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PubMed1990

Light and electron microscopic morphology of the temporomandibular joint in growing and mature crab-eating monkeys (Macaca fascicularis): the condylar articular layer.

In an attempt to establish maturational alterations in the morphology of the articular tissue layer, mandibular condyles of four immature and four mature male monkeys (Macaca fascicularis) were studied using light microscopy as well as scanning and transmission electron microscopy. Specimens were fixed in situ by perfusion in the presence of ruthenium red to stabilize proteoglycans. Preparations intended for observation in the scanning electron microscope were first dehydrated and sputtered for the examination of articular surfaces, and afterwards treated with trypsin to expose the spatial arrangement of collagen fibrils. Gross anatomical relations between joint components indicated that the anterior and central, but not the posterior region of the condylar articular surface can be subject to compressional load. Load-bearing and non-load-bearing regions differed with respect to the morphology of the articular layer. Load-bearing surfaces were covered by a prominent articular surface lamina similar to that observed on articular cartilage. This lamina seemed to constitute an integral part of the articular layer, distinct from the lining of synovial fluid, and to be composed largely of proteoglycans. It was unaffected by maturation. The subjacent, load-bearing articular layer differed markedly in structure, both from articular cartilage, and between immature and mature animals. Articular cells of immature animals were classified as fibroblastlike, but unlike typical fibroblasts, were surrounded by a thin, often incomplete halo of fibril-free pericellular matrix, presumably consisting of proteoglycans. In mature animals, articular cells closely resembled chondrocytes, but exhibited prominent nuclear fibrous laminae, which usually are found only in fibroblasts. Thus, the load-bearing part of the articular layer seems to undergo a maturation-dependent metaplastic conversion, from a dense connective tissue with some features of fibrocartilage, to a fibrocartilage-like tissue containing chondrocyte-like cells with some features of fibroblasts. This conversion might reflect an adaptation to a maturation-associated increase in articular stress.

Animals↗
PubMed1990

Potency of atracurium on masseter and adductor pollicis muscles in children.

The sensitivity of the masseter to atracurium was measured in ten children aged 3-10 yr undergoing elective surgery, and compared with that of the adductor pollicis. During nitrous oxide-halothane anaesthesia and mechanical ventilation, supramaximal nerve stimulation was applied to the ulnar nerve at the elbow and to the nerve to the masseter, at a point inferior to the zygomatic arch, anterior to the mandibular condyle. Jaw closure was measured by a force displacement transducer system attached to an oral airway and connected to a metal frame fixed to the operating table 10 cm caudad to the chin. Cumulative dose-response curves for atracurium were obtained by the injection of doses followed by an infusion to compensate for elimination. The mean ED50s and ED95s were similar at the masseter and the adductor pollicis. At the masseter, these were 0.150 +/- 0.013, mean +/- SEM, mg.kg-1 and 0.254 +/- 0.021 mg.kg-1, respectively. At the adductor pollicis, corresponding values were 0.145 +/- 0.009 mg.kg-1, and 0.259 +/- 0.016 mg.kg-1. However, this relationship was not constant in every patient, and in some patients the masseter was much more sensitive than the adductor pollicis. The time from injection of the first dose of atracurium to maximum blockade was 2.5 +/- 0.2 min at the masseter and 3.2 +/- 0.2 min at the adductor pollicis (P less than 0.05). It is concluded that when atracurium is administered to paediatric patients, neuromuscular blockade is usually of the same intensity at each muscle but occurs sooner at the masseter than at the adductor pollicis.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, Inhalation↗
PubMed1994

Analysis of mathematical model for osseous factors in difficult intubation.

A two-dimensional model of the factors relevant to difficult laryngoscopy was analysed mathematically to determine clinical implications and limitations. The model describes the space into which the "inevitable residual volume" of the tongue (that part remaining anterior to the blade at laryngoscopy) can be displaced to permit a view of the larynx. Four points are used: the tip of the upper incisors; a point on the anterior airway just above the larynx; the mid-point between the mandibular condyles and the internal mid-point of the symphysis. The number, F, was defined by a formula developed from their spacial relationships. Decreasing F values imply an increasing likelihood of difficult laryngoscopy. The analysis investigated the effects of: translation of individual points; plotting individual point positions for specified F-values; translating adjacent pairs of points; treating any three points as a triangle which rotates about each of its apices; and lastly, translating three points independently. During manipulations the model behaved well mathematically. Single point analysis implied that jaw recession and a non-protruding mandible were comparable in effect. Closing the mouth around the laryngoscope blade maximised F-values. Prominence of the maxilla required greater forward displacement than backward movement of the symphysis for equivalent F-value change. One particular triangular rotation suggested an entirely novel mechanism for difficulty (the "hi-slung mandible") where the condyles are positioned more rostral than normal. An otherwise normal jaw with this configuration recedes markedly on opening. Further studies are required to validate the model. Accurate quantification of individual factors in difficult laryngoscopy may then be feasible.

Adult↗
PubMed1998

Clinical trial of panoramic dental radiography using a CCD receptor.

The objective of this study was to evaluate the perceived clinical efficacy of a charge-coupled device (CCD) detector for panoramic radiography by comparing the images produced to conventional film/screen radiographs using the same machine and patient population. For clinical evaluation, 18 criteria were selected. These included overall assessment of the area of coverage, clarity of dental structures, clarity of bony outlines, specific anatomic details such as the maxillary sinus floor, mandibular canal and mandibular condyle, and region-by-region assessment of the dentition. Observers acted independently using identical optimal viewing conditions. Film and digital radiographs were evaluated separately. A five interval Likert rating scale was used. Digital images were rated superior to the conventional film radiographs for 14 criteria. Film radiographs marginally outperformed digital images for three criteria. For one criterion (periodontal bone status) the two modalities showed no difference in terms of the means ratings. It was concluded that digital images are clinically equivalent to conventional film/screen images for panoramic dental radiography.

Humans↗
PubMed1998

[Endoscope-assisted fixation of condylar fractures of the mandible].

The reduction and plate osteosynthesis of condylar fractures often require a wide extraoral approach with the risk of facial nerve palsy. The endoscopic technique is an alternative. Seven condylar fractures were operated on under endoscopic control. In three patients a newly developed device for endoscopically controlled plate application was clinically tested for osteosynthesis. In two cases fracture healing was achieved. In the third case the plate had to be removed early due to insufficient screw fixation. The new device and the application technique are described in detail. This technique may be helpful in further minimizing trauma surgery.

Bone Plates↗
PubMed2002

TMJ remodeling after condylar fracture and functional jaw orthopedics a case report.

BACKGROUND: Condylar fractures in childhood are generally treated in a conservative-functional manner. As a rule, very good healing results are achieved by functional orthodontic treatment alone or, after immobilization, by splinting. HISTORY AND TREATMENT: Here we report on a patient who suffered a deep condylar dislocation fracture as a result of trauma at the age of 5. After initial immobilization with Schuchardt splints she underwent functional jaw orthopedics with activators. Subsequent orthodontic treatment with removable and fixed appliances enabled her to be followed up form functional and radiographic aspects over a period of 13 years. The remodeling process of the condylar head and neck could be clearly seen in the panoramic control radiographs. RESULT: Although the traumatized right TMJ was completely pain-free and fully functional after only a short time, the remodeling of the head and neck of the originally traumatized TMJ took 13 years to correspond fully to the healthy TMJ on the opposing side.

Activator Appliances↗
PubMed2004

Immunolocalization of heat shock protein 27 in developing jaw bones and tooth germs of human fetuses.

27 kDa Heat shock protein (Hsp27), which is also identified as p29 estrogen-receptor associated protein, plays a crucial role in specific growth stages. It also seems to be involved in the balance between differentiation and apoptosis. To determine whether Hsp27 is involved during craniofacial development and odontogenesis, its expression was studied through immunohistochemistry of developing jaw bone as well as the odontogenesis of heads from human fetuses. Formalin-fixed paraffin-embedded specimens of 7 human fetuses (3 female, 4 male), obtained from miscarriages occurring between the 9th and 16th weeks of pregnancy, were examined by using a monoclonal antibody against Hsp27. Staining intensity (weak, +; moderate, ++; strong, +++) was evaluated semiquantitatively. The sample slice was cut through a coronal plane, which included eyes, nasal cavities, tongue, and primitive dental lamina with tooth germs. A transient and spatially restricted expression of Hsp27 in developing human jaw bones and teeth was observed. Osteoblasts around the uncalcified bone matrix showed Hsp27 immunoreaction products (+++), whereas osteocytes were not immunolabeled. In mandibular condyle, immunolabeling was restricted to hypertrophic chondrocytes (++). In developing tooth germs, Hsp27 immunostaining was detected throughout the bud (+++). At the early cap stage, a strong immunolabeling for Hsp27 was seen in the dental lamina (+++), and a moderate staining was seen in the outer dental epithelium (++). At the late cap stage, Hsp27 expression was detected in the outer dental epithelium (++) as well as in the cells of the future stellate reticulum (++). The spatiotemporal-restricted expression of Hsp27 in craniofacial bones during development suggests that this protein could be involved in the balance between differentiation and apoptosis, by modulating the viability of osteoblasts and chondrocytes. The specific regional and temporal expression patterns of Hsp27 during tooth development sustains that this small Hsp might be related to the morphogenesis and cytodifferentiation processes of tooth germs.

Female↗
PubMed2001

A case of head and neck kaposiform hemangioendothelioma simulating a malignancy on imaging.

Kaposiform hemangioendothelioma (KH) is an endothelial-derived spindle cell neoplasm often associated with Kasabach-Merritt syndrome. Most cases arise in infancy and childhood and are soft-tissue tumors. The tumor displays an appearance between capillary hemangioma and Kaposi's sarcoma. We report a case of KH in a 1-year-old girl involving a mass that showed abnormal enhancement of soft tissue superficial to the right temporal bone with partial destruction of the temporal bone, the temporomandibular joint, mandibular condyle, and occipital bone. The physical finding of a discolored mass led clinicians to consider a hemangiomatous lesion, whereas the radiological picture suggested a more aggressive diagnosis of rhabdomyosarcoma and aggressive fibromatosis.

Anemia, Hemolytic↗
PubMed1999

Genomic organization and chromosomal localization of the Itm2a gene.

Itm2A is a novel type II integral membrane protein that is involved in osteo- and chondrogenic differentiation. Itm2a cDNA was originally isolated from a cDNA library of organ cultures from prenatal mouse mandibular condyles, by subtractive hybridization and differential screening. The Itm2a gene was isolated from a BALB/c liver genomic library. In total, 9.4 kb of the gene were sequenced, of which 2649 bp are 5' flanking sequences. The Itm2a gene contains six exons and five introns. The splice sites conform to the GT/AG rule. The 5' flanking region, which contains the presumed promoter sequence, lacks the common TATAA and CCAAT sequences, but contains consensus binding sites for various transcription factors. Several of these transcription factors are known to play a role in transcriptional regulation of cartilage- or bone-specific genes (e.g. Cbfa1, Cart-1, MHox, HES-1, and CIIS1). Itm2a was mapped to mouse chromosome position XA2-XA3 by fluorescent in situ hybridization (FISH) analysis. The human homolog, ITM2A, was mapped to chromosome position Xq13.3-Xq21.2.

Animals↗
PubMed2006

A nasal tooth associated with septal perforation: A rare occurrence.

Supernumerary teeth occur in a wide variety of sites, including the palate, mandibular condyle, coronoid process, orbit, maxillary antrum, and nasal cavity. Supernumerary teeth manifest in different ways depending on the site. Reported symptoms and signs associated with supernumerary teeth in the nasal cavity (nasal teeth) include facial pain, external nasal deformities, foul-smelling rhinorrhea, recurrent epistaxis, and oronasal fistula. Very rarely, septal perforation has been reported. We present a case in which eruption of a tooth into the nasal cavity was associated with nasal septal perforation. The tooth was extracted endoscopically.

Humans↗
PubMed2003

Association of metalloproteinases, tissue inhibitors of matrix metalloproteinases, and proteoglycans with development, aging, and osteoarthritis processes in mouse temporomandibular joint.

The temporomandibular joint (TMJ) is an important growth and articulation center in the craniofacial complex. In aging it develops spontaneous degenerative osteoarthritic (OA) lesions. Metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPS) play key roles in extracellular matrix remodeling and degradation. Gelatinase activities and immunohistochemical localization of MMP-2, -3, -8, -9, and -13 and TIMP-1 and -2 were examined in mandibular condyle cartilage of neonatal mice up to 18 months old. The most intense immunostaining for all enzymes and TIMPs and the peak of gelatinase activities were found in animals in the stages of early growth (1 week to 3 months) followed by a decrease during maturation and aging. However, clusters of positively immunoreactive chondrocytes were detected in cartilages of old animals displaying OA lesions. Positive safranin-O staining, indicative of sulfated proteoglycans (PGs), was prominent in the TMJ of newborn mice up to 3 months old followed by reduction during maturation and aging, except in regions displaying OA lesions. Temporal codistribution of PGs, MMPs, and TIMPs during skeletal maturation reflected an active growth phase, whereas their reduction coincided with the more quiescent articulating and maintenance phase in the joint cartilage. Osteoarthritic lesions were associated with both increased PG synthesis and MMP immunoreactivity, indicating limited repair activity during initial stages of osteoarthritis.

Aging↗
PubMed2003

Treatment of recurrent temporomandibular joint dislocation with intramuscular botulinum toxin injection.

Recurrent dislocation of the mandibular condyle poses a difficult problem for affected patients. In the course of time, dislocations often become more frequent and more difficult to avoid. Even with good patient compliance, conservative treatment is often not sufficient. Operative procedures have also been described for the treatment of temporomandibular joint dislocation. However, these interventions are invasive, involving open arthrotomy with possible complications, and cannot safely guarantee a successful outcome. On the other hand, botulinum toxin injections into the lateral pterygoid muscles offer the option of a predictable and prolonged period without renewed dislocation. We present the results of this treatment carried out in 21 patients with recurrent temporomandibular joint dislocation. Four patients were treated following unsuccessful physical therapy and the use of occlusal splints. The remaining 17 patients were treated for a number of conditions resulting in dislocation, including some with senile dementia and mental impairment in whom compliance with conservative measures was poor or completely absent. Injections were given on a 3-month basis in order to have a sustained effect. Within the study period of 6 months to 3 years, only two of the 21 patients suffered further dislocation. There were no side effects recorded as a result of treatment.

Adult↗
PubMed2002

[Surgical vs. conservative therapy of diacapitular and high condylar fractures with dislocation. A comparison between MRI and axiography].

AIMS: At present the discussion about the correct management of high condylar and diacapitular fractures has been reopened. The aim of the present prospective study was to evaluate the role of condylar mobility, disk mobility, and vertical dimension regarding the postoperative functional outcome after open reduction and osteosynthesis compared to nonsurgical treatment. METHODS: Since 1993 a total of 130 high condylar and diacapitular fractures have been treated by open reduction and osteosynthesis. Thirty-nine subjects with 51 fractures classes V and VI according to Spiessl and Schroll (surgical treatment, ST) were assessed postoperatively (mean 24 months) including magnetic resonance imaging (MRI) and axiography. Sixteen conservatively treated fractures served as a reference (conservative treatment, CT). RESULTS: Surgically treated temporomandibular joints presented a better condylar mobility (11.4 mm after ST, 5.9 mm after CT) and a less remarked loss of vertical ramus height (1.6 mm after ST, 5.4 mm after CT). Conservatively treated high condylar fractures formed a nearthrosis with the articular eminence in an anteromedial malposition (x axis 6.9 mm, y axis 10.3 mm). Disk mobility was reduced in both groups (3.8 mm after CT, 5.8 mm after ST), with major interindividual variations after ST. Significant correlations were found in the surgically treated group between axiographic limitations and limitations of disk mobility (p < 0.01) or periarticular scar formations (p < 0.01). Helkimo indices after ST (31% symptom free, 67% light symptoms < 5 points) were clearly superior (p < 0.01) to conservative treatment, with 63% of the subjects presenting craniomandibular symptoms > 5 points. CONCLUSIONS: According to the functional results observed, high condylar and diacapitular fractures will profit by open reduction and osteosynthesis. Only effective surgical procedures can preserve both disk mobility and vertical ramus height.

Adult↗
PubMed2004

[Stability of osteosyntheses for condylar head fractures in the clinic and biomechanical simulation].

BACKGROUND: Fractures of the condylar head are traditionally managed by closed techniques, despite a considerable rate of dysfunctional problems. PDS pin osteosynthesis (presented by Rasse 1992) via a preauricular approach failed to become established as a standard procedure due to a lack of stability. Alternatively, mini- or microplating, as performed in our patients (101 condylar head fractures between 1993 and 2000), showed high-grade limitations of translatory movements in about 30% due to scarification after loosening of osteosynthesis materials. The aim of this study was to establish an efficient procedure for achieving a functionally stable and atraumatic osteosynthesis. METHODS: For the definition of a suitable procedure, models of the mandible (standardized fractures, types A, B, and C) were osteosynthesized (six samples for each type of fracture and type of screw), each with three PDS pins, 2.0 mm resorbable, 2.0 cortical, 1.7 and 1.2 mm small fragment screws, and exposed to increasing loads in centric (0-20-35 mm opening) and eccentric (35 mm opening) condylar positions. A computerized biomechanical test stand allowed a dynamic simulation of chewing forces (16 hydraulic drives). The resulting fracture gaps were measured without contact by a motion capture system. RESULTS: Within physiological limits, only 1.7 small fragment and 2.0 mm cortical screws were able to bear occlusal loadings up to 200 N (1.2 mm small fragment screws up to 150 N, resorbable 2.0 mm screws up to 100 N, and PDS-pins up to 50 N). In a pullout experiment (condylar spongious bone of young pigs, aged 4-6 months), 1.7 mm small fragment screws showed superior retention. A consecutively developed small fragment screw-system has been applied clinically in 74 condylar head fractures (58 patients). After removal of osteosynthesis material, 41 of 49 TM joints have so far shown complete restitution. CONCLUSIONS: The newly developed osteosynthesis system using a retroauricular approach based on 1.7 mm small fragment screws makes maxillomandibular immobilization unnecessary. The extra-articular position of the screw heads prevents scar-induced articular limitations. Preexisting degenerative alterations of the TMJ soft tissues, however, will affect functional results adversely.

Absorbable Implants↗
PubMed2005

[Small fragment screws vs. plate osteosynthesis in condylar head fractures].

AIMS: This prospective study evaluates the outcome after osteosynthesis of condylar head fractures using 1.7 mm small fragment screws (2/2000 ff), which were selected according to a previous biomechanical trial to optimize condylar head traumatology. Clinical and functional results were compared to a group of fractures fixed mainly by mini- and microplates (1993-2000) and to a control group after conservative therapy with early functional training. PATIENTS AND METHODS: Functional values (axiography and MRI) regarding loss of vertical height, disk mobility, protrusive and translatory movements were assessed (a) in 34 of 83 condylar head fractures (groups V and VI according to Spiessl and Schroll, 22/69 subjects) managed by osteosynthesis with 1.7-mm small fragment screws (KFS), (b) a reference group (43/84 subjects) fixed mainly by mini- or microplates (PLO), comprising 56 of 101 fractures (1993-2000), and (c) 16 condylar head fractures after conservative therapy with early functional training (KT) as a control. RESULTS: In cases of small fragment screws, loss of vertical height (0.3 mm) was significantly reduced (p<0.01) in comparison to PLO (1.6 mm) and KT (6.9 mm). Disk mobility in KFS reached 90% of the non-fractured sides (NFS), thus clearly superior (p<0.01) to PLO (63% of NFS) and KT (40% of NFS). Translatory movements after KFS showed better results, too (p<0.05), with mediotrusion 84% and protrusion 80% of NFS. After PLO, mediotrusion was 62%, protrusion 71% of NFS, whereas KT showed only 53% (mediotrusion) and 56% (protrusion) of NFS. High-grade limitations of translatory movements presented in about 30% after PLO and <10% in KFS (p<0.01). Fragment displacements were found in <5% after small fragment screws, and in the plate osteosynthesis group in 15% (p<0.01). CONCLUSIONS: Due to better stability and reduced articular scarification osteosynthesis with 1.7-mm small fragment screws in condylar head fractures showed clearly superior functional results compared to mini- and microplates, and to conservative therapy.

Adolescent↗
PubMed2005

[Transparotidean approach to surgical management of condylar neck fractures. A prospective study].

AIM: Different surgical approaches for the open treatment of mandibular condylar fractures are described in the literature. We evaluated the morbidity of the transparotidean approach in a prospective study over 5 1/2 years. PATIENTS AND METHODS: A total of 48 patients with 52 condylar neck fractures class II and IV according to the Spiessl and Schroll classification were treated by a transparotidean approach. Rigid internal fixation was performed by means of miniplate fixation. After surgery, no mandibulomaxillary fixation was performed. The occurrence of surgical and functional complications was documented both during hospitalization and 1, 3, 6 and >9 months after surgery. RESULTS: In none of our patients were major problems in wound healing such as infection of the fracture site observed. At the beginning of the study, in four cases a fistula of the parotid gland was seen within the initial days after surgery; after careful wound closure of the parotid capsula in the following operations, no further complications involving fistulas were observed. Signs of temporary palsy of the facial nerve caused by the hooks occurred in ten (19.6%) of all patients but was completely reversible within the first 6 months after the procedure. One patient suffered temporarily from a minimal malocclusion and two patients from symptoms of the temporomandibular joint 6 months postoperatively. In three patients we observed miniplate fractures without consecutive dysfunction of the TMJ or malocclusion. CONCLUSION: Open reduction and rigid internal fixation of condylar neck fractures by transparotidean approach is a recommendable procedure in class II and IV fractures. With the advantages of minimal tissue alteration and rare complications on the one hand and sufficient exposure of the fracture site on the other hand, this technique has been established as a standard procedure in treating condylar neck fractures by open reduction.

Adolescent↗
PubMed1999

[New aspects for indications of surgical management of intra-articular and high temporomandibular dislocation fractures].

Conservative treatment of TMJ condylar fractures (groups V and VI according to Spiessl and Schroll 1972) often shows poor clinical results. This follow-up study was designed to objectify the benefits of an operative procedure by electronic computer-assisted recording of condylar movements. Sixty-three individuals with a total of 77 condylar fractures (42 diacapitular fractures, 35 high condylar process fractures) underwent surgery over a preauricular approach. Osteosynthesis was performed according to the intraoperative site either by PDS pins, titanium lag screws, microplates, miniplates or a combination of these materials. Radiological controls showed a considerable loss of height of the condylar process in the diacapitular group of fractures affecting the lateral condylar pole (n = 20). Condylar deformations in these cases were similar to the high condylar process group, whereas diacapitular fractures not affecting the lateral condylar pole (n = 22) had better radiological results. Axiographic tracings of TMJ movements in all groups as well as clinical functional analysis demonstrated highly satisfactory functional results within physiological limits. Compared to data referring to individuals treated conservatively, far fewer irregularities of axiographic tracings were observed in this group. Limitations of condylar movements nevertheless were found frequently in the high condylar process group (35%). As a severe complication, permanent facial nerve palsies occurred in six individuls due to the preauricular approach employed. After a modification using a temporal extension, only one minor partial lesion occurred in 97 operations.

Adolescent↗