Bone Scintigraphy SPECT/CT Evaluation of Mandibular Condylar Hyperplasia

A facial asymmetry revealed: Active mandibular condylar hyperplasia

Condylar hyperplasia (CH) is a rare condition characterized by excessive growth of the mandibular condyle, leading to facial asymmetry, temporomandibular joint (TMJ) dysfunction, and functional impairments such as chewing and speech difficulties. This report presents a 15-year-old patient with mandibular deviation, limited TMJ mobility, and facial asymmetry. Diagnostic imaging, including CT and planar bone scintigraphy with 99mTc-HMDP, revealed active right condylar hyperplasia, with a 14.29% radiotracer uptake difference, surpassing the 10% threshold for metabolic activity. The patient underwent condylectomy, successfully restoring facial symmetry, masticatory function, and TMJ stability. Early physiotherapy complemented the surgical outcome. This case highlights the importance of combining anatomical and functional imaging modalities for accurate diagnosis and treatment planning. Advanced imaging, such as 3D CT and bone scintigraphy, plays a critical role in confirming condylar hyperplasia activity and guiding surgical decisions. Multidisciplinary management is essential, as timely intervention prevents progression, enhances aesthetics, and improves functionality. Condylectomy remains the treatment of choice for active CH, with orthognathic surgery reserved for severe deformities or malocclusion. Early recognition and comprehensive management of CH are crucial to optimizing patient outcomes and ensuring improved quality of life.

A Novel Virtual Planned-Orthodontic-Surgical Approach for Proportional Condylectomy in Condylar Hyperplasia

Background/Objectives: Condylectomy is a delicate and intricate procedure commonly employed in the management of temporomandibular joint (TMJ) disorders, osteochondromas, condylar hyperplasia, hemimandibular hyperplasia, and other pathologies affecting the condylar region. The advent of surgical cutting guides has introduced a new dimension to condylectomy procedures as they enable surgeons to plan and execute precise cuts with a heightened level of accuracy. In the literature already exists cases of cutting guide-based condylectomy, but they only depend on the mere mirroring procedure in virtual planning, which has accuracy limitations because it does not consider asymmetry of peri-condylar structures at the level of the ramus, body, and mandibular angle. Methods: CAD-CAM orthodontic preparation through the NEMOFAB Software was performed to correct the canting of the occlusal plane, following the "orthodontic first" technique. The same software was used for VSP of the surgical cutting guide to perform the condylectomy, basing not to the mere mirroring of the opposite side but considering the whole condylar-TMJ-glenoid fossa structure. Results: At 6 months follow-up, the patient showed good occlusion and an almost totally recovered lower third symmetry as median-upper and lower interincisive lines coincide with each other and with the chin median. A good occlusal and masticatory outcome was obtained. The joint structure was preserved with remodeling of the glenoid cavity caused by the presence of the joint disc, which was preserved during surgery. Conclusions: The goal of this study is to propose a method of therapeutic management of condylar hyperplasia that benefits from accurate pre-operative orthodontic treatment (orthodontics first) to maximize the results of proportional condylectomy, reducing post-operative orthodontic care as well as any need for any adjuvant orthognathic surgery. A new virtual surgical planning method is also proposed for creating a cutting guide that not only takes advantage of the mirroring technique to accurately calculate the amount of condyle to be cut but also considers the entire condyle-TMJ complex to perform a condylectomy that is more precise.

A proposed protocol for correlation between bone density in hemimandibular hyperplasia radiography and histopathological findings - A retrospective study

The role of low-dose computed tomography (LDCT) in surgical planning can be assessed based on the correlation among bone density (BD/HU), radiographic values, and the histopathological appearance of hyperplastic overgrowth in mandibular condyles (hemimandibular hyperplasia/osteochondroma). The aim of this study was to evaluate the correlation between LDCT indices of bone-density measurements in surgical planning and histopathological specimens. The patients incuded in this study underwent detailed radiological evaluation as preparation for further clinical procedures. Excised condyles were evaluated in terms of bone density index using LDCT, and then histopathologically to investigate the accuracy of surgical procedures and set the basis for future surgical planning. An index value between both condyles' bone densities represented the relative difference between the healthy condyle and the side with hemimandibular hyperplasia (HH). Patients with unilateral condylar hyperplasia (UCH) showed a statistical correlation between condyle heads with increased bone density (BD) and scintigraphic (SCI) values (p < 0.001). On the other hand, correlation between BD and histopathological studies alone was significant (p < 0.001). With the increase in BD measured in HU in UCH condyles, the overall value of fibrous cartilage layer thickness decreased (p < 0.001). Furthermore, histopathological evaluation indicated that increased bone density on the UCH side resulted in increased total thickness (p > 0.001). The proposed index measurements in the mandibular condyles based on LDCT/BD can be used to estimate the degree of required surgical resection. Results from LDCT radiographic studies correlate with histopathological specimens more than scintigraphy.

'Adaptable condylectomy' for acquired facial asymmetry and malocclusion caused by temporomandibular joint condylar hyperplasia

This article describes the 'adaptable condylectomy' and highlights two innovative treatment protocols for the variety of acquired facial asymmetry and associated malocclusion caused by condylar hyperplasia, as illustrated by the cases of seven patients presenting different manifestations of condylar hyperplasia. Protocol I (three cases) is applied for condylar hyperplasia with a normal occlusion and involves a high condylectomy, with the goal of guiding the mandible back to the original occlusion. Protocol II (four cases) is applied for condylar hyperplasia with diverse acquired malocclusions and involves condylectomy at a level adapted to the malocclusion, allowing the mandible to be guided back to the occlusion that pre-existed the active change caused by the condylar hyperplasia, or to a position as close to the midline as possible. Both protocols are followed by gradual self-correction of the acquired facial asymmetry. These protocols often obviate the need for further surgical intervention and, if further correction is needed, it is much simpler.

Single photon emission computed tomography (SPECT) diagnostic accuracy in active unilateral condylar hyperplasia: Retrospective study

The aim of this study was to assess the diagnostic accuracy of single photon emission tomography (SPECT) in unilateral condylar hyperplasia (UCH). To this end, 3D morphometric changes of the mandibles in one year were assessed (T0 vs. T1) and compared over SPECT results in T1, in a sample of 40 patients. A contingency table was constructed based on these results for SPECT diagnostic accuracy evaluation, classifying patients as SPECT true-positive, true-negatives, false positives and false-negatives. Additionally, the morphometric analysis was used to describe the presentation of mandibular changes using principal component analysis (PCA) and non-parametric statistics. We obtained diagnostic accuracy results of sensitivity 81%, specificity 63%, positive predictor value (PPV) 59%, negative predictor value (NPV) 83% and accuracy 70%, showing that SPECT yields poor results regarding accuracy diagnostic performance. The morphometric analysis showed that individuals without progress of asymmetry and those with more progress differ particularly in a group of landmarks representing the mental region and the right mandibular body. Based on these landmarks, difference among the four SPECT-accuracy groups was statistically significant (p < 0.001), where the landmark showing the largest change within a year had a mean increase of 1.13 + 0.66 mm. Within the limitations of the study, it seems that SPECT alone is not suitable for making surgical decisions regarding condylectomy in active UCH. Follow up with morphological assessment methods are recommended for confirming an active UCH in combination with SPECT.

Diagnostic performance of SPECT-CT imaging in unilateral condylar hyperplasia

Nuclear imaging plays an important role in the diagnostic path of patients with unilateral condylar hyperplasia (UCH). The purpose of this study was to determine the performance of single-photon emission computed tomography-computed tomography (SPECT-CT) in a large group of patients with suspected UCH. This study prospectively included 156 patients with a clinical presentation of progressive mandibular asymmetry. All patients underwent ^99 mTc-HDP SPECT-CT and extensive baseline and follow-up documentation. The relative activity of the ipsilateral condyle in relation to the contralateral condyle was calculated for both the mean and maximum count, and the diagnostic accuracy of different cut-off values was determined. The area under the receiver operating characteristic curve of the SPECT-CT scan was 0.892 for the mean count and 0.873 for the maximum count. The optimal cut-off of> 8% (SPECT-CT mean count) resulted in a sensitivity of 87.0% and a specificity of 88.6%. SPECT-CT showed good diagnostic performance in UCH; however the benefit of the CT scan is questionable and the potential disadvantages have to be weighed against the benefits when compared to standard SPECT scanning. When using SPECT-CT in the diagnostic path in UCH, a mean value cut-off of>8% for the relative activity between the condyles is most accurate.

Standard orthodontic treatment after condylectomy for patients with active unilateral condylar hyperplasia

INTRODUCTION

Unilateral condylar hyperplasia (UCH) is a progressive, nonneoplastic overgrowth of the condyle of the temporomandibular joint. For treating active UCH, a popular method combines orthognathic surgery with high condylectomy and orthodontic treatment. The goal of this study was to introduce a new method to correct asymmetry for active UCH.

METHODS

Retrospectively, 47 patients with active UCH were divided into horizontal-type, vertical-type, and combined-type. All patients were treated with condylectomy plus postsurgery standard orthodontics (CPSO) with applied miniscrews implanted in infrazygomatic crest and hard palate to intrude affected side of maxillary molars and apply intermaxillary traction for contralateral molars. Cone-beam computed tomography was taken at presurgery, postsurgery, and the end of orthodontics (T3).

RESULTS

In the vertical (n = 10) and combined (n = 28) types, deviation of the chin and the canting of the mandible and maxillary occlusal plane were significantly reduced at T3. A difference in the torque of bilateral maxillary first molar (U6) and bilateral mandibular first molar (L6) was significantly reduced at T3. The anterior, superior, and posterior joint spaces in the vertical-type and combined-type were significantly decreased at T3 compared with postsurgery. In contrast, in the horizontal-type group (n = 9), the deviation of the chin was corrected; however, the canting of the mandible and maxillary occlusal plane was significantly increased at T3 compared with presurgery.

CONCLUSIONS

CPSO restored facial and occlusal symmetry for vertical-type and combined-type active UCH and returned affected-side condyle to the glenoid fossa. However, CPSO was not suitable for treating the horizontal-type UCH.

Panoramic Radiograph and CBCT in Unilateral Mandibular Condylar Hyperplasia—A Case Report

Condylar hyperplasia (CH) of the mandible is a rare developmental disorder that results in enlargement of the condyle. It is predominant in females, mostly unilateral and self-limiting. This report presents a case of a 35-year-old female patient with unilateral condylar hyperplasia with an increase in vertical height of mandibular ramus of the affected side. After initial radiographic evaluation, the asymmetry index using a panoramic radiograph was determined and also analyzed using cone-beam computed tomography (CBCT). Condylar dimensions in all the planes were measured for both sides using CBCT. This case report emphasizes the importance of CBCT and its role in the diagnosis and assessment of mandibular condylar hyperplasia.

Case Report: unilateral condylar hyperplasia

Case: This report describes a clinical case of unilateral condylar hyperplasia (CH) with unique, atypical morphology. An important feature of this report is the documentation of a series of clinical photographs of the patient, showing a gradual increase in facial asymmetry associated with the CH. The main symptom reported in this case was facial asymmetry. The main intraoral clinical features observed in the patient were contralateral crossbite and ipsilateral open bite associated with CH. Surgical reshaping of the condyle was the treatment plan for this case. Conclusions: The main take away point from this case is the importance of obtaining previous photographs of the patient at different ages during case diagnosis, which helps the clinician to determine the approximate time of commencement of CH. This case also highlights the imaging features of rarely observed atypical shape of the hyperplastic condyle.

Utility of Single-Photon Emission Computed Tomography/Computed Tomography in Suspected Unilateral Condylar Hyperplasia: A Histopathologic Validation Study

PURPOSE

The purpose of this study is to evaluate the utility of hybrid single-photon emission computed tomography (SPECT) and computed tomography (CT) with technetium-99m methylene diphosphonate in patients with suspected active unilateral condylar hyperplasia (UCH) using histopathology as the reference standard.

METHODS

Twenty-four patients with suspected active UCH prospectively underwent technetium-99m methylene diphosphonate planar bone scintigraphy with SPECT/CT of the mandible. Qualitative and quantitative readings for growth activity were performed by 3 nuclear medicine physicians and the final diagnosis was derived from postoperative histopathological examination. Readings were reported as positive, equivocal, or negative. Total, maximum, and mean counts were recorded for each condyle on SPECT/CT images. The uptake of the index (suspected) condyle was expressed as a count ratio (R_total, R_mean, R_max), a percentage uptake (P_total, P_mean, P_max), background-corrected counts (B_total, B_mean, B_max), as well as CT-based condylar diameters (R_CT,P_CT) relative to the contralateral condyle.

RESULTS

Interobserver agreement was 0.79 and 0.83 for planar bone scintigraphy and SPECT/CT, respectively, with a total of 5 and 1 equivocal readings from the respective modalities. Surgery was performed in 22 patients; all of them had pathologically proven UCH. SPECT/CT was slightly more sensitive than planar bone scintigraphy (91 vs 78%) with identical specificity (96%). R_total, R_mean, P_total, and P_mean demonstrated area under the curve between 84% and 86%. Metrics based on CT diameters and background-corrected counts were not associated with UCH diagnosis.

CONCLUSIONS

Quantitative approaches based on total or mean count ratio or relative count percentage were equally predictive for UCH diagnosis; however, they were slightly less sensitive compared with qualitative technetium-99m methylene diphosphonate SPECT/CT evaluation. SPECT/CT evaluation has the potential to decrease the equivocal readings.

Active unilateral condylar hyperplasia: Assessment of the usefulness of single photon emission computed tomography

Background

This study aims to evaluate whether the uptake difference by the condyles evaluated using single photon emission computed tomography (SPECT) examination is useful for predicting the activity of the feature and the advance of this pathology.

Material and Methods

An observational and prospective study has been carried out on nine patients affected by unilateral condylar hyperplasia (UCH) with complete bone maturation, with a follow-up over 18 months. At the beginning of the study, a test-battery was conducted including dental casts, articular examination, teleradiography and cephalometry, computed tomography and SPECT, creating two groups of patients from a difference in uptake between both condyles greater than 10% over the follow-up period. Evolution of data obtained with the rest of the diagnostic tests were compared to confirm UCH activity predicted by SPECT.

Results

The comparison of both groups did not show hardly any significant differences, with little clinical significance. Deviation of the mandibular line, the size of the branches or condyles behaved similarly in both study groups.

Conclusions

From the data obtained in our study, we can conclude that the use of the difference in uptake between both condyles by applying the SPECT technique is not a valid approach for predicting clinical activity in cases of UCH.

Key words:Temporomandibular joint, facial asymmetry, single photon emission computed tomography, scintigraphy, condylar hyperplasia.

Imaging of the temporomandibular joint

Temporomandibular disorders are common, especially in young to middle-aged women, and most settle with supportive treatment. Imaging is indicated for the small percentage of cases that do not respond to conservative management and when the diagnosis is no doubt. The temporomandibular joint (TMJ) is a bilateral synovial articulation between the mandible and skull base. It has an intra-articular disc dividing the joint into superior and inferior compartments and the articular surfaces are lined with fibrocartilage. The normal imaging anatomy of the TMJ is described and illustrated. Different movements occur in each joint compartments: a hinge movement in the inferior joint space and translation or gliding in the superior joint space. Internal derangement is the commonest disorder affecting the TMJ and is most commonly due to disc displacement, followed by osteoarthritis and inflammatory arthritides. The imaging findings, primarily on magnetic resonance imaging (MRI) and computed tomography (CT), of internal derangement and less common disorders of the joint, are reviewed and illustrated. Optimal imaging protocols are discussed with detailed reporting guidelines.

Histologic findings and related diagnostic methods in condylar hyperactivity

Condylar hyperactivity (CH) is a rare condition that entails a progressive deviation and deformation of the mandible. There is no consensus regarding characteristic histopathological features or a standardized diagnostic process; thus, histopathological analysis of the condyle cannot confirm or exclude an active CH after condylectomy is performed. An electronic search was performed in Medline, Embase, Web of Science, LILACS and grey literature up to December 2019. Additionally, a manual search was performed. Risk of bias of the included studies was assessed using the Newcastle-Ottawa Scale and the Institute of Health Economics Quality Appraisal. All analyses were performed independently and in duplicate. Seventeen articles from 660 were included. Six articles were cross-sectional studies and 11 were case series. Almost all the articles (14) described an augmented thickness of the cartilage layer associated with cartilage islands within the subchondral bone in patients affected by CH. Histological findings seem to be mostly related to the age of the sample rather than a characteristic description of CH. No clear association was found between SPECT/scintigram uptake and a specific histological finding. Hence, there is a necessity for the development of specific tools for evaluating and reporting studies where histology is needed for diagnosis confirmation.

Assessment of relative uptake by mandibular condyles in a "normal" population

Hyperplasia of the mandibular condyle is self-limiting, but can lead to facial asymmetry, malocclusion, pain, and dysfunction of the temporomandibular joint (TMJ). Bone scintigraphy, particularly with single photon emission computed tomography (SPECT), is effective in assessing relative condylar uptake, but we know of no standardised methods or values. Our aim, therefore was to validate the values currently used to measure relative condylar uptake in our population. Between December 2015 and June 2018 44 patients had skull SPECT (15 male and 29 female patients, whose ages ranged from 4-33 years). They were having bone scans (hydroxydiphosphonate (HDP) -^99MTc, 740 MBq ev) for unrelated reasons and had no known abnormalities of the head, facial asymmetry, or symptoms of the TMJ. Two research workers measured the relative uptake between the condyles using the summed transaxial images. The Hospital Ethics Committee approved the investigation. The maximum difference in condylar uptake was 8.33% with research worker 1 and 8.77% with research worker 2, and the mean (SD) differences were 3.03 (0.17) % and 3.29 (0.18) %, respectively. Data were tested for normality, and the t test and one-way ANOVA were used to assess the significance of differences. None was found in total counts either between sexes or age groups, and there were none between the total counts measured by the two research workers. We conclude that our results are within the published ranges, and the variation in condylar uptake was less than 5% in 37/44 patients, and in none was it 9% or more. When the results indicate less than 10%, but there is a high clinical suspicion of active hyperplasia, surgeons should use their clinical judgement to decide whether condylar surgery is required.

Nuclear Medicine Imaging in the Dentomaxillofacial Region

Nuclear medicine studies evaluate physiology on a molecular level providing earlier detection of lesions before morphologic change is evident. ^99mTc-MDP and ¹⁸F-fluoride bone scans detect osteomyelitis earlier than radiographs and computed tomography (CT); aid in diagnosis of temporomandibular joint disorder; and evaluate activity of condylar hyperplasia, extent of Paget disease, and viability of bone grafts. ¹⁸F-FDG PET/CT distinguish between soft tissue and bone infections and diagnose osteomyelitis complicated by fracture or surgery. FDG PET is more accurate than CT alone and has a major role in staging, restaging, and assessing response to therapy for head and neck malignancies and in detecting sequelae of therapy.