Condylar Hyperplasia of the Temporomandibular Joint

Post-condylectomy orthodontic treatment for a severe asymmetrical open bite in a condylar hyperplasia patient

A satisfactory treatment of an 18-year-old lady was reported with right combination-type condylar hyperplasia (CH) in active phase. The chin severely deviated to the left, with the right gonial angle locating at a lower level. Intraorally, the lower centre line shifted to the left, the scale of which reached the width of one lower incisor. The right molar relation was mesial. Right maxillary second molar over-erupted without contact to lower teeth. There had been 2.5-mm anterior open bite (AOB) before surgery (T1) due to the tongue-spitting habit. After judging the benefits and disadvantages of all treatment alternatives, the decision was made to perform a right condylectomy and post-surgery orthodontics. Before orthodontics (T2) when the chin was positioned centred, an asymmetrical open bite occurred, caused by pre-contact between the right maxillary and mandibular second molars. Meanwhile, the AOB at T2 became 11.5mm. Orthodontic-related treatment included four premolars extraction and intrusion of bilateral maxillary molars using four miniscrews. Finally, this treatment achieved a clinically centred chin with two gonial angles at the same level. Post-condylectomy, the large AOB was resolved, together with a bilateral neutral molar relationship and alignment of the incisor midlines. Besides, the resected right condyle was covered by a continuous cortex bone and returned to the glenoid fossa. In sum, a high-challenging combined-type CH case was accomplished with impressive improvement in facial and occlusal symmetry, thanks to condylectomy and post-surgery miniscrew-assisted orthodontics.

Late Outcomes of Undiagnosed Unilateral Condylar Hyperplasia and Reoccurrence of Mandibular Asymmetry

Unilateral condylar hyperplasia (UCH) is a rare cause of asymmetrical mandibular overgrowth because of the presence of an atypical growth in the affected condyle. SPECT (single-photon emission computed tomography) can easily establish the presence of an atypical, prolonged growth exceeding far beyond normal condylar growth and activity. A CT, CBCT, or LDCT (computed tomography, cone-beam computed tomography, or low-dose computed tomography) can confirm the diagnosis by evaluating the scope of bone overgrowth, mandibular basis/ramus asymmetry, tendency to condylar head enlargement, changes in bone density, and occurrence of differences in condylar head shapes, size, and bone structure. In most cases, a condylectomy is the procedure of choice in growing cases of UCH to remove the pathological condyle and reduce asymmetry levels. Sometimes, the growth is very slow and progressive over time, causing slowly growing asymmetry with similar symptoms to any other mandibular asymmetry, and this causes some troublesome procedures in UCH diagnostics, resulting in patients being underdiagnosed; it can even lead to some relapses in mandibular asymmetry and skeletal malocclusion after previously performed orthodontic and surgical treatment of such discrepancies. When the source of asymmetry is not identified in time, possible inadequate treatment protocols can be used. If any relapse of facial and mandibular asymmetry re-occur, SPECT and CT evaluation are necessary to evaluate if condylar hyperplasia is present and to establish what kind of surgical intervention should be used in each case.

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.

Condylar Hyperplasia: Case Report and Literature Review

Condylar hyperplasia is a rare pathology characterised by excessive bone growth that presents virtually unilaterally, resulting in facial asymmetry. The aetiology of this disorder is not well understood. This pathology has been reported to be a rare entity with very few cases being reported in the literature, mostly seen between 11 and 30 years of age, with males and females being equally affected and having no predominance to the left or right side. It has also been reported to be a self-limiting condition, that is, the active growth can cease at any point in time. We report two cases of unilateral condylar hyperplasia in 24- and 19-year-old male and female patients, where the first was treated by condylectomy and BSSO, and the latter was treated by high condylectomy and recontouring of the mandible.

Correction of Facial Asymmetry due to Different Complex Mandibular Pathologies by Aesthetic Surgical Procedures: A Case Series and Assessment of Quality of Life Following Corrective Surgeries

Background

A numerous diseases may result in facial asymmetry, one of them is the presence of any condylar pathology. Patients with such condylar pathology resulting in facial asymmetry have a functional, aesthetic and psychological impact on them. The present study aims to identify the effect of corrective surgeries of such cosmetic deformities on the quality of life of the patients.

Case Reports

Patients diagnosed with condylar pathologies resulting in facial asymmetry subjected to the corrective surgeries. The quality of life assessment was done preoperatively and 3 months postoperatively, by assessing the oral health using the Japanese version of the Oral Health impact profile (OHIP). A total of 12 patients were operated and assessed with an age ranges of 18-42 years. Seven out of 12 patients were diagnosed with condylar hyperplasia, and five patients were having benign tumor of the mandibular condyle. The mean preoperative OHIP score was 68.25 ± 7.19, which significantly improved to 24.58 ± 4.88 postoperatively.

Conclusion

Corrective surgeries of facial deformity dramatically improves the quality of life of the patients.

Can Condylectomy Alone Achieve Facial Symmetry in Patients With Hemimandibular Hyperplasia (Condylar Hyperplasia Type 2)?

The purpose of the present study was to evaluate the 3-dimensional orofacial changes occurring after proportional condylectomy in patients with unilateral condylar hyperplasia type 2 (hemimandibular hyperplasia). Eight patients underwent proportional condylectomy that was not followed by orthognathic surgery or orthodontic treatment for at least 1 year. The precondylectomy and postcondylectomy photographs and radiographs were analyzed cephalometrically and compared. The average length of the condylar segment removed was 13 mm and this resulted in almost equal heights of the ramus-condyle units of both sides. Evaluations in the vertical plane improved after surgery; however, when the preoperative asymmetry was significant, the residual asymmetry continued to be notable after condylectomy. Transverse plane evaluations improved after condylectomy, and chin position was satisfactorily centralized in all patients. In the horizontal plane, mandibular setback occurred, and this was considered favorable when the preoperative skeletal profile was class III, whereas the opposite was when the patient was class I before surgery. The occlusion improved gradually over the postoperative months by the intrusion on the affected side and extrusion on the unaffected side into a bilaterally balanced posterior contacts with residual anterior open bite. In conclusion, condylar hyperplasia type 2 patients with mild asymmetry and low esthetic demands can benefit from proportional condylectomy as the sole treatment to both stop the hyperplastic condylar growth and improve the asymmetry to some extent. Surgeons should be able to predict the change that is expected to occur after proportional condylectomy and discuss this with the patient before surgery.

Evaluation of treatment with unilateral mandibular sagittal split ramus osteotomy and maxillary osteotomy in patients with condylar osteochondroma and mandibular asymmetry: A retrospective case series

The aim of the study was to describe an approach where condylar resection with condylar neck preservation was combined with Le Fort I osteotomy and unilateral mandibular sagittal split ramus osteotomy (SSRO). Patients with a unilateral condylar osteochondroma combined with dentofacial deformity and facial asymmetry who underwent surgery between January 2020 and December 2020 were enrolled. The operation included condylar resection, Le Fort I osteotomy and contralateral mandibular sagittal split ramus osteotomy (SSRO). Simplant Pro 11.04 software was used to reconstruct and measure the preoperative and postoperative craniomaxillofacial CT images. The deviation and rotation of the mandible, change in the occlusal plane, position of the "new condyle" and facial symmetry were compared and evaluated during follow-up. Three patients were included in the present study. The patients were followed up for 9.6 months on average (range, 8-12). Immediate postoperative CT images showed that the mandible deviation and rotation and occlusion plane canting decreased significantly postoperatively; facial symmetry was improved but still compromised. During the follow-up, the mandible gradually rotated to the affected side, the position of the "new condyle" moved further inside toward the fossa, and both the mandible rotation and facial symmetry were more significantly improved. Within the limitations of the study it seems that for some patients a combination of condylectomy with condylar neck preservation and unilateral mandibular SSRO can be effective in achieving facial symmetry.

"Proportional Condylectomy" for Vertical Condylar Hyperplasia Without Intermaxillary Elastics: Clinical Results and Patient Satisfaction

OBJECTIVES

First, to investigate the clinical outcome of 'proportional condylectomy' for patients with active unilateral condylar hyperplasia without complementary treatment by intermaxillary elastics and, second, to examine their level of satisfaction regarding function and esthetics.

STUDY DESIGN

A retrospective observational descriptive study was conducted. All patients included in the study suffered from active unilateral condylar hyperplasia with a vertical component. The length of the condylar-ramus unit was measured on both sides by an multidetector computed tomography scan. The difference was calculated and resected from the hyperplastic condyle during the operation. Facial, occlusal, and skeletal changes were evaluated using photographic and radiologic records, and a satisfaction questionnaire regarding function and esthetics was completed. P<0.05 was considered significant.

RESULTS

Fifteen patients were included in the study. The mean participants' age was 27.93±13.06 years, and the mean follow-up duration was 12.40±6.55 months. The mean chin deviation improved by 58.47% (P=0.001). Mean lip commissure plane tilt was improved by 61.31% (P=0.001). Six months postoperatively, all patients exhibited centered dental midlines (P=0.001). Occlusal plane tilt was significantly improved by 70.02% (P=0.001), and high patient satisfaction was recorded. Twenty-six percent (4/15) of patients did not require the complementary orthodontic treatment, and none of them required complementary orthognathic surgery.

CONCLUSIONS

'Proportional condylectomy' for patients with active unilateral vertical condylar hyperplasia without complementary treatment by intermaxillary elastics is a predictable procedure in terms of function and esthetics.

Can malocclusion provide clinicians with information for differential diagnosis of temporomandibular joint diseases?: A review

The aim of this literature review was to summarize the clinical characteristics and symptoms of temporomandibular joint diseases, and to discuss the associations between temporomandibular joint diseases and categorization of malocclusion. Electronic literature searches were performed using the PubMed database. The authors established a differential diagnostic method for temporomandibular joint diseases related to malocclusion. A literature search using PubMed yielded 213 texts, of which based on exclusion criteria, 28 were included in this study. Malocclusions were categorized into 5 types. The authors suggested a diagnostic tree of temporomandibular joint diseases based on the types of malocclusion and 4 variables in clinical characteristics and symptoms. Clinicians treating malocclusions must attempt to clarify the cause of the occlusal condition. If caused by temporomandibular joint disease, it is important to make a proper differential diagnosis at first, and not to overlook the causative disease. Further clinical knowledge of associations between temporomandibular joint diseases and malocclusions should be accumulated, and the diagnostic tree should be improved based on new information.

Can electrocautery of the mandibular condyle effectively treat condylar hyperplasia?

This study aims to introduce and evaluate a novel technique to treat unilateral condylar hyperplasia (UCH) by electrocauterization of the mandibular condyle via an intraoral approach. Patients suffering from unilateral condylar hyperplasia (UCH) were included in this study. All patients underwent electrocauterization of the affected condyle. An intraoral incision on the anterior border of the mandibular ramus was made to expose the external surface of the ramus and access the anterior border of the condylar head. A hole was then drilled into the condyle and cauterization was performed; six patients also received orthognathic surgery during the procedure. Patients underwent careful clinical assessment and radiological evaluation including panoramic view, lateral and posteroanterior cephalometry, cone-beam computed tomography (CBCT) and scintigraphy to assess condylar growth for a period of 12-24 months. Ten patients (5 male and 5 female) with active UCH type 1B or 2A were included in this study with a mean age of 20.7 years (range, 18-21.7 years). At the 12-month postoperative assessment, clinical evaluation showed stable dental occlusion with no midline shift; scintigraphy showed persistently reduced cellular activity, and computed tomography scans revealed no degeneration in either of the condyles with complete healing of the drilled holes. Within the limitations of this study it seems that the proposed treatment approach might be an alternative to previously established protocols.

TMJ Position in Symmetric Dentofacial Deformity

The aim of this research was to analyze the facial class, presence of malocclusion, and the mandibular plane and to relate this to the mandibular condyle position. A cross-sectional study in subjects under analysis for orthognathic surgery was done. The mandibular plane, the gonial angle, and the molar class were included to compare the coronal and sagittal position of the condyle and the joint space observed in the CBCT. The measurements were obtained by the same observer at an interval of two weeks. In addition, the Spearman test was performed to determine the correlation using a p value < 0.05 to observe any significant differences. Eighty-nine male and female subjects (18 to 58 years old, 24.6 ± 10.5) were included. In the coronal section, subjects with CIII had a greater mediolateral distance (MLD, p = 0.0001) and greater vertical distance (SID, p = 0.0001) than subjects with CII. In terms of the skeletal class and the mandibular plane, it was observed that subjects in the CII group had a greater mandibular angle (open angle) (p = 0.04) than the CII group and was related to the anterior position of the condyle. The most anterior condylar position was observed in the CII group (p = 0.03), whereas a posterior condylar position was significant in CIII subjects (p = 0.03). We can conclude that the sagittal position of the TMJ was related to the mandibular plane and the skeletal class showing a higher mandibular angle and most anterior position of the condyle in CII subjects and a lower mandibular angle and most posterior position of the condyle in CIII subjects. The implications for surgical treatment have to be considered.

Robotic and Microrobotic Tools for Dental Therapy

Robotic and microrobotic tools such as dental operating microscopes and dental endoscopes are being used extensively in dental therapy, which have a significant impact on dental therapy and education. Herein, this paper reviews the state of the art of robotic and microrobotic tools for dental therapy. This article starts with a brief introduction of current robotic and microrobotic tools for dental therapy and then displays their applications in various dental problems; strengths and weaknesses are also surveyed. Lastly, the conclusion and outlook are discussed, referring to the emerging dental clinic problems and demands. This review is expected to provide guidelines for the therapeutic application of robotic and microrobotic tools and to promote the development of robots in dentistry.

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

OBJECTIVE

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

The condylar SUVmax varied with age. Different cutoff values of condylar SUVmax should be employed for diagnosing active UCH for patients in different ages.

Growth trends analysis of unilateral condylar hyperplasia followed up with planar scintigraphy: Retrospective overview of 249 cases

The current research aimed to retrospectively investigate the trends of the growth of condylar hyperplasia with serial planar scintigraphs.Patients of unilateral condylar hyperplasia with at least one follow-up planar scintigraph were retrospectively included in the study. Patients' age, gender at the initial scan, durations of following scans, and ratios between condylar activities were recorded.The study retrospectively included 111 patients of unilateral condylar hyperplasia. Patients were divided into 3 groups (progressive, relatively stable, regressive) according to ratio variation between initial and last scans. There were 23 (21%) patients fell into the progressive group, 40 (36%) patients into the relatively stable group, and 48 (43%) patients into the regressive group. More female patients were in the progressive group than those in the other groups (P < .01). There were no significant differences among the 3 groups in terms of age or durations of follow-up (P > .05). There were no strong relations between ratio differences and ages. However, a weak relation seems to exist in the regressive group with r = -0.240, (P = .10).Our investigation showed that more than a half of patients with condylar hyperplasia remain constantly or progressively active growth in patients in the follow-up scans. Roughly less than a half of patients showed regressive trends toward normal growth. Patients' age seemly does not play a role in the growth trend pattern, although there are no optimum follow-up periods, regularly follow-up scans are needed to determine the growth status of condylar hyperplasia.

[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.

Unilateral Condylar Hyperplasia With Active Bony Overgrowth: A Case Report

Condylar hyperplasia (CH) is an overgrowth disorder of the temporomandibular joint bones caused by growth center overactivity of the mandibular condyle. Although the disorder is mostly idiopathic, several etiologies have been proposed. CH presents as progressive facial asymmetry with functional abnormalities. A combination of clinical, histopathological, and radiological findings is crucial to determine the diagnosis. Several diagnostic algorithms have been described in the literature. Management of CH is variable and depends on the growth of the bone. Here, we present the case of a 36-year-old female who presented with progressive facial asymmetry which was diagnosed as unilateral CH with active bony overgrowth.

Using 3D Medical Modeling to Evaluate the Accuracy of Single-Photon Emission Computed Tomography (SPECT) Bone Scintigraphy in Diagnosing Condylar Hyperplasia

PURPOSE

To evaluate the accuracy of single-photon emission computed tomography (SPECT) in diagnosing unilateral condylar hyperplasia (UCH) and to describe the condylar growth of patients with UCH.

MATERIALS AND METHODS

Using a retrospective study design, patients with UCH who had undergone SPECT and cone-beam computed tomography (CBCT) examinations at the same time were included in the study. We used 3D medical models based on CBCT data as the gold standard. The SPECT results were compared with the model data, and the sensitivity and specificity were calculated. To further describe the condylar growth activity, statistical analysis was performed, and the P value was set at 0.05.

RESULTS

The sample was composed of 75 patients. The sensitivity of SPECT was 55.3%, the specificity was 48.6%, and the area under the receiver operating characteristic curve was 0.53. There was no significant difference in sex between patients with and without active growth.

CONCLUSION

The sensitivity and specificity of SPECT are poor, and SPECT alone is not suitable for evaluating the active stage of condylar growth. 3D medical modeling has good prospects for application in the diagnosis of condylar hyperplasia.

Mandibular condylar remodeling characteristics after simultaneous condylectomy and orthognathic surgery

INTRODUCTION

The objectives of this study were to evaluate postsurgical condylar remodeling using a radiographical interpretation, quantify condylar volumetric asymmetry, and assess soft tissue symmetry after simultaneous unilateral high condylectomy and bimaxillary osteotomies.

METHODS

Sixteen patients diagnosed with unilateral condylar hyperplasia underwent unilateral high condylectomy and orthognathic surgery to correct skeletal and facial asymmetries. Cone-beam computed tomography scans were acquired before and 1-year after surgery. A radiographic consensus was evaluated for signs of reparative or degenerative changes. The condyles were mirrored and registered for assessment of volumetric and morphologic asymmetry. Soft tissue symmetry was evaluated by measurement of the distance of soft tissue pogonion from the skeletal midsagittal plane.

RESULTS

Patients who undergo unilateral high condylectomy and orthognathic surgery present radiographic signs suggestive of degenerative changes, including sclerosis, osteophytes, flattening, and erosion in both the surgical and nonsurgical condyles (P ≤0.01). There was an average volumetric improvement of 531.9 ± 662.3 mm³ 1-year postsurgery (P = 0.006). Soft tissue symmetry improved in all patients, with an average improvement of 65.8% (4.0 mm ± 2.6 mm, P ≤ 0.01). There was no correlation between the change in condylar volumetric asymmetry and the stability of the soft tissue correction.

CONCLUSIONS

High condylectomy for the correction of a skeletal asymmetry in patients with condylar hyperplasia successfully reduces the volumetric asymmetry between the condyles. Postsurgical dysmorphic remodeling and degenerative changes were noted in both the surgical and nonsurgical condyles. Despite remarkable changes and remaining joint asymmetry, the soft tissue correction is stable 1-year postsurgery.

Unilateral Condylar Hyperplasia: Two Case Reports and a Literature Review

Condylar hyperplasia (CH) is a rare idiopathic condition affecting the mandibular condyle where the growth of the condylar head and/or neck continues beyond the normal growth period. The disorder presents clinically as facial asymmetry and occlusal discrepancy. Here, we present two cases of CH managed at our centers between 2012 and 2017 with a successful outcome. We highlight the clinical presentation, investigation, and surgical management and give a brief literature review.

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.

Anatomical and Clinical Implications in Neocondyle Stability After a Condylectomy

: A condylectomy of the mandibular condyle is considered to be the treatment of choice in most cases of condylar head hyperactivity. The aim of the procedure is to remove the growth center of the mandible which is responsible for the mandibular enlargement and asymmetry. This surgical procedure has an impact on the condyle shape and position, but the restoration of mandibular movement and a stable joint position (namely, the proper alignment of the newly shaped condylar head within the condyle fossa) should also be considered important surgical outcomes. In this article, the authors present their own experience in performing condylectomies with an arthroplasty procedure and a special forced suturing technique (FST) in terms of achieving early, accurate mandibular movement and maintaining a stable condyle position in early and late outcomes.

MATERIALS AND METHODS

A modified high condylectomy with arthroplasty and FST results had been studied in anatomical, radiological, and clinical model.

RESULTS

Early findings after FST are promising. A slight improvement in lateral jaw movement was noted after condylectomy with arthroplasty (P < 0.05) both in early and late follow-up. Incisal opening, mandibular protrusion, and lateral movement were sustained. A stable condyle position within the fossa was achieved in each case of condylectomy with arthroplasty (P < 0.05).

CONCLUSIONS

The FST condylectomy and reattachment of the lateral pterygoid muscle in a new, wider position provided an improvement in lateral jaw movement as well as in incisal opening and mandibular protrusion in early follow-up examination compared to the presurgical values. It seems that the FST enabled a better new condylar head position in the glenoid fossa and improved early functional mandibular movement.

Are There Mandibular Morphological Differences in the Various Facial Asymmetry Etiologies? A Tomographic Three-Dimensional Reconstruction Study

PURPOSE

Facial asymmetries (FAs) have been classified according to the mandibular morphological differences to obtain better diagnostic and treatment decisions. The purpose of the present study was to establish diagnostic differentiation among FAs using computed tomography (CT) and 3-dimensional (3D) reconstruction.

MATERIALS AND METHODS

We performed a cross-sectional study of patients with a diagnosis of FA, who had been evaluated by CT and 3D reconstruction in the same clinical center from 2015 to 2018. The following mandibular anatomic characteristics were compared between the 2 sides (deviated side vs contralateral side) and type of FA: condylar length, mandibular ramus length and width, mandibular body length, and symphysis deviation.

RESULTS

The 53 patients included 23 men and 30 women (age range, 16 to 25 years). Six categories of FA were identified: hemimandibular elongation (n = 25), hemimandibular hyperplasia (n = 2), hybrid hyperplasia (n = 3), asymmetric mandibular prognathism (n = 14), asymmetry of the glenoid fossa (n = 2), and functional laterognathism (n = 7). The condylar length and mandibular ramus width were greater in the displaced side than in the contralateral side, with differences of -2.0 ± 2.8 mm (P < .001) and -0.5 ± 1.7 mm (P = .009), respectively. The mandibular body length was greater on the contralateral side (mean difference, 2.1 ± 3.5 mm; P < .001). The symphysis deviation was 5.0 ± 3.4 mm, and those with a hybrid form presented with a greater deviation, with values greater than 10 mm, followed by those with hemimandibular elongation.

CONCLUSIONS

The evaluation of the CT images and 3D reconstructions in patients with FA provided detailed information of the mandibular structure that is useful to compare the differences between sides and to classify the entities associated with FA.

Is Single-Photon Emission Computed Tomography/Computed Tomography Superior to Single-Photon Emission Computed Tomography in Assessing Unilateral Condylar Hyperplasia?

PURPOSE

Single-photon emission computed tomography (SPECT) with technetium-99m diphosphates plays an important role in assessing unilateral condylar hyperplasia (UCH). The aim of this study was to evaluate whether quantification methods of SPECT plus CT (SPECT/CT) based on precise region-of-interest (ROI) drawings made under the guide of CT images were more accurate than conventional SPECT methods in the assessment of UCH growth.

MATERIALS AND METHODS

This study is a nonblinded retrospective case series. Patients with UCH who had undergone SPECT/CT were enrolled. CT images were used to guide ROI drawings around the anatomic contour of the affected and contralateral condyles on SPECT/CT images versus fixed ROIs on conventional SPECT images. Mean and maximum values within the ROIs were recorded to compute percentile ratios. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and receiver operating characteristic (ROC) curves were calculated separately for SPECT-based methods (SPECTaver, SPECTmax) and SPECT/CT methods (SPECTCTaver, SPECTCTmax). The area under the ROC curve of each method was calculated and compared pairwise.

RESULTS

Fifty-six patients (30 patients with progressive and 26 patients with nonprogressive mandibular asymmetry) were evaluated. SPECTmax had the highest sensitivity of 83.3%, followed by SPECTCTmax, SPECTaver, and SPECTCTaver. In contrast, SPECTaver, SPECTCTmax, and SPECTmax had similar specificities, PPVs, and NPVs. Nonetheless, SPECTCTaver had the lowest specificity, PPV, and NPV among all methods. ROC analysis also showed similar diagnostic performances among SPECTaver, SPECTmax, and SPECTCTmax (P > .05) and poorer diagnostic performance of SPECTCTaver compared with the other 3 methods (P < .05).

CONCLUSIONS

The method of using ROIs drawn around the contour of the condyle on SPECT/CT images does not show improved accuracy over conventional SPECT-fixed ROI methods in assessing UCH.

Morphometric Characterization of Asymmetric Mandibles Due to Condylar Hyperactivity

PURPOSE

Mandibular asymmetry related to condylar hyperactivity (CH) presents a complex set of morphologic features that pose challenges for its correction. Using state-of-the-art morphometric techniques, this report provides a detailed and hierarchical description of the features present in CH-related asymmetric mandibles and offers new knowledge for the surgical treatment of CH.

MATERIALS AND METHODS

Sixty patients were included in the sample. Thirty had CH-related asymmetric mandibles and the other 30 had clinically symmetric mandibles. Twenty-eight 3-dimensional landmarks were placed on computed tomographically based reconstructions of each participant's mandible and analyzed using geometric morphometric analysis for the quantitative and qualitative comparison of their morphologic features.

RESULTS

All 60 participants exhibited asymmetry. However, those with CH exhibited a broad range of shapes and even shared several morphologic features with the controls. Mainly the ramus and then the body were the main contributors of the differences between groups.

CONCLUSIONS

There is considerable overlap of anatomic features characterizing symmetric and asymmetric mandibles; based on shape alone, the 2 groups can be easily misclassified. The ramus and body of the affected side in CH-related asymmetric mandibles were the main contributors to asymmetry of the structure. The chin, a usual diagnostic structure, did not greatly contribute to the structural asymmetry of the mandible.

Comparison of four methods for quantitative assessment of 99mTc-MDP SPECT in patients with suspected condylar hyperplasia

OBJECTIVE

To compare variability, reproducibility and repeatability of four quantitative evaluation methods to interpret the ^99mTc-MDP SPECT reports in patients with clinically suspected unilateral condylar hyperplasia.

METHOD

This was a descriptive observational study carried out with SPECT images of 38 patients with clinical and radiographic signs of unilateral condylar hyperplasia, and interpreted using four quantitative methods: 1) one image, variable-size region of interest (ROI); 2) one image, fixed-size ROI (1.76cm²), 3) five image variable-size ROI; 4) five image, fixed-size ROI (1.76cm²). Each of the images was reported simultaneously (but in an independent way) by two nuclear medicine experts, in both total radioactive counts as well as normalized counts to evaluate the reproducibility (inter-operator variability) and the repeatability (intra-operator variability).

RESULTS

Higher reproducibility and repeatability were obtained in 5-image fixed-size ROI method (intra-class correlation coefficient: 0.979 [0.959; 0.989]). A high grade of diagnostic agreement (97.4%) was also attained in fixed methods (Kappa 0.940, p value: .000) from either total or normalized counts. There was no difference between fixed-size 1 vs 5 image methods. The methods based on variable-size ROI had a low grade of agreement (Kappa<0.20). More positive cases were identified using one image, ROI variable total counts (27 cases), but when the counts were normalized, they presented a lower number (5 cases).

CONCLUSION

Five-image fixed-size ROI provides the best intra-operator and inter-operator reliability for the diagnosis of unilateral condylar hyperplasia. In the four methods using normalized counts fewer positive cases were detected (≥10%), unlike with total counts when more positive cases were found.

Three-Dimensional Orofacial Changes Occurring After Proportional Condylectomy in Patients With Condylar Hyperplasia Type 1B (Unilateral Hemimandibular Elongation)

PURPOSE

To evaluate 3-dimensional orofacial changes that occurred after proportional condylectomy that was not followed by orthognathic surgery in patients with condylar hyperplasia type 1B (unilateral hemimandibular elongation).

MATERIALS AND METHODS

This retrospective analysis used the medical records of 14 skeletally mature patients. Transverse, vertical, and horizontal cephalometric analyses of photographs and radiographs were undertaken. A comparison of preoperative and postoperative measurements was conducted.

RESULTS

After proportional condylectomy, transverse chin position and vertical lip cant improved to various degrees, whereas ramus and condyle height and mandibular lower border discrepancy worsened to different extents. The prominence of the gonial angle of the affected (operated) side increased in all patients after surgery, and this contributed to better symmetry only when the preoperative prominence was small (flat), whereas the opposite occurred when the preoperative prominence was large (bulky). After condylectomy, there was posterior displacement of the pogonion point (setback), which was favorable in cases with a preoperative concave profile and unfavorable in cases with a preoperative convex profile.

CONCLUSION

Proportional condylectomy can successfully arrest the hyperplastic growth of the affected condyle; however, it rarely achieves perfect symmetry of the face. Although it improves some facial features, other facial traits are worsened. Surgeons should have a full understanding of the 3-dimensional changes occurring after proportional condylectomy and should be able to predict, based on preoperative findings, the anticipated improvement or worsening of different facial features.

[Temporomandibular joint (TMJ): Condyle hyperplasia and condylectomy]

The mandibular condyle is a special structure. Its embryology and physiology provide to the TMJ a particular behavior that explains the occurrence of specific diseases. Condyle hyperplasia is one of these disorders. It can be explained by a dysregulation of the prechondroblast cell layer within the cartilage cap providing an increase in volume first of the condyle, then of the ramus and finally of the entire affected hemiface. Mandible deformation affects the basal bone, leading to dento-alveolar deformations related to compensation attempts. Controversies, condylectomy is performed by many surgeons. This procedure allows for the correction of some of the dento-alveolar compensations. In some cases, an additional orthognathic surgery will be required to achieve a perfect result.