Is mandible derived mesenchymal stromal cells superior in proliferation and regeneration to long bone-derived mesenchymal stromal cells?

Mesenchymal stromal cells(MSCs)are cells with the characteristic ability of self-renewal along with the ability to exhibit multilineage differentiation.Bone marrow(BM)is the first tissue in which MSCs were identified and BM-MSCs are most commonly used among various MSCs in clinical settings.MSCs can stimulate and promote osseous regeneration.Due to the difference in the development of long bones and craniofacial bones,the mandibular-derived MSCs(M-MSCs)have distinct differentiation characteristics as compared to that of long bones.Both mandibular and long bone-derived MSCs are positive for MSC-associated markers such as CD-73,-105,and-106,stage-specific embryonic antigen 4 and Octamer-4,and negative for hematopoietic markers such as CD-14.

Solitary intraosseous neurofibroma in the mandible mimicking a cystic lesion:A case report and review of literature

BACKGROUND Neurofibromas are benign tumors of a neurogenic origin.If these tumors occur without any other signs of neurofibromatosis,they are classified as isolated neurofibromas.Neurofibromas in the oral cavity mostly occur within soft tissues,indicating that solitary intraosseous neurofibromas in the mandible are rare.Due to the absence of specific clinical manifestations,early diagnosis and treatment of these tumors are difficult to achieve.CASE SUMMARY A 37-year-old female patient visited our hospital due to numbness and swelling of the gums in the right lower molar area that had persisted for half a month.The patient’s overall condition and intraoral examination revealed no significant abnormalities.She was initially diagnosed with a cystic lesion in the right mandible.However,after a more thorough examination,the final pathological diagnosis was confirmed to be neurofibroma.Complete tumor resection and partial removal of the right inferior alveolar nerve were performed.As of writing this report,there have been no signs of tumor recurrence for nine months following the surgery.CONCLUSION This case report discusses the key features that are useful for differentiating solitary intraosseous neurofibromas from other cystic lesions.

Clinical and Paraclinical Epidemiological Aspects of Multifocal Fractures of the Mandible in Chuo

Introduction: Multifocal fractures of the mandible are responsible for the modification of anatomy with functional and aesthetic repercussions. The aim of our work is to determine the clinical and paraclinical epidemiological aspects of multifocal mandible fractures. Materials and Methods: Retrospective, descriptive study conducted at the Department of Stomatology and Maxillofacial Surgery of the University Hospital of Owendo, from January 2018 to January 2021. All mandibular multifocal fractures with radiological images were included, while all incomplete records and monofocal fractures were not included. Data collection was done on a form from patient records. Age, sex, mode of transport, periodicity, mechanisms, etiologies, soft tissue lesions, dental joint disorder, sensitivity disorder, dental damage, radiological examination, the number and location of fracture features, and associated lesions were the variables studied. Results: 49 files collected;the average age of 28 ± 8.4 years;male predominance at 75.5%. Personal transport was used at 53%, November was the most accident-prone month, road accident was the dominant etiology at 59%, and direct mechanism at 88%. Stomatoragia predominated at 98%, and hypoaesthesia predominated at 30%. The lesional association with the facial massif was 20%. The CT scan was performed at 61%. The bifocal fracture was the most common at 84%. Discussion: According to Alexander violent assaults are the main cause but for Mala it is MVA. The dental panoramic is the basic examination. For Rocton and Mala, the bifocal fracture is the most frequent of the multifocal fractures. Conclusion: Multifocal fractures are the prerogative of the young subject and road accident is the dominant etiology.

Cemento-ossifying fibroma of the left mandible:A case report

BACKGROUND Ossifying fibroma is a type of benign fibro-osseous lesion.Most lesions affect the mandible region,particularly the molar and pre-molar areas.It predominantly affects females between the second to fourth decades of life.Larger ossifying fibroma tumors require more extensive resection.CASE SUMMARY A 39-year-old female complained of occasional pain and tumor enlargement on her left jaw for the 3 years prior to presentation.Intraoral examination revealed a firm swelling on her left lower gum.Extraoral examination revealed swelling on the left mandible body with no erythema and superficial ulcer.Computed tomography scan revealed a circular-shaped lesion on the patient’s left mandible body with a well-defined radiolucent border,sized 3.2 cm×2.8 cm×0.9 cm.The tumor was removed by marginal mandibulectomy.Biopsy from the resected tumor suggested cemento-ossifying fibroma(COF).CONCLUSION COF is often unnoticed,but this slow-growing tumor can cause significant symptoms regarding its distortion into adjacent structures.

Radiation-induced osteosarcoma of the maxilla and mandible after radiotherapy for nasopharyngeal carcinoma

Background:The increasing incidence of radiation-induced osteosarcoma of the maxilla and mandible(RIOSM) has become a significant problem that can limit long-term survival.The purpose of this study was to analyze the association of clinicopathologic characteristics with treatment outcomes and prognostic factors of patients who developed RIOSM after undergoing radiotherapy for nasopharyngeal carcinoma(NPC).Methods:We reviewed the medical records of 53,760 NPC patients admitted to Sun Yat-sen University Cancer Center during the period August 1964 to August 2012.Of these patients,47 who developed RISOM and met inclusion criteria were included in this study.Two of these 47 patients refused treatment and were then excluded.Results:For all patients treated for NPC at Sun Yat-sen University Cancer Center during the study period,the total incidence of RIOSM after radiotherapy was 0.084%(47/53,760).Two patients(4.4%) had metastases at the diagnosis of RIOSM.Thirty-nine of the 45(86.7%) patients underwent surgery for RIOSM;most patients(24/39;61.5%) who underwent resection had gross clear margins,with 15 patients(38.5%) having either a gross or microscopic positive margin.All patients died.The 1-,2-,and 3-year overall survival(OS) rates for the entire cohort of 45 patients were 53.3%,35.6%and 13.5%,respectively.The independent prognostic factors associated with high OS rate were tumor size and treatment type.Conclusions:RISOM after radiotherapy for NPC is aggressive and often eludes early detection and timely intervention.Surgery combined with postoperative chemotherapy might be an effective treatment to improve patient survival.

Establishment of a three-dimensional finite element model for gunshot wounds to the human mandible

Objective:To investigate the feasibility of a finite element model as an ideal research tool for human maxillofacial gunshot wounds.Methods:Mandible CT scan data on the Chinese Visible Human were imported into MIMICS software to obtain the surface mesh of the mandible.Then,these surface-meshed models were imported into ANSA software for automatic net generation.Elements and nodes were partitioned on the basis of the mesh to obtain a three-dimensional finite element model for the mandible with every internal parameter consistent with those of our previously developed model in the pig mandible.The finite element model was imported into LS-DYNA for computation.Finally,the LS-POST was used to complete the simulation and the measurements.Results:A three-dimensional finite element model was successfully established for gunshot wounds in the human mandible.The stress distribution and the degree of injury were simulated dynamically for shots from two types of projectiles in the mandible at one entry angle and at three impact velocities.Conclusion:Three-dimensional finite element models will become ideal research tools for treatment of ballistic wounds of the human maxillofacial region.Using this human mandibular model as a foundation,we will be able to successfully develop three-dimensional finite element models for human maxillofacial gunshot wounds.

Dynamic navigation system-guided trans-inferior alveolar nerve implant placement in the atrophic posterior mandible: A case report

BACKGROUND In atrophic posterior mandibular areas,where the bone height superior to the inferior alveolar nerve(IAN)is less than 6 mm,short implants are not applicable.Conventional alternatives such as IAN transposition and various alveolar bone augmentation approaches are technically demanding and prone to complications.CASE SUMMARY Computer-guided dynamic navigation implantation improves the accuracy,predictability,and safety of implant placement.This case report presents a dynamic navigation system-guided trans-IAN implant placement technique,which can successfully treat a posterior mandibular dentition defect when the bone height is only 4.5 mm.The implant was inserted into the buccal side of the IAN and was 1.7 mm away from the IAN.The implantation deviations were controlled within a satisfying range,and the long-term restoration outcome was stable.CONCLUSION Dynamic navigation system-guided trans-IAN implant placement might be a recommended technique for patients with extremely insufficient residual bone height and sufficient bone width in the posterior mandibular area.

Fixed Bicortical Screw and Blade Implants as a Non-Standard Solution to an Edentulous (Toothless) Mandible

Aim This paper deals with the treatment of an atrophied toothless mandible with a fixing bridge carried by two nonstandard implant systems. Methodology Four bicortical screws were implanted into the frontal part of the mandible and one implant on each side was placed into the distal area of the mandible as a support for a fixing bridge. Results During the years 2002–2007 the authors placed a total of 256 bicortical screw and 84 blade implants. During this period only four bicortical screws and one blade implant failed. The primary and secondary surgical success rate was therefore above 98%, while the prosthetic success rate was 100%. （Bridges which had to be re-fabricated due to implant failure were not taken into account.） Conclusion This approach is recommended as a highly successful and affordable option for a wide range of patients.

3D kinematicmandiblemodel to designmandibular advancement devices for the treatment of obstructive sleep apnea

Mandibular advancement devices(MADs)are one of the treatments used for Obstructive sleep apnea(OSA).MADs try to maintain the mandible in an advanced position to keep the upper airways open when sleeping.To achieve this goal,most current MADs limit the mouth opening to a few millimetres.The study of the kinematic behaviour of the patient’s jaw is essential in order to design devices that allow greater aperture ranges.For this purpose,a 3D multibody model that reproduces jaw movement has been developed in this work.To this end,the movement of the lower incisor has been determined by means of a vision system and reflective markers.In addition,the kinematics of the temporomandibular joint has been modelled.Next,the device is designed and printed using a cam-follower mechanism.This way,the cam profiles and the followers are optimally designed and positioned for each patient depending on the physiognomy of the jaw and the opening and advancing movement prescribed by the specialist.

BRAF inhibitor:a novel therapy for ameloblastoma in mandible

Ameloblastoma is a benign but locally aggressive odontogenic neoplasm that accounts for 10% of all tumors arising in the mandible and maxilla (1). Eighty percent of ameloblastomas arise in the mandible, and they are usually found in young adults. It frequently recurs if not adequately

Stafne’s Bone Defect in Atypical Location: Between the Subcondylar Region and Neck of the Mandible Ramus

CONTEXT: Stafne’s bone defect is a benign lesion appearing on the image as a round radiolucent lesion within a cortical defect on the mandible. CASE REPORT: We attend one 46-year-old male patient came for diagnostic evaluation of a rounded and radiolucent lesion in the transition of the subcondylar region and neck of the left mandible ramus incidentally found by a dentist. Computed tomography and magnetic resonance imaging were performed in medical radiology and a Stafne’s cyst was diagnosed in an atypical location. CONCLUSION: We emphasize that Stafne’s bone defect is a benign lesion, whose imaging diagnosis can be conclusive, avoiding unnecessary surgical procedures.

A New Method for 3D Finite Element Modeling of Human Mandible Based on CT Data

This study presents a reliable method for the semi-automatic generation of an FE model, which determines both geometrical data and bone properties from patient CT scans.3D FE analysis is one of the best approaches to predict the stress and strain distribution in complex bone structures, but its accuracy strongly depends on the precision of input information. In geometric reconstruction, various methods of image processing, geometric modeling and finite element analysis are combined and extended. Emphasis is given to the assignment of the material properties based on the density values computed from CT data. Through this technique, the model with high geometric and material similarities were generated in an easy way. Consequently, the patient-specific FE model from mandible CT data is realized also.

Commentary on “Mandible exosomal ssc-mir-133b regulates tooth development in miniature swine via endogenous apoptosis”

This report,"Mandible exosomal ssc-mir-133b regulates tooth development in miniature swine via endogenous apoptosis" by Li et al. is an important step forward in describing the factors that control tooth development in a large animal model. That many of the regulatory miRNA pathways have been elucidated in murine species have always begged the question as to how relevant they

Spindle cell carcinoma of the mandible:a case report

Spindle cell carcinoma is a rare highly malignant squamous cell carcinoma.Here,we describe a case of a 74-yearold Chinese female who presented with a 2-week history of pain and swelling in the left retromolar region.Surgical resection and titanium plate prosthesis were performed and histological analysis revealed spindle squamous cell carcinoma.

Longgupo Hominoid Mandible Belongs to Ape

The present author made comparisons between the mandibular fragment and teeth attached on it from longgupo,Wushan on one side,and the corresponding specimens of early \%Homo\% of East Africa,\%Homo erectus\% from Dmanisi and \%Lufengpithecus \% from Yuanmou on other side.The results showed that the size of Wushan specimens are much smaller than those of early \%Homo\% of East Africa and Dmanisi mandible,and are concordant with that of \%Lufengpithecus \%from Yuanmou.Most of the characters which have been used to attribute Wushan mandible to \%Homo \%by some scholars,are shared by both hominid and ape. Among these characters,bifurcation of the root of the premolar is one of the characters of \%Lufengpithecus\% and seldom seen in hominid.The position of the anterior contact facet and the ratio of the length of talonid to that of the crown of Wushan premolar are characteristic in ape.Among the ape fossils avaliable in China \%Lufengpithecus \% is the closest relative of Wushan ape.Whether they have ancestor\|descendant relation is waiting for more findings to prove.

A Pediatric Case of Tuberculous Osteomyelitis of the Mandible Mimicking a Bony Malignant Tumor

Background: Tuberculosis is a granulomatous infectious disease which is still being a real health problem in developing countries. Mainly, this specific infection affects pulmonary sites, but, the occurrence in extra-pulmonary sites is more and more reported. However, when extra-pulmonary tuberculosis affects the cervico-facial region, the cervical lymph nodes are the most involved. Aim: Throughout this case report, we put emphasis on keeping in mind of the possible tuberculous infection in a chronic lesion of mandible in children. Case presentation: In this article, we present a case of a 2-year-old child who was complaining of swelling of the right angle of the mandible. The computed tomography showed an osteolytic lesion suggesting tuberculous osteomyelitis but didn’t rule out a bony malignant neoplasm of the mandible. The histological examination of biopsy of the lesion proved the tuberculous osteomyelitis of the mandible. The child has received anti-tubercular therapy for 9 months, and she marked a good recovery. Conclusion: In children, tuberculous osteomyelitis of the mandible is a curable disease without sequel when diagnosis is given at the right time.

Sexual Dimorphism in Adult Human Mandible of North Indian Origin

Background: In forensic science the identification of a human is based on three important factors: Age, Sex and Stature. Bones are an important tool for it and among human bones the pelvis and the skull are the most reliable source for sex determination. In the absence of complete pelvis, mandi-ble becomes the important source for sex determination since mandible is the most durable and movable part of skull that can resist postmortem changes. The present study is conducted to assess the accuracy and role of few metric and morphological parameters in determination of the sex of dry adult human mandible of North Indian origin. Material & Methods: The Study is conducted on 50 dry intact human adult mandibles of North Indian origin. The metric parameters i.e. bigonial breadth, bicondylar breadth are measured with a Vernier Calliper by two observers. Non-metric parameters being observed are the morphological features like gonion flaring, muscular markings and shape of angle of symphysis menti. Result & Conclusion: It is concluded that bigonial breadth and bicondylar breadth exhibit the sexual dimorphism. Morphological Parameters: Gonion flaring, muscular markings and shape of angle of symphysis menti also demonstrate the sexual dimorphism. These parameters taken together may determine the sex of adult human mandibles. The present study shows that the mandible is an important tool in the determination of gender with high accuracy.

Single Nucleotide Polymorphisms and Haplotypes in Vascular Endothelial Growth Factor Gene and Residual Ridge Resorption of Mandible in Korean Population

The tooth extraction is a routine surgical procedure in the dental treatment where the healing process results in a saddle-shaped residual ridge in the edentulous jaw. There are substantial differences among individuals in the end result. In some cases, there is excessive bone atrophy, which complicates the dental restorative treatment. The alveolar ridge receives the mechanical load continuously from the periodontal ligament connected to the teeth and it diminishes dramatically as a consequence of dental extraction;thus it is believed the continuing pattern of the alveolar bone resorption is related to this change. The reduced partial pressure of oxygen is the most prominent event from the reduced mechanical load. Vascular Endothelial Growth Factor (VEGF), regulated by HIF-1, reported close association with angiogenesis and bone turn over, where partial oxygen pressure has changed. Therefore the genetic association between Single Nucleotide Polymorphsim (SNP) of VEGF gene and RRR was investigated. 120 subjects (70.93 ± 9.28 years) which were treated at Dental clinic of Yonsei University with edentulous mandible were recruited. Mandibular bone height was measured following the protocol of the American College of Prosthodontists. Three variants, rs1570360, rs25648, and rs3025039 in VEGF from previous study, were used as tag-SNPs and genotyping for the study. Student’s t-test and ANOVA were used for statistical analysis. There was a notable association with rs1570360 (P = 0.051) in dominant group and haplotype A-C-C showed a statistically significant association with RRR in dominant group (P = 0.042). Results of this study may be useful in developing novel genetic diagnostic tests and identifying Koreans susceptible to developing severe RRR after dental extraction.

Fanconi anemia manifesting as a squamous cell carcinoma of the mandible: a case report

Progressive bone marrow failure and development of malignancies, particularly acute myeloid leukemia and solid tumors the most important features of Fan- coni’s Anemia (FA). This paper reports the case of a 16-year-old patient with FA who developped squa- mous cell carcinoma of the mandible, ten years after the bone marrow transplantation (BMT).

Sexual Dimorphism in the Mandible Shape of <i>Neospondylis upiformis</i>(Coleoptera: Cerambycidae)

Sexes of adult Cerambycidae (Coleoptera) are usually discriminated by the greater length of male antennae. However, in Spondylidinae, adult antennae are short and the difference between sexes is negligible and difficult to appraise. Only two species belong to this subfamily in North America, one of these being Neospondylis upiformis (Mannerheim), a species rarely caught in eastern North America. Unexpectedly, we collected numerous specimens of Neospondylis upiformis on Anticosti Island, Quebec, which appears as a hotspot for this species in eastern Canada. We show that sexual dimorphism in the mandible shape of N. upiformis (Mannerheim) can be used to discriminate sexes. Females have robust mandibles with a sharp cutting inner edge while males have thin mandibles and a well-rounded inner edge. There was no overlap between sexes in all measures done on mandibles, showing that mandible shape was a reliable criterion for sexing N. upiformis. We also tested previously reported criteria using antennae, as well as other characteristics such as body size, and show that they can hardly discriminate between sexes in N. upiformis. We also present illustrations of male and female genitalia, which is rarely available for Cerambycidae.