Endoscopically-assisted intraoral resection of osteochondroma of the mandibular condyle with a piezoelectric surgical device

Background: Osteochondromas of the mandibular condyle show facial asymmetry and malocclusion. Because condylar osteochondromas are generally resected in a preauricular approach with risks of facial nerve injury and visible scar, the authors report endoscopically assisted intraoral resection of osteochondroma of the mandibular condyle with a piezoelectric surgical device.Case presentation: A 38-year-old woman presented with malocclusion and facial asymmetry caused by deviation of the chin to the left. Computed tomography showed a hyperdense, well-circumscribed mass arising from the medial aspect of the right mandibular condyle with resorption of the skull base. The patient underwent an endoscopically-assisted intraoral condylectomy with a piezoelectric surgical device. The postoperative course was uneventful without trismus, malocclusion, or facial asymmetry, and there was no recurrence 4 years after surgery.Conclusion:Endoscopically assisted intraoral resection of osteochondroma of the mandibular condyle with a piezoelectric surgical device is a minimally invasive and safe surgery.

DLL4/Notch blockade disrupts mandibular advancement-induced condylar osteogenesis by inhibiting H-type angiogenesis

BACKGROUND

Blocking Delta-like 4 (DLL4)/Notch has emerged as a promising therapeutic target for the treatment of tumours by deregulating angiogenesis. However, DLL4/Notch serves as a negative regulator of angiogenesis in multiple organs while acting as a positive regulator of H-type angiogenesis in postnatal long bones. Therefore, the effect of DLL4/Notch signalling blockade on mandibular condylar osteogenesis attracted our attention.

OBJECTIVE

To explore the effect of blocking DLL4/Notch on mandibular advancement (MA)-induced condylar osteogenesis.

METHODS

Six-week-old young male C57BL/6J mice (n = 40) were randomly divided into four groups: control group, MA group, MA + Anti-DLL4 group and MA + IgG group. Of note, IgG served as the isotype control for the anti-DLL4. The femurs, tibias and mandibular condyles were collected after sacrificing mice on Day 31 for morphology, micro-computed tomography, immunofluorescence, histology and immunohistochemistry evaluation.

RESULTS

First, DLL4/Notch blockade shortened femoral length and reduced bone mass by inhibiting H-type angiogenesis. Second, DLL4/Notch blockade disrupted MA-induced condylar head volume and quality by inhibiting H-type angiogenesis. Mechanistically, blocking DLL4/Notch reduced the number of runt-related transcription factor 2+ (RUNX2+ ) early osteoprogenitors and the expression of Noggin protein in the condylar subchondral bone by inhibiting H-type angiogenesis. In addition, blockade of DLL4/Notch also destroyed the condylar cartilage layer.

CONCLUSION

DLL4/Notch blockade results in shortened femurs and osteopenia, as well as impaired MA-induced condylar osteogenic volume and quality in growing mice by inhibiting H-type angiogenesis. Therefore, when blocking DLL4/Notch is used as a treatment target for diseases, attention should be paid to its impact on the bone mass of mandibular condyle.

Evaluation of joint kinematics in patients with condylar reconstruction using mandibular motion simulation based on intraoral scanning registration

AIM

To summarize the features of condylar kinematics in patients with condylar reconstruction using a mandibular motion simulation method based on intraoral scanning registration.

MATERIALS AND METHODS

Patients undergoing unilateral segmental mandibulectomy and autogenous bone reconstruction as well as healthy volunteers were enrolled in the study. Patients were grouped based on whether the condyles were reconstructed. Mandibular movements were recorded using a jaw tracking system, and kinematic models were simulated after registration. The path inclination of the condyle point, margin of border movement, deviation, and chewing cycle were analyzed. A t test and one-way analysis of variance (ANOVA) were carried out.

RESULTS

A total of 20 patients, including 6 with condylar reconstruction and 14 with condylar preservation as well as 10 healthy volunteers were included. The patients with condylar reconstruction showed flatter movement paths of the condyle points. The mean inclination angle of the condylar movement paths of the patients with condylar reconstruction (0.57 ± 12.54 degrees) was significantly smaller than that of those with condylar preservation (24.70 ± 3.90 degrees, P = 0.014) during both maximum opening and protrusion (7.04 ± 12.21 degrees and 31.12 ± 6.79 degrees, respectively, P = 0.022). The inclination angle of the condylar movement paths of the healthy volunteers was 16.81 ± 3.97 degrees during maximum opening and 21.54 ± 2.80 degrees during protrusion; no significant difference compared with the patients. The condyles of the affected side tended to deviate laterally in all patients during mouth opening and protrusion. Patients with condylar reconstruction showed more severe symptoms of mouth opening limitation and mandibular movement deviation as well as shorter chewing cycles than patients with condylar preservation.

CONCLUSION

Patients with condylar reconstruction showed flatter movement paths of the condyle points, greater lateral motion range, and shorter chewing cycles than those with condylar preservation. The method of mandibular motion simulation based on intraoral scanning registration was feasible to simulate condylar movement.

Correlation between Malocclusion and Mandibular Fractures: An Experimental Study Comparing Dynamic Finite Element Models and Clinical Case Studies

Mandibular fractures are very common in maxillofacial trauma surgery. While previous studies have focused on possible risk factors related to post-operative complications, none have tried to identify pre-existing conditions that may increase the risk of mandibular fractures. We hypothesized, through clinical observation, that anatomical conditions involving poor dental contacts, such as malocclusions, may increase the risk of mandibular fractures. This work was subdivided into two parts. In the first part, Digital Imaging and Communications in Medicine (DICOM) data of four healthy patients characterized by different dentoskeletal occlusions (class I, class II, class III, and anterior open bite) have been used to develop four finite element models (FEMs) that accurately reproduce human bone structure. A vertical and lateral impact have been simulated at increasing speed on each model, analyzing the force distribution within the mandibular bone. Both vertical and lateral impact showed higher level of stress at the impact point and in the condylar area in models characterized by malocclusion. Specifically, the class III and the open bite models, at the same speed of impact, had higher values for a longer period, reaching critical stress levels that are correlated with mandibular fracture, while normal occlusion seems to be a protective condition. In the second part of this study, the engineering results were validated through the comparison with a sample of patients previously treated for mandibular fracture. Data from 223 mandibular fractures, due to low-energy injuries, were retrospectively collected to evaluate a possible correlation between pre-existing malocclusion and fracture patterns, considering grade of displacement, numbers of foci, and associated CFI score. Patients were classified, according to their occlusion, into Class I, Class II, Class III, and anterior open bite or poor occlusal contact (POC). Class I patients showed lower frequencies of fracture than class II, III, and open bite or POC patients. Class I was associated with displaced fractures in 16.1% of cases, class II in 47.1%, class III in 48.8% and open bite/POC in 65.2% of cases (p-value < 0.0001). In class I patients we observed a single non-displaced fracture in 51.6% of cases, compared to 12.9% of Class II, 19.5% of Class III and 22.7% of the open bite/POC group. Our analysis shows that class I appears to better dissipate forces applied on the mandible in low-energy injuries. A higher number of dental contacts showed a lower rate of multifocal and displaced fractures, mitigating the effect of direct forces onto the bone. The correlation between clinical data and virtual simulation on FEM models seems to point out that virtual simulation successfully predicts fracture patterns and risk of association with different type of occlusion. Better knowledge of biomechanics and force dissipation on the human body may lead to the development of more effective safety devices, and help select patients to plan medical, orthodontic/dental, and/or surgical intervention to prevent injuries.

Local injection of abaloparatide promotes mandibular condyle lengthening in adolescent rats via enhancing chondrogenesis and ossification

BACKGROUND

Mandibular condylar hypoplasia negatively affects patient's facial appearance and dentofacial function.

OBJECTIVE

To investigate the effect of local injection of the drug abaloparatide (ABL), an analogue of parathyroid hormone related protein (PTHrP), on promoting lengthening of the mandibular condyle.

METHODS

Thirty adolescent male Sprague-Dawley rats were randomly divided into two groups, which received the injection of ABL or normal saline (the control) every 3 days in the temporomandibular joint (TMJ) cavity. Cone-beam computed tomography and immunohistochemistry assays were performed at 2, 4 and 6 weeks since the injection. Mandibular condylar chondrocytes (MCC) and pre-osteoblasts were treated with ABL or PBS, followed by the CCK-8 detection, IC50, real-time PCR assay, Western Blot and immunofluorescence staining.

RESULTS

In vivo, compared with the control, the ABL group significantly increased the mandibular condylar process length (by 1.34 ± 0.59 mm at 6 weeks), the thickness of the cartilage layer, and enhanced the matrix synthesis. The ABL group had significant up-regulation of SOX 9, COL II, PTHrP and PTH1R, down-regulation of COL X in the cartilage, up-regulation of RUNX 2, and unchanged osteoclastogenesis in the subchondral bone. In vitro, the intra-TMJ injection of ABL promoted the MCC proliferation, with up-regulated expression of chondrogenic genes, and enhanced osteogenic differentiation of the pre-osteoblasts.

CONCLUSIONS

Intra-TMJ injection of abaloparatide promotes mandibular condyle lengthening in the adolescent rats via enhancing chondrogenesis in the mandibular condylar cartilage and ossification in the subchondral bone.

The effect of tooth loss on the temporomandibular joint space: A CBCT study

OBJECTIVE

The tooth loss has a significant impact on the positioning of the condyle in the glenoid fossa and joint spaces of the temporomandibular joint (TMJ). The aim of this study was to assess the association between tooth loss and TMJ spaces using cone beam computed tomography (CBCT) images.

MATERIALS AND METHODS

This retrospective investigation involved the evaluation of CBCT images of the bilateral TMJs in a cohort of 111 individuals, comprising 68 males and 43 women. The dentition of the patients was categorized into three categories, including A (65.4%), B (19.1%), and C (16.4%), based on the Eichner index. Anterior, superior, and posterior joint spaces were then measured in sagittal views. The Kruskal-Wallis test and Mann-Whitney test were employed to identify significant differences among the three Eichner groups.

RESULTS

The findings of the present study suggested that there was no statistically significant variation in the anterior joint space among different Eichner groups within the general population (p = .781). Nevertheless, the superior and posterior joint spaces exhibited statistically significant alterations, as indicated by p-values of .039 and .010, respectively. It was detected that condyles were positioned inferiorly and posteriorly in group C when compared to groups A and B.

CONCLUSION

The present study indicated that greater loss of tooth-supporting zones is associated with posterior and inferior displacement of condyles. Understanding these relationships helps emphasize how crucial it is to replace missing teeth to enhance occlusion support and, in turn, stop the progression and further deterioration of temporomandibular disorders.

Gelatin methacryloyl hydrogel with and without dental pulp stem cells for TMJ regeneration: An in vivo study in rabbits

BACKGROUND

In the last decade, tissue-engineering strategies for regenerating the temporomandibular joint (TMJ) have been investigated. This may be a promising strategy for the minimally invasive restoration of joint integrity.

OBJECTIVES

To evaluate whether dental pulp stem cells (DPSCs) loaded in a light-occured hydrogel made of gelatin methacryloyl (GelMA) enhance the regeneration of osteochondral defects in the rabbit TMJ.

MATERIALS AND METHODS

Defects were filled with GelMA alone (control group; n = 4) or filled with GelMA loaded with rabbit DPSCs (experimental group; n = 4), In one group, the TMJ capsule was opened without creating a defect (sham group; n = 2). The following micro-CT parameters were analysed: bone volume to total volume ratio (BV/TV%) and bone mineral density (BMD). Histological evaluation was performed to assess cartilage regeneration features. A semi-quantitative scoring system was also used to evaluate the defects.

RESULTS

All groups had no statistical difference regarding the micro-CT parameters. The highest mean healing score was found for the experimental group. After 4 weeks, there were no signs of hydrogel in either group or no signs of inflammation in the adjacent tissues. The tissue formed in the defect was dense fibrous connective tissue.

CONCLUSION

Adding DPSCs to GelMA did not provide a regenerative enhancement in TMJ osteochondral defects. This resulted in similar micro-CT parameters after 4 weeks of healing, with improved signs of subchondral bone regeneration but no cartilage regeneration.

Developing a universal and reliable temporomandibular joint reference system for quantifying morphological and positional changes

OBJECTIVES

This study aimed to provide a universal and reliable reference system quantifying temporomandibular joint (TMJ) morphological and positional changes.

METHODS

Large field-of-view (FOV) cone-beam computed tomography (CBCT) images (20 TMJs) from 10 preorthognathic surgery patients and limited FOV CBCT images (40 TMJs) from 20 splint therapy-treated patients with temporomandibular disorders were collected. TMJ-specific reference system including a TMJ horizontal reference plane (TMJHP) and a local coordinate system (TMJCS) was constructed with landmarks on cranial base. Its application for TMJ measurements and its spatial relationship to common Frankfort horizontal plane (FHP) and maxillofacial coordinate system (MFCS) were evaluated.

RESULTS

Five relevant landmarks were selected to optimally construct TMJ-specific reference system. General parallelism between TMJHP and FHP was demonstrated by minimal angular and constant distance deviation (1.714 ± 0.811º; 2.925 ± 0.817 mm). Additionally, tiny axial orientational deviations (0.181 ± 6.805º) suggested TMJCS rivaled MFCS. Moreover, small deviations in orientations and distances (1.232 ± 0.609º; 0.310 ± 0.202 mm) indicated considerable reliability for TMJCS construction, with intraclass correlation coefficients (ICCs) ranging from 0.999 to 1.000. Lastly, slight discrepancies in translations and rotations revealed high reliability for condylar positional and morphological measurements (ICC, 0.918-0.999).

LIMITATIONS

TMJ-specific reference system was merely tested in two representative FOVs.

CONCLUSIONS

This study provides a universal and reliable reference system for TMJ assessment that is applicable to both limited and large FOV CBCT. It would improve comparability among diverse studies and enable comprehensive evaluations of TMJ positional and morphological changes during TMJ-related treatment follow-up such as splint therapy and disease progression.

Assessment of relationships between condylar fracture pattern and mandibular third molar position by panoramic radiography and computed tomography: A retrospective comparative study

BACKGROUND/AIM

Although previous studies have revealed the influence of the mandibular third molar (M3) on mandibular condylar fracture risk and that the presence of M3 could result in different incidences of condylar and angle fractures, there have been no analyses of the influence of M3 on fracture patterns. Moreover, evaluations of M3 position using panoramic radiography have shown insufficient accuracy. This study investigated the relationship between condylar fracture patterns and M3 position using panoramic radiography and computed tomography.

MATERIALS AND METHODS

This retrospective study included 280 patients with unilateral mandibular condylar fractures and ipsilateral M3 admitted to West China Hospital of Stomatology between January 2016 and June 2022. Patient medical records, panoramic radiographs, and computed tomography images were collected. The vertical and horizontal positions of M3 were classified using the Pell and Gregory system. M3 angulation was defined as the angle between the long axis of M3 and the mandibular occlusal plane. Condylar fracture patterns were classified as intracapsular (Types A-C) or extracapsular (neck and base). Data were analyzed using McNemar-Bowker test, Pearson chi-squared test, and Fisher's exact test.

RESULTS

Classification of M3 position differed significantly between panoramic radiography and computed tomography images (p < .05). There was a significant association between the mandibular condylar fracture pattern and M3 horizontal position on computed tomography (p < .05). Class I M3 position on computed tomography was associated with a higher incidence of intracapsular than extracapsular fractures, along with a higher incidence of Type B than base fractures; the opposite relationships were observed for Class II. No such association was identified on panoramic radiography.

CONCLUSIONS

Mandibular condylar fracture patterns were presumably influenced by M3 horizontal position on computed tomography. The imaging modality affected the classification of M3 position and subsequent analyses. Computed tomography is recommended for future studies to improve accuracy and reliability.

Condylar Position in the Treatment of Obstructive Sleep Apnea with a Mandibular Advancement Device: A Pilot Study

Objective  To evaluate, through a tomographic analysis, the positional changes of the condyle when using a mandibular advancement device (MAD) for the treatment of obstructive sleep apnea (OSA), and to assess if the condylar positions influence OSA polysomnographic patterns. Materials and Methods  Ten OSA patients underwent treatment with an MAD, and polysomnographic and tomographic examinations were performed before therapy (T0) and after MAD placement (T1). Results  By comparing the T0 and T1 measurements, we observed advancement and extrusion of the condyles in all patients ( p  < 0.001), as well as a decrease in the apnea-hypopnea index (AHI) ( p  < 0.001), increases in the mean ( p  = 0.001) and minimum ( p  < 0.001) oxyhemoglobin saturation, and a significant correlation between the anterior displacement of the right ( p  = 0.003) and left ( p  = 0.015) condyles. Discussion  Condylar advancement was directly correlated with OSA improvement: the greater the advancement, the better the AHI.

Simulating A Subcondylar Mandibular Fracture With Intraoral Open Reduction and Internal Fixation: A Novel Education Tool for Residents

Study Design

Face and content validation of a surgical simulation model.

Objective

Open reduction and internal fixation in displaced subcondylar mandibular fractures is standard care. This requires an extraoral (eg: retromandibular, transparotideal) or intraoral approach. An intraoral approach requires further training since specialized instrumentation such as the 90° screwdriver system and endoscopes might be needed. Currently, no simulation models are available for training residents in intraoral reduction and fixation of subcondylar mandibular fractures. Therefore, we present a validated simulation model for intraoral treatment of subcondylar mandibular fractures.

Methods

Based on a computer tomography data set, we designed and printed a 3D model of a mandible with a unilateral subcondylar fracture. To simulate intraoral work depth, it was positioned inside a dental phantom. We tested the model by a group of experts (n = 8), simulating intraoral reduction and fixation of a unilateral subcondylar fracture, using a 90° screwdriver system, a 1.0 subcondylar plate (lambda), and 5-6 mm screws.We assessed Face and Content validity by survey.

Results

We provided an open-source printable fracture model. Printing costs were approximately US $10. Experts "Agreed" the model resembling the real scenario and its use for training intraoral reduction and fixation of subcondylar mandibular fractures.

Conclusions

We developed a low cost, reproducible, open-source simulator for subcondylar mandibular fractures. Face and Content validity was achieved through evaluation by a group of experts.

Osteochondroma of the Mandibular Condyle: A Rare Case Presentation With Literature Review

Osteochondromas (OCs) are benign bone tumors characterized by their growth with a cartilage cap and typically occurring at the ends of long bones. Their occurrence in the head and neck region is infrequent, accounting for only around 1% of head and neck tumors. Notably, the mandibular coronoid process and the mandibular condyle are the primary sites where an OC is reported. Patients often exhibit facial asymmetry, limited mouth opening, and malocclusion. Possible treatment options depending on the condition include partial or total condylectomy, vertical ramus osteotomy, and supplementary orthognathic surgery. The recurrence rate of under 1%- 2% is reported after local resection.  In this case report, we present a unique case of an OC in a 27-year-old woman. It involved the mandibular condyle, resulting in a left-sided mouth deviation while opening and closing her mouth. The purpose of this article is to detail the clinical and radiographic features, histopathological aspects, and treatment strategies and differentiate potential diagnoses, for such OCs.

Spatial and Temporal Expression of Ectodysplasin-A Signaling Pathway Members During Mandibular Condylar Development in Postnatal Mice

A growing body of evidence emerging supported that ectodysplasin-A (EDA) signaling pathway contributed to craniofacial development. However, their expression in condyle has not been elucidated yet. This study investigated the expression patterns of EDA, EDA receptor (EDAR), and EDAR-associated death domain (EDARADD) in condyle of postnatal mice. Histological staining and micro-computed tomography (CT) scanning showed that as endochondral ossification proceeded, the thickness of chondrocyte layer decreased, and the volume of mandibular condyle increased. Osteoclasts remained active throughout the condylar development. Immunohistochemistry staining demonstrated that EDA was expressed in almost all layers during the first 2 weeks after birth. EDA shifted from the mature and hypertrophic layers to fibrous and proliferating layers at postnatal 3 weeks. As condyle matured, the distribution of EDA tended to be limited to hypertrophic layer. The distribution patterns of EDAR and EDARADD were consistent with EDA, while the level of EDAR expression was slightly lower. mRNA expression levels of EDA signaling pathway-related components increased after birth. Furthermore, we evaluated the expression of EDA using ATDC5 in vitro. EDA increased during the late stage of chondrogenesis. These findings proved that EDA signaling pathway was involved in condylar development and acted as a regulatory factor in condylar maturation and differentiation.

Assessing the reliability of CBCT-based AI-generated STL files in diagnosing osseous changes of the mandibular condyle: a comparative study with ground truth diagnosis

OBJECTIVES

This study aims to evaluate the reliability of AI-generated STL files in diagnosing osseous changes of the mandibular condyle and compare them to a ground truth (GT) diagnosis made by six radiologists.

METHODS

A total of 432 retrospective CBCT images from four universities were evaluated by six dentomaxillofacial radiologists who identified osseous changes such as flattening, erosion, osteophyte formation, bifid condyle formation, and osteosclerosis. All images were evaluated by each radiologist blindly and recorded on a spreadsheet. All evaluations were compared and for the disagreements, a consensus meeting was held online to create a uniform GT diagnosis spreadsheet. A web-based dental AI software was used to generate STL files of the CBCT images, which were then evaluated by two dentomaxillofacial radiologists. The new observer, GT, was compared to this new STL file evaluation, and the interclass correlation (ICC) value was calculated for each pathology.

RESULTS

Out of the 864 condyles assessed, the ground truth diagnosis identified 372 cases of flattening, 185 cases of erosion, 70 cases of osteophyte formation, 117 cases of osteosclerosis, and 15 cases of bifid condyle formation. The ICC values for flattening, erosion, osteophyte formation, osteosclerosis, and bifid condyle formation were 1.000, 0.782, 1.000, 0.000, and 1.000, respectively, when comparing diagnoses made using STL files with the ground truth.

CONCLUSIONS

AI-generated STL files are reliable in diagnosing bifid condyle formation, osteophyte formation, and flattening of the condyle. However, the diagnosis of osteosclerosis using AI-generated STL files is not reliable, and the accuracy of diagnosis is affected by the erosion grade.

The effect of myotonic dystrophy type 1 on temporomandibular joint and dentofacial morphology: A CBCT analysis

BACKGROUND

Myotonic dystrophy type 1 (DM1) is a neuromuscular multisystem disease. Early involvement of facial muscles may produce an extra load on the temporomandibular joint (TMJ) in DM1.

OBJECTIVES

This study aimed to investigate the morphological analyses of the bone components of temporomandibular joint (TMJ), and dentofacial morphology in myotonic dystrophy type 1 (DM1) patients by cone-beam computed tomography (CBCT).

METHODS

Sixty-six individuals (33 DM1, and 33 healthy subjects) age ranging from 20 to 69 were included in the study. Clinical examinations of the patients' TMJ regions and evaluation of dentofacial morphology (maxillary deficiency, open-bite, deep palate and cross-bite) were performed. Dental occlusion was determined based on Angle's classification. CBCT images were evaluated regarding mandibular condyle morphology (convex, angled, flat and round) and osseous changes observed in the condyle (normal, osteophyte, erosion, flattening, sclerosis). DM1-specific morphological and bony TMJ alterations were determined.

RESULTS

DM1 patients showed a high prevalence of morphological and osseous TMJ changes, and statistically significant skeletal alterations. The analysis of CBCT scans indicated the prevalent condylar shape among patients with DM1 was flat, the main osseous abnormality was flattening, there was a tendency towards skeletal Class II and a posterior cross-bite was frequently detected in DM1 patients. There was no statistically significant difference between the genders on the parameters evaluated in both groups.

CONCLUSION

Adult patients with DM1 presented a high frequency of crossbite, tendency to skeletal Class II and morphological osseous alterations of TMJ. The analysis of the morphological condylar alterations in patients with DM1 may be beneficial in the diagnosis of TMJ disorders. This study reveals DM1-specific morphological and osseous TMJ alterations to provide an appropriate orthodontic/orthognathic treatment planning to patients.

Relationship between Changes in Condylar Morphology and Masticatory Muscle Volume after Skeletal Class II Surgery

The treatment of dentofacial deformities generally includes orthognathic surgery in which mandibular condyle changes following surgery are a common cause of relapse. This study investigated the changes in the mandibular condyle and related muscles to identify the factors that affected the changes in the mandibular condyle after orthognathic surgery in skeletal class II patients. This research studied 60 joints in 30 patients with skeletal class II dentofacial deformities who received surgical orthodontic treatment, including bilateral sagittal split ramus osteotomy, and underwent computed tomography before and after orthodontic treatment. The mandibular condyle, masseter, and medial pterygoid muscles were reconstructed and measured in 3D. Condylar positional and morphology changes, masseter and medial pterygoid muscle volume, temporomandibular joint (TMJ) pain, and distal segment movement were analyzed. The study observed that both the masseter and medial pterygoid muscle volumes decreased with statistical significance. The changes in the horizontal direction were positively correlated with the amount of movement. The findings indicated that mandibular condyle changes were significantly affected by the movement of the distal segment, the medial pterygoid muscle volume, and the direction of the distal segment, which influenced the treatment's long-term stability after orthognathic surgery.

Evaluation of the Relationship of Screw Pullout and Plate Fracutre in Fixation of Mandible Condyle Fractures: A Mechanistic Study

BACKGROUND

The mandible is the most injured part of the facial skeleton, and 25-40% of mandibular fractures involve the condyle process. The aim of this study is to answer the question of the relationship between screw pullout and/or plate fracture during osteosynthesis.

METHODS

We tested polyurethane models of mandibles whose condylar process was cut (simulating a fracture) and fused using plates and screws.

RESULTS

A total of 672 plates were tested. A total of 25.6% of them were fractured during the test, with most being fractures of the base of the condyle. More screws (81.97%) are pulled out from the ramus than from the condyle-69.15%.

CONCLUSIONS

The gold standard in the osteosynthesis of condylar fractures is two straight plates. Other than these, there is no one-size-fits-all plate for every type of fracture. Plates fixed with fewer screws (smaller plates used in higher-lying fractures) are more likely to result in screw pullout. On the other hand, in plates fixed with more screws, plate fracture is more common.

Association between the Temporomandibular Joint Morphology and Chewing Pattern

This study aimed to investigate whether the morphology of the temporomandibular joint (TMJ) is associated with chewing patterns while considering skeletal morphology, sex, age, and symptoms of temporomandibular disorder (TMD). A cross-sectional observational study of 102 TMJs of 80 patients (age 16-40 years) was performed using pretreatment records of cone-beam computed tomography imaging of the TMJ, mandibular kinesiographic records of gum chewing, lateral and posteroanterior cephalometric radiographs, patient history, and pretreatment questionnaires. To select appropriate TMJ measurements, linear regression analyses were performed using TMJ measurements as dependent variables and chewing patterns as the independent variable with adjustment for other covariates, including Nasion-B plane (SNB) angle, Frankfort-mandibular plane angle (FMA), amount of lateral mandibular shift, sex, age, and symptoms of TMD. In multiple linear regression models adjusted for other covariates, the length of the horizontal short axis of the condyle and radius of the condyle at 135° from the medial pole were significantly (p < 0.05) associated with the chewing patterns in the frontal plane on the working side. "Non-bilateral grinding" displayed a more rounded shape of the mandibular condyle. Conversely, "bilateral grinding" exhibited a flatter shape in the anteroposterior aspect. These findings suggest that the mandibular condyle morphology might be related to skeletal and masticatory function, including chewing patterns.

retrospective evaluation of condylar morphology using panoramic radiography in a sample of Turkish population

BACKGROUND

The temporomandibular joint is one of the most complex anatomic structures. It takes a great role in masticatory system and helps to make possible some functions such as speaking, chewing and swallowing. Clinicians should have sufficient anatomical knowledge to assess relationships of the hard and soft tissues, including the mandibular condyle, glenoid fossa, articular eminence of the temporal bone, the articular disc and its attachments. The aim of this study was to evaluate the frequency of different types of mandibular condyles and its distribution according to the age and gender. It was also evaluated whether the condyle types were bilaterally symmetrical or not.

MATERIALS AND METHODS

A total of 1315 digital panoramic images which obtained from the patients suffering from the dental problems were assessed. Demographic data, condylar morphology were noted. All obtained data were analysed by using descriptive statistics. Morphology of mandibular condyles were classified into four shapes as identified in other studies, namely: type I - oval shape, type II - diamond shape, type III - bird beak shape, type IV - crooked finger shape. Two independent examiners, who have 19 and 7 years of experience in oral and dentomaxillofacial radiology, made a consensus and evaluated all images.

RESULTS

A total of 1315 digital panoramic images were assessed. Seven hundred sixty-seven [58.3%] the patients were female and 548 [41.6%] were male. The age range of patients was from 18 to 84 years. Right-left condyle types were found to be symmetrical in the range of 67% of the subpopulation examined in the study. For the consensus, 'oval' condyle was common on both the right and left, while 'crooked finger' condyle was the rarest.

CONCLUSIONS

The temporomandibular joint is the most important structure for all jaw functions such as speech, swallowing. In order for all these functions to continue in a healthy way, the anatomical structure should be known very well down to the finest detail. Identification of anatomical structures and their variations can play an important role in implant dentistry. Clinicians commonly prefer conventional radiologic methods to evaluate dentomaxillofacial region. Although the most of the variations are asymptomatic and require no treatment,correct identification of these findings will reduce unnecessary further diagnostic assessments and will provide more appropriate treatment plans.

The Condylar Effects of Mesenchymal Stem Cells, Low-Level Laser Therapy and Grape Seed Extract on Functional Mandibular Advancement of the Rat Mandible

Objective

Functional treatment of Class II malocclusion is expected to lead to adaptation in the condyle. This study aimed to evaluate the effects of adipose tissue-derived mesenchymal stem cells (ADMSCs), low-level laser therapy (LLLT), and grape-seed extract (GSE) on condylar growth after functional mandibular advancement.

Methods

Forty-five rats were randomly divided into 8 groups. Functional appliances were applied to all groups (n=6) except the control group (n=3). One group was treated with appliances only; the other six groups received various combinations of ADMSCs, LLLT, and GSE. Analyses for new osteoblasts and new bone formation, vascular endothelial growth factor, and Type II collagen were performed on condylar tissues, after an experimental period of four weeks. The quantitative data obtained from the results of the experiments were evaluated by H-score and analyzed using One-Way ANOVA by Tukey-Kramer multiple comparisons test (p≤0.05).

Results

Levels of all investigated parameters increased in all groups (p≤0.05). The highest increases were achieved by a combined application of functional appliance, ADMSCs, LLLT and GSE (p≤0.05). Single LLLT administrations or single GSE applications did not create a statistical difference from appliance alone (p>0.05). A positive effect of ADMSCs or LLLT on osteoblast formation, neovascularization, and Type II collagen level was apparent (p≤0.05), however, neither affected new bone formation (p>0.05).

Conclusion

This study shows that ADMSCs with LLLT and GSE applications provide differing levels of new osteoblast and bone formation, new vascular formation, and Type II collagen formation in rat condyles after functional mandibular advancement.

Evaluation of the mandibular condylar bone microarchitecture in people living with HIV

OBJECTIVES

People living with HIV (PLWH) have been shown to have lower bone density at the spine, hip, and radius. However, whether a similar bone phenotype is seen in craniofacial bones is not known. The goal of this study was to evaluate the bone microarchitecture of the mandibular condyle in PLWH.

METHODS

We recruited 212 participants, which included 88 HIV-negative participants and 124 PLWH on combination antiretroviral therapy with virological suppression from a single academic center. Each participant filled out a validated temporomandibular disorder (TMD) pain screening questionnaire and had cone beam computed tomography (CBCT) of their mandibular condyles. Qualitative radiographic evidence of temporomandibular joint disorders-osteoarthritis (TMJD-OA) assessment and quantitative microarchitecture analysis of their mandibular condylar bones were conducted.

RESULTS

There was no statistically significant difference in either self-reported TMD or in radiographic evidence of TMJD-OA in PLWH compared with HIV-negative controls. Linear regression analysis revealed that positive HIV status remained significantly associated with increased trabecular thickness, decreased cortical porosity, and increased cortical bone volume fraction after adjusting for race, diabetes, sex, and age.

CONCLUSION

PLWH have increased mandibular condylar trabecular bone thickness and cortical bone volume fraction compared with HIV-negative controls.

Superior Dislocation of the Mandibular Condyle into the Middle Cranial Fossa: A Comprehensive Review of the Literature

The superior dislocation of the condyle into the cranium occasionally requires invasive procedures due to the absence of a timely diagnosis. This review analyzed the available clinical data to provide information on treatment decisions. The reports were assessed using electronic medical databases from inception to 31 October 2022. A total of 116 cases from 104 studies were assessed; among the patients, 60% and 87.5% of the affected women and men required open reduction, respectively. The ratio of closed to open procedures within 7 days after injury was maintained; however, closed reduction decreased over time, and all cases required open reduction after 22 days. Eighty percent of the patients with a total intrusion of the condyle required open reduction, whereas the frequency for both procedures was comparable in the remaining patients. Open reduction was significantly more frequently performed for men (p = 0.026, odds ratio; 4.959, 95% confidence interval; 1.208-20.365) and less frequently performed in cases with partial intrusion (p = 0.011; odds ratio: 0.186; 95% confidence interval: 0.051-0.684); the frequency varied according to the time until treatment (p = 0.027, odds ratio; 1.124, 95% confidence interval; 1.013-1.246). Appropriate diagnostic imaging and prompt diagnosis are indispensable for minimally invasive treatment of this condition.

Infinitesimal Periangular Pterygomasseteric Transectioning Approach for the Base Fractures of the Mandibular Condyle: A Technical Note and Quality of Life Outcome

Purpose Infinitesimal Periangular Pterygomasseteric Transectioning Approach (IPPTA) is a minimal access surgical approach utilized for the management of base fractures of the mandibular condyle. The aim of the study was to evaluate and report the long-term post-operative functional outcome using this surgical access approach. Materials and method A prospective clinical study involving 20 patients was undertaken to evaluate the post-operative functional and aesthetic outcome for the patients that underwent surgery for base fractures of the mandibular condyle using IPPTA. The various parameters assessed were wound healing, marginal mandibular nerve injury, diet intake, mandibular function, and any other complications at twelfth post-operative month. Results IPPTA provided adequate exposure to the condylar base fracture for open reduction and internal fixation (ORIF) and was found to have an uneventful post-operative recovery phase in terms of functional and aesthetic outcomes. Conclusion IPPTA involves utilizing a smaller incision and provides adequate exposure to the condylar base region for ORIF to establish a satisfactory form and function with a predictable outcome.

Deferoxamine mesylate enhances mandibular advancement-induced condylar osteogenesis by promoting H-type angiogenesis

BACKGROUND

The effect of functional orthopaedic treatment for mandibular deficiency relies on mandibular advancement (MA)-induced condylar new bone formation. However, this is not easy to achieve, especially in non-growing patients. Therefore, how to obtain reliable MA-induced condylar osteogenesis is a subject much worthy of study.

OBJECTIVE

To investigate whether deferoxamine mesylate (DFM) enhances MA-induced condylar osteogenesis in middle-aged mice.

METHODS

Forty 30-week-old male C57BL/6J mice were randomly divided into 4 groups: the control (Ctrl), DFM, MA + Ctrl and MA + DFM groups. After a 4-week experimental period, femurs, tibias and condyles were collected for morphological, micro-computed tomography and histological evaluation.

RESULTS

For long bones, DFM reversed osteoporosis in middle-aged mice by promoting H-type angiogenesis. For mandibular condyles, MA promoted condylar osteogenesis in middle-aged mice, thereby allowing the mandible to achieve a stable protruding position. In addition, DFM enhanced the volume and quality of MA-induced condylar new bone formation. Furthermore, histological analysis revealed that DFM enhanced MA-induced condylar subchondral ossification. Mechanistically, it was confirmed that DFM increased the number of H-type vessels and their coupled Osterix⁺ osteoprogenitors by upregulating the hypoxia-inducible factor (HIF)-1α signalling pathway, thereby enhancing MA-induced condylar osteogenesis.

CONCLUSION

Applying DFM to enhance MA-induced condylar osteogenesis through H-type angiogenesis is expected to be an effective strategy to achieve favourable functional orthopaedic treatment effectiveness in non-growing patients.

Oral functioning after open versus closed treatment of unilateral condylar neck or base fractures: A two-centre controlled clinical trial

BACKGROUND

Oral functioning and rehabilitation in patients after condylar trauma can be measured by objective functional outcomes and patient-reported outcomes. The similarities or differences between these outcomes may contribute to the decision if open treatment (OT) or closed treatment (CT) will obtain the most advantageous results.

OBJECTIVES

The aim of this study was to compare OT versus CT for unilateral condylar mandibular neck or base fractures in a two-centre controlled clinical trial by objective functional outcomes and patient-reported outcomes measured at 6 weeks and 6 months follow-up. Additionally, these outcomes were compared within each group.

METHODS

Patients were enrolled between January 2017 and November 2019. In one centre, patients received OT by extra-oral open reduction and internal fixation. In another centre, patients received CT by maxillomandibular fixation. Objective measurements included the mixing ability test (MAT) and mandibular active range of motion (ROM). Patient-reported outcomes included the mandibular function impairment questionnaire (MFIQ) and visual analogue scale (VAS) for pain. Independent t-tests and Mann-Whitney U-tests were used to determine differences between the treatment groups at 6 weeks and 6 months follow-up. Paired t-tests and Wilcoxon signed rank tests were used to determine differences within each group.

RESULTS

Thirty-three patients were enrolled. No differences were found between the groups treated with OT or CT for MAT, ROM, MFIQ and VAS. Both groups showed functional improvement.

CONCLUSION

Good objective functional outcomes and patient-reported outcomes were achieved with both OT and CT in patients with unilateral condylar mandibular neck or base fractures.

Effects of condyle on disc status of the reducing and nonreducing anterior disc displacement of the temporomandibular joint based on 3D reconstructive imaging: a pilot study

OBJECTIVES

Morphologic study is a common approach in the field of anterior disc displacement (ADD) pathology; however, analysis based on 3D reconstructive imaging has not been investigated. This study investigated the association between ADD and the status of the mandibular condyle and articular fossa.

METHOD AND MATERIALS

Thirty-four patients were divided into a normal articular disc position (NADP) group, an ADD with reduction (ADDwR) group, and an ADD without reduction (ADDwoR) group. Images reconstructed were used to determine multiple grouped comparisons of these three different types of disc position, and the diagnostic efficacy for the morphologic parameters with significant grouped difference was analyzed to assess.

RESULTS

The condylar volume and condylar superficial area of the NADP, ADDwR, and ADDwoR groups exhibited obvious changes (P < .05). A multivariate logistic ordinal regression model showed that the condylar volume (odds ratio [OR], 1.011; regression coefficient [RC] = .011, P = .018), superior joint space (OR, 8.817; RC = 2.177; P < .001), and medial joint space (OR, 1.492; RC = 0.400; P = .047) had a significantly positive impact on the groups.

CONCLUSION

The mandibular condyle and articular fossa in temporomandibular joint ADD exhibited altered dimensions. The condylar volume, condylar superficial area, superior joint space, and medial joint space could be considered as promising biometric markers for assessing ADD, and were investigated in this current pilot study. (Quintessence Int 2023;54:156-166; doi: 10.3290/j.qi.b3512027).

Mandibular condyle changes in rats with unilateral masticatory function

OBJECTIVE

Certain malocclusions or unilateral tooth loss can lead to asymmetric functional load of the two mandibular sides during mastication and induce skeletal asymmetries to the condylar process of growing individuals. However, in adults, asymmetric function may have a different impact. The aim of the present study was to investigate three-dimensionally the effects of unilateral masticatory function on the condylar process morphology in growing and adult rats and the adaptive processes to differential condylar loading.

MATERIALS AND METHODS

Fifty-six growing and adult Wistar rats aged 4 and 26 weeks respectively were obtained. The maxillary right molars of the experimental animals were extracted and all animals were followed for 12 weeks. Three-dimensional images were obtained by an in-vivo microcomputed tomography (micro-CT) examination. The following measurements were studied: condylar process height, condylar base width, and condylar cross-sectional surface.

RESULTS

While no differences were found with regards to condylar process height and base width, the cross-section of the condyle on the extraction side did not increase during growth in the young rats. No such differences were found in adults. Young rats had statistically significantly shorter condylar height, base width and cross-sectional surface than the adult rats and showed significant growth of these structures during the experimental period.

CONCLUSION

Condylar height and base width growth are not hindered by reduced occlusal function, contrary to the average cross-sectional surface, which implies that the condyle form of growing individuals becomes thinner while maintaining its length, in the absence of occlusal stimuli. The condyle of adult rats with extractions is less affected by occlusion changes.

[Quality Evaluation of Temporomandibular Joint Images from 3 High-resolution Dynamic Sequences]

Objective To compare the image quality of three high-resolution dynamic MRI methods for evaluating the motion of temporomandibular joint disc and condyle. Methods Twenty-five patients with suspected temporomandibular joint disorders were examined by single-shot fast spin-echo (SSFSE),fast imaging employing steady-state acquisition (FIESTA),and spoiled gradient echo (SPGR) on the oblique sagittal position.Two radiologists performed subjective and objective evaluation on the images with double-blind method.The subjective evaluation included the signal intensity of mandibular condyle,articular disc,soft tissue around articular disc,and lateral pterygoid muscle,the contrast between articular disc and condyle,the contrast between articular disc and surrounding soft tissue,condylar motion,and disc movement.The objective evaluation indexes included image signal intensity,signal-to-noise ratio (SNR),and contrast-to-noise ratio (CNR).The subjective and objective indexes of the image quality were compared between the three sequences. Results The SSFSE sequence had lower signal intensity of articular disc and higher signal intensity of condyle and surrounding soft tissue than FIESTA and SPGR sequences (all P<0.001).The SPGR sequence showed higher signal intensity of lateral pterygoid muscle than the SSFSE and FIESTA sequences (P=0.017,P<0.001).Among the three sequences,SSFSE sequence showed the clearest articular disc structure (χ2=41.952,P<0.001),the strongest contrast between articular disc and condyle (χ2=35.379,P<0.001),the strongest contrast between articular disc and surrounding soft tissue (χ2=27.324,P<0.001),and the clearest movement of articular disc (χ2=44.655,P<0.001).SSFSE and FIESTA sequences showed higher proportion of disc displacement and reduction than SPGR sequence (all P<0.001).The CNR (χ2=21.400,P<0.001),SNR (χ2=34.880,P<0.001),and condyle signal intensity (F=337.151,P<0.001) demonstrated differences among SSFSE,FIESTA,and SPGR sequences.The CNR of SSFSE sequence was higher than that of FIESTA sequence (P<0.001),while it had no significant difference between SSFSE and SPGR sequences (P=0.472).In addition,the SSFSE sequence had higher SNR and signal intensity than FIESTA and SPGR sequences (all P<0.001). Conclusion The best image quality can be observed from SSFSE sequence where both the structure and movement of temporomandibular joint are well displayed.Therefore,SSFSE is preferred for the examination of temporomandibular joint movement.

The Role of Maxillofacial Structure and Malocclusion on Condylar Displacement in Maximum Intercuspation and Centric Relation in Patients Seeking Orthodontic Treatment-A Scoping Review

BACKGROUND

Available knowledge about malocclusion and cephalometric variables and their connection with an increased risk of condylar displacement (CD) is scarce. This article aims to present current information on the relationship between centric relation-maximum intercuspal position discrepancies and maxillofacial morphology and malocclusion in patients seeking orthodontic treatment as well as to identify those who require expanded diagnostic evaluation for this disorder.

METHODS

This review analyzed the PubMed, Cochrane Library, Web of Science, and Scopus electronic databases up to February 2022. Keywords and additional manual searches were performed. Literature selection was based the PRISMA-ScR checklist. The JBI Critical Appraisal Tool assessed the methodological quality of included studies.

RESULTS

The databases search provided 2321 studies. A total of 10 studies were included in this review after eligibility criteria and JBI assessment. This review was separated into five parts that evaluated CD correlations depending on the following: maxillofacial structure in different vertical and sagittal skeletal patterns, vertical, horizontal, and transverse malocclusions.

CONCLUSIONS

A hyperdivergent facial skeletal structure is a risk factor for increased CD, particularly in the vertical dimension. The condylar processes are usually displaced in a posteroinferior direction. Further studies are warranted to elucidate the relationship among remaining skeletal and dental malocclusions and the occurrence of CD.

Three-Dimensional Assessment of Temporomandibular Joint Morphology and Facial Asymmetry in Individuals with Different Vertical Skeletal Growth Patterns

The aim of the current study was to investigate, by means of Cone-Beam Computed Tomography (CBCT), condyle−fossa relationship, temporomandibular joint (TMJ) morphology and facial asymmetry in subjects with different vertical skeletal growth patterns. CBCT of 56 patients (112 TMJs) were categorized into three groups according to the mandibular plane angle (MP): Hypodivergent (MP ≤ 23°), Normodivergent (23° < MP < 30°), and Hyperdivergent (MP ≥ 30°). TMJ spaces, width and depth of the condyle and thickness of the fossa were measured. Horizontal and vertical measurements were used to assess facial asymmetry. One-way Analysis of Variance (ANOVA) and post-hoc Turkey tests were computed for the between-groups comparison. Statistical significance was set at p < 0.05. Larger anterior joint space and smaller condylar dimensions (medio-lateral diameter and medio-lateral thickness) were observed in the hyperdivergent group compared to the normodivergent and hypodivergent groups. Right condylar distances to midsagittal plane were significantly larger than left distances in all the three groups. A vertical pattern of growth in healthy individuals seems to be associated with condylar position and dimension, while facial asymmetry values do not differ among different vertical groups.

Evaluation of Cortical Bone Formation on Mandibular Condyle in Asymptomatic Adolescents and Young Adults Using Cone-Beam Computed Tomography

The aim of this study was to evaluate cortical bone formation on the mandibular condyle using cone-beam computed tomography (CBCT) in asymptomatic adolescents and young adults and to evaluate the relationship between age and sex. CBCT images that can evaluate the shape of the mandibular condyle were selected from asymptomatic patients aged 13−25. The degree of cortication on the mandibular condyle (CMC) was evaluated using CBCT images reconstructed in the axial, sagittal, and coronal planes. CBCT data of 829 patients (413 males, 416 females) were selected and then the left and right images of all patients were acquired; consequently, a total of 1658 temporomandibular joint-related images were evaluated in this study. The degree of CMC was correlated with age in men and women (p < 0.05). The frequency of CMC 0 disappeared in woman aged 20 years and in men aged 21 years. Cortical bone formation of the mandibular condyle was completed at age 22 years in women and 24 years in men. The degrees of cortical bone formation of the mandibular condyle between men and women showed significant differences between the ages of 15−19 and 22 years. This difference can be interpreted as a different mandible growth period between the sexes.

Relationship between Posterior Permanent Dentition Pattern and Radiographic Changes of the Mandibular Condyle

This study assessed the relationship between posterior permanent dentition and radiographic changes of the mandibular condyle. This descriptive, cross-sectional study was conducted on 300 panoramic radiographs of patients over 40 years of age (188 females and 112 males). Panoramic radiographs were evaluated for condylar changes such as flattening, subcortical sclerosis, subcortical cyst, erosion, osteophytes, and generalized sclerosis. Presence of muscle pain and temporomandibular joint (TMJ) pain and sounds, and history of TMJ trauma were also assessed. The occlusal scheme of posterior teeth was analyzed according to the Eichner's index. The frequency of condylar changes was calculated in the right and left sides, and their association with posterior permanent dentition was analyzed by the Chi-square test (alpha = 0.05). The frequency of flattening, muscle pain, TMJ sounds, and erosion was 11.7%, 9.7%, 5.7%, and 3.7% in the right side, respectively. The frequency of flattening, muscle pain, erosion, and subcortical cyst was 12%, 9.3%, 5%, and 5% in the left side, respectively. The frequency of bilateral muscle pain, flattening, TMJ sounds, and TMJ pain was 18%, 16.7%, 11.7%, and 9.3%, respectively. Cases with TMJ trauma, generalized sclerosis, and osteophytes were few. According to the Eichner's index, most patients with condylar changes had classes A and B, and a smaller percentage had class C. No significant difference was noted between healthy individuals and those with condylar changes regarding dentition patterns. No relationship existed between condylar changes and posterior permanent dentition pattern.

The Correlation Between Morphologic Characteristics of Condyle and Glenoid Fossa with Different Sagittal Patterns of Jaw Assessed by Cone-Beam Computed Tomography

OBJECTIVE

This study aimed to determine the relationship between the morphologic characteristics of condyle and glenoid fossa in different sagittal skeletal patterns using cone-beam computed tomography.

METHODS

In this cross-sectional study, the lateral cephalometric and cone-beam computed tomography images of 90 patients were evaluated. The patients were categorized into three equal groups of sagittal skeletal patterns, according to the ANB angle. The greatest anteroposterior and mediolateral diameters of the mandibular condyles, as well as the angle between the long axis of the mandibular condyles and the midsagittal plane, were measured on the axial view of cone-beam computed tomography images. The anterior joint space, superior joint space, posterior joint space, articular eminence inclination, depth of the glenoid fossa, and width of the glenoid fossa were also measured on the central sagittal slices. One-way analysis of variance (ANOVA), Tukey's post hoc test and chi-square test were performed.

RESULTS

Patients with the skeletal Class III had a significantly higher articular eminence inclination, while Class II patients had a lower articular eminence inclination (P = .001). In Class III patients, the depth of the glenoid fossa was greater, and the width of the glenoid fossa was smaller than in the other groups (P < .01). The anterior and posterior joint space did not show any significant differences between the 3 groups.

CONCLUSION

There were significant differences in some morphological characteristics of the condyle and glenoid fossa in patients with different sagittal skeletal patterns; therefore, this relationship should be considered in the treatment of these patients.

The Treatment Perspective of Pediatric Condyle Fractures and Long-Term Outcomes

PURPOSE

In our study, the characteristics, treatment approach and long-term outcomes of condyle fractures treated in the pediatric plastic surgery and reconstruction unit in the last 10 years were evaluated.

MATERIALS AND METHODS

This study consisted of two retrospective and prospective sections with the participation of pediatric patients with condylar fractures who were treated in the Plastic, Reconstructive and Aesthetic Surgery clinic of a university hospital in the last 10 years. In the retrospective section, data were obtained from the electronic patient records and patient files regarding the treatment applied, as well as the characteristics of the patient and condyle fractures. In the perspective section, patients were invited to the clinic and the effectiveness of the treatment was evaluated. Statistical analyses were performed with SPSS (Statistical Package for Social Sciences) for IBM 25 package program.

RESULTS

It was determined that 55.8% of the pediatric patients had accompanying facial fractures, and 72.4% had unilateral condyle fractures. It was determined that 59.5% of the pediatric patients underwent intermaxillary fixation (IMF). Physical complications were seen in 6.75% in the long term after treatment.

CONCLUSION

Falling from height and traffic accidents, which are the most important factors in the occurrence of condyle fractures, should be eliminated by increasing parental attention and awareness. Surgical treatment should be considered in the treatment of pediatric condyle fractures, especially if there are accompanying facial and mandible bone fractures.

Three-dimensional radiological anatomy of condyle trabecular bone based on a Volume-of-Interest analysis

OBJECTIVES

Three-dimensional radiological anatomic characteristics of condyle trabeculae was obtained quantitatively based on a volume-of-interest (VOI) analysis.

METHODS

Nine human mandibular condyle specimens were scanned by micro-computed tomography (micro-CT). A total of 34 VOIs were selected from each condyle specimen, which were divided into six layers and four parts to analyze the morphological characteristics of trabeculae based on cylindrical VOIs with a diameter and height of 2 mm. One-way analysis of variance was used to compare the regional differences of morphological parameters among each layer and part.

RESULTS

Values for bone mineral density, bone volume/total volume, trabecular thickness, and trabecular bone number were greater in the anterior part compared with the posterior part; and the lateral part was larger than the medial part in the first, second, and third layers, while the medial part was larger in the fourth and fifth layers; these values in the first and sixth layers were much larger, while those in the third and fourth layers were smaller. Bone surface area/bone volume, trabecular spacing, and trabecular bone pattern factor were larger in the posterior part than in the anterior part; and the lateral part was larger than the medial part in the fourth and fifth layers, while the medial part was larger in the first and second layers.

CONCLUSIONS

The morphological distribution of VOIs was anisotropic within trabecular bone of human mandibular condyles. The upper and lower ends of trabecular bone were much more compact, with higher bone density, trabecular thickness, and trabecular number than in the middle layers.

Profile of patients with TMJ dislocation in a level-1 emergency hospital: A cross-sectional study

OBJECTIVE

To describe a cross-sectional study of TMJ dislocation in a Brazilian level-one trauma center.

METHODS

The data were collected and analyzed from electronic medical records in a period from 2013 to 2020.

RESULTS

Bilateral TMJ dislocation occurred in the majority of cases, being reduced by the Nélaton maneuver associated with Barton's bandage. The average time between the dislocation and specialist appointment was 30.69 hours. Elderly patients were associated with an increased number of recurrent dislocations (p = 0.03). Furthermore, a longer dislocation time was associated with the reduction under intravenous (IV) sedation (p < 0.05).

CONCLUSION

The literature is still scarce concerning demographic data, treatment modalities, and follow-up. More studies are necessary to better understand TMJ dislocation management.

Characteristics of patients with temporomandibular joint idiopathic condylar resorption

OBJECTIVE

To investigate characteristics of temporomandibular joint (TMJ) idiopathic condylar resorption (ICR) and analyze the related factors.

METHODS

A total of 755 consecutive patients (150 with ICR and 605 with anterior disc displacement [ADD]) from July 2015 to December 2018 were recruited. A comprehensive questionnaire characterizing the multidimensional impact of the TMJ was designed. Clinical examination and radiological evaluation were also performed. The odds ratio for each variable in the ICR group versus the ADD group was computed using logistic regression analysis.

RESULTS

Multivariate logistic regression analysis showed significant correlations between mouth opening restriction, disease course, mandibular retrusion, mandibular retrusion progression, skeletal Class II profile, and overjet in ICR patients.

CONCLUSION

These results suggest that a longer ADD disease course might have a strong relationship with ICR.

Gli1+ Osteogenic Progenitors Contribute to Condylar Development and Fracture Repair

The condyle plays a pivotal role in mandible development, which is regulated by various signaling molecules. The hedgehog (Hh) signaling pathway is known to modulate several processes during bone formation. However, the role of Gli1, as the read-out of Hh signaling activity, in condylar development and fracture healing has not been clarified. In this study, we discovered that a population of Gli1+ cells residing immediately below the cartilage functions as osteogenic progenitors by using Gli1-Cre ^ERT2 ;tdTomato mice. These Gli1+ cells contributed to nearly all osteoblasts in the subchondral bone during condyle postnatal development. Interestingly, Gli1-lineage cells could differentiate into osteoblasts and chondrocytes during fracture healing. Inhibiting Wnt/β-catenin signaling downregulated the proliferation and differentiation of Gli1+ cells in vitro. These findings suggest that Gli1+ progenitor cells participate in not only normal bone formation but also fracture healing; moreover, these cells may provide a potential target for promoting bone regeneration of the mandible.

The use of SPECT/CT to assess resorptive activity in mandibular condyles

The aim of this study was to clarify the clinical significance of bone metabolism in the mandibular condyles in determining condylar resorptive changes. Twelve condyles of patients with idiopathic condylar resorption and degenerative joint disease were analysed using ^99mTc HMDP SPECT/CT at baseline and subsequent computed tomography during the follow-up period. Twenty-two healthy condyles were enrolled as controls. After generating three-dimensional SPECT/CT images, two independent observers scored the degree of condylar uptake and measured the morphological changes in the condylar height and condylar volume. In the group with positive condylar uptake, the follow-up computed tomography showed significant decreases in condylar height (-1.69 ± 0.93 mm) and condylar volume (-12.51 ± 10.30%) when compared to healthy controls (condylar height, 0.09 ± 0.54 mm; condylar volume, -0.29 ± 4.22%) (P < 0.001). Moreover, the degree of uptake correlated with the changes in condylar height (observer 1, P = 0.012; observer 2, P = 0.039) and condylar volume (observer 1, P = 0.005; observer 2, P = 0.037). These results suggest that condylar bone metabolism is closely related to the resorptive activity. Thus, SPECT/CT would be useful in the prognostic evaluation or determination of treatment strategies for idiopathic condylar resorption and degenerative joint disease.

Three-dimensional condylar displacement and remodelling following correction of asymmetric mandibular prognathism with maxillary canting

The aim of this study was to investigate the three-dimensional condylar displacement and long-term remodelling following the correction of asymmetric mandibular prognathism with maxillary canting. Thirty consecutive patients (60 condyles) with asymmetric mandibular prognathism >4 mm and occlusal canting >3 mm, treated by Le Fort I osteotomy and bilateral sagittal split ramus osteotomy, were included. Spiral computed tomography scans obtained at different periods during long-term follow-up (mean 17 ± 7.2 months) were gathered and processed using ITK-SNAP and 3D Slicer. The condyles were subjected to translational and rotational displacements immediately after the surgery (T2), which had not fully returned to the original preoperative positions at the last follow-up (T3). Condylar remodelling was observed at the last follow-up (T3), with the shorter side condyles subjected to higher surface resorption and overall condylar volume loss. The overall condylar volume on the shorter side was significantly reduced compared to the volume on the elongated side (-11.9 ± 90.6 vs -131.7 ± 138.2 mm³; P = 0.001). About 73%, 87%, 53%, and 54% of the shorter side condyles experienced resorption on the posterior, superior, medial, and lateral surfaces, respectively; in contrast, only 50% of the elongated side condyles showed resorption on the superior surface. Higher preoperative asymmetry was significantly correlated with increased postoperative condylar displacement (P < 0.05). The vertical asymmetry and the vector of condylar displacement were associated with the resultant remodelling process. It is concluded that condylar resorption of the shorter side condyle, which may affect the long-term surgical stability, has to be considered.

Morphological variations of the condylar head among children aged 4-15 years: A panoramic study

BACKGROUND

Growth and development of dentocraniofacial complex occurs during various stage of development of dentition with TMJ as one of its centres of growth. The condition of temporomandibular joint can be visible from its condylar head form; therefore, it is crucial to recognize the normal morphology of condylar head during different stages of development of dentition.

AIMS

The aim of the study is to view the morphological appearance of condylar head during primary dentition, mixed dentition and permenant dentition.

SUBJECT AND METHODS

400 panoramic images of 194 boys and 296 girls were collected and were divided into three groups bases on the stage of dentition. Shape of the condylar head were determined by tracing the print out of the panoramic image on an X ray viewer.

RESULTS

The study showed that during primary dentition stage shape of the conylar head was dominated by round shape and as growth and development occurs the condylar head shape changes to convex.

CONCLUSION

The study describes the normal morphology of mandibular condyles in a child population attending The dentition status as well as growth of craniofacial has a significant role in determining condylar morphology.

[Clinical and imagenological evaluation of the temporomandibular joint in patients undergoing condylectomy for the treatment of unilateral hyperplasia. Case series study]

Unilateral condylar hyperplasia is a non-neoplastic and self-limiting overgrowth of the mandibular condyle that usually begins during puberty, predominates in women and is considered an aberration of the normal growth mechanism of the condyle. This abnormal growth continues until the mid-20s and produces mandibular prognostism, facial and occlusal asymmetry with progressive displacement of the mandible to the contralateral side. The purpose of this report was to describe the cases of two female patients (23 and 25 years old) with unilateral condylar hyperplasia treated with high condylectomy and orthognathic surgery, with emphasis on clinical and imaging aspects and late post-surgical follow-up. Both patients presented satisfactory cosmetic results, without pain / noise related to the temporomandibular joint, mouth opening within the normal range, and class I canine and molar relationship. Computed tomography showed signs of remodeling in the affected condyle. High condylectomy combined with orthognathic surgery is an adequate treatment in cases of unilateral hyperplasia, restoring functionality and aesthetics to the patient. The bone remodeling observed in the intervened condyles seems to indicate that the condylar head maintains its adaptive capacity even in adult patients.

Muscle-Bone Relationship in Temporomandibular Joint Disorders after Partial Discectomy

OBJECTIVES

Temporomandibular joint osteoarthritis (TMJ-OA) causes degenerative changes in TMJ tissues. The inter-tissue crosstalk that exacerbates illness and organic changes in bone secondary to TMJ-OA potentially affects the muscles; therefore, patients with a muscular disease might also suffer from bone disease. However, knowledge gaps exist concerning muscle pathology at the onset of TMJ-OA. In this study, we documented the pathogeneses of the bone and muscle at the onset of TMJ-OA using a mouse model.

METHODS

We performed a partial resection of the TMJ disk to establish a mouse model of TMJ-OA. After the onset of TMJ-OA, we performed various measurements at 8, 12, and 16 weeks post-surgery in the defined groups.

RESULTS

The volume of the mandibular head in the TMJ-OA group was significantly greater than that in the control group. The temporal muscles in the TMJ-OA group were significantly deformed compared with those in the control group; however, between-group comparisons did not reveal significant differences in the mandibular head or temporal muscles after surgery. Therefore, we hypothesized that the degree of mandibular head hypertrophy would alter the temporal muscles. A subsequent analysis of the correlation between the bone and muscle confirmed that the deformity of the temporal muscle increased with increasing hypertrophy of the mandibular head. Temporal and masseter muscle contact was observed in 25% of surgical groups.

CONCLUSIONS

This study demonstrates that TMJ-OA progressed when organic changes occurred in bones and muscles, supporting the symbiotic relationship between bones and muscles.

Chondroblastoma of mandibular condyle: Case report and literature review

Chondroblastoma is one of the uncommon benign bone tumors, particularly when located in the mandibular condyle. Such a location makes its diagnosis difficult when based on only its clinical presentation and radiographic features. Herein the current report presents a case of chondroblastoma of the mandibular condyle: its clinical presentation, radiographic features, and immediate condylar reconstruction after resection. Additionally, the relevant literature is discussed to provide clinical recommendations for its diagnosis and treatment. Chondroblastoma has been reported so infrequently in the temporomandibular joint (TMJ), more common entities should first be considered in the differential diagnosis of masses in this location. Osteochondroma is the most frequent bone neoplasm in the TMJ. Since a correct diagnosis is difficult, additional tools, such as magnetic resonance imaging (MRI) and immunohistochemical analyses, should be used for diagnostics and surgical planning.

Three-dimensional condylar displacement and remodelling in patients with asymmetrical mandibular prognathism following bilateral sagittal split osteotomy

This study aims to assess the postoperative condylar displacement and the long-term condylar remodelling in patients with mandibular prognathism with transverse asymmetry after bilateral sagittal split ramus osteotomy (BSSRO). Forty-one consecutive patients (82 condyles) with a transverse mandibular asymmetry of more than 4 mm without occlusal canting treated by BSSRO were included. The preoperative (T1), immediate postoperative (T2) and long-term follow-up of an average of 16.2 months (T3) spiral computed tomography scans were gathered and processed to measure the condylar displacement and remodelling based on cranial base voxel-based and rigid regional registrations. The statistical analysis revealed that the majority of condyles (T1-T2) were transitionally displaced forwards, downwards and laterally, and were not fully returned to the preoperative position at T3. Condylar lateral displacement was significantly higher on the deviated side (DS) (P = 0.035). Non-deviated side (NDS) condyles were mainly subjected to upward pitch, medial yaw and medial roll compared with downward pitch, lateral yaw and lateral roll on DS. Condylar remodelling at T3 was observed, with the superior and posterior surfaces commonly subjected to bone resorption, whereas the anterior and medial surfaces were commonly subjected to bone apposition. Condylar volumetric changes were relatively comparable on NDS (3 ± 85.2 mm³) and DS (8.3 ± 111.7 mm³) condyles. Age, amount of preoperative asymmetry and follow-up period were not correlated with the condylar remodelling. Transitional and rotational displacements were to some extent significantly correlated with the condylar remodelling on both sides. Consequently, passive condylar seating without torque might prevent the long-term unfavourable condylar remodelling.

IGF-1 TMJ injections enhance mandibular growth and bone quality in juvenile rats

OBJECTIVES

Dentofacial orthopaedic treatment of mandibular hypoplasia has unpredictable skeletal outcomes. Although several biomodulators including insulin-like growth factor 1 (IGF-1) are known to contribute to chondrocyte proliferation, their efficacy in modulating mandibular growth has not been validated. The aim of this study was to determine the effect of locally delivered IGF-1 on mandibular growth and condylar bone quality/quantity in juvenile rats.

SETTING AND SAMPLE POPULATION

Institutional vivarium using twenty-four 35-day-old male Sprague-Dawley rats.

METHODS

PBS or 40 µg/kg (low-dose) IGF-1 or 80 µg/kg (high-dose) IGF-1 was injected bilaterally into the temporomandibular joints of the rats at weekly intervals for four weeks. Cephalometric and micro-computed tomography measurements were used to determine mandibular dimensions. Bone and tissue mineral density, volume fraction and mineral content were determined, and serum IGF-1 concentrations assayed.

RESULTS

Intra-articular administration of high-dose IGF-1 contributed to a significant 6%-12% increase in mandibular body and condylar length compared to control and low-dose IGF-1-treated animals. Additionally, IGF-1 treatment resulted in a significant decrease in the angulation of the lower incisors to mandibular plane. Condylar bone volume, bone volume fraction, mineral content and mineral density were significantly increased with high-dose IGF-1 relative to control and low-dose IGF-1 groups. Serum IGF-1 levels were similar between all groups confirming limited systemic exposure to the locally administered IGF-1.

CONCLUSION

Local administration of high-dose 80 µg/kg IGF-1 enhances mandibular growth and condylar bone quality and quantity in growing rats. The findings have implications for modulating mandibular growth and potentially enhancing condylar bone health and integrity.

A magnetic resonance imaging study on the temporomandibular joint disc-condyle relationship in young asymptomatic adults

The aim of this study was to assess the temporomandibular joint (TMJ) disc-condyle relationship in asymptomatic young adults. Ninety-three volunteers aged 19-23 years without temporomandibular disorder (TMD) symptoms underwent TMJ magnetic resonance imaging (MRI). The condylar centre and apex methods were used to measure and analyse the position of the disc in the oblique sagittal plane, and the reliability of the two methods was compared by calculating the intra-class correlation coefficient (ICC). Furthermore, 18 of the volunteers were randomly selected for three-dimensional (3D) reconstruction of the TMJ structure and the disc-condyle relationship. The 3D TMJ structure was established by semi-automatic segmentation of the condyle and articular disc in ITK-SNAP software; the condylar apex method was then performed. It was found that only 33.3% of the posterior edge of the articular discs were located in the normal 12 o'clock position with respect to the condyle. Moreover, this study suggests that the condylar centre method lacks accuracy when compared to the condylar apex method in regard to the measurement of the TMJ disc-condyle relationship (0 < ICC_cen < ICC_apex < 1). The position of the articular disc (left and right) was more forward in young women when compared to young men. However, there was no significant difference in the TMJ disc-condyle position between the left and right sides in the same individual, although the two joint discs in the same individual were not completely symmetrical.

A novel instrument for the prevention of condylar torque in bilateral sagittal ramus osteotomy when using bicortical screw fixation

When using the bilateral sagittal split osteotomy (BSSO) technique, rigid internal fixation (RIF) remains the standard method to accurately fix the distal and proximal osteotomy fragments. A concern with the use of RIF, especially with bicortical screws, is the increased risk of condylar torque and its functional consequences. This technical note introduces a new method for preventing torque of the mandibular condyles after BSSO, using a sagittal split space maintainer.

The need for secondary orthognathic surgery after high condylectomy in patients with active unilateral condylar hyperplasia

The need for secondary orthognathic surgery (OS) after a high condylectomy (HC) in patients with active unilateral condylar hyperplasia was assessed in 25 patients, reviewing patient characteristics and treatment planning. At 6-12 months after HC, 13 patients (52%) required secondary OS. The amount of mandibular dental midline shift before the HC (P=0.037), and a dental crossbite that was present before the HC (P=0.017) were significantly associated with the need for secondary OS. Overall, the mandibular dental midline coincided with the facial midline in eight patients (32%) at 2 weeks after HC. In 16% of the patients, no additional OS was needed despite this being the initial treatment plan. Additionally, the initially planned type of secondary OS was modified in six other patients. Early HC in skeletally immature patients provided very good results, both aesthetic and functional, with only two of them needing supplementary OS at 6-12 months after HC. The HC remains a valuable treatment in patients with active unilateral condylar hyperplasia, as it can eliminate the need for secondary OS and is very well tolerated by most patients.

Assessment of radiographic morphology of mandibular condyles: a radiographic study

BACKGROUND

Panoramic radiographs are the most common radiographic tool used by the dental clinicians to evaluate teeth, mandible and other related structures of the jaws. Mandibular condyle is an important anatomical landmark for facial growth, expressed in an upward and backward direction. The presentation of mandibular condyle differs widely among different group of ages and individuals.

MATERIALS AND METHODS

The retrospective cross-sectional study was conducted from Nov 2018 to March 2019 at Dow International Dental College (DIDC) Karachi that includes radiographic evaluation of 500 mandibular condyles. All retrievable OPGs were obtained and data were extracted regarding age, gender and condylar morphology.

RESULTS

The morphological appearances of mandibular condyle have great variation among different age groups and subjects. Normally we recognize five basic shapes i.e. Oval, Bird beak, crooked finger, diamond and mixed. Out of 250 pair of condylar heads that were evaluated, 50% were oval, 40% bird beak, 4.8% crooked finger and diamond 4.8%.

CONCLUSIONS

All four morphological types of mandibular condyles were observed and the oval shape condyles were most prevalent among both genders and all age groups. In future studies, the inclusion of other parameters and large sample size may provide unique information.