Mandibular Coronoid Process Research Articles

Cadaveric study of type of mandibular coronoid process in Marathwada region

Cadaveric study of type of mandibular coronoid process in Marathwada region

Mandibular coronoid process hyperplasia: a case report

ABSTRACT Coronoid Process Hyperplasia is a rare condition characterized by the increase in size of a histologically normal bone. It can be confused with Temporomandibular Joint Dysfunction, due to the presence of major signs/symptoms, including the limitation of mouth opening, pain, and facial asymmetry. Although several theories have been proposed, the etiology remains unknown. The recommended treatment is mandibular coronoidectomy. In the present study, the importance of computed tomography to reach the proper diagnosis and the surgical treatment plan is demonstrated.

Mechanical implications of the mandibular coronoid process morphology in Neandertals.

Among the diagnostic features of the Neandertal mandible are the broad base of the coronoid process and its straight posterior margin. The adaptive value of these (and other) anatomical features has been linked to the Neandertal's need to cope with a large gape. The present study aims to test this hypothesis with regard to the morphology of the coronoid process. This admittedly simple, intuitive hypothesis was tested here via a comparative finite-element study of the primitive versus modified state of the coronoid process, using two-dimensional models of the mandible. Our simulations demonstrate that a large gape has an unfavorable effect on the primitive state of the coronoid process: the diagonal, almost horizontal, component of the temporalis muscle resultant (relative to the long axis of the coronoid process) bends the process in the sagittal plane. Furthermore, we show that the modification of the coronoid process morphology alone reduces the process' bending in a wide gape increasing the compression to tension ratio. These results provide indirect evidence in support of the hypothesis that the modification of the coronoid process in Neandertals is necessary for enabling their mandible to cope with a large gape.

Osteochondroma of Coronoid Process in a Pediatric Patient: Treatment and Literature Review of Jacob's Disease

Benign unilateral hypertrophy of mandibular coronoid process is an uncommon condition wherein abnormal growth takes place in histologically normal bone. As first described in 1899 by French anatomist Oscar Jacob, the condition is termed JacobÕs disease when an osteochondroma within the coronoid results in development of a pseudo-joint with the zygoma. The literature has also described clinical and radiographic evidence of pseudo-joint with histologic diagnosis of cartilage with coronoid hyperplasia, osteoma, or exostoses, depending on the bone:cartilage ratio.1 The main sequelae of this enlargement are progressive limitation in mandibular opening, expansion of the zygoma or zygomatic arch, and deflection of the mandible to the affected side. As of 2016, only 43 cases of histology-proven cases of JacobÕs disease have been published in the literature.2

Severe trismus due to bilateral elongated mandibular coronoid process in an infantile-onset Pompe disease patient: A case report

Abstract Pompe disease is a rare neuromuscular disorder characterized by orofacial muscle weakness with consequent dysphagia and poor weight gain. We report the first case of severe trismus due to abnormal elongation of the coronoid process of the mandible in a child with infantile-onset Pompe disease. Bilaterally elongated mandibular coronoid processes cause abnormal impingement between the coronoid process and the zygomatic process, which in this patient, resulted in a maximal interincisal opening of only 6 mm. Although rare, clinicians should be aware of the development of coronoid process elongation in neuromuscular disorders with hypotonia, specifically those involving hypotonic orofacial muscles.

Associated fracture of the zygomatic bone and mandibular coronoid process

Associated fracture of the zygomatic bone and mandibular coronoid process

Keen's Approach: A Dynamic Approach for Zygomatic Arch Fracture Management

AbstractMaxillofacial fractures are often associated with blunt head injuries of which the outward projection of the Zygomatic Arch exposes it to frequent injury. Isolated Zygomatic arch fractures account for 10% of all Zygomatic bone fractures. Depressed Zygomatic arch fractures causes restricted mouth opening due to the partial or total obstruction of the movement of mandibular coronoid and condylar processes. Numerous techniques have been used to approach the site and reduce the fractured fragments, such as the Gillie's temporal approach, Keen's intraoral approach, anterior cheek skin incision and direct open approach.Below is a case report of an isolated Zygomatic arch fracture following a road accident in a middle aged woman that was surgically treated by open reduction through the Keen's intraoral approach. Successful reduction of the fractured segments and restoration of function was achieved with no scarring, minimal post-operative pain and satisfactory aesthetics.

Morphological variations in the shape of the mandibular coronoid process and its clinical implications

Morphological variations in the shape of the mandibular coronoid process and its clinical implications

Improvement of life quality of patients with allergic rhinitis treated with acupuncture on sphenopa-latine ganglion:a randomized controlled trial

To compare the effects of acupuncture on sphenopalatine ganglion and acupuncture on the common acupoints for life quality of patients with allergic rhinitis(AR). Eighty patients with AR,who were in accord with the inclusive criteria,were randomly divided into an observation group and a control group,40 cases in each one. Acupuncture on sphenopalatine ganglion was used in the observation group. The needle was inserted into the gap between zygoma and mandibular coronoid process about 55 mm. Acupuncture was adopted on the main acupoints,Yingxiang(LI 20),Yintang(GV 29) or Fengchi(GB 20) in the control group. The course was four weeks. Follow-up was applied one month after treatment. Rhinoconjunctivitis quality of life questionnaire (RQLQ),rhinitis symptoms scale and visual analogue scale(VAS) were evaluated at different time points before and after treatment,and follow-up was implemented to know the recurrence situation,satisfactory degree and adverse reaction. (1) RQLQ scores:along with treatment,the RQLQ scores were gradually apparently decreased in the two groups(P<0.01),and the reducing trend from the first week to the second week of the observation group was more obvious than that of the control group. The differences of the RQLQ scores at all timepoints after treatment between the two groups were not statistically significant(all P>0.05). The interaction of the time factor and the group factor had statistical significance(P<0.01). (2) Rhinitis symptoms scores:along with treatment,the scores presented decreasing trend in the two groups(P<0.01). The scores of the two groups after treatment and the interaction of the time factor and the group factor were not statistically different(both P>0.05). (3)VAS scores:the VAS scores after treatment were lower than those before treatment(both P<0.01). The differences before and after treatment were statistically significant(P<0.01),with more change in the observation group(P<0.05). (4)There was no statistical significance about the number of recurrence days between the two groups(P>0.05). (5) Above 80 percent patients were content with the therapeutic method in each group,with no statistical difference(P>0.05). (6)The method of the observation group spent less time. (7) Two patients with light adverse reaction came up in the observation group,but no special treatment was needed. Acupuncture on sphenopalatine ganglion acquires more obvious short-term effect than conventional acupuncture. It spends less time to relieve symptoms and improves life quality.

Cyst-like lesion in mandibular coronoid process: an unusual location

Cyst-like lesion in mandibular coronoid process: an unusual location

Case Report of a True Accessory Mandibular Condyle - an Exceptionally Rare Abnormality

Mandibular accessory condyle is rare. Literature search found most of the accessory condyles to arise from the mandibular coronoid process due to hyperactivity of attached temporalis muscle. Although neoplastic growth at mandibular coronoid mimicking an accessory condyle also been cited. Absence of report in recent publications regarding accessory mandibular condyle arising from the main mandibular condyle makes this anomali extremely rare. The present case report is about a true accessory mandibular condyle which caused the patient facial and occlusal disharmony. A 3D computerized tomographic imaging ascertained the exact location of the accessory condyle, its origin and resting position of the accessory and the main condylar head. The facial and occlusal disharmony settled completely within a short postoperative time following surgical intervention and mild elastic traction.Delta Med Col J. Jan 2016 4(1): 45-50

Jacob’s disease: Report of a case

Purpose: Jacob’s disease (JD) is an uncommon disorder that presents as pseudojoint formation between the enlarged mandibular coronoid process and the zygoma, resulting in mouth opening limitation (MOL). Intraosseous lipoma (IOL) usually presents in the long bone, but it is very rare in the mandible. The authors present a rare case of JD and coexisting IOL in the same anatomical area and discuss diagnosis and surgical intervention. Clinical presentation and intervention: The patient was a 39-year-old Korean female with MOL. Magnetic resonance imaging showed a large lobulated mass with fat-specific signal intensity. A combined extraoral and intraoral approach was used to resect the large mass. Histopathologic examination revealed a degenerated lipomatous tumor replacing the marrow cavity, with cartilaginous cap formation on the articular surface. Conclusion: Postoperatively, the patient showed uneventful healing and resolution of MOL.

Mandibular coronoid process fractures: Prevalence and characteristic multidetector CT findings

AimThe aim of this study was to investigate the prevalence and characteristic multidetector computed tomography (CT) (MDCT) findings of mandibular coronoid process fractures. MethodsA retrospective study was conducted on 376 patients with maxillofacial fractures who underwent 64-MDCT. For patients with mandibular coronoid process fractures, age, gender, cause of injury, coronoid process fracture location, and other maxillofacial fracture location were analyzed. ResultsOf all patients with maxillofacial fractures, 1.6% had mandibular coronoid process fractures. All patients with mandibular coronoid process fractures sustained other maxillofacial fractures as well. Furthermore, five (83.3%) of six patients with mandibular coronoid process fractures also had posterior maxillary sinus fractures. ConclusionsThe results of the present study indicate the prevalence and characteristic MDCT findings of mandibular coronoid process fractures. Patients with mandibular coronoid process fractures may sustain other maxillofacial fractures, especially posterior maxillary sinus fractures.

The morphology of the mandibular coronoid process does not indicate that Canis lupus chanco is the progenitor to dogs.

The domestication of wolves is currently under debate. Where, when and from which wolf sub-species dogs originated are being investigated both by osteoarchaeologists and geneticists. While DNA research is rapidly becoming more active and popular, morphological methods have been the gold standard in the past. But even today morphological details are routinely employed to discern archaeological wolves from dogs. One such morphological similarity between Canis lupus chanco and dogs was published in 1977 by Olsen and Olsen. This concerns the “turned back” anatomy of the dorsal part of the vertical ramus of the mandible that was claimed to be specific to domestic dogs and Chinese wolves C. lupus chanco, and “absent from other canids”. Based on this characteristic, C. lupus chanco was said to be the progenitor of Asian and American dogs, and this specific morphology has been continuously used as an argument to assign archaeological specimens, including non-Asian and non-American, to the dog clade. We challenged this statement by examining 384 dog skulls of 72 breeds and 60 skulls of four wolf sub-species. Only 20 % of dog mandibles and 80 % of C. lupus chanco showed the specific anatomy. In addition, 12 % of Canis lupus pallipes mandibles showed the “turned back” morphology. It can be concluded that the shape of the coronoid process of the mandible cannot be used as a morphological trait to determine whether a specimen belongs to a dog or as an argument in favour of chanco as the progenitor to dogs.

Keratocystic odontogenic tumor arising at the mandibular ramus with an impacted tooth: a case report and mimic lesions

Objectives: To consider the biologic behaviors of keratocystic odontogenic tumors (KCOTs) andameloblastomas and dentigerous cysts.Methods: A 63-year-old Japanese man presented with swelling and discomfort in the left cheek during jaw movement. Examination revealed a multilocular lesion within the mandible extending from the left second premolar to the left mandibular ramus and coronoid process; the lesion contained a deviated impacted tooth. The tumor had expanded beyond the bone and was invading the masseter and medial pterygoid muscles. Marginal mandibulectomy with a free iliac bone graft was performed.Results: No recurrence was observed during a 7-year follow-up.Discussion: The histopathological diagnosis of the lesion showed it was a KCOT. These tumors usually grow within the bone, causing bone expansion. However, this tumor had expanded beyond the bone and invaded surrounding muscles. Thus, KCOTs can, in rare cases, manifest themselves as described here. Evaluating preoperative images and histopathological findings is important to determine the optimal treatment strategy.

著しい開口障害をきたした両側筋突起過形成症の1例

Hyperplasia of the mandibular coronoid process is a clinical condition that causes an indolent trismus by elongated coronoid processes that impinge on the zygomatic medial surface when opening the mouth. We report a case of hyperplasia of the mandibular coronoid process which was progressive temporally and was treated by bilateral coronoidectomies.A 10-year-old boy consulted our department with a complaint of mouth opening limitation. Maximum mouth opening (MMO) between upper and lower incisors was 20mm. Based on the image findings a diagnosis of hyperplasia of the mandibular coronoid process was made, but he and his parents did not desire treatment. Thereafter, his trismus progressed temporally and he visited our department again for treatment of hyperplasia of the mandibular coronoid process at 15 years old. The image findings showed that both enlarged coronoid processes had extended above the zygomatic arch. Bilateral coronoidectomies were performed through an intraoral approach under general anesthesia at 16 years old, and the intraoperative MMO was 50mm. Training with a mouth opening training device was started seven days after surgery, but MMO at 17 days after surgery was only 19mm. Self-training of mouth opening was continued and MMO at 15 months after surgery was 34mm. On the other hand, new island-shaped bone formation in areas of resected coronoid processes was observed on CT images three months after surgery, and the bone fragments were enlarged and connected on CT images 12 months after surgery. Therefore, continued follow-up is required for this patient.

Species-specific modifications of mandible shape reveal independent mechanisms for growth and initiation of the coronoid.

BackgroundThe variation in mandibular morphology of mammals reflects specialisations for different diets. Omnivorous and carnivorous mammals posses large mandibular coronoid processes, while herbivorous mammals have proportionally smaller or absent coronoids. This is correlated with the relative size of the temporalis muscle that forms an attachment to the coronoid process. The role of this muscle attachment in the development of the variation of the coronoid is unclear.ResultsBy comparative developmental biology and mouse knockout studies, we demonstrate here that the initiation and growth of the coronoid are two independent processes, with initiation being intrinsic to the ossifying bone and growth dependent upon the extrinsic effect of muscle attachment. A necessary component of the intrinsic patterning is identified as the paired domain transcription factor Pax9. We also demonstrate that Sox9 plays a role independent of chondrogenesis in the growth of the coronoid process in response to muscle interaction.ConclusionsThe mandibular coronoid process is initiated by intrinsic factors, but later growth is dependent on extrinsic signals from the muscle. These extrinsic influences are hypothesised to be the basis of the variation in coronoid length seen across the mammalian lineage.

The Evolution and Development of The Mandibular Coronoid Process in Mammals

The coronoid process of the mammalian dentary bone is an evolutionary novel structure reflecting the new role of the dentary in mammals as an attachment site for the muscles of mastication. Previous studies have shown that the size and shape of the coronoid is correlated to the bite force required by the adult animal, and is dependent upon the mechanical force acting upon it during development. However little is known about the developmental programme leading to the specification of the processWe demonstrate that the paired homeobox transcription factor Pax9 is expressed in the ossifying front of the future coronoid process, and that Pax9 expressing cells contribute to the coronoid process, but not the other mandibular processes. In Pax9 mutants the coronoid is absent, however the temporalis muscle, which attaches to it, develops normally. Histological and gene expression studies indicated that the muscle attachment site remains. Loss of the coronoid is therefore driven by changes in the intrinsic patterning of the bone. In contrast other mouse mutants lacking the coronoid, such as the Tbx1 null, loss of the coronoid is a consequence of the loss of the muscle acting on the developing bone. Changes to this structure can therefore be influenced by intrinsic and extrinsic factors. The relative size of the coronoid process varies considerably across mammals, with herbivores, such as the guinea pig having a reduced or absent coronoid, while carnivores can have extremely large coronoid processes. The contribution of genes such as Pax9 and Tbx1 to changes in size of this processes on other mammals have therefore also been investigated. Our data implicates cooption of Pax9 in to the osteogenic program of the dentary enabled the development of the coronoid process, a key component in the emergence of the novel jaw.

Assessment of Volume and Height of the Coronoid Process in Patients With Different Facial Types and Skeletal Classes: A Cone-Beam Computed Tomography Study

To determine the height and volume of the mandibular coronoid process (CP) by cone-beam computed tomography (CBCT) and to identify the presence of any correlations of these measurements with age, gender, facial type, and skeletal class. The sample consisted of 132 patients from a departmental routine patient base. After CBCT, CP height was determined using OnDemand 3D software (CyberMed, Seoul, Republic of Korea), and CP volume was obtained using ITK-SNAP 3.0 software (Cognitica, Philadelphia, PA). Measurements were subjected to analysis of covariance against facial type, skeletal class, gender, and age, with a significance level of 5%. CP height and volume were similar regardless of age, facial type, and skeletal class. However, the 2 measurements were statistically different regarding gender, with larger values for men than for women. These observations suggest that gender is the only factor influencing the height and volume of the CP.

Peripheral osteoma of condylar neck following trauma

Osteomas are solitary, benign, slow-growing osteogenic tumors that sometimes involve the craniofacial region, such as the paranasal sinuses, temporal bone, or jaw bones. They can be classified as central and peripheral osteomas. The peripheral osteoma of the mandible is relatively uncommon. Though most of the cases involving the mandible arise from the mandibular body, angle, condyle head, or coronoid process, we report one such case unusually arising from the anterior surface of the neck of the condyle, the pterygoid fovea region. We believe it is the first recorded case of an osteoma arising from the pterygoid fovea region.