Unilateral Condylar Hyperplasia Patients Research Articles

Bilateral TMJ Changes Secondary to Unilateral Condylar Hyperplasia

Background: Patients with unilateral condylar hyperplasia (UCH) may present with TMJ symptoms, rather than concerns or recognition of asymmetry. Localization of TMJ pain may be on the affected (long) side, unaffected side, or both. Flattening, severe erosion and internal derangement on the opposite side can be appreciated radiologically. This can be a red herring, shielding the true diagnosis of UCH from the contralateral side. We hypothesize that excessive growth of the ipsilateral condylar neck and head on the side of UCH results in an upward and backward force on the opposite side TMJ, with resultant symptoms and findings (condylar flattening, anterior disk displacement, eminence changes). The purpose of this paper is to highlight the bilateral TMJ findings in UCH, and address potential treatment strategies. Methods: This is a retrospective study involving radiologic and biographical data from subjects with TMJ UCH, as well as controls. Patient details and high quality Cone beam CT (CBCT) scans (1 mm slices or less) were analyzed. CT scans were digitized and morphometric points were placed using Planmeca software (Hoffman Estates, Illinois). Linear and volumetric measures were taken in reference to the eminence, TMJ space, condylar position, and neck lengths. Volumetric analysis of the condylar head and neck was done using Analyze 14.0 software (Overland Park, KS, USA). Results were assessed using univariate analysis (T-Wilcoxon test). Results: Forty patients were included (29 with UCH, 11 controls). The condylar head was flatter and erosive appearing on the contralateral UCH side compared to both ipsilateral side in the same subject, and compared to controls. Analysis between the affected and unaffected sides in patients with UCH showed a significant difference in condylar head and neck length ( P = .0019) and volume ( P = .0030); anterior glenoid space ( P = .035) and vertical height of condylar eminence ( P = .00044). The difference in ramus length was not significant ( P = .6533). Between the controls and the UCH patients, there was a significant difference in the variance in condylar head and neck length ( P = 1.98e-07) and volume between the 2 sides ( P = 1.94e-08) but not ramus length ( P = 1). The vertical height of the condylar eminence was smaller on the affected side than in the controls ( P = .0018) and the anterior glenoid space was significantly smaller on the unaffected side compared to the controls ( P = .0053). Conclusion: This study highlights TMJ morphological differences in patients with UCH. These differences in condylar and glenoid morphology are consistent and should be used to aid and underpin the diagnosis and direct treatment. Importantly, patients who present with TMJ pain and erosion on one side, should be assessed for opposite side UCH, as the underlying culprit.

Evaluation of optimal single-photon emission computed tomography reference value and three-dimensional mandibular growth pattern in 54 Chinese unilateral condylar hyperplasia patients

BackgroundThe research aimed to evaluate the optimal Single-Photon Emission Computed Tomography (SPECT) cut-off value in differentiating condylar growth activeness, to observe 3-dimensional (3D) mandibular growth pattern, and to explore the potential correlation between 3D measurement parameters and SPECT uptake ratios in Chinese unilateral condylar hyperplasia (UCH) patients.Methods Data of fifty-four Chinese UCH patients were analyzed retrospectively. All patients underwent SPECT within 1 month before or after the first CT examination (CT1); and received a second CT examination at least 12 months later (CT2). Data from CT scans were analyzed by comparing bilateral differences between CT1 and CT2. The sensitivity and specificity of SPECT were calculated by the receiver operating characteristic (ROC) curve. Pearson’s correlation analysis was performed to investigate whether the mandibular growth was correlated with SPECT value.ResultsSPECT had a sensitivity of 68.00% and a specificity of 72.41%, with an area under the ROC curve being 0.709. The optimal SPECT cut-off value for evaluating condylar activity has been determined to be 13%. In patients with an active growing condyle, there was a significant increase in Co-Gn and Co-Go, but not in Go-Gn, Go-MF, or MF-Gn. Pearson’s correlation analysis revealed no correlation between 3D measurement parameters and differences in relative condylar uptake ratios.ConclusionSPECT showed good diagnostic performance in UCH with the cut-off value of 13%. For those with an active growing condyle, the mandible grows diagonally and vertically, while the relative condylar uptake ratio was not directly related to mandibular growth.

Reference values of mandibular condylar growth activity: a study of SUVmax with quantitative bone SPECT/CT.

To assess the condylar growth activity (CGA) with quantitative bone single photon emission computed tomography/computed tomography (SPECT/CT) to establish reference values of maximum standardized uptake value (SUVmax) and cutoff values for identifying active unilateral condylar hyperplasia (UCH) in different ages. We analyzed the CGA of 58 UCH patients and that of 125 volunteers as a control group by SUVmax of quantitative bone SPECT/CT imaging. The SUVmax and the uptake difference between bilateral condyles among different age groups were analyzed. SUVmax cutoff values for detecting active condyle were calculated by receiver operating characteristic curve analysis. The condylar SUVmax in 10-19, 20-29, 30-39, 40-49 and 50-59 years old groups of volunteers were 6.24 ± 1.39, 4.76 ± 0.98, 3.23 ± 0.64, 3.00 ± 0.61 and 2.90 ± 0.53, respectively. The uptake difference between bilateral condyles in the control group was 3.84% ± 1.71%. The affected condylar SUVmax was significantly higher than that of the contralateral condyle in active UCH patients (6.03 ± 2.85 vs. 3.96 ± 1.07; Z = -5.264; P = 0.000). SUVmax of the affected condyles in active UCH patients was not statistically higher than condylar SUVmax in the corresponding age group (6.03 ± 2.85 vs. 5.50 ± 1.41; Z = -0.173; P = 0.863). SUVmax of the unaffected condyles was significantly lower than condylar SUVmax in the corresponding age group (3.96 ± 1.07 vs. 5.50 ± 1.41; Z = -5.833; P = 0.000). SUVmax cutoff values for identifying active condyle were 6.26 and 4.53 in patients of 13-19 and 20-29 years old, respectively. The condylar SUVmax varied with age. Different cutoff values of condylar SUVmax should be employed for diagnosing active UCH for patients in different ages.

Molecular basis of unilateral condylar hyperplasia?

Unilateral condylar hyperplasia (UCH) causes progressive asymmetry of the mandible. The aetiology of this growth disorder is unknown. A two-centre prospective study was established, and 10 consecutive adult UCH patients scheduled for high condylectomy were included. The resected condylar tissue was divided into two parts, one for regular histopathology and one for DNA extraction. A panel of eight selected overgrowth genes (AKT1, AKT3, MTOR, PIK3CA, PIK3R2, PTEN, TSC1, TSC2) were sequenced using next-generation sequencing, with coverage of a minimum 500 times in order to be able to detect low-grade mosaicisms. Subsequently, untargeted whole exome sequencing (WES) was performed to detect variants in other genes present in three or more patients. No mutation was detected in any of the overgrowth genes, and untargeted exome sequencing failed to detect any definitively causative variant in any other gene. Ten genes had a rare variant in three or more patients, but these cannot be designated as causative without additional functional studies. The hypothesis that the cause in at least some patients with UCH is a somatic mutation in a gene that controls cell growth could not be confirmed in this study.

Condylectomy as the treatment for active unilateral condylar hyperplasia of the mandible and severe facial asymmetry: retrospective review over 18 years

Unilateral condylar hyperplasia (UCH) of the mandible is a disorder affecting the condyle size, resulting in facial asymmetry. This study was a retrospective review of 27 patients with UCH who underwent condylectomy between 2000 and 2017 at Yonsei University Dental Hospital. Patient demographic characteristics were summarized. UCH was divided into three subtypes: hemimandibular elongation (HE, n=15), hemimandibular hyperplasia (HH, n=4), and osteochondroma (OC, n=8). Of the 27 patients, only one with the HE type and five (18.5%) with the OC type complained of joint pain. Bone scans of all patients showed higher uptake on the UCH side. Lip and maxillary canting was prominent in the HH and HE types. Five patients (18.5%) underwent condylectomy alone, 13 (48.1%) underwent condylectomy with orthodontic treatment, and nine (33.3%) underwent adjunctive jaw surgery with orthodontic treatment. The treatment modalities varied according to the subtype. In all OC type patients, removal of the hyperplastic condyle treated the facial asymmetry. Additional post-surgical orthodontic treatment was necessary in only three cases (37.5%). All HH type patients required mandibuloplasty. All patients showed a stable occlusal outcome without relapse and an improvement in subjective symptoms, despite a decrease in mouth opening of 2.2mm. These findings might be useful in treatment planning for UCH patients.

3-Dimensional CBCT analysis of mandibular asymmetry in unilateral condylar hyperplasia.

Three-dimensional quantification of asymmetry in UCH has not been reported yet, but would be useful for diagnosing and evaluating the degree of deformity in this disease. It enables profound decision-making and timing of surgery. Unilateral condylar hyperplasia (UCH) can subjectively be classified in hemimandibular elongation (HE), hemimandibular hyperplasia (HH) and a combination of these two (hybrid form). The main purpose of this study was to quantify mandibular asymmetry in UCH patients with a reliable and reproducible method. Secondly, it was evaluated whether the existing classification can be confirmed. 37 UCH-patients with progressive mandibular asymmetry, supported by a positive bone scan and/or such clinical progression that condylectomy was performed, were included in this retrospective study. A group of healthy subjects, matched for age and gender, was used as the control group. Cone-beam computed tomography (CBCT) scans were imported in Maxilim® software. Each mandibular half was divided into three skeletal segments (condyle, ramus, and body). Linear and volumetric measurements were calculated for these skeletal units on the affected and unaffected side, for both patients and controls. Significant differences between affected and unaffected sides in the patient group were found in condylar, ramus, and body segments for linear (p<0.01) as well as for volumetric quantitative measurements (p<0.0040). A mean linear difference between affected and unaffected sides in the condylar region of the UCH patient group was found of 3.6mm (sd 2.9) versus 0.2mm (sd 1.5) in controls. For volumetric measurements there was a mean difference between the left and right condyle of 718mm3 (sd 638) in the patient group versus 8mm3 (sd 225) difference in the control group. The condyle was the most affected segment. Differences between sides were significantly larger in the patient group than in the control group (p<0.001). It was not possible to objectify differences between HE and HH. CBCT is a useful and accurate modality for quantification and evaluation of mandibular asymmetry in UCH. It enables objective monitoring. The existing classification in HE and HH could not be confirmed.

Evaluation of three analysis methods for 99mTc MDP SPECT scintigraphy in the diagnosis of unilateral condylar hyperplasia

The aims of the study were to evaluate the diagnostic accuracy and utility of the mean region of interest (ROI) and mean and maximum volume of interest (VOI) analysis methods for 99mTc MDP SPECT scintigraphy in the diagnosis of active unilateral condylar hyperplasia (UCH). Inactive UCH (n=43) and active UCH (n=8) patients, and patients without condylar hyperplasia (controls, n=41) were analyzed. Inter-observer agreement was good for all methods. Condylar uptake was not normally distributed, with a longer right tail in UCH patients compared to control patients. Receiver operating characteristic curve analysis indicated that the ROI method was slightly superior to both VOI methods for the diagnosis of active UCH (area under the curve=0.866, 0.811, and 0.817, and J=0.642, 0.596, and 0.573, respectively). The ‘traditional’ 55% cut-off value proved optimal for ROI and mean VOI methods, but a cut-off of 56.125% was optimal for maximum VOI. Sensitivity was 88% for all three methods using these cut-off values, while specificity was 77%, 65%, and 70% for mean ROI, mean VOI, and maximum VOI, respectively. These results indicate that corrective surgery for negative scan patients can be performed without delay, with an error rate of only 3%, but not in positive scan patients.

Role of fluorine-18 fluoride PET-CT scan in the assessment of unilateral condylar hyperplasia in faciomandibular asymmetry patients

This prospective study was aimed to determine and quantify the change in mandibular condylar hyperactivity over a period of time by using a fluorine-18 (18F) fluoride PET-computed tomography (CT) scan. Sixteen patients (age 19.50 ± 2.58 years) with noticeable faciomandibular asymmetry caused by unilateral condylar hyperplasia (UCH) were included in the test group and underwent an 18F-fluoride PET-CT scan at the beginning of the study (T0); these patients were then followed up for a minimum of 12 months, after which the 18F-fluoride PET-CT scan was repeated at first follow-up (T1). An age-matched control group consisted of 10 patients with apparently symmetrical faces whose PET-CT scans were acquired for some other medical conditions. Statistical analysis of maximum standardized uptake values (SUV max) obtained through 18F-fluoride PET-CT was performed using the paired t-test. Mean SUV max of the affected condyle at T0 and T1 was 9.18 ± 4.07 and 9.18 ± 3.88, respectively. The mean SUV max of the contralateral condyle at T0 and T1 was 6.21 ± 2.30 and 6.66 ± 2.64, respectively. The mean right-left difference in tracer uptake between the test and control groups both at T0 and T1 was statistically significant. Right-left percentage difference of isotope uptake of the test group was 16.87 ± 15.75% at T0 and 14.97 ± 12.72% at T1. Right-left percentage difference of isotope uptake of the control group was 5.51 ± 5.72%. Although these differences were statistically significant, their clinical relevance was insignificant. SUV max of the higher uptake side and the lower uptake side of the control group was 5.63 ± 1.85 and 5.09 ± 1.83, respectively. Great diversity exists in the clinical presentation of UCH. The growth trend of UCH is highly variable because of the age and sex of patients. The results of the present study show that the 18F-fluoride PET-CT scan may guide us in determining the right time and in making the right choice of surgico-orthodontic intervention in UCH patients. The clinical presentation and SUV max of PET-CT of UCH patients were in agreement with each other. The baseline values of the control group indicated that these could also be used to differentiate normal from abnormal condylar growth in potential class III skeletal pattern cases - that is, patients having sagittal skeletal dysplasia resulting from either maxillary deficiency or mandibular protrusion, or both in combination, thus resulting in a concave facial profile.

High condylectomy versus proportional condylectomy: is secondary orthognathic surgery necessary?

The objective of this study was to assess the need for secondary orthognathic surgery in patients undergoing two different condylectomy protocols for active unilateral condylar hyperplasia (UCH). A retrospective cohort study evaluated UCH patients treated by condylectomy. Two groups were established: group 1 comprised those who had undergone a high condylectomy (5mm removed) and group 2 comprised those who had undergone a proportional condylectomy (removing the difference observed between the measurements of the hyperplastic and the healthy side). Data analysis was done with the Levene test and t-test; a P-value of <0.05 indicated a statistically significant relationship. Forty-nine patients, with an average age of 19.83 years, were analyzed; 11 were included in group 1 and 38 in group 2. There was no statistical difference between the two groups with regard to age or sex (P=0.781). An average of 5.81mm was removed in the high condylectomy group, while an average of 9.28mm was removed in the proportional condylectomy group; this difference was statistically significant (P=0.042). Comparing the two groups, proportional condylectomy reduced the need for secondary orthognathic surgery (P<0.001). The proportional condylectomy can be used as the sole surgical treatment in cases of UCH, thus avoiding the need for secondary orthognathic surgery.

No differences in morphological characteristics between hyperplastic condyle and class III condyle

The aim of this research was to compare the condylar morphology of patients with unilateral condylar hyperplasia (UCH) and patients with a class III skeletal relationship using cone beam computed tomography (CBCT). A prospective study was conducted on patients with facial asymmetry attending the division of oral and maxillofacial surgery of the study university in Chile. Fifteen patients with UCH and 15 with a class III skeletal relationship were selected. Linear measurements of the condylar processes were obtained at a scale of 1:1 using the software Ez3D Viewer Plus. Analysis of variance (ANOVA) and the paired t-test were used, considering P<0.05. Patients with UCH presented statistical differences between the hyperplastic condyle and non-hyperplastic condyle for anteroposterior and mediolateral diameters, condylar neck length, and ramus height. Patients with a class III skeletal relationship showed no differences between the right and left sides; the morphology of their condyles was similar to the condyles with hyperplasia and presented statistical differences when compared with the non-hyperplastic condyles (one-way ANOVA, P<0.05). The condylar morphology of UCH patients could be related to the development of a class III skeletal relationship. These findings provide an insight into the possibility of some class III patients presenting bilateral condylar hyperplasia.

Clinical value of 99Tcm-MDP SPECT bone scintigraphy in the diagnosis of unilateral condylar hyperplasia.

Purpose. To investigate the clinical value of 99Tcm-MDP SPECT for the diagnosis of unilateral condylar hyperplasia (UCH). Methods. One hundred forty-nine patients who underwent mandibular 99Tcm-MDP SPECT between January 2009 and December 2012 were studied, including 105 cases that were clinically suspected of UCH and 44 comparable cases without UCH as a control group. Results. Increased bone activity was observed in the affected condyles for all UCH patients. In the UCH group, the relative percentage uptake on the affected side was 59% (SD ± 4.3%), significantly higher than the 41% (SD ± 4.1%) uptake on the contralateral side (P<0.001). Similarly, the condyle/skull ratio was significantly higher for the affected side (1.66 ± 0.63) than for the contralateral side (1.34 ± 0.34, P < 0.01. No significant difference was found in the control group between the left and right condyles. Values for the sensitivity (95%), specificity (61%), positive (84.4%) and negative (84.6%) predictive values, and accuracy (84.5%) for 99Tcm-MDP SPECT in the diagnosis of UCH were calculated. However, for the hyperplastic condyle, no correlation was observed between the thickness of each cartilage layer and the relative uptake in the SPECT image. Conclusion. 99Tcm-MDP SPECT is accurate for diagnosing UCH and can provide a reference for treatment options.

Value of 99Tcm-MDP SPECT bone scintigraphy in diagnosis of unilateral condylar hyperplasia of the mandible

Objective To investigate the clinical value of 99Tcm-MDP SPECT scintigraphy in diagnosis of unilateral condylar hyperplasia (UCH) of the mandible.Methods Temporomandibular joint tomography using 99Tcm-MDP SPECT was performed in 56 UCH patients (22 males,34 females,mean age 21.5 y) preoperatively and 10 controls with other diseases (5 males,5 females,mean age 22.6 y).Thirtyone UCH patients received high condylar resection,and the corresponding histopathological results were analyzed.All scintigrams were visually interpreted and supported by semi-quantitative assessment of activity in bilateral using the skull as the reference site.The results of UCH patient and control groups were compared using two-sample and paired t tests.Pearson correlation analysis was also used.Results Affected condyle/parietal bone and affected condyle/bilateral condyles activity ratios (1.66 ±0.63 and 0.59 ±0.44) were significantly higher than those of the contralateral side (1.34 ±0.34 and 0.41 ±0.04 ; t =3.687 and 6.590,respectively,both P ＜ 0.01) and controls (1.12 ± 0.07 and 0.50 ± 0.01,t =6.459 and 4.750,respectively,both P ＜ 0.001).The sensitivity,specificity,positive and negative predictive values for the diagnosis of condylar hyperplasia were 95.2％ (20/21),60.0％ (6/10),83.3％ (20/24),and 6/7.The uptake on scintigraphy was not significantly related to the thickness of the cartilage (respective mean thicknesses of fibrous,proliferative,hypertrophic cartilage layers:(150.5 ± 94.9),(185.2 ±113.6),(167.7±76.9) μm,r=0.46,0.47,-0.12,all P＞0.05).Conclusion 99Tcm-MDPSPECT scintigraphy may be useful for assessment of growth activity of the mandibular condyle and to provide important information for condylar hyperplasia in surgical planning. Key words: Temporomandibular joint diseases; Mandibular condyle; Radionuclide imaging; MDP

Planar scintigraphy in assessment of mandibular asymmetry: Unilateral condylar hyperplasia vs asymmetric mandibular hyperplasia

Objectives: To 1) explore the planar scintigraphic findings in asymmetry patients caused by unilateral condylar hyperplasia (UCH) or asymmetric mandibular hyperplasia (AMH); 2) develop a local agecondylar activity reference norm; and 3) check the accuracy of the new norm and compare with other analytical methods. Material and Method: Chinese patients with mandibular asymmetry and scintigraphic findings available were recruited. Clinical, radiographic records and scintigraphic condylar activity ratio (CAR) were studied. Regression analysis was performed to quantify the relationship between age and CAR to develop a new norm. The sensitivity of condylar activity assessment using a) traditional norm; b) new norm; and c) percentile difference was compared. In patients with serial data available, longitudinal analysis of the scintigraphic changes were checked. Result: 109 patients were eligible for the study. Significant difference in CAR was noted between UCH and AMH patients. Linear relationship was observed between age and CAR. A new norm of the age-CAR was established, which showed improved sensitivity in condylar activity prediction in UCH and AMH when compared with traditional norm. Relative to percentile difference, the sensitivity of new norm was lower in AMH but not in UCH patients. Serial analysis revealed gradual decline in CAR with minimal change in percentile difference. Conclusion and Clinical Relevance: There is difference in scintigraphic condylar activity between UCH and AMH patients. A norm of age-CAR relationship was established, which showed improved sensitivity in condylar activity prediction in UCH patients. Further study is required to confirm the role of scintigraphy in AMH.

Female Predominance and Effect of Gender on Unilateral Condylar Hyperplasia: A Review and Meta-Analysis

The objective of this review and meta-analysis was to determine the existence and extent of the predominance of women among patients with unilateral condylar hyperplasia (UCH). Furthermore, we examined the laterality of UCH in women and men from international study populations. We performed a review using a standardized search strategy and meta-analysis. We included 10 studies in this review, with a total of 275 UCH patients. The meta-analysis showed a clear predominance of female patients in the UCH study populations; the pooled proportion of female patients was 0.64 (95% confidence interval [CI], 0.58-0.70; n = 275 patients). The pooled percentage of female patients with left-sided UCH was 42% (95% CI, 34%-51%; n = 138), whereas 45% (95% CI, 33%-57%; n = 74) of male patients had left-sided UCH (P = .69 for female patients vs male patients). Female UCH patients outnumber male UCH patients in international study populations; therefore female gender may be considered a risk factor for UCH. We found no evidence of an association between laterality of UCH and gender: male patients and female patients have an almost equal distribution of left- and right-sided UCH.

Quantitative analysis of planar bone scintigraphy in patients with unilateral condylar hyperplasia

This study compares quantitative analysis of planar bone scintigrams with visual interpretation in patients having unilateral condylar hyperplasia (UCH) and normal control subjects. The possibility of using a bony structure in a region near the condyle as an objective measurement of bone activity is assessed. Planar bone scintigrams from 20 subjects suspected of having active UCH were analyzed both qualitatively and quantitatively. Bone activity was assessed in both condyles as well as in reference sites in the cervical spine and the skull. Percentile activities for both condyle regions and ratios using condyle activity versus reference regions were assessed. All UCH patients had unilateral increased activity on qualitative visual interpretation of the bone scan. The mean percentile activities of the affected and unaffected condyles in the UCH group were significantly different at 55.3% and 44.7%, respectively (P < .001). No significant difference was found in the control group, with the ratios between left and right condyle being 49.5% and 50.5%, respectively (P = .46). In the ratios between the region of interest (ROI) in the condyles versus the ROIs selected for the cervical spine and the skull, a significant difference was noticed in the UCH group; however, there was a considerable overlap between condyle and reference ROI ratios. Symmetrical uptake of diphosphonate reliably excluded continued asymmetrical growth of the condyles. Quantitative analysis of planar scintigrams in unilateral condylar hyperplasia patients was not found to be superior to qualitative visual interpretation of the scans. Because of a considerable overlap in condyle/reference ROI ratios, quantified ratios did not seem to be clinically helpful in the differentiation of a hyperplastic condyle from a normal condyle. In the case of unilateral increased condylar uptake of diphosphonate, clinical assessment is mandatory.