Body Of Mandible Research Articles

Critical-sized marginal defects around implants in the rabbit mandible.

The mandible of the rabbit is considered a reliable model to be used to study bone regeneration in defects. The aim of the present study was to evaluate the formation of new bone around implants installed in defects of either 5 or 10mm in the mandible of rabbits. In 12 rabbits, 3mm deep circumferential defect, either 5 or 10mm in diameter, were prepared bilaterally and an implant was placed in the center. A collagen membrane was placed to close the entrance. After 10 weeks, biopsies were taken, histological slides were prepared, and different regions of the defects were analyzed. Similar amounts of new bone were found in both defects. However, most of the 5mm defects were filled with new bone. New bone was observed closing the entrance of the defect and laid onto the implant surface. Only in a few cases the healing was incomplete. Despite a similar percentage of new bone found within the 10mm defects, the healing was incomplete in most of the cases, presenting a low rate of bone formation onto the implant surface within the defect. Only one case presented the closure of the entrance. The dimensions of the defect strongly influenced the healing so that a circumferential marginal defect of 10mm around an implant in the mandible body should be considered a critical-sized defect. The presence of the implant and of residues of teeth might have strongly influenced the healing.

Primary Mandibular Tuberculous Osteomyelitis Mimicking Ameloblastoma: A Case Report and Literature Review of Mandibular Tuberculous Osteomyelitis.

Primary tuberculous osteomyelitis involving the mandible represents less than 2% of skeletal locations. In this paper, we report a case of mandibular tuberculosis (TB) detected after histopathological analysis of the surgically resected specimen during surgical management of a suspected case of ameloblastoma. A 14-year-old male patient presented to us with history of right-sided chin swelling. The clinical examination revealed a swelling, involving right body and parasymphysis of mandible, measuring approximately 6 cm in length and 2 cm in width, extending from right lateral incisor till the first molar. Radiological scans revealed a large multiloculated osteolytic expansive lesion measuring 52 × 20 × 18 mm. Excision of the lesion was performed and reconstruction was done with iliac bone grafting. The histopathological findings revealed a granulomatous lesion, suggestive of tuberculous osteomyelitis. The patient was successfully treated with standard multidrug therapy. One year after completion of therapy, there were no signs of recurrence. Primary mandibular TB is an extremely rare entity. Its clinical presentation is not specific. Radiologically, TB has no characteristic appearance. The positive diagnosis is based on histology. Primary mandibular TB is rare and should be kept among differential diagnoses in susceptible population and in endemic areas.

Exploring Socioeconomic Disparities in Mandibular Trauma: A Retrospective Cohort Analysis of Patient Profiles and Treatment Outcomes

Study Design Retrospective Chart Review. Objective Mandible fracture is a life-altering event, and its complications can have devastating consequences for patients. Patients are therefore well-served if providers can identify their risk factors and engage strategies to reduce complication risk. The present study examines mandible trauma in an urban tertiary hospital serving an economically disadvantaged population. Methods This review identified all patients undergoing operative repair of traumatic mandible fractures from January 2015 to December 2020. Patient risk factors, operative technique, and surgical complications (including infection, hardware failure, malunion, and mandible nonunion) were analyzed. Results Two hundred and seventy-two patients were identified with mandible fractures; 78.3% of these injuries were related to interpersonal violence; 83.4% of patients were male, and 55.5% were African American. Based on multivariable logistic regression models, increased rates of postoperative complications were observed in patients with increasing Area Deprivation Index (Odds Ratio 1.02), mandible body fracture (OR 3.11), tobacco use disorder (OR 3.75), history of hepatitis C infection (OR 7.35), and discharge to drug and alcohol rehabilitation (OR 23.42). Conclusions For providers treating patients with mandible fractures, the effects of comorbid substance use—including tobacco use—and inadequate discharge disposition (a reflection of financial means and insurance status) should be identified early, and steps to mitigate their consequences should be taken. Providers must recognize that patients with these comorbidities require more patience, support, and attention than patients without these risk factors. Increased engagement with multidisciplinary services such as psychiatry, addiction medicine, primary care, and social work may improve outcomes for these vulnerable patients.

Influence of exposure protocol, voxel size, and artifact removal algorithm on the trueness of segmentation utilizing an artificial-intelligence-based system.

To evaluate the effects of exposure protocol, voxel sizes, and artifact removal algorithms on the trueness of segmentation in various mandible regions using an artificial intelligence (AI)-based system. Eleven dry human mandibles were scanned using a cone beam computed tomography (CBCT) scanner under differing exposure protocols (standard and ultra-low), voxel sizes (0.15mm, 0.3mm, and 0.45mm), and with or without artifact removal algorithm. The resulting datasets were segmented using an AI-based system, exported as 3D models, and compared to reference files derived from a white-light laboratory scanner. Deviation measurement was performed using a computer-aided design (CAD) program and recorded as root mean square (RMS). The RMS values were used as a representation of the trueness of the AI-segmented 3D models. A 4-way ANOVA was used to assess the impact of voxel size, exposure protocol, artifact removal algorithm, and location on RMS values (α = 0.05). Significant effects were found with voxel size (p < 0.001) and location (p < 0.001), but not with exposure protocol (p = 0.259) or artifact removal algorithm (p = 0.752). Standard exposure groups had significantly lower RMS values than the ultra-low exposure groups in the mandible body with 0.3mm (p = 0.014) or 0.45mm (p < 0.001) voxel sizes, the symphysis with a 0.45mm voxel size (p = 0.011), and the whole mandible with a 0.45mm voxel size (p = 0.001). Exposure protocol did not affect RMS values at teeth and alveolar bone (p = 0.544), mandible angles (p = 0.380), condyles (p = 0.114), and coronoids (p = 0.806) locations. This study informs optimal exposure protocol and voxel size choices in CBCT imaging for true AI-based automatic segmentation with minimal radiation. The artifact removal algorithm did not influence the trueness of AI segmentation. When using an ultra-low exposure protocol to minimize patient radiation exposure in AI segmentations, a voxel size of 0.15mm is recommended, while a voxel size of 0.45mm should be avoided.

The role of implants and implant prostheses on the accuracy and artifacts of cone-beam computed tomography: an in-vitro study

To assess the accuracy of CBCT in implant-supported prostheses and to evaluate metal artifacts with and without implants or implant prostheses. Accuracy and artifacts were assessed in the dried mandible at three points on the buccal and lingual cortical plates on the mandible's body near the crest and the base. On the buccal cortical plate, these points were labelled as A, B and C near the crest and D, E and F near the base of the body of the mandible. Similarly, points a to f were marked on the lingual cortical plate corresponding to points A to F. The study had two control groups, C0 for physical linear measurement (PLM) and C1 for radiographic linear measurement (RLM) and artifact assessment. There were seven test groups, TG 1 to 7, progressing from a single implant to implant full-arch prosthesis. For accuracy assessment, PLM was compared to RLM. CBCT artifacts were investigated in images integrated at 0.25 mm, 10 mm, and 20 mm at regions of interest on concentric circles at different intersecting angles by comparing grayscale values at C1 and TG1 to 7. The data were collected and statistically analyzed. A significant difference was observed between C0 and C1, and RLM in test groups at the superior axial plane. Similarly, PLM and test RLM in the sagittal plane at A-B, B-C, and D-E were statistically significant. A significant difference between PLM and RLM was also observed in the vertical plane at A-D, B-E, and C-F. Quantification of CBCT artifacts in the presence of implants or prostheses revealed that full-arch prostheses had the highest mean grayscale value, whereas single implants with a prosthesis had the lowest. The mean grayscale change was greatest around the implant and implant prosthesis. The mean grayscale value was maximum at 20 mm voxel integration scales (VIS) and lowest at 0.25 mm. CBCT is a clinically reliable device. Metal in implants or implant-supported prostheses prevents true assessment of the peri-implant area; therefore, lower VIS is suggested in the presence of implants or implant prostheses.

Photoelastic Stress Induced by Maxillary Denture on the Mandibular Denture and Overdentures Lined with Silicone-based Material

Objectives: This study evaluated the stress induced by maxillary denture over mandibular denture and overdentures lined with silicone-based material. Materials and Methods: Three maxillary dentures, a mandibular denture, an overdenture supported by a single implant, and other supported by two implants were made for the following groups: MCD—Mandibular complete denture lined with silicone-based material, OSI—Overdenture lined with silicone-based material supported by single implant, and OTI— Overdenture lined with silicone-based material supported by two implants. The mandibular photoelastic model was axially loaded by the maxillary denture with intensities of 10, 20, or 30 kgf. Photoelastic analysis took place with the maxillary denture in maximum intercuspation with the mandibular prostheses. Results: Photoelastic analysis showed that the 10 kgf load promoted in the mandibular denture greater stress along the photoelastic model mainly in the anterior region. Stress occurred around the single implant with higher intensity at the apex. Stress occurred between the two implants and no stress was shown along the implants and apices. For 20 kgf, stress occurred in the anterior region of the mandible denture; Higher stress is shown around the single implant and apex and smaller at the mandible left side. Stress occurred between the two implants, and few stress at the apex of the left implant. For 30 kgf, stress occurred in the anterior region of the mandible with more intensity on the left side. Stress is shown around and at the implant apex and both mandible frontal sides. Stress is shown between the two implants and little stress at the apex of the left implant. Conclusions: The lined overdentures supported by single or two implants exhibited stress concentration in the implant region compared to lined mandibular denture showing stress along the mandible body. The stress in the overdentures occurred mainly around the single implant or between the two implants. The increase in load intensity had little influence on the increase in stress for the prostheses with lined bases. Clinical Relevance: Intercuspation in the overdenture must have the same importance given to the vertical relationship to relieve the chewing effort in overdenture lined with silicone-based material.

SAT554 Follicular Variant of PTCA Initially Presenting with Widespread Metastases

Abstract Disclosure: N.N. Bisquera: None. R.C. Mirasol: None. Background: Papillary thyroid carcinoma accounts for most cases of thyroid cancer. Most cases of PTC have a good prognosis and low incidence of metastases. The follicular variant is the most common variant. First described in the 1960’s, the understanding of FV-PTC began to evolve with molecular profiling demonstrating a similarity with FTC, and clinical behavior profiling showing that a subtype may behave like PTC with a propensity for lymph node metastases. We are presented with an unusual case of an infiltrative FV-PTC presenting with widespread multiple metastases on diagnosis. Clinical Case: A 64-year-old female, presented with 1-year history of a slowly enlarging mass on the left mandible, which was also associated with an enlarging anterior neck mass. She had no constitutional symptoms and had previously been in good health. On examination, there was a 7x8x3 cm hard, fixed left mandibular mass. There was also a palpable right thyroid nodule measuring 2.5x2 cm. There was no difficulty in swallowing or breathing, but she had some difficulty in eating due to trismus. There were no associated symptoms of hypo/hyperthyroidism. Investigations revealed a euthyroid status. CT scan showed a solid lobulated heterogeneously enhancing mass measuring 4.2x5.1x5.2cm on the body and angle of the left mandible. Ultrasound showed multiple thyroid nodules, the largest - a mixed cystic and solid mass measuring 2.9 x 2.7 x 2.17 cm on the right thyroid lobe, for which FNA was performed. Histopathology showed benign follicular nodules. Incision biopsy of the mandibular mass showed presence of thyroid tissue. Further imaging showed metastases to the left frontal, parietal bone, T7 vertebra, and bilateral lungs. The case was discussed in a multi-disciplinary tumor board meeting. With a pre-operative diagnosis of a primary thyroid malignancy, the patient then underwent a total thyroidectomy with segmental mandibulectomy. Post-operative histopathology showed a metastatic multifocal infiltrative follicular variant of PTC. RAI was administered post-surgery, and she was started on suppressive thyroxine therapy. Steroids were given during RAI, with no untoward events post treatment. Post-ablative whole body scanning revealed increased tracer uptake in multiple areas: left frontal and parietal bone, bilateral thyroidal beds, left supraclavicular lymph node, the sternomanubrial junction, bilateral lung lobes, right humeral head and T7 vertebra. Further doses of RAI was planned and she is currently maintained on suppressive thyroxine therapy. Conclusion: Diagnosis of FV-PTC may be a greater challenge than conventional forms because of possible false-negative results on cytology. The infiltrative subtype has greater metastatic potential and higher recurrence rates. Multidisciplinary team management and careful preparation prior to treatment with RAI is indicated in these cases. Presentation Date: Saturday, June 17, 2023

Mutiple Hybrid Odontomas Involving All Four Quadrants of Jaws: A Rare Case Report

Odontomas are odontogenic tumors in which complete functional discrepancy of ameloblasts or odontoblasts occur with the development of enamel and dentine in an irregular arrangement due to lack of association of these cells to reach usual state of morphodifferentiation. Multiple hybrid odontomas present as many complex or compound odontomas involving one to all four quadrants of jaws. this present case is of a female aged 12 years who presented with mild pain and swelling in the right body of mandible for 1 year. After initial clinical and radiographic assessment, a tentative diagnosis of multiple hybrid odontomas involving all four quadrants of jaws was made. Surgical excision of the lesion which was causing facial deformity was performed. Excisional&#x0D; biopsy report verified the clinical diagnosis. This case report describes the first unique case of multiple hybrid odontomas involving all four quadrants of jaws presented in last five years' literature.

855 Mirror-Image Large Complex Odontomes

Abstract Background This report outlines a nine-year follow-up of two 10-year-old patients who attended the paediatric dental department reporting an absent mandibular first permanent molar (FPM). Both reported no pain, no familial history of hypodontia and no altered sensation in the inferior dental (ID) nerve distribution. Clinical examination revealed mandibular expansion in the unerupted tooth area. Special Investigations Panoramic jaw radiographs revealed extensive radio-opaque masses in the mandibular FPM area in both children, in mirror-image sites. Subsequent cone beam CT identified extensive displacement of the FPM with an associated large mixed radiopaque/radiolucent lesion in the body of mandible. Interestingly, the mandibular second permanent molar (SPM) was present in one case and absent in the other. Diagnosis/Management The provisional diagnosis for both cases was a complex odontome however, heavily calcified ameloblastic fibro-odontoma could not be excluded. Management involved surgical removal of the odontogenic tumour with FPM maintenance. Histopathology confirmed the diagnosis of a complex odontoma in both cases. On long-term review in both cases the FPM failed to erupt. Cystic follicular enlargement of the FPM in one case prevented eruption, and a coronectomy was performed in the other on the FPM apices were too close to the ID nerve to be extracted. Discussion These cases highlight the importance of monitoring dental eruption patterns in childhood. Despite the mirror image diagnosis, multiple factors were considered when identifying treatment options for each individual patient. Aetiological questions regarding this particular odontogenic tumour type are raised by the presence or absence of the SPM.

Relationship between bruxism and mandibular bone modifications based on medical imaging: a scoping review

ObjectivesThis scoping review aimed to assess the current state of knowledge regarding the relationship between bruxism and changes in density or volume of mandibular bone, based on medical imaging.MethodsLiterature review was conducted following the PRISMA-ScR protocol. PubMed, Web of Science and Cochrane library databases were searched for peer-reviewed articles by two blinded reviewers. Studies based on the evaluation of mandibular bone density and/or bone volume with imaging examination in adult patients were examined. The selected articles were summarized in PICOS tables and assessed for methodological quality.ResultsNine articles were included, according to the inclusion criteria. They showed that bruxer patients had more bony exostoses of the mandibular angle, smaller condyles, and morphological changes for cancellous and cortical mandibular bone compared to non-bruxer patients.ConclusionBruxism seems to induce morphological and anatomical changes in the different regions of the mandibular bone (condyles, mandibular angle, mandible body). Given the heterogeneity of the included studies, these results should be interpreted with caution. Further studies are needed to support these results, in particular via the analysis of three-dimensional imaging to overcome the limitations of panoramic radiograph.

An Insight Into the Effect of Odontogenic Keratocysts on Surrounding Structures: Cone-Beam Computed Tomography-Based Analysis of Cases.

Introduction An odontogenic keratocyst (OKC) is a benign intraosseous lesion with potential to demonstrate aggressive and invasive behavior. The aim of this retrospective study was to analyze the imaging features of the OKCusing cone-beam computed tomography (CBCT) and to evaluate the association between the internal structure of the lesion and the effect of the lesion on surrounding structures. Methods Overall, 32 CBCT scans of histopathologically diagnosed cases of OKC were analyzed retrospectively. The following variables were analyzed: anatomic location of the lesions (mandible body (right/left), ramus (right/left), mandible body+ramus (right/left), maxilla (right/left), and both jaws), the internal structure of the lesion (unilocular/multilocular), and the effect ofthe lesion on the surrounding anatomical structures (involvement of the inferior alveolar nerve canal (IANC), displacement of the IANC, cortical expansion, displacement of the tooth, resorption of the root, associated impacted tooth, associated missing tooth). We also looked for the association between the internal structure and the effect of the lesion on anatomic structures. Results Out of 32 cases, 29 (90.6%) cases involved the mandible alone. Statistically significant association (p-value 0.005) was present between the internal structure and mean age of presentation as well as between the internal structure and impacted tooth (p-value 0.027). The association between the internal structure and other variables was statistically not significant. Conclusions The radiographic features of OKCs can be variable, and these lesions have a considerable effect on the tooth, IANC, and cortical bone. Significant association was found between the internal structure, age, and impacted tooth. Since OKCs have a high recurrence rate, CBCT is advised for evaluating the extent and location of any cortical perforations.

The "sand watch" mandible.

The lingual surface of the mandible's body is commonly indicated as presenting the submandibular and sublingual fossae, which are separated by the mylohyoid line. The mylohyoid line attaches to the mylohyoid muscle (MM). Less attention has been paid to the 'mylohyoid boutonnières', which allow the 'sublingual buttons' to pass through the mylohyoid muscle in the submandibular space. The cone-beam computed tomography files of patients were routinely examined for anatomical studies. Two cases were found with unexpected morphologies of the mandible's body - the mylohyoid lines were incomplete anteriorly, and herniated sublingual tissue determined an additional fossa inferior to that line in the premolar region. That fossa was termed the 'accessory submandibular fossa'. It determined on coronal slices a 'sand watch' contour of the mandible's body. With such a peculiar morphology, the mandible is more prone to fracture. Moreover, when inserting endosseous implants, the procedure should be carefully personalised in such rare cases.

Mandibular fractures at a tertiary health care facility: a pilot study

Background: Facial trauma patients were analyzed to determine the incidence, type, presentation, management, and outcome of fractures of the mandible. Methods: The 61 patients admitted in the trauma units of Dayanand medical college Ludhiana were analyzed prospectively during a period of two years (January 2010-December 2012). Results: In patients with multiple fractures, the common combination included zygoma and mandible (35.2%) and Le Fort II, mandible and nasoethmoid (41.2%). Out of 35 patients with mandible fractures, 8 had bilateral and 27 had single fractures making a total of 43 fractures. The body of mandible. 46.5% followed by the angle 34.8%, symphysis 9.3%, and parasymphysis 4.6% ramus and condoyle in 2.3% each were seen. Of the single mandibular fractures, the body and angle were almost equally affected in 48% and 44% cases, respectively. Isolated fracture of symphysis and parasymphysis was seen in 3.7% cases each. Isolated fracture of the ramus or condyle was not seen in any case. Half of the angle fractures were treated by wiring while shown in 1/4th each, plating and external fixation was used for treatment. Almost half (6/13) of fractures of the body were treated with external fixation. All bilateral fractures were treated with bone plating. Conclusions: Road traffic accidents are the major cause of these fractures. Mandibular fractures are commonly associated with fractures of other facial bones. The fracture line commonly seen is in the body of mandible, followed by the angle.

Renal osteodystrophy and brown tumours of the jaw associated with tertiary hyperparathyroidism in the context of cystinosis: a case report

Chronic kidney disease is one of the main manifestations of cystinosis that may lead to hyperparathyroidism. Although head and neck involvement in hyperparathyroidism is rare, lesions can occur in the jaws and cause serious functional handicap. We presented the case of a 24-year-old woman with congenital cystinosis and chronic renal failure complaining from symptomatic expansion of the jawbones. Medical imaging showed radiolucent lesions particularly in anterior hard palate and body of mandible. A diagnosis of renal osteodystrophy and brown tumours related to tertiary hyperparathyroidism was established. Following a subtotal parathyroidectomy and stabilization of parathyroid hormone levels, a conservative mandibular osteoplasty was undertaken to increase the available space for tongue movements. Although non-surgical management remains the primary modality for the treatment of brown tumours, adjunctive surgical approach may be considered in cases of severe functional impairment. It is imperative that underlying systemic imbalances be addressed prior to any maxillofacial intervention to prevent relapse.

Do Racial and Ethnic Disparities Exist in Management of Pediatric Mandible Fractures? A 30-Year Outcome Analysis.

Mandibular fractures are the most common of pediatric facial fractures. The effect of race on management/outcomes in these injuries has not been previously studied. Given the significant association between race and healthcare outcomes in many other pediatric conditions, an in-depth study of race as related to mandibular fractures in the pediatric patient population is warranted. This was a 30-year retrospective, longitudinal study of pediatric patients who presented to a single institution with mandibular fractures. Patient data were compared between patients of different races and ethnicities. Demographic variables, injury characteristics, and treatment variables were analyzed to find predictors of surgical treatment and posttreatment complications. One hundred ninety-six patients met inclusion criteria, of whom 49.5% were White, 43.9% were Black, 0.0% were Asian, and 6.6% were classified as "other." Black and "other" patients were more likely than their White counterparts to be injured as pedestrians (P = 0.0005). Black patients were also more likely than White patients or "other" patients to be injured by assault than by sports-related injuries or animal-related accidents (P = 0.0004 and P = 0.0018, respectively). Race or ethnicity were not found to be a predictor of receiving surgical treatment (ORIF) or of posttreatment complications. The posttreatment rates for all the complications observed were comparable among all race and ethnic groups. Higher mandible injury severity score (odds ratio [OR], 1.25), condyle fracture (OR, 2.58), and symphysis fracture (OR, 3.20) were positively correlated with receiving ORIF as treatment. Mandible body fracture (OR, 0.36), parasymphyseal fracture (OR, 0.34), bilateral mandible fracture (OR, 0.48), and multiple mandibular fractures (OR, 0.34) were negatively correlated with receiving ORIF as treatment. Only high mandible injury severity score (OR, 1.10) was identified as an independent predictor of posttreatment complications. Lastly, Maryland's transition to an all-payer model in 2014 also had no impact on treatment modality; treatment of fractures among race and ethnicity were not significantly different pre- and post-2014. There is no difference in how patients are treated (surgically vs nonsurgically) and no difference in outcomes for patients based on race at our institution. This could be due to institutional ideology, services provided by a tertiary care center, or simply the more diverse patient population at baseline.

Contribution of masticatory muscle pattern to craniofacial morphology in normal adults: A cross-sectional MRI study.

The study aimed to determine the muscle pattern of medial pterygoid, lateral pterygoid, and masseter (length, cross-section, and angulation) in adult non-orthodontic patients and its effect on craniofacial structures. The study was conducted from January 14, 2019 to January 14, 2020. Ethical clearance of this study was obtained from the ethical committee Ethical Clearance was obtained from Faculty of Dental Sciences, IMS, BHU, Institutional Ethical Committee with Ref no. Dean/2019/EC/1824 dated 23.04.2019 of the university. The sample size was estimated using the G-power statistical program. Power analysis indicated a minimum sample size of 27. Inclusion and exclusion criteria were set. Consent was taken from participants. Seventy-seven subjects who were willing to participate and have given written consent were enrolled for the study. Participants were sent for lateral cephalometry (Dolphin Cephalometric software) Dolphin Imaging and management solution, for 6 angular and 11 linear measurements. Nineteen subjects did not turn up for the scan. Twenty-eight participants underwent MRI (magnetic resonance imaging) to evaluate muscle patterns (masseter, medial, and lateral pterygoid). The intra-class correlation coefficient (ICC), Kolmogorov-Smirnov (KS) test, descriptive statistics, and multiple regression analysis were computed. The P value was set as ≤0.001(highly statistically significant) and ≤0.05 (significant relation). There was a highly statistically significant (p ≤ 0.001) association between masseter length to upper facial height (N-Ans) and ramal length (Cd-Go). Length of medial pterygoid was significantly related (p ≤ 0.05) with SNB and length of body of mandible (Pog-Go). The cross-section of this muscle showed significant relation with upper facial height (N-Ans) and ramal length (Cd-Go). The correlation of the length of lateral pterygoid with upper facial height (N-Ans) and maxillary length (A-Ptm) was highly significant. The muscle pattern has a significant correlation with maxillofacial morphology. The masseter muscle is the longest and thickest (cross-section) and is angulated vertically than the other two muscles (medial pterygoid and lateral pterygoid). Of the three muscles, the medial pterygoid influences more common craniofacial parameters suggestive of its symbiotic activity. Lateral pterygoid affects the maxillary length and facial height.

Results of surgical treatment of the mandible body fractures with own designedexternal fixator in two horses

Mandibular fractures are the most common among all skull fractures. Most of them are the result of blunt trauma resulting from hitting an obstacle, kicking by another horse, or falling after a jump. The majority of fractures are open and infected. Some of them are complicated, involving the molar or premolar teeth. Treatment of such fractures is challenging because results depend on stable bony union and functional integrity of the occlusal surface. Osteosyntheses were performed under general anesthesia. Complications included infection around one implant close to the fracture line and fistulation in case 2 created by a fractured tooth which had to be extracted. In spite of the mentioned problems, good results were achieved in both cases. Stabilization of unilateral mandibular fractures with our own design fixator which is minimally invasive and provides sufficient fixation to obtain good results. The use of the fixator has proved to be beneficial and has a number of advantages in the treatment of this kind of fracture.

The Versatility of Extraoral Vertical Ramus Osteotomy for Mandibular Prognathism: A Prospective Study.

Orthognathicsurgery simply means alignment of thejaws.The aim of orthognathic surgery is to normalize the relationship of thejawsbetweenthemselves andtherestof thecraniofacialcomplex. Mandibularprognathism is a common clinical problem all over the world. Currently, sagittal ramus osteotomy is the primary choice for correcting most cases of mandibular retrognathism and prognathism. The surgical option for extreme cases ofmandibular prognathism is extraoral vertical ramus osteotomy (EVRO) or intraoral vertical ramus osteotomy (IVRO) or inverted L osteotomy. The aim of this study was to evaluate the versatility of EVRO for mandibular prognathism. Ten patients with the chief complaint of mandibular prognathism with no history of keloid tendency were included in the study. EVRO was done for all patients. The parameters based on which the outcome of the surgical procedure was assessed weretime taken for the surgical procedure, facial harmony both in frontal and profile views postoperatively, and intraoperativeand postoperative complications, and assessment of the postoperative results was done through orthopantomogram (OPG) and 3D CT scan. Thetime takenfortheentiresurgicalprocedure, startingfrom incisiontoclosure, variedbetween80 and 94 minutes with the average time taken for the surgery being 90 ± 8.80 minutes. It was found that there was a statistically significant difference between preoperative (M = 53.4, SD = 5.854) and postoperative evaluation (M = 47.5, SD = 5.039) of the posterior nasal spine to nasion 1 (PNS-N 1) horizontal plane (HP)(mm) withp < 0.001. Similarly, there was a statistically significant difference between preoperative (M = 81.4, SD = 2.716) and postoperative evaluation (M = 74.4, SD = 3.627) of mandible body length (mm) withp < 0.001. However, no statistically significant difference exists between the preoperative and postoperative evaluation of anterior nasal spine (ANS) to PNS (mm) and ramus height Ar-Go (mm). EVRO is an acceptable surgical procedure owing to the fact that it is relatively simple to carry out, its lack of complications, and its good results.

Comparing the effect of demineralized versus hybrid dentin matrices on inducing bone regeneration in New Zealand white rabbits' Mandibular defect

ObjectivesThe aim of this study was to compare the effect of using demineralized dentin matrix (DDM) versus hybrid dentin matrices; Demineralized and undemineralized dentin particles (DDM +UDDM) on inducing bone regeneration in mandibular defects. DesignThe study was conducted on fifty adult New Zealand rabbits, twenty for preparation of experimental materials and thirty for surgical procedures. They were randomly assigned into 3 equal groups as follow one control group: no treatment and two experimental groups including demineralized group: treated with DDM only; and hybrid group: treated with a hybrid of (50% DDM+50% UDD). A rounded critical size defect (10 mm in diameter- 5 mm in depth) was created in the body of mandible. After 3- and 6-weeks post-surgery, the bone regeneration was evaluated by light microscope, scanning electron microscope and histomorphometry. ResultsHistological, histomorphometrical observation and SEM revealed that both dentin matrices had largely resorbed and induced new bone formation at both experimental groups compared to the control group, with statistically higher percentage of new bone formation in the hybrid group. ConclusionWe concluded that although both dentin matrices induced new bone formation; however, hybrid dentin matrix yielded better results compared to DDM group.

Treatment of a Mandibular Diastemal Fracture Using Locking Compression Plate and Cerclage Wire in a Mare.

This report describes the combination of two surgical fracture repair techniques and the postoperative management of a mandibular diastemal fracture in a two-year-old mare. The mare was referred to a veterinary hospital with a laceration over the body of the right mandible. Radiographic assessment revealed two mesial fracture lines involving the second premolar tooth and a ventrally displaced bone fragment. The mare was treated under general anesthesia and the fracture was corrected using open reduction and plate fixation. A 3.5 mm narrow 15-hole locking compression plate with seven locking screws were used in a bridge form. Cerclage wire was also used to anchor the incisor teeth to the second and third premolar teeth. The cerclage wire and incisor teeth were covered with polymethylmethacrylate to prevent implant failure and avoid injury to the oral mucosa. Implants were removed 55 days after surgery and the mare was discharged from hospital five days later. The mare returned for cerclage wire removal after 90 days and was allowed to resume exercise thereafter. The combination of two surgical techniques, proper implant choice and appropriate postoperative management, including use of pelleted feed, contributed to successful bone healing and return to function.