Condylar hyperplasia: current thinking

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.

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.

Assessment of unilateral condylar hyperplasia with quantitative SPECT/CT

Purpose

The current study aimedto assess condylar activityin patients with unilateral condylar hyperplasia (UCH) with quantitative SPECT/CT.

Patients and methods

This retrospective study included patients with UCH who underwent quantitative SPECT/CT. SPECT analysis and quantification of SPECT/CT were performed, and the maximum count per pixel and SUVmax of either side of the condyles were calculated.

Results

39 patients were included in the analysisand classified into three subgroups according to the percentile differential right-left ratio: inactive group, left active (LA) group, and right active (RA) group. Totally, the SUVmax of the affected side is significantly higher than the unaffected side (active:5.93 ± 2.43 vs inactive:3.62 ± 1.76, P < 0.001), SUVmax-based ratios correlated well with the ratios based on maximum count (R = 0.944, P < 0.001). ROC analysis showed poorSUVmaxperformance in differentiation between theactive condyles and the inactive condyles due to the lower area under the curve (AUC) (0.588). In subgroup analysis, the affected side is significantly higher than the unaffected side in active groups with SUVmax, no significant difference was found between the active sides or the inactive sides of active groups. Interestingly, the SUVmax of the left side was statistically higher than that of the right sidein the inactive group (P = 0.01),while the left side of the right active group has significantlylower activitythan that in the inactive group, meanwhile,the right side showed no significant difference. Furthermore, each side showed no significant difference between the left active group and the inactive group.

Conclusions

SUVmax is not an optimal measurement effectively used to evaluate active condyles. However, SUV ratios correlated well with the count ratios, and the left side of condyles showed a peculiar feature in condyle growth status reflected in radioactivity quantified with SPECT/CT, which needs further study to determine the role in the development of the UCH.

The Role of Digital Surgical Planning and Surgical Guides in the Treatment of Unilateral Condylar Hyperplasia

Unilateral condylar hyperplasia (UCH) results in facial asymmetry, malocclusion, and temporomandibular joint dysfunction. Treatment consists of both surgical and orthodontic intervention. A review was performed for 4 patients with UCH who underwent digital surgical planning (DSP)-assisted condylectomy. All patients were female, aged 14 to 35 years at the time of operation with facial asymmetry and class III malocclusion. None of the patients had prior treatment and all had perioperative orthodontic appliances to provide fixation and postoperative elastic therapy. All patients underwent DSP-guided condylectomy, and intraoperative surgical cutting guides were used for 3 of the patients. All had significant improvement in facial symmetry and occlusion. None had recurrence, and additional intervention has not been required. If UCH is recognized before marked secondary changes in the maxilla, mandible, and occlusion, future orthognathic surgery may be potentially obviated. Craniomaxillofacial surgeons should consider using DSP and surgical guides in the treatment of UCH.

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.

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.

Diagnosis and Treatment in Unilateral Condylar Hyperplasia

Unilateral condylar hyperplasia (UCH) is an uncommon disease involving progressive facial asymmetry. The aim of this research was to perform an analysis of the diagnosis and treatment of patients with UCH in a clinical series. An observational retrospective study was performed on subjects with progressive facial asymmetry in the lower third of the face; all the subjects were under treatment with condylectomy and orthodontics to improve occlusion and face balance. Variables such as age, sex, clinical type, SPECT (single photon emission computed tomography) intensity and a requirement for secondary surgery were included; the Shapiro Wilk test was performed to analyze the normality of the data and nonparametric analysis and the Kruskal-Wallis or Mann-Whitney tests were used to assess the association between the SPECT difference and the variables, where 2-tailed p values < 0.05 were considered to be statistically significant. Forty-nine patients between 10 and 45 y.o. (average age: 19.1 ± 7.4 y.o.) were included in the study. There were 41 female (83.6%) and 8 male (16.4%) subjects. The SPECT analysis comparing the right and left condyles with more than 10% in caption of the isotope was present in 46 subjects; the results obtained using SPECT were not statistically related to the age or sex of the sample (p = 0.277). The patients were classified into clinical types I, II and III, and no correlations could be confirmed between the clinical type and other variables. High condylectomy was conducted on all patients, among which 14 patients underwent a secondary surgery for orthognathic or cosmetic treatment, and was not related to the initial variables used in diagnosis (p = 0.98); interestingly, the second surgical treatment was more present in the clinical type I and in subjects under 16 years old with no statistical differences. Clinical analysis, medical records, 3D imaging and SPECT should be used as a complementary analysis in assessing the diagnosis of UCH and progressive facial asymmetry.

"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.

Bone characteristics in condylar hyperplasia of the temporomandibular joint: a microcomputed tomography, histology, and Raman microspectrometry study

Unilateral condylar hyperplasia (UCH) of the temporomandibular joint is a progressive deformation of the mandibular condyle of unknown origin. UCH is characterized by excessive growth of the condylar head and neck, leading to an increase in size and volume. The aim of this study was to investigate the characteristics of the bone in patients with UCH using microcomputed tomography (micro-CT), histology, and Raman microspectroscopy. The mandibular condyles of six patients with UCH were analysed using micro-CT, histology, and Raman microspectrometry and imaging, and the results were compared with those obtained for a normal control subject. Three-dimensional micro-CT models revealed focal abnormalities of the bone microarchitecture, with foci of osteosclerosis. Histological sections showed that these foci included islands of calcified cartilage matrix with live chondrocytes. Raman analysis revealed that the cartilage matrix was more heavily calcified than the bone matrix and that the cartilage could be identified by the phenylalanine (PHE) band of its matrix, as well as by its glycosaminoglycan (GAG) content. The persistence of foci of live and active chondrocytes within the bone matrix is intriguing and appears to be pathognomonic of UCH. These new findings on UCH could help to determine its pathophysiology and thus prevent this disease, which can lead to major facial deformity.

Methods of Definitive Correction of Mandibular Deformity in Hemimandibular Hyperplasia Based on Radiological, Anatomical, and Topographical Measurements-Proposition of Author's Own Protocol

In order to fully evaluate and establish the degree of bone overgrowth, various radiological studies are essential in the careful planning of the amount of surgical excision. In the presented paper, the authors use self-designed anatomo-topographical reference points for planning the surgeries. Routine panoramic radiographs and low-dose computed tomography based on anatomical landmarks help in measuring the proportions of mandibular bone overgrowth with the following preoperative anatomical landmarks: (Go-Go), (Go(Right)-Gn), (Go(Left)-Gn), and (Me−Gn). Measurements taken at selected points and landmarks (gonion-gnathion/gnathion-menton) are easy to conduct. In the authors’ proposal, the main key factor is total chin correction, which is necessary in cases of severe overgrowth; when F0 > C and Go-Gn>, there is >7 mm of vertical bone overgrowth, and the mandibular canal is positioned <5 mm from the inferior mandibular border—MIB. Larger overgrowths (>7 mm) have a greater outcome on the final symmetry than smaller overgrowths. As no guidelines are known, the authors present their own proposal.

What Features on Routine Panoramic Radiographs Could Help Orthodontists to Estimate the Occurrence of Condylar Hyperplasia from Other Mandibular Asymmetries—Retrospective Analysis Study

Hemimandibular hyperplasia (HH) and elongation (HE) are the most common pathologies present in the mandible. Presented condylar hyperplasias have their own radiological and clinical features. In most cases, patients suffer from various forms of malocclusion. From a total of 150 asymmetrical jaw radiographs evaluated, 46 were evaluated and included in this study. A retrospective study on the data of 46 selected patients treated, diagnosed, and consulted from various forms of mandibular and skeletal asymmetry based on routine diagnostic panoramic radiographs evaluated typical and atypical radiological and anatomical symptoms of condylar hyperplasia. The presented evaluation focused on mandibular, maxillary, and other bones, in order to distinguish condylar hyperplasia from other forms of mandibular asymmetry. The degree of maxillary downward growth followed by the occurrence of an open bite on the affected side estimate the degree/presence or cessation of growth in the affected condyle. Mandibular asymmetry with incisor teeth inclination remains the most typical characteristic of condylar hyperplasia. Increased height of mandibular ramus differentiates between condylar hyperplasia and elongation, which also influences the position of the inferior alveolar nerve. Mentioned symptoms, described as the acronym “Go Moira!”, are useful in a quick and simple “glimpse of an eye” differential diagnostic approach. It is possible to quickly and accurately establish the first diagnosis simply by a careful evaluation of patients’ panoramic radiographs.

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.

Acquired Facial, Maxillofacial, and Oral Asymmetries—A Review Highlighting Diagnosis and Management

Facial asymmetry refers to the absence of, or the deviation from the regular mirror image of facial structures, relative to a referenced midline axis. It can be attributed to a wide spectrum of deformities, including congenital, developmental, or acquired conditions, which can originate either prenatally or postnatally. Though highly prevalent, asymmetry commonly goes undiagnosed due to its subtle or relative nature. Among the spectrum of conditions, acquired cases are triggered postnatally, in previously normal individuals, thus subjecting them to sudden, eventful psychological and psychosocial disharmony. When detected early, timely management may help intervene progressive growth of these conditions. This, therefore, emphasizes the need for a thorough diagnostic workup including medical/dental history, clinical examinations, study models, photographic and radiographic records for a case-by-case basis to prevent severe functional and aesthetic complications. Recently, advanced diagnostic procedures, such as stereophotogrammetry, 3D stereolithographic models, skeletal scintigraphy (radionucleotide scans), 3D computed tomographic scans, cone-beam computed tomography, and magnetic resonance imaging, have provided innovative diagnostic instruments for numerous craniofacial defects. This descriptive review aims at focusing on the factors leading to frequently encountered conditions of acquired facial asymmetry and highlights their clinical evaluation, conservative and surgical interventions by a multi-disciplinary team of clinicians.

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

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

Treatment measures of hemimandibular hyperplasia and associated facial deformities

This study aims to show our institute's experience in the treatment of HH and its associated facial deformities in adults and growing adolescents and to investigate condylar remodeling and volumetric changes and long-term stability of orthognathic surgery in adults. The study included consecutive patients with clinical and radiological features of HH who underwent high condylectomy with or without simultaneous orthognathic surgery from 2013 to 2018. The clinical outcomes were assessed based on functional activities, TMJ pain, and recurrence. Postoperative 3D condylar remodeling and orthognathic stability were evaluated with the use of ITK-Snap and 3D Slicer. Thirteen patients (8 females and 5 males) with a mean age of 26.3 ± 5.79 years (range; 13-34 years) were included with facial asymmetry as the chief complaint. The patients were followed up for a minimum of 12 months and a maximum of 4 years (mean; 16.85 ± 10.04). There were no postoperative complications, and all patients achieved a satisfactory functional and aesthetic outcome using a one-stage surgical procedure. There was no incidence of recurrence or further asymmetries, with long-term stability at the selected points showing a mean difference of less than ±1 mm. The affected condylar volume was significantly reduced following high condylectomy, with mean changes between T1 and T2 of -144. 80 mm³ (p = .012). However, the contralateral condylar volume remained stable, with a mean change of 2.54 mm³ (p = .881). One-stage high condylectomy and orthognathic surgery is a viable measure for the treatment of HH and associated deformities in adults. High condylectomy in early adolescence could result in termination of the disease, and aesthetic improvement with further constant orthodontist-surgeon follow-up is required.

Facial Asymmetry in Unilateral Condylar Hyperplasia: Comparing Treatment for Active versus Burnt-Out Disease

BACKGROUND

Facial asymmetry caused by unilateral condylar hyperplasia requires treatment to address facial and occlusal imbalances. There is no definitive evidence to suggest that a single intervention strategy (during either active condylar overgrowth or the burnt-out phase) results in better/more symmetric correction. This study sought to quantify preoperative and postoperative facial asymmetry in unilateral condylar hyperplasia patients comparing treatment for active versus burnt-out disease.

METHODS

Preoperative and postoperative three-dimensional photographs were obtained. Images were compared to those of unaffected controls as a standard for normal facial symmetry. Facial asymmetry was assessed using root-mean-square deviation. Paired t tests were performed to compare the root-mean-square deviations of preoperative and postoperative images between the unilateral condylar hyperplasia groups and against controls.

RESULTS

Forty patients were included (11 active, nine burnt-out, and 20 controls) and 60 three-dimensional images were evaluated. Preoperatively, patients in the burnt-out group had worse asymmetry than those with active unilateral condylar hyperplasia (p = 0.011). Both groups demonstrated significantly improved symmetry postoperatively (active, p = 0.0069; burnt-out, p = 1.74E-4). However, burnt-out patients remained with some residual asymmetry (p = 4.75E-4), whereas their active counterparts showed no significant difference compared to unaffected controls (p = 0.089).

CONCLUSIONS

Patients with end-stage unilateral condylar hyperplasia have more severe facial asymmetry that is more difficult to normalize compared to earlier intervention during active unilateral condylar hyperplasia. These findings suggest that, if possible, corrective intervention is preferable during active unilateral condylar hyperplasia.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, II.

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.

Cross-talk between synovial fibroblasts and chondrocytes in condylar hyperplasia: an in vitro pilot study

OBJECTIVE

Increasing evidence indicates an interaction between the synovium and the cartilage in the temporomandibular joint (TMJ) and other joints. We recently demonstrated that the expression of proangiogenic factors was enhanced and that of factors promoting matrix degradation was decreased in synovial fibroblasts in condylar hyperplasia (CH). The aim of this study was to explore whether CH chondrocytes can affect the expression of these factors of synovial fibroblasts in a co-culture system.

STUDY DESIGN

The expressions of vascular endothelial growth factor (VEGF), cluster of differentiation 34 (CD34), fibroblast growth factor 2 (FGF-2), and tissue inhibitor of metalloproteinase 1 (TIMP1) from CH condylar tissues were observed by using immunohistochemical methods. Synovial fibroblasts of control tissues were co-cultured with the chondrocytes of CH, and protein expressions of VEGF, FGF-2, thrombospondin 1 (TSP1), matrix metalloproteinase 3 (MMP3), and TIMP1 were examined by using Western blotting.

RESULTS

Positive staining for VEGF, CD34, FGF-2, and TIMP1 was found in the hypertrophic cartilage layer of CH condylar tissues. Protein expressions of VEGF, FGF-2, and TIMP1 were significantly increased in co-cultured synovial fibroblasts, but TSP1 and MMP3 expressions were decreased.

CONCLUSIONS

The angiogenic factors and matrix degradation-related factors in synovial fibroblasts co-cultured with CH chondrocytes showed the same trends as those in synovial fibroblasts from CH tissue, suggesting potential cross-talk between synovial fibroblasts and chondrocytes during CH progression.

Review of Etiology of Posterior Open Bite: Is There a Possible Genetic Cause?

Posterior open bite (POB) is one of the most severe malocclusions that can impair patients' masticatory functions, yet it is also a condition that is poorly understood and not well studied. Most reported cases are either sporadic or idiosyncratic with a diverse yet poorly understood etiology. Although primary failure of eruption (PFE), lateral tongue thrust, and certain medical syndromes or pathology of the temporomandibular joints have all been shown to cause POB, the complex interplay of environmental and genetic factors makes its etiopathogenesis a difficult subject to understand and investigate. Here, we provide a comprehensive review of the etiology of posterior open bite. Additionally, a genetic cause for POB is proposed through a report of an apparently non-syndromic familial case series with high POB penetrance across two generations. Further investigations of the gene(s) and mechanism(s) involved can not only provide a unique opportunity to better understand POB and the intricate muscular-occlusal relationship, but also offer powerful insight into the most effective approaches to clinical management of these (and potentially other) malocclusions.

Choosing the best method to utilise single positron emission computed tomography (SPECT) scans in the management of unilateral condylar hyperplasia

Facial asymmetry secondary to unilateral condylar hyperplasia can be a diagnostic challenge to oral and maxillofacial surgeons. Single positron emission computed tomography (SPECT) scans provide a useful adjunct. We report a brief summary of the evidence describing the effectiveness of different methods of analysing SPECT scans and compare it with the results of a 10-year study at Sunderland Royal Hospital. Overall, both the evidence base and our study strongly favour use of the condyle:condyle ratio over the condyle:reference bone ratio, suggesting that no further comparisons are needed.

One-Stage Computer-Guided Customized Management of Skeletal Asymmetry by Concomitant Proportional Condylectomy and Orthognathic Surgery in Patients With Unilateral Condylar Hyperplasia

PURPOSE

Facial asymmetry associated with unilateral condylar hyperplasia can benefit from condylectomy, which aims to arrest the pathologic condylar growth and restore an appropriate posterior height. However, there are several cases in which condylar hyperplasia is combined with various dentofacial deformities, for which joint surgery has to be accompanied by concomitant orthognathic surgery. The literature is relatively poor of examples in which virtual planning for orthognathic surgery includes the evaluation of condylectomy, which is often manually performed. The aim of this study was to present and discuss a workflow for 1-stage computer-guided customized management of skeletal asymmetry by simultaneous condylectomy and orthognathic surgery.

MATERIALS AND METHODS

Five patients were enrolled in this study from 2018 to 2019. All patients underwent combined virtual planning of orthognathic surgery and condylectomy. Virtual surgery was translated into real surgical coordinates using patient-specific surgical guides and custom-designed osteosynthesis plates.

RESULTS

All surgical procedures were uneventful, and in all patients, virtual planning was successfully brought into the operating room with high accuracy, as confirmed by superimposition analyses. Symmetrization of the face and achievement of correct occlusion were observed in all cases.

CONCLUSIONS

The presented protocol is a reliable solution for the combined planning of orthognathic surgery and condylectomy. Virtual planning, surgical guides, and custom-designed plates allow computerized simulations to be replicated in the real patient.

Unilateral Condylar Hyperplasia: Is Reactivation After a Long Latency Period of Inactivity Plausible?

Unilateral condylar hyperplasia (UCH) is characterized by an overgrowth of the mandibular condyle responsible for a facial and dental asymmetry associated with temporomandibular joint function and maxillary growth consequences. The diagnosis is based on a body of clinical, radiological and histological arguments. A 38 years old woman with a reactivation of UCH after a latency period of 16 years following an orthognathic surgery performed for facial asymmetry normalization is presented. She was addressed to our department for a facial progressive asymmetry relapse and dental prosthetic consequences.The radiological images and the planar scintigraphy combined with single-photon emission computed tomography scans showed an active left unilateral condylar hyperplasia. A left proportional condylectomy was performed.The case presented highlights the possibility for the UCH to be reactivated after a long period of latency, leading to a relapse of the occlusal and facial disorders and so advocates the need for first condylectomy or at least a long-term follow-up if condylectomy is not performed as a first-line treatment.

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.

An Updated Protocol for the Treatment of Condylar Hyperplasia: Computer-Guided Proportional Condylectomy

PURPOSE

To present an updated protocol for proportional condylectomy in which virtual surgical planning and 3-dimensional (3D) printing allow precise definition of the osteotomy level.

MATERIALS AND METHODS

Three-dimensional mirroring was performed to generate a virtual replica of the healthy hemimandible, which was subsequently aligned and overlapped with the actual mandible to estimate the level for condylectomy. A custom-fitted 3D printed surgical guide was modeled for the condylar head to reproduce the virtual plan in the surgical scenario. The updated protocol for computer-guided condylectomy was applied to 7 patients.

RESULTS

All patients were followed for 12 months. Surface deviation color maps showed a strong correspondence between the virtually calculated condylectomy and the surgical outcome achieved with the aid of the surgical guide. No cases of condylar hyperplasia recurrence were observed.

CONCLUSION

An updated protocol based on accurate 3D analysis was performed by virtual surgical planning and 3D printing. Virtual surgical planning allows the precise definition of the level of condylectomy, and custom-made 3D printed cutting guides are useful to reproduce virtual measurements during surgical maneuvers.

Review and Classification Update: Unilateral condylar hyperplasia

Unilateral condylar hyperplasia is characterised by slow progressive growth of the different parts of mandible, the aetiology of which is still unclear. It is a self-limiting condition mostly seen between the age of 11-30 years causing facial asymmetry and its progression ceases after a certain time. In literature until now very few cases have been reported and every case that is being reported adds to its features or the aetiology. Previously, it has been classified into two types that is, hemimandibular hyperplasia and hemimandibular elongation. Here, we report a similar case with a few features distinct from those reported earlier.