Mandibular Process Research Articles

Craniomaxillofacial Features in Hereditary Multiple Exostosis

Hereditary multiple exostosis is the most common form of bone dysplasia. This entity is also known as diaphyseal aclasis, hereditary deforming chondrodysplasia, multiple hereditary exostoses, multiple osteochondromatosis, multiple cartilaginous exostosis, dyschondroplasia, and Ehrenfried disease. It is an inherited autosomal dominant disease with predominance in males and a benign condition characterized by the presence of multiple exostosis or osteochondromas arising from long and flat bones.Osteochondroma is the most common benign tumor in persons between 10 and 30 years of age. It accounts for 20% to 50% of all benign tumors and 10% to 15% of all bone tumors. It is more commonly located at the level of the metaphysis of long bones. However, osteochondroma is rare at the level of the facial bones and skull base. It has been reported in the maxillary sinus and in different parts of the mandible, such as the condyle, ramus, body, and symphyseal region. It is very uncommon in the coronoid process and occipital bone.Jacob disease, or osteochondroma of the mandibular coronoid process, is a benign skeletal tumor that is rare in the oral and maxillofacial skeleton. A review of the literature revealed only 41 histologically proven cases of 52 reported cases. To the best of the authors' knowledge this is the first clinical report of bilateral coronoid osteochondroma and associated occipital exostosis in a patient with hereditary multiple exostosis.

Identification of novel transcription‐regulating genes expressed during murine molar development

The mechanism of tooth development is a complex process regulated by numerous genes including transcription factors, growth factors, and other intra- and extracellular molecules. Especially, transcription factors play a central role in gene expression, regulating a wide spectrum of biological processes including organogenesis. Substantial evidence has been demonstrated by a number of studies using genetically engineered animal models. However, detailed molecular mechanisms of tooth development have not been completely elucidated, partially because numerous genes that play essential roles in tooth development remain unidentified. In this study, we conducted an expression-based screening using gene expression database and in situ hybridization assays. Based on the gene expression database "EMBRYS," 207 out of 1,520 genes were expressed in the maxillary and/or mandibular processes and thus were selected for further analysis by section in situ hybridization. Among these candidates, 28 genes were newly identified as potential factors associated with tooth development by in situ hybridization assays with frontal sections of embryonic day 13.5 and 14.5 mouse embryos. The expression patterns were also examined at embryonic day 16.5 and 18.5. These results will contribute to elucidating the mechanisms of tooth development and to improving the technology for regeneration of tooth.

Innovation in anterior mandibular alveolar distraction osteogenesis: Introduction of a new bone-borne distraction device and first clinical results

Segmental distraction osteogenesis of the anterior mandibular alveolar process (frontblock) is a sufficient method to avoid extractions in patients with dental crowding and to decompensate retroalveolism. Up to now dental-borne devices were used, but limitate the indications for front-block distraction.A new bone-borne distraction device for mandibular alveolar front-block movement is introduced in this study. The distractor allows sufficient segmental transport without loading on the teeth. Clinical evaluations of 7 patients have been performed including the feasibility and predictability of the distraction, postoperative pain and patients’ discomfort. The results indicate that this technique is a promising strategy in the correction of dental crowding, correcting the curve of Spee and to decompensate mandibular retroalveolism even in patients with impaired periodontal health and a thin mandibular symphysis.

Comparison of various approaches for the treatment of fractures of the mandibular condylar process

Fractures of the mandibular condyle process are the most common fractures of the lower jaw. Unfortunately, the type of treatment is still a matter of debate. PurposeThe aim of this investigation was to compare the outcome of different treatment approaches regarding function and surgical side-effects. Patients and methods111 fractures of the mandibular condyle representing all types according to the classification of Spiessl and Schroll were included. Both closed reduction (CR) and open reduction with internal fixation (ORIF) including the retromandibular/transparotid, submandibular, preauricular and intraoral approach were performed. The clinical examination included functional and aesthetic aspects at least 1 year after the fracture. ResultsThe majority of fractures (45%) were classified into Type II and IV according to Spiessl and Schroll followed by fractures without any displacement or dislocation (29.7%). The submandibular approach showed the worst outcome regarding permanent palsy of the facial nerve and hypertrophic scarring. No significant differences between the various approaches were detected in the functional status in any diagnosis group. ConclusionInferior condylar neck fractures benefit from ORIF by an intraoral approach whereas in high condylar neck fractures the retromandibular/transparotid approach shows the best results. Fractures of the condylar head were almost all treated by CR and our results cannot contribute to the debate of CR vs. ORIF in this type of fracture.

Skeletal and dental stability of segmental distraction of the anterior mandibular alveolar process. A 2-year follow-up

33 patients (27 females; 6 males) were retrospectively analysed for skeletal and dental relapse before distraction osteogenesis (DOG) of the mandibular anterior alveolar process at T1 (17.0 days), after DOG at T2 (mean 6.5 days), at T3 (mean 24.4 days), and at T4 (mean 2.0 years). Lateral cephalograms were traced by hand, digitized, superimposed, and evaluated. Skeletal correction (T3−T1) was mainly achieved through the distraction of the anterior alveolar segment in a rotational manner where the incisors were more proclined. The horizontal backward relapse (T4−T3) measured −0.8mm or 19.0% at point B (p<0.001) and −1.6mm or 25.0% at incision inferior (p<0.001). Age, gender, amount and type (rotational versus translational) of advancement were not correlated with the amount of relapse. High angle patients (NL/ML′; p<0.01) and patients with large gonial angle (p<0.05) showed significantly smaller relapse rates at point B. Overcorrection of the overjet achieved by the distraction was seen in a third of the patients and could be a reason for relapse. Considering the amount of skeletal relapse the DOG could be an alternative to bilateral sagittal split osteotomy for mandibular advancement in selected cases.

Re-Visiting the Embryogenesis of the Human Lower Lip: An Overlooked Paradigm

The rare opportunity to study a human fetus showing bilateral clefting of the lower lip along with other associated anomalies resembling those of the equally rare Pena–Shokeir phenotype prompts this report. The scarcity of reports on bilateral clefts of the lower lip has strengthened the conventional understanding or, perhaps even dogma that the lower lip and jaw develop from the progressive midline merging of just two mandibular prominences in the embryo. On the basis of observations stemming from this case report, it is proposed that yet another developmental event or process (in addition to the midline merging of the mandibular prominences) may be operable in the normal morphogenesis of the lower lip and anterior mandibular region. The bilateral paramedian clefting observed provides evidence that another distinct developmental region, a small medial process complements mandibular morphogenesis.

Characterization of Embryonic and Fetal Development of Necromys Lasiurus (Rodentia, Cricetidae)

Background: Necromys lasiurus belongs to a group that includes New World rats and mice. The few studies concerning N. lasiurus consider this species to be a good experimental model because they adapt easily and because maintenance in captivity is low-cost. Moreover, Cricetidae are epidemiologically important as vectors of various diseases. The aim of the present study was to describe the macroscopic and microscopic features of embryonic and fetal development in this species. Methods: Totally, 8 embryos and 12 fetuses were used and allocated in 6 groups. Gestational age was determined by the crown-rump length (CR) and weight. After the gross descriptions, samples were processed for light microscopy. Results: The groups differed both macroscopically (due the characteristics related to the cervical curve, elongation of limbs and appearance of digits, closing of the auditory canal, blood vessels, elongation of the cranium, appearance of eyelids, skin thickness and coloration) and microscopically (the development of structures that constitute the facial region - mandibular, maxillary and nasal prominences). The structures preceding the appearance of the pituitary, lung, heart, brain cavity, fourth ventricle, liver development, the oral cavity, and layers that make up the cornea, retina, pigmented layer of the retina, and the lens were observed. Ossification of some regions was also observed. Conclusion: The results showed that embryonic stage is present until day 15 of gestation. After this, during the fetal life the individuals showed a quickly development and maturation of the internal organs. These morphological results in regard to the development of N. lasiurus, can be used as a standard for interpretation of experiments that use this species as a model in science, including too compared with pathological results in disturbed gestations that can affect the normal development.

Central Giant Cell Granuloma of the Mandible: A Rare Presentation

ABSTRACTCentral giant cell granuloma (CGCG) is an intraosseous lesion consisting of cellular fibrosis tissue that contains multiple foci of hemorrhage, multinucleated giant cells and trabeculas of woven bone. This lesion accounts for less than 7% of all benign jaw tumors. Jaffe considered it as a locally reparative reaction of bone which can be possibly due to either an inflammatory response, hemorrhage or local trauma. Females are affected more frequently than males. It occurs over a wide age range. It has been reported that this lesion is diagnosed during the first two decades of life in approximately 48% of cases and 60% of cases are evident before the age of 30. It is considerably more common in the mandible than in maxilla. The majority of the lesions occur in the molar and premolar area, and some of these extend to the ascending ramus.The presence of giant cell granuloma in the mandibular body area, entire ramus, condyle and coronoid creates a diagnostic and therapeutic challenge for the oral and maxillofacial surgeons. The purpose of this report is to describe an unusual presentation of CGCG involving mandibular body, ramus, condylar and coronoid processes and to discuss the differential diagnosis, radiographic presentation and management of this lesion.How to cite this articleMalik S, Singh V, Singh G, Dahiya N. Central Giant Cell Granuloma of the Mandible: A Rare Presentation. Int J Head and Neck Surg 2012;3(3):172-174.

Severe trismus due to bilateral coronoid process hyperplasia in growth hormone therapy patient: a case report

J Korean Assoc Oral Maxillofac Surg 2012;38:249-54) Bilateral coronoid process hyperplasia is a rare condition characterized by an enlarged mandibular coronoid process. The painless progressive reduction of a mouth opening is caused by coronoid process impingement on the posterior aspect of the zygomatic bone. Hyperplasia of the bilateral coronoid process leads to the restriction of a mandibular opening consequent to the impingement of the enlarged coronoid process on the temporal surface of the zygomatic bone or with the medial surface of the zygomatic arch. The process has been diagnosed as developmental hyperplasia. Otherwise, the development of the coronoid process may be associated with growth hormone. This paper describes a case of trismus caused by coronoid hyperplasia in an idiopathic short-stature patient who received growth hormone therapy by somatropin injections.

A developmental staging series for the African house snake, Boaedon (Lamprophis) fuliginosus

Embryonic staging series are important tools in the study of morphological evolution as they establish a common standard for future studies. In this study, we describe the in ovo embryological development of the African house snake (Boaedon fuliginosus), a non-venomous, egg-laying species within the superfamily Elapoidea. We develop our staging series based on external morphology of the embryo including the head, eye, facial prominences, pharyngeal slits, heart, scales, and endolymphatic ducts. An analysis of embryonic growth in length and mass is presented, as well as preliminary data on craniofacial skeletal development. Our results indicate that B. fuliginosus embryos are well into organogenesis but lack well-defined facial prominences at the time of oviposition. Mandibular and maxillary processes extend rostrally within 8 days (stage 3), corresponding to the first appearance of Meckel's cartilages. Overall, the development of the craniofacial skeleton in B. fuliginosus appears similar to that of other snake species with intramembraneous bones (e.g., dentary and compound bones) ossifying before most of the endochondral bones, the first of which to ossify are the quadrate and the otic capsule. Our staging series is the first to describe the post-ovipositional development of a non-venomous elapoid based on external morphology. This species is an extremely tractable captive that can produce large clutches of eggs every 45 days throughout the year. As such, B. fuliginosus should be a good model for evolutionary developmental biologists focusing on the craniofacial skeleton, loss of limbs, generational teeth, and venom delivery systems.

Soft tissue stability in segmental distraction of the anterior mandibular alveolar process. A 2-year follow-up

This study evaluated soft tissue changes in adult patients treated with distraction osteogenesis (DOG) of the anterior mandibular alveolar process and related it to different parameters. 33 patients (27 females; 6 males) were analysed retrospectively before surgery at T1 (17.0 days), after surgery at T2 (mean 6.5 days), at T3 (mean 24.4 days), and at T4 (mean 2.0 years). Lateral cephalograms were traced by hand, digitized, superimposed, and evaluated. Statistical analysis was carried out using Kolmogorov–Smirnov test, paired t test, Pearson's correlation coefficient, and linear backward regression analysis. 2 years postoperatively (T4), the net effect of the soft tissue at point B′ was 100% of the advancement at point B whilst the lower lip (labrale inferior) followed the advancement of incision inferior to 46%. Increased preoperative age was correlated (p<0.05) with more horizontal backward movement (T4–T3) for labrale superior and pogonion′. Higher NL/ML′ angles were significantly correlated (p<0.05) with smaller horizontal soft tissue change at point B′. Gender and the amount of skeletal and dental advancement were not correlated with postoperative soft tissue changes (T4–T3). DOG of the anterior mandibular alveolar process is a valuable alternative for mandibular advancement regarding soft tissue change and predictability.

Evaluation of surgical treatment in mandibular condyle fractures

AimIn the past, fractures of the mandibular condylar process were, as a rule, treated conservatively. At the Department of Maxillofacial and Oral Surgery of the University Medical Centre Ljubljana, Slovenia, our doctrine was changed in 2002 on the basis of preliminary results and reports in the literature, and these fractures were started to be treated surgically by open reduction and internal fixation with miniplates and screws, which led to good results and a shorter rehabilitation period. The goal of this study was to determine the safety and efficiency of surgical treatment, as well as to compare long-term results of surgical and conservative treatment, as objectively as possible. Patients and methodsTwo groups of patients, which had all sustained a unilateral, extra-articular mandibular condyle fracture, were compared. In the test group, there were 42 surgically treated patients, and in the control group, 20 conservatively treated patients. Clinical parameters and X-ray images were assessed in both groups and compared by the two tailed Student t test, and in case of attributive variables by the χ2 test. Within the surgically treated group, postoperative and intraoperative complications were noted: temporary facial nerve palsy, development of a parotid salivary fistula, disturbance of auricle sensibility due to injury of the greater auricular nerve, miniplate fracture, as well as intraoperative bleeding, postoperative haematoma formation, infection, reoperation due to fragment malposition and other complications. Postoperative scars were also assessed. ResultsStatistically significant differences between the surgically and conservatively treated patients were found when comparing clinical parameters as well as X-ray images, the results being better in the surgically treated group. Complications of surgical treatment were also noted, the most important among them temporary paresis of facial nerve branches, which occurred in 10 patients (24%). Plate fractures occurred in five patients (12%), in four of them miniplates of sizes less than 2.0mm were used. There were no cases of significant intraoperative bleeding, two cases (5%) required drainage of postoperative haematomas, and one patient (2%) experienced a mild postoperative infection, which was easily controlled with amoxicillin with clavulanic acid. The scar was hidden best if a facelift incision was used, and a hypertrophic scar developed in only one patient (2%). ConclusionResults of surgical treatment of condylar process fractures are superior to the results of conservative treatment, and the procedure is safe with the transparotid surgical approach and adequate surgical technique.

Clinical Use of Allogeneic Bone Granulates to Reconstruct Maxillary and Mandibular Alveolar Processes

Introduction Lack of adequate mass of a patient's own bone is still a clinical problem in dental implantology; it precludes dental embedment. Surgical widening of an atrophied alveolar process with the use of an allogeneic bone granulate to fill the bone defect constitutes a first-line method to prepare for implant-prosthetic treatment. Transplantation of allogeneic material allows reconstruction of optimal height, thickness, and width of the alveolar process facilitating a procedure with a good long-term outcome. The study assessed outcomes following augmentation of atrophied alveolar processes before intraosseous implantation. Materials and Methods Filling bone defects in the maxilla and mandible as an introductory measure for implant-prosthetic treatment was performed in 59 patients (24 females and 35 males of age range 22–65 years). Bone granulate was used for maxillary sinus floor elevation (n = 29), augmentation of the postextraction alveoli (n = 12), and filling of defects in the outer table of the compact bone formed following inflammatory conditions (n = 18). The bone grafts were covered with plasma-rich fibrin (PRF) obtained from the patient's blood to accelerate the formation of synostoses and prevent epithelial penetration between the patients' own bone and the bone graft. Results In all of the patients normal union was observed, as confirmed by radiological images as well as intraprocedural assessment. Sufficient height and width as well as thickness of the alveolar process was obtained, which allowed embedment. Conclusions Allogeneic bone granulate constitutes a good material to reconstruct maxillary and mandibular alveolar processes in out-patient care.

Temporomandibular joint and normal occlusion: Is there anything singular about it? A computed tomographic evaluation

The purpose of this study was to investigate the condyle-fossa relationship, the position of the condyles in their respective mandibular fossae, and the dimensional and positional symmetries between the right and left condyles in a sample with normal occlusion. Thirty subjects from 15 to 32 years of age with normal occlusion had computed tomography scans of their temporomandibular joints. The images obtained from the axial slices were evaluated for possible asymmetries in size and position between the condylar processes. The images obtained from the sagittal slices were used to assess the depth of the mandibular fossa, the condyle-fossa relationship, and the centralization of the condyles in their respective mandibular fossae. Paired Student t tests were applied, and Pearson product moment correlations were determined after measurements on both sides were obtained. The largest mediolateral diameter of the mandibular condylar processes (P= 0.022) and the posterior joint spaces (P= 0.048) showed statistically significant differences between the right and left sides. Statistically significant (P<0.05) anterior positioning of the condyles (noncentralized position) was observed. No singular characteristic in the temporomandibular joints of the normal occlusion group was verified. The largest mediolateral diameter of the mandibular condylar processes and the posterior joint spaces showed statistically significant differences between the right and left sides. Evaluation of the position of the condyles in their respective mandibular fossae showed noncentralized positioning for the right and left sides.

Foreign Body in Preauricular Region

Foreign bodies, although they are often found throughout the body, to a lesser degree in the face, still constitute a diagnostic challenge for the trauma surgeon. Its removal means danger of damaging important facial anatomic structures, even if its exact position from the image data was known. So, the objective is to describe a clinical report of a patient (42 years of age, male sex) who experienced falling to the ground, attended by the Department of Surgery and Traumatology Bucco-Maxillo-Facial Surgery, Faculty of Dentistry of Araçatuba, São Paulo State University, and 2 days after the trauma, he reported difficulty in mouth opening and pain. After clinical evaluation, we observed the presence of injury in the left preauricular region already in the process of healing. During the intraoral physical examination, a limitation of the mouth opening was noted. Radiographic posteroanterior and profile of the face showed 2 radiopaque foreign bodies in the left side, lying apparently at the region of the mandibular condylar process. Under local anesthesia, foreign body removal was carried from there with access to it through the preexisting facial injury. Further clinical examinations showed an improvement in mouth opening, absence of pain complaints, and/or functional complaints.

Surgical Complications of Mandibular Condylar Fractures

The purpose of this study was to retrospectively evaluate the complications of 58 patients who underwent surgery for mandibular condylar process fractures. Data were collected from patients during a 10-year period (1999-2009). The data recorded included demographic data, etiology, diagnosis, type of condylar fracture, surgical approaches, and postoperative complications. A total of 58 underwent surgery for reduction of the condylar fractures. There were 22 patients with bilateral condyle fractures and 36 patients with unilateral condyle fractures, accounting for 65 surgeries. In 8 fractures, a preauricular approach was performed to access the fractures condyle, whereas the retromandibular approach was performed in 57 fractures. There were 2 temporary facial palsies, 1 permanent facial palsy, and 1 sialocele. There were no cases of hypertrophic scar, Frey syndrome, or salivary fistula. In conclusion, permanent deformities after surgical complications were unusual, and the results are acceptably safe.

Closed Reduction of Laterally Displaced Fracture/Dislocation of the Mandibular Condylar Process in a Child

This is a unique case of isolated lateral fracture/dislocation of the condylar process in a 3-year-old child injured on an escalator. Immediate closed reduction under general anesthesia successfully restored condylar height and premorbid dental occlusion. Maxillomandibular fixation was not used because mandibular mobilization was encouraged. Clinical follow-up confirmed maintenance of normal dental occlusion and temporomandibular joint function.

Endoscope-Assisted Transoral Reduction and Internal Fixation Versus Closed Treatment of Mandibular Condylar Process Fractures—A Prospective Double-Center Study

The aim of this international AO-study was to compare the functional outcome after open versus closed treatment of mandibular condylar neck fractures. A prospective comparative study with two follow-ups (FU) at 8-12 weeks and 1 year was undertaken in two clinics, which exclusively privileged either surgical or conservative treatment due to different therapeutic agendas. Patients from clinic 1 (ENDO group) received endoscope-assisted transoral open reduction and internal fixation, whereas patients from clinic 2 (CONS group) were treated conservatively without surgery. Patients with unilateral condylar neck fractures showing one or more of the following conditions were included: displacement of the condyle with an inclination >30° and/or severe functional impairment such as malocclusion or open bite, with or without dislocation of the condylar fragment; severe pain upon palpation or movement, and/or vertical shortening of the ascending ramus. High or intracapsular condylar neck fractures were excluded. 75 patients (44 CONS and 31 ENDO patients) with condylar neck fractures were included in this study. The Asymmetric Helkimo Dysfunction Score (A-HDS) was slightly lower in the CONS group than in the ENDO group at the 8-12-week FU, corresponding to better function on the short-term. At the 1-year FU, however, there were slightly better values in the ENDO group. For the Clinical Dysfunction Index (Di) and the Anamnestic Dysfunction Index (Ai), CONS patients had a better outcome than ENDO patients at the 8-12 week FU, ie, a higher proportion of ENDO patients had severe symptoms due to the operative trauma. Yet these symptoms improved by one year, finishing with a significant higher proportion of symptom-free patients in the ENDO group. In addition, these patients had better values for the Index for Occlusion and Articulation Disturbance (Oi) at both FU examinations, ie, the proportion of patients without any occlusal disturbances was significantly higher in the ENDO group. On average, the duration of postoperative maxillo-mandibular fixation (MMF) was 3 times longer for the CONS group than for the ENDO group (33 vs. 11 days). Both treatment options may yield acceptable results for displaced condylar neck fractures. Especially in patients with severe malocclusion directly after trauma, however, endoscope-assisted transoral open reduction and fixation seems to be the appropriate treatment for prevention of occlusal disturbances during FU.

Agnathia‐otocephaly with holoprosencephaly on prenatal three‐dimensional ultrasound

Agnathia‐otocephaly with holoprosencephaly on prenatal three‐dimensional ultrasound

Evolutionary patterns and processes in the radiation of phyllostomid bats

BackgroundThe phyllostomid bats present the most extensive ecological and phenotypic radiation known among mammal families. This group is an important model system for studies of cranial ecomorphology and functional optimisation because of the constraints imposed by the requirements of flight. A number of studies supporting phyllostomid adaptation have focused on qualitative descriptions or correlating functional variables and diet, but explicit tests of possible evolutionary mechanisms and scenarios for phenotypic diversification have not been performed. We used a combination of morphometric and comparative methods to test hypotheses regarding the evolutionary processes behind the diversification of phenotype (mandible shape and size) and diet during the phyllostomid radiation.ResultsThe different phyllostomid lineages radiate in mandible shape space, with each feeding specialisation evolving towards different axes. Size and shape evolve quite independently, as the main directions of shape variation are associated with mandible elongation (nectarivores) or the relative size of tooth rows and mandibular processes (sanguivores and frugivores), which are not associated with size changes in the mandible. The early period of phyllostomid diversification is marked by a burst of shape, size, and diet disparity (before 20 Mya), larger than expected by neutral evolution models, settling later to a period of relative phenotypic and ecological stasis. The best fitting evolutionary model for both mandible shape and size divergence was an Ornstein-Uhlenbeck process with five adaptive peaks (insectivory, carnivory, sanguivory, nectarivory and frugivory).ConclusionsThe radiation of phyllostomid bats presented adaptive and non-adaptive components nested together through the time frame of the family's evolution. The first 10 My of the radiation were marked by strong phenotypic and ecological divergence among ancestors of modern lineages, whereas the remaining 20 My were marked by stasis around a number of probable adaptive peaks. A considerable amount of cladogenesis and speciation in this period is likely to be the result of non-adaptive allopatric divergence or adaptations to peaks within major dietary categories.