Active Unilateral Condylar Hyperplasia Research Articles

Unilateral “Inactive” Condylar Hyperplasia: New Histological Data

Background: Unilateral condylar hyperplasia (UCH) is characterized by slow progression and enlargement of the condyle, accompanied by elongation of the mandibular body, resulting in facial asymmetry, occlusal disharmony, and joint dysfunction. This condition can be defined as “active” or “inactive”: the active form is characterized by continuous growth and dynamic histologic changes, whereas the inactive form indicates that the growth process has stabilized. Since there are few microscopic studies on the inactive form, this study aims to investigate the histological features and expression of key proteins and bone markers in patients diagnosed with inactive UCH. Methods: A total of 15 biopsies from patients aged 28 to 36 years were examined by light microscopy and immunofluorescence for collagen I and II, metalloproteinases 2 (MMP-2) and 9 (MMP-9), receptor activator of nuclear factor- kappa B (RANK), and osteocalcin. Results: Our findings indicate that during inactive UCH, the ongoing process is not entirely stopped, with moderate expression of collagen, metalloproteinases, RANK, and osteocalcin, although no cartilage islands are detectable. Conclusions: The present study shows that even if these features are moderate when compared to active UCH and without cartilage islands, inactive UCH could be characterized by borderline features that could represent an important trigger-point to possible reactivation, or they could represent a long slow progression that is not “self-limited”.

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

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

Factors affecting duration of post-surgical orthodontics in the Surgery First/Early Approach: A retrospective study

BackgroundSurgery First Approach (SFA) and Surgery Early (SE) are considered promising alternatives, compared to the conventional three-stages orthodontic-surgical approach, for treatment of dento-maxillofacial deformities. However, many features need further study, like the role of the orthodontist. Aim of the study was to analyse the clinical characteristics of patients who underwent SFA and SE, and if differences in duration of orthodontics could be influenced by clinical features. MethodsA retrospective research was performed on patients who met the inclusion criteria for SFA (31) and SE (12), of the total of patients affected by dento-facial deformities in our Unit (191) in the period 2012–2017. After collection of clinical data, duration of orthodontics, age, pre-treatment PAR Index, ANB angle, amount of the curve of Spee were compared. A regression analysis evaluated if these clinical parameters, together with type of bracket and type of intervention, could influence the duration of post-surgical orthodontics. ResultsAll patients who performed the SFA/SE were affected by class III, II and active Unilateral Condylar Hyperplasia (22% of total population). Pre-treatment mean differences of age (p = 0.0518), PAR Index (p = 0.0916), curve of Spee (p = 0.1006) between groups were not statistically significant. A statically significant difference was found for the overall duration of therapy, for the significant shorter duration of pre-surgical orthodontics, while the difference of post-surgical orthodontics duration was not significant (p = 0.4753). Type of bracket (rho=-0.19039, p = 0.266) and intervention performed (rho=-0.11522, p = 0.5034) were not correlated with duration of post-surgical orthodontics, as well as pre-treatment PAR Index, ANB angle and depth of the curve of Spee. ConclusionsSurgery First/Early Approach is a therapeutic choice that could be performed only in patients affected by specific malocclusions and who exactly meet indications. Protocol and post-surgical occlusal stability are factors that should influence the duration of therapy more than clinical characteristics.

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

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. 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. 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. '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 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.

Active Unilateral Condylar Hyperplasia Treated With Simultaneous Condylectomy and Orthognathic Surgery: A Clinical Report

To review and report the demographic and diagnostic data in a population with active unilateral condylar hyperplasia. The surgical intervention, sequencing of surgery, and treatment outcomes, including a quality-of-life survey, are described. Eighty patients were diagnosed with active disease. Demographic, treatment, and treatment outcomes were assessed. Quality of life was assessed by a 21-question questionnaire. Women were affected more frequently than men (W- 52; 65%; P = .008). Hemimandibular elongation (HE) (49; 61%; P - .004) occurred more frequently than hemimandibular hyperplasia (HH) (24; 30%) and HH-HE (7; 9%). Right side was affected more than left (R- 49; 61%; P - .003) overall, and when stratified. All racial groups were represented. Of the 80 patients in the sample, 80 (100%) underwent condylectomy on the side of active growth, 70 (87%) underwent bimaxillary osteotomies, 53 patients (66%) had single-piece maxillary osteotomies, 17 (21%) underwent segmental maxillary osteotomies, and 38 (48%) genioplasties were performed. Four patients (5%) underwent a second operation within a year of the first surgery to adjust the position of the mandible. Four (5%) facial nerve deficits were recorded. Class I cuspid occlusion was achieved with coincident maxillary and mandibular midlines and resolution of crossbite in 70 (88%) patients. Twenty three of the 24 respondents (96%) reported that they were satisfied with the treatment. Both HH and HE are diagnosed through clinical and radiographic examinations. Our results showed that HE occurs more frequently, all deformity subclassifications occur more frequently in females, the majority present in adolescence, and all racial groups are affected. The right side predominated. This study suggests that simultaneous condylectomy and orthognathic surgery provides predictable and stable outcomes for patients with active unilateral condylar hyperplasia and associated dentofacial deformities with an improvement in quality of living.

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

Unilateral condylar hyperplasia (UCH) is a progressive, nonneoplastic overgrowth of the condyle of the temporomandibular joint. For treating active UCH, a popular method combines orthognathic surgery with high condylectomy and orthodontic treatment. The goal of this study was to introduce a new method to correct asymmetry for active UCH. Retrospectively, 47 patients with active UCH were divided into horizontal-type, vertical-type, and combined-type. All patients were treated with condylectomy plus postsurgery standard orthodontics (CPSO) with applied miniscrews implanted in infrazygomatic crest and hard palate to intrude affected side of maxillary molars and apply intermaxillary traction for contralateral molars. Cone-beam computed tomography was taken at presurgery, postsurgery, and the end of orthodontics (T3). In the vertical (n= 10) and combined (n= 28) types, deviation of the chin and the canting of the mandible and maxillary occlusal plane were significantly reduced at T3. A difference in the torque of bilateral maxillary first molar (U6) and bilateral mandibular first molar (L6) was significantly reduced at T3. The anterior, superior, and posterior joint spaces in the vertical-type and combined-type were significantly decreased at T3 compared with postsurgery. In contrast, in the horizontal-type group (n= 9), the deviation of the chin was corrected; however, the canting of the mandible and maxillary occlusal plane was significantly increased at T3 compared with presurgery. CPSO restored facial and occlusal symmetry for vertical-type and combined-type active UCH and returned affected-side condyle to the glenoid fossa. However, CPSO was not suitable for treating the horizontal-type UCH.

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.

Improved Quality of Living following Simultaneous Condylectomy and Orthognathic Surgery: A Retrospective Analysis for Active Unilateral Condylar Hyperplasia

The objective was to assess quality of life in patients who underwent simultaneous condylectomy and orthognathic surgery in conjunction with orthodontic treatment for active unilateral condylar (TMJ) hyperplasia. This pathologic process leads to the development of esthetic and functional concerns. High condylectomy (7-10mm of bone removed from condylar process) simultaneously performed with orthognathic surgery is the treatment studied1, but currently, there is no published literature that analyzes patient satisfaction.A total of 51 patients who underwent simultaneous condylectomy and orthognathic surgery for active unilateral condylar hyperplasia at UNC hospitals between 2004 and 2017 (minimum 4 years postop) were mailed a questionnaire containing 21 questions to assess their quality of life after undergoing treatment. All patients underwent orthodontic treatment in conjunction with surgery.A total of 24 (47%) patients completed and returned the questionnaire. Sixteen (67%) were female and 8 (33%) were male, similar to the treatment population. Twenty-three (96%) reported that they are satisfied with their results. Even after fully realizing the consequences of treatment, these 23 respondents endorsed that they would do it again. Benefits of treatment included appearance change, improved mastication, reduction of discomfort, and improvement of jaw functioning, etc. Indication for treatment differed for each patient, but when polled on their greatest benefit derived from treatment, 13 (54%) reported appearance change, 18 (75%) reported improved mastication, and 7 (29%) reported reduction of discomfort (10 respondents provided more than 1 “greatest benefit”). Overall, 8 (33%) patients endorsed TMJ pain prior to surgery, and 4 (50%) of those individuals reported that they no longer suffer from TMJ arthralgia of any magnitude. Furthermore, 9 (38%) patients reported “clicking” prior to treatment, with 12 (50%) reporting “clicking” afterwards. Of the 24 surveyed patients, 9 (38%) reported frequent headaches prior to treatment. All of these individuals reported a decrease in frequency and intensity of headaches since treatment. Based on the pre-operative clinical findings of the 24 patients, 13 (54%) patients were classified Hemimandibular Elongation, 4 (17%) were Hemimandibular Hypertrophy, and 7 (29%) were a hybrid of Hemimandibular Elongation and Hemimandibular Hypertrophy, according to the Obwegeser and Makek classification2 of condylar hyperplasia.Overall, a significant majority of patients undergoing simultaneous condylectomy and orthognathic surgery combined with orthodontics benefited from treatment. This is important for healthcare providers when considering referral for condylar hyperplasia. Prior to these data, treatment was agreed upon between provider and patient based on the practical idea that surgical intervention will improve quality of life. Now, potential patients can be educated on tangible treatment outcomes when determining whether to pursue treatment, regardless of their presenting concern.

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.

SPECT/CT Correlation in the Diagnosis of Unilateral Condilar Hyperplasia.

Objective: To evaluate the correlation between metabolic bone activity measured by single photon emission computed tomography (SPECT) and the anatomic condylar characteristics acquired by computed tomography (CT), in patients with unilateral condylar hyperplasia (UCH). Method and Materials/Patients: Observational, descriptive study in a group of 71 patients with clinical diagnosis of UCH and indication of SPECT/CT. Bone SPECT images obtained in a gamma-camera GE Infina and processed in a station Xeleris 3 with the program Volumetrix MI Evolution for bone. CT images acquired in a PET/CT Biograph mcT20 equipment (Siemens) processed in a station Osirix V 7.5.1 (Pixmeo, Bomex, Switzerland). Results: The sample included 24 men (33.8%) and 47 women (66.2%). Active state UCH was detected in 40 (56.3%) cases (over 55% uptake in the affected condyle) and 38 (53.5%) presented mandibular deviation to the right side. No significant differences related to sex, age, or mandibular deviation side were found. Mandibular deviation was the only morphologic feature related to active/inactive UCH (p = 0.003). The likelihood of active CH was significantly higher in patients with mandibular deviation higher than 6 mm compared with <6 mm (odds ratio (OR): 3.51, confidence interval (CI) 95%: 1.27–9.72). Conclusion: There is a significant correlation between the magnitude of mandibular deviation quantified on CT and metabolic findings obtained by SPECT in patients with UCH. The risk of active UCH is 3.5 times higher in patients with a mandibular deviation ≥6 mm.

Condilectomía baja intraoral para el tratamiento de Hiperplasia Condilar Reporte de un caso

ABSTRACT Condylar hyperplasia is a developmental malformation that causes abnormal growth of the mandibular condyle. It is a generic term that describes conditions that cause excessive growth and elongation of the mandibular condyle, altering the occlusion and indirectly affecting the maxilla. The usual treatment for this pathology consists of a condylectomy through an extraoral approach. The objective of this work is to present the case of an active unilateral condylar hyperplasia, which was treated by low condylectomy with an intraoral approach and orthognathic surgery. The intraoral approach to a condylectomy has been poorly documented; however it offers numerous advantages and can be performed safely.

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

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. 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 (Rtotal, Rmean, Rmax), a percentage uptake (Ptotal, Pmean, Pmax), background-corrected counts (Btotal, Bmean, Bmax), as well as CT-based condylar diameters (RCT,PCT) relative to the contralateral condyle. 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%). Rtotal, Rmean, Ptotal, and Pmean demonstrated area under the curve between 84% and 86%. Metrics based on CT diameters and background-corrected counts were not associated with UCH diagnosis. 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.

Concurrent High Condylectomy and Orthognathic Surgery for Treatment of Patients With Unilateral Condylar Hyperplasia.

Facial asymmetry from unilateral condylar hyperplasia (UCH) may be definitively treated in the presence of active disease (with high condylectomy and concurrent orthognathic surgery) or after waiting for disease inactivity (orthognathic surgery alone). There is currently no consensus on the standard of care. In this study, we sought to compare functional and esthetic outcomes, as well as treatment duration, between these 2 management options. Patients who underwent treatment for UCH were identified through retrospective review. Pre- and postoperative 3-dimensional (3D) images were obtained. Short- and long-term operative outcomes of those treated during the active (group 1) were compared to those treated in the inactive phase (group 2). Total treatment time, operative time, and length of hospital stay were evaluated. Facial asymmetry was also assessed by laypersons using a Likert scale. Fifteen patients (mean 25.6 years, range 14-56) were included: 6 in group 1 and 9 in group 2. All surgical outcomes were statistically independent of procedure type. Treatment time was significantly longer in the group 2 (P = 0.03). Both groups demonstrated significant improvement in facial asymmetry scores postoperatively with no significant difference in pre- or postoperative asymmetry between groups (P = 0.64). In patients with active UCH, high condylectomy and orthognathic surgery is a procedure that restores facial symmetry and improves jaw function while halting mandibular growth. Good esthetic and functional outcomes, as well as reduced treatment time and disease burden, support the use of this treatment option for this population.

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.

Concurrent High Condylectomy and Orthognathic Surgery to Address Mandibular and Facial Asymmetry.

Correction of facial asymmetry caused by active unilateral condylar hyperplasia (CH) requires proper diagnosis, arrested ongoing condylar growth, and ultimately orthognathic surgery. Traditionally, prior to performing orthognathic surgery, active CH is addressed either by: awaiting natural cessation of condylar overgrowth, or performing an interval high condylectomy (to stop growth). However, these strategies both add to the total treatment time, by either waiting and confirming no active growth, or performing a first stage growth-arresting procedure. In this report, the authors describe concurrent high condylectomy, and 3-jaw orthognathic surgery, to address the root of the problem and provide aesthetic correction in the same setting. This clinical series illustrates a detailed description of this approach, highlighting operative order, and an analysis of outcomes.

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.

Three-dimensional skeletal changes after early proportional condylectomy for condylar hyperplasia

The purpose of this study was to evaluate volumetric and dentoskeletal changes in 21 patients with active unilateral condylar hyperplasia (AUCH) after proportional condylectomy. A split-mouth design was used: control group healthy joints (HS, healthy side) and test group affected joints (AS, affected side) (21 per group). Cone beam tomography scans were obtained at T0 (preoperative), T1 (10days after the intervention), and T2 (approximately 12 months post-surgery). The condylar unit volume (CUV), articular cavity volume (ACV), and dentoalveolar units (DAUs) were measured. CUV showed a difference of 1.12cm3 between T0 and T1, increasing 0.4cm3 between T1 and T2 on AS. There was no difference between T0 and T2 on HS. ACV increased 0.65cm3 between T0 and T1 on AS, after which it decreased by 0.36cm3 at T2 (0.30cm3 larger than the initial articular cavity at T0). ACV showed no post-surgery differences on HS. Midline DAU showed extrusion of 0.20mm for maxilla and 0.52mm for mandible, while in the lateral area, maxilla was extruded by 0.3mm on HS and was intruded 0.12mm on AS. For the mandible, both sides showed extrusion (0.4–0.6mm). In the distal to canine and molar areas, intrusion of 0.2mm and 0.9mm, respectively, was observed on AS; there was extrusion of 0.6mm distal to the canine on HS. At the mandibular level, AS distal to the canine showed extrusion of 1mm, while intrusion of 0.2mm was observed in the molars. For HS, only extrusion at the molar level (0.2mm) was observed. In conclusion, after proportional condylectomy, a neocondyle forms within 12 months to equal the healthy contralateral side. The articular cavity, which is reduced in the initial stage, increases in size after surgery and the volume gradually approaches that of the healthy side. Dentoalveolar changes occur at the anterior and posterior levels, causing intrusion and extrusion of the interdental crests. An early proportional condylectomy as the sole surgical treatment for patients with AUCH allows normalization of the maxillomandibular relationship.

P090] Optimalization of quantification of mandibular growth

Purpose Excessive growth of one condyle suspected of active unilateral condylar hyperplasia (UCH) may lead to asymmetric facial deformities and malocclusion. Single photon emission computed tomography (SPECT) bone scintigraphy is becoming current global standard for diagnostic of UCH. The examination is performed after intravenous administration of radioactive technetium-labelled diphosphates (99mTc-MDP). The aim of this research is to select the most suitable method for the evaluation of asymmetry and mandibular growth in comparison with the normal values. Methods 17 patients were evaluated (11 represent normal values, 6 patients with UCH). No patient from normal database had a previous history of growth abnormality or pathological condition involving the maxillofacial skeleton or mandible. These patients underwent an additional mandibular SPECT to create a normal database. Except the asymmetry, mandibular growth was also examined. The internal (clivus) and external standard (source of known activity) was used to evaluate the growth. The region and volume of interest (ROI/VOI) across each condyle and clivus were drawn by various methods. For each ROI/VOI, the total number of counts, maximum and average values in ROI/VOI and their size were recorded. Results The correlation analysis suggested that it is inappropriate to substitute the values obtained from different sizes of ROI for one another. The ratio of the right and left condyle may be used to evaluate the mandibular asymmetry. For the evaluation of the growth activity of condyle is necessary to use standardization. Therefore, external standard located near patient head is the most appropriate approach. The evaluation method and criteria were determined by the analyses. Conclusions The use of 99mTc-MDP SPECT appears to be a suitable quantitative method for assessing the growth activity of the mandible. The average counts in same size of ROI and usage of external standardization appears to be most suited method for assessing the growth activity of a condyle. Similar conclusion holds for assessing asymmetric growth. However, it is still necessary to monitor these parameters and criteria and adapt them on the basis of a wider database of normal values.

Cone–beam computed tomographic analysis of maxillary and mandibular changes after high condylectomy combined with orthodontic treatment for active unilateral condylar hyperplasia

Our aim was to evaluate the efficacy of high condylectomy combined with orthodontic treatment for active unilateral condylar hyperplasia in 25 affected patients, by an analysis of the maxillary and mandibular changes on cone–beam computed tomography (CT). High condylectomy was the sole operative treatment. Variables that reflected the canting of the occlusal plane, the height of the maxillary complex, the buccolingual angulation of the maxillary first molar, the height of the ramus, the total length of the mandible, and the deviation of the chin were measured and compared between the two sides and between time intervals: preoperatively (T1) and the end of treatment (T2). The differences between time intervals in the deviation of the chin (p<0.001) and the canting of the occlusal plane (p<0.001) were significant, but there were no significant differences in the height of the ramus (p=0.476) and the total length of the mandible (p=0.838) between the affected and unaffected sides at T2. There were significant differences between time intervals in the buccolingual angulation on the unaffected side and the height of the maxillary complex on the affected side (p<0.001). Facial asymmetry was corrected and the occlusal plane was improved. In conclusion, high condylectomy as the sole operative treatment combined with orthodontic treatment can provide an alternative method for correction of facial asymmetry associated with active unilateral condylar hyperplasia.