these drugs in pediatric patients.

MECHANISMS OF NITROSATIVE STRESS AND DESTRUCTION OF THE ORGANIC MATRIX OF THE RAT MANDIBLE IN THE RECOVERY PERIOD AFTER ITS INCOMPLETE FRACTURE UNDER CONDITIONS OF CHRONIC ALCOHOL INTOXICATION

The mechanisms of nitrosative stress and depolymerization of biopolymers of the mandibular bone tissue after its incomplete fracture under conditions of chronic alcohol intoxication were investigated. The experiments were conducted on 20 white Wistar rats weighing 190-240 g, divided into 4 groups: Group 1 - intact animals, Group 2 - after reproduction of chronic alcohol intoxication, Group 3 - after modeling of mandibular fracture, Group 4 - after reproduction of mandibular fracture in the setting of chronic alcohol intoxication. The activity of total NO synthase, its constitutive and inducible isoforms, ornithine decarboxylase, concentrations of peroxynitrites of alkaline and alkaline-earth metals, free hydroxyproline, N-acetylneuraminic and hexuronic acids were determined in the homogenate of the standard mandible area by spectrophotometric method. It has been shown that the reproduction of chronic alcohol intoxication significantly increases the total and inducible NO synthase activity in the mandibular homogenate, accompanied by an increase in the concentration of the key marker of nitrosative stress – peroxynitrite. On the 14th day after the reconstruction of a mandibular fracture on the background of chronic alcohol intoxication, NO synthase activity and the content of peroxynitrites of alkaline and alkaline-earth metals in the bone homogenate exceed the results of groups with separate action of pathogenic factors. Under these conditions, the activity of the key enzyme of polyamine biosynthesis, ornithine decarboxylase, significantly decreases, and the depolymerization of bone biopolymers (collagen, glycoproteins, and proteoglycans) increases, which creates prerequisites for disruption of reparative processes in the fracture site.

A Case of Chronic Meniere's Disease Improved by Korean Medicine Treatment Including Pharmacoacupuncture of Cervical and Temporomandibular Area - A Case Report

Meniere’s disease is characterized by episodic vertigo, fluctuating hearing loss, tinnitus and ear fullness. The main pathological finding is endolymphatic hydrops, but the etiology of disease and effective treatment methods are still disputed. Recently, Cervical spine disorders(CSD) and Temporomandibular disorders(TMD) have been attracting attention as one of the causes of Meniere’s disease. A 65-year-old female Meniere patient with musculoskeletal problems in the cervical and mandible area was treated by Korean medical therapies including pharmacoacupuncture treatment. After 5 weeks of treatment, there was no meaningful change in hearing level evaluated with pure tone audiometry, but the subjective symptoms of Meniere improved significantly. Numerical rating scale (NRS) decreased from 10 to 0 for hearing loss, 10 to 3 for tinnitus and 8 to 3 for ear fullness. Also NRS of cervicalgia was reduced from 5 to 0 after treatment. The result suggests that the Korean medical therapy including pharmacoapuncture targeting CSD and TMD could be safe and effective method for patients with Meniere’s disease.

Incidence and Management of Tooth Root Fracture in Mandibular Fracture Line - A Retrospective Study.

In cases of trauma, the most common fractures of the facial region are the nasal bone fractures followed by mandibular fractures. About 60% of mandible fractures are associated with teeth in the fracture line; however conversely, the dentulous mandible has a higher susceptibility of fracture in any impact. Whenever a tooth is involved in the fracture line, it is not unlikely that the tooth root fracture will be associated with it. The prognosis and treatment of such a tooth persistent in a fracture line depends upon the level of tooth root fracture. This retrospective study was conducted in the Department of Oral and Maxillofacial Surgery in a Meerut hospital. The eligibility criteria were based on the cases involving fracture line passing through the teeth bearing area of mandible. Total of 56 cases of mandibular fracture treated from January 2021 till December 2022 by open reduction and fixation were included in the study. A total of 56 patients (66 fracture lines) with mandibular fractures were selected, out of which 18 (32%) patients had fracture of the root of the tooth in the fracture line. Third molar root fracture were present in 12 cases (66.6%), first premolars in 4 cases (22.2%), and first molars in 2 cases (11.1%). There were 14 multi rooted teeth (77.7%) and 4 single rooted teeth (22.2%) involvement. All the multi rooted teeth fracture were treated by extraction during open reduction and fracture fixation. The single rooted teeth were successfully treated by endodontic treatment postoperatively. The fracture line passing through the dentate segment may fracture the tooth crown and/or root or propagate through the socket without any injury to the root. Root fracture at cervical and middle third is constantly exposed to oral fluids. The affected tooth may be mobile and lose vitality. Teeth in the line of fracture must be removed when they preclude the correct reduction of the segments or if they represent a risk for infection. If the tooth or root does not cause any hindrance during reduction or it is not infected, the tooth can be salvaged by endodontic therapy. The incidence of root fracture was seen in 32% of cases. Fracture of the third molar roots was the single largest group (66.6%). No root fracture was observed in the anterior segment.

3D-printed gelatin/sodium alginate/58S bioactive glass scaffolds promote osteogenesis in vitro and in vivo.

Three-dimensional (3D)-printed scaffolds are a new strategy to fabricate biomaterials for treating bone defects. Here, using a 3D-printing technique, we fabricated scaffolds consisting of gelatin (Gel), sodium alginate (SA), and 58S bioactive glass (58S BG). To evaluate mechanical properties and biocompatibility of Gel/SA/58S BG scaffolds, the degradation test, compressive strength test, and cytotoxicity test were performed. The effect of the scaffolds on cell proliferation in vitro was determined by 4',6-diamidino-2-phenylindole (DAPI) staining. To evaluate osteoinductive properties, rBMSCs were cultured on the scaffolds for 7, 14, and 21days and the expression of osteogenesis-related genes was analyzed using qRT-PCR. To examine the bone healing properties of Gel/SA/58S BG scaffolds in vivo, we used a rat mandibular critical-size defect bone model. The scaffolds were implanted into the defect area of rat mandible and bone regeneration and new tissue formation were assessed using microcomputed tomography (microCT) and hematoxylin and eosin (H&E) staining. The results showed that Gel/SA/58S BG scaffolds had appropriate mechanical strength as a filling material for bone defects. Furthermore, the scaffolds could be compressed within certain limits and then could recover their shape. The extract of the Gel/SA/58S BG scaffold showed no cytotoxicity. In vitro, the expression levels of Bmp2, Runx2, and OCN were increased in rBMSCs cultured on the scaffolds. In vivo, microCT and H&E staining demonstrated that scaffolds induced the formation of new bone at the mandibular defect area. These results indicated that Gel/SA/58S BG scaffolds have excellent mechanical characteristics, biocompatibility, and osteoinductive properties, suggesting that it could be a promising biomaterial for the repair of bone defects.

Morphometric analysis of paired fibula and mandible for optimal fibular mandibular reconstruction in a Chinese population

To analyze the morphology of paired fibula and mandible aiming to choose optimal fibular segments for mandibular reconstruction in a Chinses population. A total of 118 cases of paired mandible and fibula was collected. All patients were received preoperative cone beam CT (CBCT) scans for mandibular evaluation and CT-angiographical (CTA) examination of the bilateral lower legs, respectively. The cross-sectional morphological differences between proximal (Side P), middle (Side M) and distal (Side D) segments of fibula and anterior, premolar and molar areas of mandible were compared. The most frequent cross-sectional shape at Side D, Side M and Side P portion of fibula was circular (75.4%), triangular (67.8%) and circular (49.2%), respectively. In anterior, premolar and molar areas of mandible, the most of the cross-section was s-shape (90.82%), straight (83.64%) and oblique (91.89%), respectively. The height and width of upper one third (W1) at Side M were significantly larger than those of Side D and Side P (p < 0.0001). There was significantly difference of width of lower one third (W2) among three groups (p < 0.0001). As for the height and widths of mandible, there was significant difference among anterior, premolar and molar regions (p < 0.0001). The rate of height between Side M of fibula and mandible (H (Side M/area)) was significantly larger than H (Side D/area) and H (Side P/area) (p < 0.01). The ratio of W1 between Side D of fibula and mandible (W1 (Side D/area)) was significantly larger than that of W1 (Side M/area) and W1 (side P/area) (p < 0.05). As for the ratio of W2 between fibula and mandible (W2 (plane/area)), there was significant difference among groups (p < 0.01). The distal and middle segments of fibula were suitable for reconstructing the anterior area of mandible and the proximal segment of fibula was more compatible with the premolar and molar areas of mandible.Clinical Relevance Presurgical morphometric analysis of paired fibula and mandible aids for optimal fibular-based mandibular reconstruction.

A Novel Approach to Guided Implant Surgery: A Technical Note

Computer-guided software and kits have significantly improved the clinical applications of implant surgery. Nonetheless, some technical problems are still in evidence during clinical procedures because of cumbersome surgical tools that can limit access to implant sites, mainly in posterior areas of the mouth in the presence of bulky anatomical structures and in patients with reduced mouth-opening capacity. The present paper aimed to present a novel approach to guided implant surgery, describing the technical characteristics of an innovative guided surgical kit made up of modified sleeves and modular surgical drills. The proposed guided surgical kit is based on a novel patented system of sleeves and modular burs, with an increased length of the metal sleeves and a reduced height of the drills. The innovative design of the proposed system would allow the clinician to position guided fixtures in all clinical situations; the reduced encumbrance would be particularly helpful to gain access to the posterior areas of both maxilla and mandible, which have limited inter-arch space, with an easy and user-friendly approach. The modular system could overcome anatomical limitations, such as reduced mouth-opening capacity, and permit clinicians to maintain the stability and integrity of the surgical templates, even in cases where there is very limited intermaxillary space.

Pattern of Facial Fractures and Its Association with a Cervical Spine Injury in a Tertiary Hospital in Jordan.

Background Facial fractures can be accompanied by serious and life-threatening injuries such as cervical spine injury (CSI), which can lead to serious consequences if misdiagnosed. Objective To assess the patterns of maxillofacial fractures and to explore the association between these fractures and cervical spine injuries (CSIs) in patients with a traumatic facial injury. Methods A retrospective analysis was conducted on the data of the subjects who were admitted to the King Abdullah University Hospital (KAUH) and had a maxillofacial fracture in the period from January 2017 through December 2020. Stepwise binary logistic regression analysis was conducted to find the variables which are significantly and independently associated with CSIs. Results A total of 394 maxillofacial fractures were reported for a total of 221 subjects. The mandible was the most common site of the reported fractures (41.88%). The majority of the subjects had associated injuries (70.6%), of which 82.7% were CSIs. The most common type of the CSIs was the vertebral fracture (52%). Increased age (OR = 1.543, P < 0.05), having a mandibular fracture (OR = 4.382, P < 0.01), and having a maxillary fracture (OR = 3.269, P < 0.05) were significantly associated with the presence of CSI. Conclusion The current study revealed that the most common type of facial fracture occurred in the mandible area, and CSI was the most common fracture-associated injury (82.7%). Increased age and having mandibular or maxillary fracture were associated with an increased risk of developing CSI. Therefore, it is necessary to rule out the presence of concomitant CSI during the emergency management of maxillofacial fractures, particularly for elderly patients and those with mandibular or maxillary fractures.

Quantitative analysis of facial symmetry by using three-dimensional technology

BackgroundFacial symmetry is becoming increasingly important in today's orthodontic treatment. But the asymmetrical boundary is not clearly demarcated. Stereophotogrammetry has a clear advantage in measuring facial asymmetry. The aim of this study was to quantify the facial asymmetry by three-dimensional (3D) technology as well as to study whether the evaluation by non-experts about facial asymmetry was consistent with the analysis by 3D technology.MethodsThe facial symmetry of 330 patients was evaluated by 10 non-experts. 3D facial images were taken using 3dMD stereophotogrammetry equipment. The original face and its mirror shell were divided into 7 regions and the surface matching was measured in the whole face and all regional areas. The degree of symmetry was calculated by the software 3-matic STL 9.0. The difference between the two groups was analyzed by Independent-Samples T Test and the diagnostic efficiency of symmetry degree was analyzed by ROC curve analysis. The consistency between the symmetric degree and the result of evaluation was analyzed by Pearson correlation analysis.ResultsThe ROC analysis revealed significant diagnostic values in the determination of the facial asymmetry of lip, chin, cheek and lateral mandible areas. The cut-off values of symmetry degree were between 60 and 80%. The evaluation was middle correlation with the symmetric degree of the whole face.ConclusionsThe chin and lateral mandible contribute most significantly to the facial symmetry. The objective measurement of facial symmetry, 3D technology, is reliable.

How Do You Treat Trigeminal Neuralgia in Your Practice?

How Do You Treat Trigeminal Neuralgia in Your Practice?

Primary site and survival in osteosarcoma: A National Cancer Database (NCDB) analysis.

e23512 Background: Osteosarcoma (OSC) is the most common primary bone tumor and typically affects the appendicular skeleton (specifically, the long bones of the upper and lower extremities). However, this cancer can affect other regions of the body as well, such as the skull, mandible, ribs, vertebral column, and other areas involving bone and/or any articular cartilage and, to the author’s knowledge, all possible primary sites have not been investigated. The aim of this study is to see whether or not the primary site of the tumor in OSC patients may have an effect on survival outcomes. Methods: Using the NCDB, patients diagnosed with OSC between 2004-2018 were identified using ICD-O-3 histology codes 9180 through 9193. The cohort was analyzed to investigate survival outcomes in different primary sites. Univariate analysis was then performed assessing patient length of survival for each primary site subtype. Data was analyzed using SPSS and statistical significance was set at α = 0.05. Results: A total of 9826 patients with known primary site that had survival data were included. The site with the best survival was the lower limb which had significantly better survival than all other primary sites. Tumors of the upper limb had highest median survival (153 months) of those with median survival reported (which was all except for lower limb). Patients with primary tumor of ribs, sternum, clavicle had a significantly better survival than both vertebral column and pelvis/sacrum/coccyx (all p &lt; .01). Upper limb patients survived significantly longer than all groups other than the skull, face, and mandible (p &lt; .05). The labeled primary site with the highest mean survival was the lower limb at 123.1 months and the lowest survival was the pelvis, sacrum, and coccyx, with a median survival of 54.6 months. Conclusions: This study found numerous survival differences between patients diagnosed with OSC of different primary sites. Labeled primary sites of the lower limb and upper limb were associated with best survival while the pelvis, sacrum, and coccyx were associated with worst survival. Future studies should be done to investigate variables that may impact the survival of different primary sites, including staging, treatments, time from diagnosis to treatment, socioeconomic factors, and insurance status.[Table: see text]

Unilateral Ossifying Fibroma Independent of Dental Area in Mandible A Case Report

Introduction: Fibrosis lesions include a group of diseases of different origin and etiology. In which bone is replaced by connective tissue. These lesions include fibrous dysplasia, fibroid ossification, cementoceus dysplasia, and cementoma. Fibroma ossification is a benign, painless, high-expansion neoplasm that originates in almost all cases of the periodontal ligament and can be radiolucent, radiopaque, or mixed depending on the degree of maturity. Treatment plan will vary from conservative to radical depending on the extent of the lesion.

MANAGEMENT OF ODONTOMA ASSOCIATED WITH UNERUPTED TOOTH: CASE REPORT

Introduction: Odontomas represent the most common type of odontogenic benign jaws tumors among patients younger than 20 years of age. There are two types of odontoma called compound odontoma and complex odontoma. There is no difference in treatment between compound and complex odontomas, however, it needs consideration in treatment so that trauma is minimized and does not cause effects. The aim of this case report is to describe a minimally invasive surgical procedure to remove a complex odontoma localized in the mandible area associated with an unerupted permanent third molar. Case Report: A case of a 16 years old female came with complained of pain and swelling in the impacted tooth area since 5 months ago with swelling in the unerupted tooth area. Radiographically, there was a lesion located over the impacted tooth a complex odontoma-associated of impacted mandible molar is presented. The patient was diagnosed with an odontoma complex Methods: The method used in this case is performed with minimally invasive surgical technique is adopted to remove the least amount of bone tissue as far as possible. The result of treatment in this case found a mass of 4 mm in size accompanied by 38 tooth. The prognosis in these patients is ad bonam Discussion: The purpose of this technique is to preserve as much as possible the surrounding bone tissue in order to promote healing and cause less discomfort to the patient during postoperative time. In this case, it was found that the lesion was located above the unerupted tooth, which is usually in the case of odontoma the lesion was under the unerupted tooth. This technique was chosen because the mass can be removed and the unerupted tooth is removed so that the source of the infection will heal completely without causing recurrence but in this case there is a risk of paresthesia because it is close to the inferior alveolar nerve. Conclusion: The treatment of choice for complex odontomas is surgical removal, followed by histopathological analysis to confirm the diagnosis. Complications such as fractures root, loose second molar, trauma to the temporo-mandibular joint, mandible fractures and paresthesia must be considered. Adequate knowledge of clinical characteristics is necessary to establish proper diagnosis and management of odontomas. Keywords: Odontoma, Complex Odontoma, Lesion, Odontogenic Tumor .

Dentinogenic Ghost Cell Tumor: A Rare Case Report in Maxillary Sinus

Ghost Cell Tumors (GCT) are a class of lesions that can exist in the form of a cyst or solid neoplastic tumor, and in terms of behavior, they can be benign, locally invasive, or metastatic. They are identified by the presence of ame-loblastic epithelium, ghost cell, and calcification. These lesions are mostly prevalent in the lower jaw, anterior mandible area. They are distributed equally between the male and female population in the second, sixth, and eighth decades of life. Since the recurrence rate is very low, it seems that a conservative approach is sufficient for most cases. Here, we present a rare case of dentinogenic ghost cell tumor in the left sinus of a 32-year-old male patient. It is temporarily diagnosed through clinical findings and .radiographic scan, and later on, confirmed via histology

Is the Mandibular Condyle Involved in Medication-Related Osteonecrosis of the Jaw? Audit of a Single Tertiary Referral Center and Literature Review

Background: Medication-related osteonecrosis of the jaw (MRONJ) may manifest as exposed mandible bone. Recent reviews of the incidence of MRONJ report primarily as exposed cortical bone of the mandibular body, ramus, and symphysis with no reports of condylar involvement. Objective: The aim of this study is to analyze the topographical incidence of MRONJ, comorbidities, demographics data, and clinical characteristics of patients diagnosed with MRONJ between 2014 and 2019 in the Maxillo-Facial Surgery Department University of Campania “Luigi Vanvitelli”, and compare these results with published reports. Methods: Data on 179 patients were collected for the study, including gender, age, underlying malignancy, medical history, and specific lesion location-identifying premaxilla and posterior sectors area involvement for the maxilla and symphysis, body, ramus, and condyle area for the mandible. A literature review was performed in order to compare our results with similar or higher sample sizes and find if any condylar involvement was ever reported. The research was carried out on PubMed database identifying articles from January 2003 to November 2020, where MRONJ site distribution was discussed, and data were examined to scan for condylar localization reports. Results: 30 patients had maxillary MRONJ, 136 patients had mandibular MRONJ, and 13 patients had lesions located in both maxilla and mandible. None of the patients reported condylar involvement, neither as a single site nor as an additional localization. Literature review results were coherent to our findings showing no mention of condylar MRONJ. Conclusion: Results do not show reports of condylar involvement in MRONJ. Although the pathophysiology of the disease has not been fully elucidated, two possible explanations were developed: the first one based on the condyle embryogenetic origin; the second one based on the bisphosphonate and anti-resorptive medications effects on the different vascular patterns of the mandible areas.

Determination of the Accuracy of Linear Height Bone for Implant Placement in Panoramic Radiography Relative to CBCT in the Posterior Areas of the Jaws

Purpose: In the levels of implant treatment in the posterior region, determining the height of the bone has particular importance. The aim of the study was to compare the accuracy of linear bone height measurement for implant placement on panoramic view compared to CBCT in posterior jaw area.&#x0D; Materials and Methods: The study was performed on 20 patients. In each of the posterior edentulous areas, a surgical guide for each patient was marked with gutta-percha (a total of 70 points). Panoramic radiographs and CBCTs were obtained from the patients and then the distance between the marked points in the maxilla to the maxillary sinus and in the mandible to the upper border of the alveolar canal was measured by Romaxis software and analyzed by Statistical software Stata 14. The obtained measurements of panoramic view were compared to CBCTs using t-test. P≤0.05 was considered significant.&#x0D; Results: The mean difference between the sizes obtained from panoramic radiography and CBCT radiography in the maxilla was 0.34 mm (P = 0.57) and the mean difference between the sizes obtained from panoramic radiography and CBCT radiography in the mandible was 0.86 mm (P = 0.004).&#x0D; Conclusion: According to the results of study, it is logical panoramic radiography just used to pre-assessment of implant procedures in posterior area of mandible were as it could be more reliable in maxilla.

Immediate rehabilitation of edentulous mandibles with implant-supported full-arch prostheses by intra-oral welding technique: a two-year follow-up

Objective: To evaluate the 2-year clinical outcome of immediate loading implant-supported fixed full-arch prostheses in mandibles using intra-oral welding technique and to discuss the characteristics of the technique. Methods: Totally 15 patients (4 males and 11 females) who treated with immediate rehabilitation of edentulous mandibles with implant-supported full-arch prostheses from July 2015 to February 2019 in Department of Implantology, Peking University School and Hospital of Stomatology were included in the present study. The patients' average age was 64.2±9.3 years. In each case, 4 implants were placed in the mandible area, a titanium bar was connected with each of the implants by using intra-oral welding technique as the Ti-metal framework of the prostheses. Pre-fabricated abutment-level fixed prostheses were delivered immediately after the surgery. A total of 60 implants, 15 mandibles were treated. Biological and mechanical complications, hygiene of the tissue-contacted surface of the restoration and patients' satisfactory grade were recorded. The radiological fitness of welded frameworks to abutments, survival rate of implants and marginal bone loss were calculated and analyzed. The observation period of the study was 24-55 months, with an average of 34.9 months. Results: All of the 15 cases of welded bar-abutment frameworks were fixed on implants with well passive fitness in clinical and radiological level. However, 2 of the 60 implants were failed by loss of osseointegration, and the result of implant survival rate of 96.7% in 2 years. The average marginal bone loss was (0.7±0.2) mm. The average bleeding index of the 58 implants remained was under 3 without clinical signs of gingival swelling, tenderness or fistula. No mechanical complications, such as break or distortion of the implants, occurred. Fracture of artificial teeth and complex resin area happened in 6 of the 15 prostheses. The average debris index was 3.4±0.4 and the hygiene of the tissue-contact areas was under satisfactory condition. Conclusions: Using the intra-oral welding technique to achieve a rigid splint of implants, the clinical outcome of the newly performed technique was predictable in early stage. The frame structure remained stable to avoiding the occurrence of mechanical complications. The provisional restoration could be expected to provide long functional period. Long term result of the treatment were needed for further observation.