An evaluation of condylar and ramal vertical asymmetry in adolescents with unilateral and bilateral posterior crossbite using cone beam computed tomography (CBCT)

AIMS

The primary purpose was to evaluate condylar and ramal vertical asymmetry in adolescent patients displaying unilateral posterior (UCB) and bilateral posterior crossbite (BCB) malocclusions. A secondary aim was to compare the findings with a matched control group exhibiting normal occlusion (CG) using cone beam computed tomography (CBCT).

MATERIAL AND METHODS

The study groups consisted of (1) 30 patients (Mean age: 14.49 +/- 1.91 years) with a UCB, (2) 29 patients (Mean age: 14.57 +/- 1.84 years) with a BCB, and (3) 36 patients (Mean age: 14.24 +/- 2.42 years) as a matched control group (CG). Condylar, ramal, condylar-plus-ramal height and index measurements were performed using CBCT images following the method of Habets et al. A paired t-test was performed for side comparison in each group. Oneway ANOVA (Analysis of Variance) was used to determine statistically-significant differences between the groups for asymmetry index measurements and Tukey's HSD test was employed for individual group differences.

RESULTS

There was no statistically significant difference in condylar height (CH), ramal height (RH), and condylar plus ramal height (CH + RH) measurements between the right and left sides of the UCB group and CG, except for the RH in the BCB group (p = 0.045). Tukey's HSD test showed that the ramal asymmetry index (RAI) and the condylar plus the ramal asymmetry index (CRAI) were statistically significantly different between the UCB and BCB groups (p = 0.035 and p = 0.015, respectively).

CONCLUSIONS

Although the condylar asymmetry index (CAI) values were found to be high in the groups of UCB (13.84 +/- 11.33), BCB (9.38 +/- 8.56), and CG (10.58 +/- 9.48), the comparisons amongst the groups were not statistically significant. The asymmetry between the UCB and BCB groups was observed for RAI and CRAI values, rather than CAI values.

The relationship of vertical skeletofacial morphology to oropharyngeal airway shape using cone beam computed tomography: possible implications for airway restriction

OBJECTIVE

To determine if the shape of the oropharyngeal airway is related to the vertical morphology of the skeletofacial complex, including the hyoid bone.

MATERIALS AND METHODS

Cone beam computed tomography scans from 50 pretreatment adult orthodontic records were used to obtain skeletal and airway measurements. Linear regression statistics were used to compare soft tissue variables to hard tissue predictor variables.

RESULTS

Transverse airway widening was significantly increased when the distance between the hyoid and vertebrae was reduced; when the three-dimensional (3D) facial axis angle decreased (became more vertical); when the 3D mandibular plane angle increased; when the width of the hyoid increased, or when the calculated length of the geniohyoid decreased.

CONCLUSIONS

A laterally elliptical airway-found when the face is more vertical and when the hyoid is closer to the cervical vertebrae-is hypothetically more resistant to collapse. Patients with a retrognathic, skeletal deep bite and a rounded oropharynx should be identified and corrected early to prevent potential airway problems.

Features and management of intracranial mandibular condyle dislocation after trauma

BACKGROUND

Dislocation of the mandibular condyle into the middle cranial fossa is rare in clinics. It often occurs when the mouth is open wide during the injury. It causes restriction of mandibular motion, lower facial asymmetry, pain in the temporomandibular joint (TMJ), etc.

OBJECTIVE

To introduce the features of intracranial mandibular condyle dislocation and discuss the management to this kind of trauma.

MAJOR FINDINGS

In this paper, the authors present two cases, describing the diagnosis, surgical management, and 1-year follow-up evaluation. The results of the authors' treatment to intracranial mandibular condyle dislocation were satisfactory and stable, and no surgical complications were detected.

CONCLUSION

Advanced imaging studies are mandatory for exact diagnosis and successful treatment of intracranial mandibular condyle dislocation, and individualized management is recommended.

Unspecific, idiopathic isolated osteolysis (Gorham-Stout syndrome) of the mandibular condylar process with its radiological, histological and clinical features: a case report and review of literature

BACKGROUND

The unspecific, idiopathic isolated osteolysis is a rare condition in the various known osteopathies and better known as Gorham-Stout syndrome (Gorham's disease, GD). It belongs to the primary idiopathic osteolysis, and its aetiology is poorly understood. Many different localisations have been described, but there are only 48 cases affecting the maxillofacial region until now.

CASE REPORT

A 76-year-old patient with the singular localisation of GD in the left condylar process is presented. After radical resection of the condylar process, the clinical, radiological and pathological examinations made the diagnosis of GD. Until now, there is no recurrence for two and a half years.

DISCUSSION

The unspecific and inconsistent clinical and radiological symptoms complicate the diagnosis of GD. Clinical, pathological and radiological correlation is essential to make the diagnosis. The different therapeutical options and the specific outcome are discussed.

Effect of post-orthognathic surgery condylar axis changes on condylar morphology as determined by 3-dimensional surface reconstruction

OBJECTIVE

To evaluate the effect of postoperative condylar axis changes on mandibular condylar remodeling by comparing the condylar head in three-dimensional (3D) surface reconstructions before and after surgery in skeletal Class III deformities (one-jaw [mandibular setback] or two-jaw surgery), and also to determine the relationship between condylar inward rotation and condylar surface remodeling after orthognathic surgery.

MATERIALS AND METHODS

A retrospective analysis was conducted of 30 patients with skeletal Class III deformities who had received orthognathic surgery. Group 1 underwent one-jaw surgery (10 men, five women, age 22.4 ± 3.3 years), and group 2 underwent two-jaw surgery (10 men, five women, age 22.3 ± 2.2 years). Sixty condyles were reconstructed and superimposed pre- and postoperatively to compare the changes of condylar surfaces. The relation between the condylar axis change and the surface change using the Pearson correlation were investigated from the 3D image software.

RESULTS

Condylar surface changes before and after the surgery were significant. The postoperative inward rotation of the condyles was correlated with the average absolute deviation of the condyles, regardless of the surgery type (one- or 2-jaw surgery; r  =  .70, P < .05).

CONCLUSION

After orthognathic surgery, condylar surface changes occurred, and condylar inward rotation was closely related to changes of condylar surface.

Correlation between articular eminence steepness measured with cone-beam computed tomography and clinical dysfunction index in patients with temporomandibular joint dysfunction

OBJECTIVE

The purpose of this study was to investigate the correlation between articular eminence steepness and clinical dysfunction index (Di) in patients with temporomandibular joint dysfunction (TMD) using cone-beam computed tomography (CBCT).

STUDY DESIGN

In this study, CBCT images of 60 temporomandibular joints in 30 patients with TMD were evaluated. The eminence inclination values were measured on CBCT images. Patients were subdivided into 3 groups based on Helkimo's clinical Di. The data were analyzed using Spearman's rho correlation coefficient test.

RESULTS

The results of the present study did not confirm any significant differences in the values of articular eminence inclinations among the 3 groups (P value >.05).

CONCLUSION

Based on the present study, there is no apparent relationship between the articular eminence inclination and the clinical Di in patients with TMD.

Trifid Mandibular Condyle: A Case Report

A suspected case of trifid mandibular condyle that was observed on a panoramic radiograph and confirmed using computed tomography (CT) is reported. No history of previous temporomandibular joint (TMJ) trauma was reported by the subject.

A New Approach to Improve TMJ Morphological Information from Plain Film Radiographs

The hard tissues of the temporomandibular joint (TMJ) can be assessed through radiographic imaging to provide information to assist in diagnosis and treatment. However, the quality of information gathered from such imaging is often less than desired due to the small size of the TMJ, the widely varying fossa and condylar morphology, and the surrounding dense osseous structures. These make a clear and undistorted radiographic image of the hard tissue of the joint technically difficult. It is postulated that, if the degree of inaccuracy of a given radiograph is known quantitatively and taken into account, the clinician will be able to make a better informed qualitative assessment of TMJ morphology. The aim of this study is: 1. to improve the qualitative information that can be acquired from routine clinical plain film radiographs of the TMJ; 2. to use quantitative data to test the novel Neural Network (NN) model; and 3. to statistically show the discrepancies between routine radiographic images and the actual joint. Linear measurements of excised TMJs and their radiographic images were used to train a multilayer perceptron (MP) type NN model to predict joint dimensions more accurately. Such a neural network, developed using a statistical software package such as SPSS (SPSS, Inc. Chicago, IL), functions as a computer software program and predicts joint dimensions with increased accuracy when radiographic measurements are entered into the program. The NN model described here predicts the actual linear distances of the TMJ more closely than radiographic measurements and is more reliable in assessing the TMJ morphology.

Bilateral Bifid Mandibular Condyle: Case Report and Literature Review

Bifid mandibular condyle is an infrequent and normally asymptomatic morphological alteration of the mandibular condyle. Although the underlying cause is not clear, a number of theories have been proposed, including teratogenic effects in the embryo, vascular alterations during condyle development, and condylar remodeling following fracture. Since Schier first described this anomaly in 1948 in live individuals, further cases have been documented in the literature. We present a new case of bilateral bifid condyle. The disorder was asymptomatic and constituted a casual finding in a young male presenting for the surgical extraction of two impacted molars.

Ankylosis of temporomandibular joint caused by psoriatic arthritis: a report of four cases with literature review

Psoriatic arthritis (PsA) is an inflammatory joint disease associated with psoriasis. PsA is often confused with other diseases such as osteoarthritis and rheumatoid arthritis. PsA involving temporomandibular joints (TMJs) are uncommon: only 19 articles with 43 cases have been documented in the literature. TMJ ankylosis caused by PsA is rare, with only six cases having been reported. The authors present four cases of ankylosis of the TMJ secondary to PsA and review the literature. The findings of this study suggest that more attention should be paid to psoriasis patients with TMJ symptoms and proper treatment should be taken to prevent irreversible TMJ damage.

Quantitative 3D ultrashort time-to-echo (UTE) MRI and micro-CT (μCT) evaluation of the temporomandibular joint (TMJ) condylar morphology

OBJECTIVE

Temporomandibular dysfunction involves osteoarthritis of the TMJ, including degeneration and morphologic changes of the mandibular condyle. The purpose of this study was to determine the accuracy of novel 3D-UTE MRI versus micro-CT (μCT) for quantitative evaluation of mandibular condyle morphology.

MATERIALS AND METHODS

Nine TMJ condyle specimens were harvested from cadavers (2 M, 3 F; age 85 ± 10 years, mean ± SD). 3D-UTE MRI (TR = 50 ms, TE = 0.05 ms, 104-μm isotropic-voxel) was performed using a 3-T MR scanner and μCT (18-μm isotropic-voxel) was also performed. MR datasets were spatially registered with a μCT dataset. Two observers segmented bony contours of the condyles. Fibrocartilage was segmented on the MR dataset. Using a custom program, bone and fibrocartilage surface coordinates, Gaussian curvature, volume of segmented regions, and fibrocartilage thickness were determined for quantitative evaluation of joint morphology. Agreement between techniques (MRI vs. μCT) and observers (MRI vs. MRI) for Gaussian curvature, mean curvature, and segmented volume of the bone were determined using intraclass correlation coefficient (ICC) analysis.

RESULTS

Between MRI and μCT, the average deviation of surface coordinates was 0.19 ± 0.15 mm, slightly higher than the spatial resolution of MRI. Average deviation of the Gaussian curvature and volume of segmented regions, from MRI to μCT, was 5.7 ± 6.5% and 6.6 ± 6.2%, respectively. ICC coefficients (MRI vs. μCT) for Gaussian curvature, mean curvature, and segmented volumes were 0.892, 0.893, and 0.972, respectively. Between observers (MRI vs. MRI), the ICC coefficients were 0.998, 0.999, and 0.997, respectively. Fibrocartilage thickness was 0.55 ± 0.11 mm, as previously described in the literature for grossly normal TMJ samples.

CONCLUSIONS

3D-UTE MR quantitative evaluation of TMJ condyle morphology ex-vivo, including surface, curvature, and segmented volume, shows high correlation against μCT and between observers. In addition, UTE MRI allows quantitative evaluation of the fibrocartilaginous condylar component.

Clinical and radiological outcomes after treatment of sagittal fracture of mandibular condyle (SFMC) by using occlusal splint in children

This study was designed to investigate the effects of occlusal splints in the treatment of sagittal fractures of the mandibular condyle in children. From January 1995 to December 2011, 37 sagittal fractures of the mandibular condyle in 30 patients aged 4-8 years old were included in this study. All the patients were treated with 1-2mm occlusal splints in the molar region. The mouths of the patients were kept slightly open by the occlusal splints for 3-6 months, and we reviewed the clinical and radiological remodelling of the affected condyles after treatment. Excellent (n=20) and good (n=10) clinical outcomes were achieved with full radiological remodelling seen in 19 and partial remodelling in 11. Treatment with occlusal splints is effective in delivering good results and function with minimal morbidity in children with sagittal fractures of the condyle, while permitting ongoing remodelling and growth in the short term.

Late reconstruction of condylar neck and head fractures

Condyle fractures are a common injury, but only a few of these injuries require immediate or late reconstruction. The complications that most frequently necessitate condylar reconstruction include proximal segment degeneration, malunion, and ankylosis. Costochondral grafts and total joint prostheses, both stock and custom, remain the most common methods of reconstruction. Reconstruction plates with condylar extensions should only be used temporarily as an unacceptable number cause serious complications. Distraction osteogenesis may have an occasional role in reconstructing the posttraumatic condyle.

Evaluation of bioresorbable plates in condylar fracture fixation: a case series

The objective of this study was to evaluate the efficacy and stability of bioresorbable plates in condylar fractures in adults. Twelve adult patients who had sustained a condylar fracture, either alone or in combination with other mandibular fractures, were clinically and radiologically assessed for the efficacy and stability of bioresorbable plate and screw fixation. Intraoperatively, a total of seven screw breakages were noted. Six cases showed instability of the fractured fragments after fixation with bioresorbable plates and screws; the other six cases showed adequate stability. A single bioresorbable plate does not provide satisfactory stability for condylar fractures. Also, the screw breakages add additional surgical time and cost to the patient.

Diagnostic imaging for temporomandibular disorders and orofacial pain

The focus of this article is diagnostic imaging used for the evaluation of temporomandibular disorders and orofacial pain patients. Imaging modalities discussed include conventional panoramic radiography, panoramic temporomandibular joint imaging mode, cone beam computed tomography, and magnetic resonance imaging. The imaging findings associated with common diseases of the temporomandibular joint are presented and indications for brain imaging are discussed. Advantages and disadvantages of each imaging modality are presented as well as illustrations of the various imaging techniques.

[Clinical application of condylectomy via intraoral approach under computer assisted surgical navigation]

OBJECTIVE

To assess the application of computer assisted surgical navigation in condylectomy via intraoral approach and its clinical results.

METHODS

Eight patients aged from 16 to 56 were treated by condylectomy via intraoral approach under computer assisted surgical navigation. There were 6 female and 2 male. The lesions were condyle osteoma in 3 patients, hemimandibular hyperplasia and condylar hyperplasia in 5 patients. Most patients had concomitant LeFortIosteotomy (6 cases), bilateral sagittal split ramus osteotomy (BSSRO) (5 cases),contralateral sagittal split ramus osteotomy (SSRO) (1 cases), genioplasty (4 cases) and mandible contouring (6 cases) to recover the facial symmetry.

RESULTS

All patients had good occlusion, oral function and facial symmetry after the operation. The average mouth opening was 38 mm before operation, and 41 mm one month after operation. The temporomandibular joint(TMJ) dysfunction syndrome alleviated or disappeared. The follow-up period was 3-12 months, and results were stable.

CONCLUSIONS

Computer assisted surgical navigation can precisely accomplish the condylectomy via intraoral approach.It causes less trauma to the patient than traditional condylectomy, and can better preserve the TMJ structure and function.

Cephalometric assessment of effect of head rotation toward focal spot on lateral cephalometric radiographs

INTRODUCTION

The patient's head can be slightly rotated sagittally vertically or transversely with the head holding device. Because of such improper positions due to head rotation, an error can occur in cephalometric measurements. The purpose of this study was to identify the projection errors of lateral cephalometric radiograph due to head rotation in the vertical Z-axis toward the focal spot.

MATERIALS AND METHODS

Ten human dry skulls with permanent dentition were collected. Each dry skull was rotated from 0° to +20° at 5° intervals. A vertical axis, the Z-axis, was used as a rotational axis to have 50 lateral cephalometric radiographs exposed. Four linear (S-N, Go-Me, N-Me, S-Go) and six angular measurements (SNA, SNB, N-S-Ar, S-Ar-Go, Ar-Go-Me, AB-mandibular plane angle) were calculated manually.

RESULTS

The findings were that: (1) Angular measurements have fewer projection errors than linear measurements. (2) The greater the number of landmarks on the midsagittal plane that are included in angular measurements, the fewer the projection errors occurring. (3) Horizontal linear measurements have more projection errors than vertical linear measurements.

CONCLUSION

The angular measurements of lateral cephalometric radiographs are more useful than linear measurements in minimizing the projection errors associated with head rotation on a vertical axis toward the focal spot.

[Change in condylar and mandibular morphology in juvenile idiopathic arthritis: cone beam volumetric imaging]

The aim of this study is to show the importance of Cone Beam Computerized Tomography to volumetrically quantify TMJ damage in patients with JIA, measuring condylar and mandibular real volumes. 34 children with temporomandibular involvement by Juvenile Idiopathic Arthritis were observed by Cone Beam Computerized Tomography. 4 were excluded because of several imaging noises. The mandible was isolated from others craniofacial structures; the whole mandibular volume and its components' volumes (condyle, ramus, hemibody, hemisymphysis on right side and on left side) has been calculated by a 3D volume rendering technique. The results show a highly significant statistical difference between affected side volumetric values versus normal side volumetric values above all on condyle region (P < 0.01), while they don't show any statistical differences between right side versus left side. The Cone Beam Computerized Tomography represents a huge improvement in understanding of the condyle and mandibular morphological changes, even in the early stages of the Juvenile Idiopathic Arthritis. The JIA can lead in children to temporomandibular joint damage with facial development and growth alterations.

One-year assessment of surgical outcomes in Class III patients using cone beam computed tomography

The purpose of this study was to apply a novel method to evaluate surgical outcomes at 1 year after orthognathic surgery for Class III patients undergoing two different surgical protocols. Fifty patients divided equally into two groups (maxillary advancement only and combined with mandibular setback) had cone beam computed tomography (CBCT) scans taken pre-surgery, at splint removal, and at 1-year post-surgery. An automatic cranial base superimposition method was used to register, and shape correspondence was applied to assess, the overall changes between pre-surgery and splint removal (surgical changes) and between splint removal and 1-year post-surgery at the end of orthodontic treatment (post-surgical adaptations). Post-surgical maxillary adaptations were exactly the same for both groups, with 52% of the patients having changes >2mm. Approximately half of the post-surgical changes in the maxilla for both groups were vertical. The two-jaw group showed significantly greater surgical and post-surgical changes in the ramus, chin, and most of the condylar surfaces (P<0.05). Post-surgical adaptation on the anterior part of the chin was also more significant in the two-jaw group (P<0.05). Regardless of the type of surgery, marked post-surgical adaptations were observed in the regions evaluated, which explain the adequate maxillary-mandibular relationship at 1-year post-surgery on average, with individual variability.

Erratum to: Extraorale und intraorale endoskopisch assistierte Versorgung von Kollumfrakturen

AIM OF THE STUDY

Using limited extraoral and transoral incisions for an endoscopically assisted open reduction of condylar mandible fractures, the risk of facial nerve damage and extensive visible scars can be reduced.

PATIENTS AND METHODS

The endoscopically assisted treatment of 17 consecutive patients with fractures of the condyle was performed from April 1998 to December 1999. Of the 17 patients, 14 had additional mandibular fractures, and 11 of the condylar fractures were dislocated. Of the 17 patients, 9 were treated by submandibular and 8 by transoral approach. Adequate anatomic reduction was achieved by the submandibular and transoral approaches using an endoscopically assisted technique.

APPROACHES

In four patients angulated drills and screwdrivers facilitated the transoral treatment of condylar fractures. Transbuccal stab incisions and the use of trocars were not needed in these four patients. The transoral approach proved to be a reliable surgical approach for fractures of the mandibular condyle even when dislocation with lateral override was present. The extraoral approach was used for severely dislocated fractures such as fractures with medial override or comminution.

Three-dimensional vector analysis of mandibular structural asymmetry

OBJECTIVES

The three-dimensional (3D) asymmetric structure of the mandible makes it necessary to analyze both its size and angle. Currently the developing 3D analysis techniques are not able to perform the simultaneous linear and angular measurements. Our aim was to evaluate mandibular asymmetry using a vector-based system by constructing 3D vectors for the mandibular functional units.

MATERIAL AND METHODS

We analyzed the 3D computed tomography images of normal control (N = 27) and asymmetric mandibles (N = 40). We created 3D vectors for the condylar, coronoid, body, gonial, and symphyseal functional units and compared the corresponding pairs of 3D vectors by calculating vector operations.

RESULTS

The vector difference and other vector components represented the individual 3D architectural pattern and severity of the asymmetric mandible. The body unit contributed most to mandibular asymmetry followed by the condylar unit.

CONCLUSIONS

The results indicate that 3D vector analysis can improve our understanding of the 3D architecture of asymmetric mandibles. This type of 3D vector analysis can be a useful tool for the comprehensive evaluation of its asymmetric mandibular structure.

Comparison of landmark identification and linear and angular measurements in conventional and digital cephalometry

The purpose was to compare the reliability of landmark identification and linear and angular measurements in conventional versus digital cephalometry. Using 50 cephalometric radiographs, four orthodontic residents identified 19 cephalometric landmarks followed by 18 linear and angular measurements of the same radiographs. The values of 18 measurements were compared to quantify the measurement difference and interobserver errors between these two methods. Multivariate analysis of variance showed that the "cephalometric radiograph" and "landmark" variation had greater influence than that of "method" (landmark identification on original radiograph/on digital). A statistically significant difference for interobserver errors between the two methods was noted only for 5 out of 19 cephalometric landmarks. The most accurately identified landmark in conventional and digitized method was Sella (S), followed by Nasion (N). Landmarks requiring further scrutiny in digital images were Porion (P) Articulare, ANS, UM, and LM. The advantages of digital cephalometry were also substantiated.

Diagnosis of dental and mandibular asymmetries in children according to Levandoski Panoramic Analysis

AIM

The purpose of this study was to evaluate the use of the Levandoski Panoramic Analysis in the diagnosis of dental and mandibular asymmetries and its contribution to clinical patient's evaluation and treatment planning. MATERIALS AND METHODS: Thirty-one randomly selected panoramic radiographs of children from 7 to 14 year old were analysed using 10 linear measurements. Right and left values were compared with Student's paired T tests. For each value, mean and standard deviation were computed separately for each side.

RESULTS

Statistics. A dominance for the left side over the right side was observed. The data obtained were not statistically significant with the exception of maxillary length: the right side length of the maxilla was shorter (p<0.05) compared to the left side.

CONCLUSIONS

Levandosky Panoramic Analisys represents a useful screening method in the diagnosis of dental and mandibular asymmetries.

Measurements from conventional, digital and CT-derived cephalograms: a comparative study

OBJECTIVE

The purpose of this retrospective radiographic study was to determine the reliability and reproducibility of skeletal and dental measurements of lateral cephalograms created from a computerised tomography (CT) scan compared with conventional and digital lateral cephalograms.

METHODS

CT and conventional lateral cephalograms of the same patients were obtained from university archives. The lateral cephalometric radiographs of 30 patients were manually traced. The radiographs were subsequently scanned and traced using Dolphin Imaging software version 11 (Dolphin Imaging, Chatsworth, CA, USA). The CT-created lateral cephalograms were also traced using the same software. Sixteen (10 angular and 6 linear) measurements were performed. Cephalometric measurements obtained from conventional, digital and CT-created cephalograms were statistically compared using repeated measures analysis of variance (ANOVA). Statistical significance was set at the p < 0.05 level of confidence.

RESULTS

The intra-rater reliability test for each method showed high values (r > 0.90) except for mandibular length which had a correlation of 0.82 for the CT-created cephalogram. Five measurements (N-A-Pog, N-S, ANS-PNS, Co-ANS and CoGn) were found to be significantly different between the CT-created and conventional cephalograms and three measurements (SNB, ANB, and/1-MP) were found to be significantly different between the CT-created and digital cephalograms.

CONCLUSIONS

There are statistically-significant differences in measurements produced using a traditional manual analysis, a direct digital analysis or a 3D CT-derived cephalometric analysis of orthodontic patients. These differences are, on average, small but because of individual variation, may be of considerable clinical significance in some patients.

Osteochondroma of the mandibular condyle. Report of a case with 5-year follow-up

In the current case, a 31-year-old patient who presented with a painful unilateral malocclusion and an unclear mass in the region of the right temporo-mandibular joint (TMJ) is reported. The malocclusion had been noticed by the patient a few months earlier. Chewing on the right side had become severely impaired and painful. The patient had no history of trauma to the TMJ. Plain radiographs and computed-tomographic scans depicted an enlarged and deformed mandibular condyle. A condylectomy was performed. The histological investigation of the specimen revealed an osteochondroma. The tumour did not express insulin-like growth factor-1 receptor. Five years following the surgical intervention, there has been no local recurrence and dental occlusion was re-established, without further treatment.

Open versus closed reduction: diacapitular fractures of the mandibular condyle

PURPOSE

The purpose of the study was to review the literature regarding the evolution of current thoughts on management of diacapitular fractures (DFs) of the mandibular condyle.

METHODS

An electronic search in PubMed was undertaken in March 2012. The titles and abstracts from these results were read to identify studies within the selection criteria. Eligibility criteria included studies reporting clinical series of DFs, including both animal and human studies, without date or language restrictions.

RESULTS

The search strategy initially yielded 108 references. Twenty-eight studies were identified without repetition within the selection criteria. Additional hand-searching of the reference lists of selected studies yielded three additional papers.

CONCLUSIONS

The current indications for open reduction and internal fixation (ORIF) of DFs described in the literature are: (a) fractures affecting the lateral condyle with reduction of mandibular height; (b) fractures in which the proximal fragment dislocates laterally out of the glenoid fossa, which cannot be reduced by closed or open treatment of another part of the mandibular fracture. The indications for conservative treatment are: (a) fractures that do not shorten the condylar height (a fracture with displacement of the medial parts of the condyle); (b) undisplaced fractures; (c) comminution of the condylar head, when the bony fragments are too small for stable fixation; and (d) fractures in children. As the temporomandibular joint disk plays an important role as a barrier preventing ankylosis, it is important to reposition the disk (if displaced/dislocated) during the surgical treatment of DFs. The lateral pterygoid muscle should never be stripped from the medially displaced fragment because its desinsertion disrupts circulation to the medial bony fragment, and also because this muscle helps to restore the muscle function after surgery. ORIF of selected DFs improves prognosis by anatomical bone and soft tissue recovery when combined with physical therapy. If conducted properly, surgical treatment of DFs is a safe and predictable procedure and yields good results.

Evaluation of intersegmental displacement according to osteosynthesis method for mandibular setback sagittal split ramus osteotomy using cone-beam computed tomographic superimposition

PURPOSE

To compare intersegmental displacements after mandibular setback sagittal split ramus osteotomy with reference to the fixation system applied: miniplate with monocortical screw, 3 bicortical screws, and 1 bicortical screw and 2 resorbable screws.

MATERIALS AND METHODS

The 42 subjects were divided into 3 groups according to the osteosynthesis method applied. To evaluate the intersegmental displacements from immediately after surgery (T0) to 6 months after surgery (T1), 2 cone-beam computed tomographic data sets were superimposed on the symphyseal area and the lower part of the mandible below the root apex. On the superimposed 3-dimensional images, the mean and standard deviation of the differences of the coordinates (x, y, z) between T0 and T1 were calculated.

RESULTS

From T0 to T1, group B (bicortical screws) manifested the greatest condylion (Cd) and coronoid process (Cp) displacements (P < .05). In group A, the right Cd moved anteriorly and the left Cd moved anteriorly and inferiorly, whereas the right and left Cps moved anteriorly. In group B, the right and left Cps moved laterally and inferiorly. In group C, the right Cd moved anteriorly and inferiorly, the left Cd changed laterally and anteriorly, the right Cp moved anteriorly, and the left Cp moved anteriorly and inferiorly.

CONCLUSIONS

In the present study, group B (bicortical screws) showed the greatest displacement after the healing period. In view of these findings, surgeons should consider carefully their choice of osteosynthesis method to effectively decrease intersegmental displacement.

The prevalence of TMJ osteoarthritis in asymptomatic patients with dentofacial deformities: a cone-beam CT study

Osteoarthritis of the temporomandibular joint (TMJ) can be described as non-inflammatory arthritic condition that results in degenerative changes of the joint structures. The aim of this study was to evaluate the skeletal morphology of the TMJ in patients with osteoarthritis with severe skeletal malocclusions (Class II and Class III) and patients with Class I occlusion as controls. Cone beam computed tomography images of 45 Class I, 28 Class II and 44 Class III joints of Caucasian patients were assessed for the presence of any degenerative changes in the condyle and fossa/eminence complex as described in the research diagnostic criteria for temporomandibular disorders (RDC/TMD). In all groups, the most commonly observed features were articular surface flattening and subcortical sclerosis. A combination of features that corresponds to a diagnosis of osteoarthritis was observed in 3% Class I, 43% Class II and 20% Class III patient joints. In conclusion, degenerative TMJ changes were more common in patients with skeletal jaw discrepancies, but wide inter-individual variations can be observed even in patients with clinically similar malocclusions.

The potential of hybrid SPECT/CT fusion imaging to improve diagnostic accuracy in the scintigraphic quantitative functional assessment of suspected unilateral mandibular hyperactivity

BACKGROUND

Mandibular asymmetry is commonly caused by disproportionate mandibular growth due to unilateral condylar hyperactivity. The current standard for mandibular condyle bone scintigraphy uses single photon emission computed tomography (SPECT) imaging after intravenous administration of technetium-99m-labeled diphosphates. To our knowledge, the use of hybrid SPECT integrated with multidetector computed tomography (SPECT/CT) imaging in the scintigraphic quantitative functional assessment of mandibular condyle growth has not yet been described.

CASE REPORT

A 22-year-old male with mandibular asymmetry due to suspected unilateral condylar hyperactivity underwent SPECT/CT imaging of the skull and facial bones after intravenous administration of technetium-99m methylene diphosphonate. Using CT to guide anatomical contouring, precise regions of interest were drawn over the mandibular condyles and clivus in adjacent SPECT/CT transaxial slices to calculate the mean radiotracer count ratios. For comparison of quantitative results, conventional SPECT images were obtained from the SPECT/CT data and processed according to conventional methods. Planar images were also obtained for visual assessment of mandibular condyle activity. All three methods, SPECT/CT, conventional SPECT, and planar imaging, found unilateral condylar hyperactivity of the left mandibular condyle. The condyles and clivus were easily and confidently identified on SPECT/CT images.

DISCUSSION

We speculate that SPECT/CT imaging will improve the diagnostic accuracy of unilateral condylar hyperactivity. More studies are necessary to further define its role, obtain baseline reference values, and establish analysis protocols.

Tuberculous osteomyelitis of mandibular condyle: a diagnostic dilemma

The incidence of tuberculosis (TB) is increasing worldwide and so are its consequences. Its oral manifestations are infrequent, occurring in approximately 3% of all cases. Although the primary lesion occurs as a pulmonary infection, the extrapulmonary infections have also shown an increase over the past few years. These infections generally involve the head and neck through haematogenous or lymphatic routes. The clinical presentation may be as an ulcer, granuloma, orofacial TB, TB of the salivary glands or tuberculous lymphadenitis. Rarely, secondary oral manifestations associated with pulmonary infection are seen, which can appear as lesions on the gingiva, palate, lips, tongue, buccal mucosa, frenulum and in the jaw bones. Owing to the rarity of orofacial TB, it seldom arouses clinical suspicion, especially when a positive history of a systemic infection or therapy is denied. Tuberculous involvement of the mandibular condyle is even rarer, and only two such cases are reported so far, both in English-language literature. Further, the diagnosis of such a case is extremely difficult as there are no specific signs pathogonomic of infection. The only manifestation may be a localized painful swelling of the jaw. The presented case is of osteomyelitis of the mandibular condyle in a 20-year-old male patient in whom TB was later suspected. In this case report the role of diagnostic techniques is emphasized as the osteomyelitis of the condyle has the risk of being easily missed owing to its atypical signs and symptoms and atypical radiographic appearance.

Effect of bimaxillary surgery on adaptive condylar head remodeling: metric analysis and image interpretation using cone-beam computed tomography volume superimposition

PURPOSE

The aim of the present study was to use cone-beam computed tomography volume superimposition to investigate the effect of bimaxillary orthognathic surgery on condylar head remodeling.

MATERIALS AND METHODS

Using a retrospective study design, 2 investigators evaluated the cone-beam computed tomography data of subjects who had undergone Le Fort I osteotomy and mandibular setback surgery. The predictor variable was time, grouped as preoperative versus postoperative. The outcome variables were the measurement changes of the condylar heads and the distribution of the condylar head remodeling signs. Paired t and χ(2) tests were performed for the purposes of the 2-dimensional metric analysis and the condylar head remodeling distribution. P < .05 was considered significant.

RESULTS

The sample was composed of 22 adults (11 men and 11 women, age 20.3 ± 3.2 years) diagnosed with skeletal Class III malocclusion. The intra- and interoperator reliabilities of the image interpretation showed substantial agreement, according to Cohen's kappa index. The condylar heights on the sagittal and coronal planes decreased after surgery. Bone resorption occurred predominantly in the anterior and superior areas on the sagittal plane, the superior and lateral areas on the coronal plane, and the anterolateral and posterolateral areas on the axial plane (P < .05). Bone formation was apparent only in the anteromedial area on the axial plane (P < .05).

CONCLUSIONS

Bimaxillary orthognathic surgery caused a decrease in the condylar heights and condylar head remodeling. The cone-beam computed tomography volume superimposition method showed that the condylar head had undergone remodeling after bimaxillary surgery.

Hard tissue structural changes in TMJ morphology prior to orthodontic therapy: a complex motion tomographic study

OBJECTIVE

Temporomandibular joint (TMJ) disorders have been investigated for years due to their probable association with the neuromasticatory apparatus and the myoskeletal framework of the head and neck. In this study, we explored hard tissue structural changes within the TMJ (condyle, glenoid fossa, articular eminence, and joint space) using complex motion tomography. A correlation between these morphologic changes and clinical symptoms of disc-related TMJ disorders was attempted.

METHOD AND MATERIALS

Submentovertex and complex motion tomograms were taken on 114 TMJs from 57 patients who were referred for preorthodontic TMJ imaging. The TMJs were categorized into joints that were symtomatic (S) and asymptomatic (AS). The tomograms were evaluated independently by a board-certified oral and maxillofacial radiologist, and the data were recorded.

RESULTS

In the majority of the patients with or without joint symptoms, the glenoid fossa, anterior slope, and posterior slope of the articular eminence were morphologically normal in appearance. The condylar position of the joints without symptoms was more posterior compared to those with symptoms within the glenoid fossa. Condylar heads were abnormal in the majority of the patients, both in coronal view and sagittal view, regardless of their symptomatology. Both groups of joints exhibited abnormal joint space and range of motion. The Fisher exact test was used to determine the significance of the difference between the morphology of symptomatic and asymptomatic joints. Of the results obtained, only the condylar head in coronal view (P = .0001) and joint space (P = .0007) demonstrated any statistical significance in terms of deviation from the norm between the two groups.

CONCLUSION

Examination of hard tissue structures alone is insufficient to support the joint association in the presence of TMJ-related clinical symptoms. Simultaneous MR imaging may significantly increase the predictability of any clinical correlation.

[Adoption of the condyle position of patients with extensive tooth wear during occlusal rehabilitation]

OBJECTIVE

To evaluate the adoption of the condyle position of patients with extensive tooth wear during occlusal rehabilitation, and the correlation between increased vertical dimensions and the changes of joint spaces.

METHODS

Twenty-seven patients (five from Beifang hospital, others from Peking University School and Hospital of Stomatology) with extensive tooth wear were selected and received occlusal rehabilitation treatment. The radiographs of standard Schüllers position were taken before treatment (stage 1), 1 month following delivery of temporary restoration (stage 2), and 1 month following delivery of permanent restoration (stage 3).

RESULTS

The superior, anterior and posterior joint spaces were (3.24 ± 0.16), (2.06 ± 0.11), (1.89 ± 0.13) mm at stage 1; (3.61 ± 0.15), (1.94 ± 0.10), (2.52 ± 0.11) mm at stage 2; (3.49 ± 0.19), (1.93 ± 0.10), (2.40 ± 0.13) mm at stage 3. The posterior joint spaces at stage 2 and stage 3 were significantly larger than that at stage 1(P < 0.01). The superior spaces at stage 2 were significantly larger than that at stage 1 (P < 0.05). No correlations between the increased vertical dimensions and the changes of joint spaces were found in the three stages (P > 0.05).

CONCLUSIONS

The condyle positions in the patients with extensive tooth wear changed after occlusal rehabilitation.

Is failure of condylar neck osteosynthesis predictable based on orthopantomography?

BACKGROUND

Osteosynthesis failure rates of 11.3% with 1 miniplate, 6.7% with 2 miniplates, and 4.4% with a single Medartis condyle plate were reported in previous studies of our clinic. Current science is still focused on the osteosynthesis material. Besides clinical parameters, conventional radiographs are still the first choice to detect osteosynthesis failures. This study scrutinized several factors assessable in postoperative orthopantomographs which might elevate the risk of osteosynthesis failure.

STUDY DESIGN

A total of 136 patients (22 with osteosynthesis failure, 114 without) with 151 mandibular condyle fractures were included in this study. Eight parameters were assessed in postoperative orthopantomographs.

RESULTS

The best predictor of osteosynthesis failure was a simplified concept of ramus height. In cases of reduced or normal ramus height, the odds of osteosynthesis failure was significantly (P = .000001) reduced to a 10th. Isolated fractures were significantly more error prone (P = .0009).

CONCLUSIONS

Postoperative orthopantomographs depict factors which increase the risk of osteosynthesis failure.

Open reduction and rigid internal fixation of dislocated condylar fractures: a long-term follow-up of 25 patients

OBJECTIVE

To evaluate the long-term results of open reduction and rigid internal fixation for treatment of dislocated condylar process fractures.

METHODS

Twenty-five patients with dislocated condylar fracture who underwent open reduction and rigid internal fixation were followed up for an average of 4.5 years and evaluated on the basis of occlusion, temporomandibular joint (TMJ) function and radiographs.

RESULTS

Clinically, both occlusion and TMJ function were satisfactory. Generally, the dislocated condyles were well repositioned into the glenoid fossa after rigid internal fixation and remained in the position during the follow-up on the radiographs.

CONCLUSION

Open reduction and rigid internal fixation could achieve satisfactory results for the treatment of dislocated condylar fractures.

Three-dimensional analysis of the temporomandibular joint and fossa-condyle relationship

AIM

To assess the three-dimensional (3D) position of the temporomandibular joint (TMJ) in the cranial base structure, the 3D morphology of the TMJ, and the fossa-condyle interspaces in subjects with normal occlusion and patients with mandibular asymmetries using 3D computed tomography (CT) images. We hypothesized that the fossa-condyle interspaces and the shape or size of the TMJ would correlate with mandibular asymmetry.

METHODS

Twenty women with mandibular asymmetry and nine control subjects were recruited. The TMJ position, linear distances, angles, surface areas, and the fossa-condyle relationship were assessed with 3D CT images of the TMJ.

RESULTS

The fossa surface area was larger on the contralateral side, although no significant difference was observed in the linear or angular measurements of the fossa. The condylar neck height and condylar angle on the contralateral side were larger than those on the deviated side, and the frontal neck angle on the deviated side was larger than that on the contralateral side and of the control. No significant difference was observed in the condylar area. The fossa-condyle interspaces in the posterolateral section of the TMJ were smaller on the deviated side.

CONCLUSION

The condyle in the patients with mandibular asymmetry was rotated posterolaterally within the fossa on the deviated side. Patients with mandibular asymmetry showed larger fossas and longer condylar processes on the contralateral side and narrower fossa-condyle interspaces on the deviated side, especially in the posterolateral section of the TMJ.

Skeletal and dental changes after rapid maxillary expansion: a computed tomography study

OBJECTIVES

To investigate the skeletal and dental changes induced by rapid maxillary expansion, using computed tomography (CT) scans and three-dimensional (3-D) reconstructed images.

METHODS

Twenty patients (Mean age: 12.3 +/- 1.9 years) who required rapid maxillary expansion as a part of their comprehensive orthodontic treatment underwent pretreatment (T1) and post-treatment (T2) CT scans. The T2--T1 differences between selected skeletal and dental measurements on the coronal CT and 3-D volumetric images were compared using the Wilcoxon signed ranks test.

RESULTS

At T2 the Maxillary alveolar width (4.5 +/- 3.5 mm) was greater than the Maxillary base width (1.7 +/- 0.9 mm). The greatest transverse dental change was in the Intermolar width (6.3 +/- 2.1 mm and 2.7 +/- 1.9 mm at the crown and the apex, respectively). On the 3-D volume, significant increases occurred in the Bicondylar width (1.2 +/- 1.3 mm), Bimaxillo-mandibular width (2.1 +/- 2.3 mm) and the Maxillary width (2.5 +/- 1.6 mm). The greatest change in the dental measurements was in the Maxillary first molar width (6.4 +/- 0.1 mm). The Maxillary central incisor angle decreased significantly (-7.9 +/- 8.4 mm), indicating an increase in the distance between the apices of the central incisors.

CONCLUSION

Volumetric 3-D CT scanning provides a useful method for assessing skeletal and dental changes after rapid maxillary expansion. Although significant increases occurred in most skeletal and dental measures, it appears that dental tipping explains most of the expansion.

Change in condylar and mandibular morphology in juvenile idiopathic arthritis: Cone Beam volumetric imaging

The aim of this study was to show the importance of Cone Beam Computerized Tomography (CBCT) to volumetrically quantify temporomandibular joint (TMJ) damage in patients with juvenile idiopathic arthritis (JIA), measuring condylar and mandibular real volumes. Methods. Thirty-four children with temporomandibular involvement by JIA were observed by CBCT. Four were excluded because of several imaging noises. The mandible was isolated from others craniofacial structures; the whole mandibular volume and its components' volumes (condyle, ramus, emibody, emisymphysis on right side and on left side) has been calculated by a 3D volume rendering technique. Results. The results show a highly significant statistical difference between affected side volumetric values versus normal side volumetric values, above all on condyle region (P<0.01), while there was no statistical difference between right versus left side. Conclusion. The CBCT represents a huge improvement in understanding of the condyle and mandibular morphological changes, even in the early stages of the JIA. In children the JIA can lead to TMJ damage with facial development and growth alterations.

Four hands technique in transoral endoscope-assisted fixation of condyle fractures

OBJECTIVE

We present the short-term treatment results of a modified technique in transoral endoscopic condyle repair.

DESIGN

A pilot prospective study from April 2006 to November 2007.

SETTING

Ankara University Medical School Teaching Hospital.

METHODS

Four patients with subcondylar fracture were treated with transoral endoscopic condyle repair. Preliminary restoration of the occlusion was provided with maxillomandibular fixation. Four hands endoscopic sinus surgery principles were adapted to transoral endoscopic condyle repair.

MAIN OUTCOME MEASURES

Providing condylar stabilization with good occlusion and temporomandibular joint function was expected from treatment.

RESULTS

Open reduction and internal fixation were achieved in all patients. Condylar stabilization was confirmed by intraoperative endoscopic findings and postoperative panoramic radiographs. Uneventful healing with good occlusion and temporomandibular joint function were noted in 3 to 14 months of follow-up.

CONCLUSION

Endoscope-assisted minimal invasive procedures have been taking more part in head and neck soft tissue and trauma surgery. The cost of instruments and technical difficulties are the main constraints of endoscopic techniques. In this study, we present a practical way to perform transoral endoscopic condyle repair using the otolaryngologist's standard sinus surgery endovisual equipment and a titanium miniplate system. With the addition of a surgical hand, successful treatment results could be achieved with reduced cost.

Condylar lesions in relation to mandibular growth in untreated and intra-articular corticosteroid-treated experimental temporomandibular joint arthritis

OBJECTIVES

To evaluate condylar lesions in relation to mandibular growth in experimental temporomandibular joint (TMJ) arthritis and to assess the outcome of treating this condition with repeated intra-articular corticosteroid injections (IACIs).

METHODS

Forty-two 10-week-old rabbits were randomly divided into four groups. Seven animals served as controls. Experimental TMJ arthritis was induced in five animals which received intra-articular TMJ saline injections. Fifteen animals had TMJ arthritis induced and were left untreated and 15 animals had TMJ arthritis induced and were treated with IACIs one week after each TMJ antigen-challenge procedure. Inter-group growth differences were evaluated from head computerised tomography scans taken at the time of arthritis induction and 12 weeks later. The variables assessed were: progression of condylar lesions (erosions/flattening/osteophytes), mandibular bone volume changes, condylar and sagittal ramus growth.

RESULTS

No inter-group differences in the progression of condylar lesions were observed despite reduced mandibular growth in all three experimental groups. The most pronounced unfavourable mandibular growth alterations were observed in the corticosteroid-treated arthritis animals.

CONCLUSIONS

No evidence was found in support of a relation between reduced mandibular growth and condylar lesions. We propose that: 1) condylar lesions are not the only causative factor of reduced mandibular growth in experimental TMJ arthritis, and 2) repeated IACIs have a very unfavourable impact on mandibular growth in experimental TMJ arthritis - treatment is more detrimental to mandibular growth than the TMJ arthritis itself.

Quantification of condylar resorption in temporomandibular joint osteoarthritis

OBJECTIVE

This study was performed to determine the condylar morphologic variation of osteoarthritic (OA) and asymptomatic temporomandibular joints (TMJs) and to determine its correlation with pain intensity and duration.

STUDY DESIGN

Three-dimensional surface models of mandibular condyles were constructed from cone-beam computerized tomography images of 29 female patients with TMJ OA (Research Diagnostic Criteria for Temporomandibular Disorders group III) and 36 female asymptomatic subjects. Shape correspondence was used to localize and quantify the condylar morphology. Statistical analysis was performed with multivariate analysis of covariance analysis, using Hotelling T(2) metric based on covariance matrices, and Pearson correlation.

RESULTS

The OA condylar morphology was statistically significantly different from the asymptomatic condyles (P < .05). Three-dimensional morphologic variation of the OA condyles was significantly correlated with pain intensity and duration.

CONCLUSION

Three-dimensional quantification of condylar morphology revealed profound differences between OA and asymptomatic condyles, and the extent of the resorptive changes paralleled pain severity and duration.

[An investigation of current consensus on the management of condylar fractures among Chinese senior maxillofacial surgeons]

OBJECTIVE

To determine the current consensus in the management of condylar fractures among Chinese senior oral and maxillofacial (OM) surgeons and the difference between domestic and international.

METHODS

Forty-six senior OM surgeons, who were considered to be expert in management of maxillofacial trauma, were invited to participate in this investigation. A questionnaire was designed to appraise management strategies of surgical and non-surgical treatment on the 18 fractures of condylar process of mandible, which varied in fracture patterns, the degree of fragment displacement, uni-and bi-lateral involved and the age range of patients. The consensus was analyzed and then compared with the current international practice based on Baker's survey.

RESULTS

Three fracture situations obtained a uniform opinion, 9 situations had tendency in the alternative of surgical and non-surgical approach, 6 situations had no preference. Of 18 fractures, 8 were advised to receive an open procedure in management of the condylar fracture compared with 4 which was considered to be in a close procedure. Others were obscure in the preference of treatment decision. Consensus was achieved in non-surgical treatment for the patients younger than 12 years in age, and the teenager patients were considered for an open treatment when fracture occurred at the base of condyle and the fragment located out of fossa. It was controversial over the treatment of sagittal or comminuted fracture and subcondylar fracture with slight displacement in the adults. The panel of surgeons admitted a practice that bilateral subcondylar dislocated fractures were indicated for open reduction and internal fixation. If the similar case occurred on the unilateral joint, most of the Chinese surgeon preferred a surgical intervention which was adverse opinion from international.

CONCLUSIONS

In regard to the decision of surgical and non-surgical treatment for condylar fracture of the mandible, much controversy remained in one third of the investigated cases. The shared opinion was that the children patients should be treated by the closed methods for the condylar fracture and the bilateral subcondylar dislocated fractures were identically indicated for surgical reduction. The domestic OM surgeons seem to have a more tendency to surgery compared with their international counterparts.

Age-related changes in collagen properties and mineralization in cancellous and cortical bone in the porcine mandibular condyle

Collagen is an important constituent of bone, and it has been suggested that changes in collagen and mineral properties of bone are interrelated during growth. The aim of this study was to quantify age-related changes in collagen properties and the degree of mineralization of bone (DMB). The DMB in cancellous and cortical bone samples from the mandibular condyle of 35 female pigs aged 0-100 weeks was determined using micro-computed tomography. Subsequently, the amount of collagen and the number of pentosidine (Pen), hydroxylysylpyridinoline (HP), and lysylpyridinoline (LP) cross-links were quantified by means of high-performance liquid chromatography. The amount of collagen increased with age in cancellous bone but remained unchanged in cortical bone. The number of Pen and LP cross-links decreased in both bone types. In contrast, the number of HP cross-links decreased only in cancellous bone. The sum of the number of HP and LP cross-links decreased with age in cancellous bone only. The DMB increased in cancellous and cortical bone. It was concluded that the largest changes in the number of mature collagen cross-links and the mineralization in porcine cancellous and cortical bone take place before the age of 40 weeks. The low number of mature cross-links after this age suggests that the bone turnover rate continues to be high and thereby prevents the development of mature cross-links.

Radiographic diagnosis of synovial chondromatosis of the temporomandibular joint: a case report

Synovial chondromatosis is a rare, benign condition that usually affects the larger diarthroidal joints of the axial skeleton. Approximately 120 cases of synovial chondromatosis involving the temporomandibular joint (TMJ) have been reported. People with this condition may present with swelling, pain, intracapsular sounds and limitation of mandibular movement. Because it is important to differentiate synovial chondromatosis from other joint pathologies, a thorough history and appreciation of clinical features of these conditions are necessary. Radiographs are an important component of the diagnostic armamentarium for discerning conditions that mimic synovial chondromatosis. A case of synovial chondromatosis diagnosed radiographically with the aid of volumetric computed tomography is described, followed by a discussion of potential causative factors and management strategies. A brief review of the differential diagnosis of synovial chondromatosis involving the TMJ is also provided.