Demographic features in Unilateral Condylar Hyperplasia: An overview of 309 asymmetric cases and presentation of an algorithm.

PURPOSE: Unilateral Condylar Hyperplasia (UCH) is an acquired deformity of the mandible, which can highly influence the symmetry of the face due to its progressive nature. It is caused by growth resembling pathology in one of the mandibular condyles. Definition as well as classification is subject to discussion. The aim of this study is to evaluate a large cohort of alleged UCH patients, and to describe the clinical characteristics, demographic features, classification and follow up. Secondly an algorithm is presented, in order to achieve uniformity in diagnosis and treatment. PATIENTS AND METHODS: From 1994 to 2014 a database of consecutive patients from 3 maxillofacial departments (Academic Medical Center, Amsterdam; VU Medical Center, Amsterdam and Spaarne Gasthuis, Haarlem) with suspected UCH was set up. Patients were referred by orthodontists, dentists, general practitioners or maxillofacial surgeons. Demographic features, bonescan outcomes, laterality, classification and follow-up were noted. Secondarily, all patients were retrospectively diagnosed by one surgeon (JWN), using available documentation. Missing data and follow-up were additionally retrieved from orthodontic offices. RESULTS: 394 asymmetric patients were evaluated. In 309 (78%) patients, the diagnosis UCH was justified and SPECT data were available. The mean age at presentation was 20.3 years (SD ± 7.7, range 9.0-54.5 years). In 48% of the patients, the bonescan was positive. 80% of these patients received surgical treatment, of which 62% were treated with a condylectomy only, 33% were treated with condylectomy plus additive corrective surgery, and 5% underwent corrective surgery only. Of the patient group without positive bonescan 42% of the patients received surgical treatment: 34% condylectomy only, 15% condylectomy plus additive corrective surgery, and 51% corrective surgery only. In total (N = 309) 96 (31%) patients underwent condylectomy as only surgical treatment and 124 (40%) patients received no surgical treatment at all. Treatment could be finalized with orthodontic treatment without further surgery in 64% and 41% respectively. 96 patients were subject to comparison of the classification as noted by the clinician and the author (JWN). In only 72% of the cases, the secondary screening was in agreement with the initial classification. CONCLUSION: Based on this study not all (active) UCH patients require corrective (orthognathic) surgery. A (transoral) partial condylectomy for active patients is recommended, with a postoperative remodeling period of 6 months with or without orthodontic treatment. Second stage correcting surgery may be necessary upon evaluation, using general orthognathic diagnostic and planning procedures. It appears difficult to classify patients reliably using the available clinical and radiological documentation. Objectivity and quantification in the diagnostic process is necessary: uniformity in documentation and parameters. The attached documentation form and UCH treatment algorithm is recommended.

IMF-screws or arch bars as conservative treatment for mandibular condyle fractures: Quality of life aspects.

OBJECTIVE: Arch bars as treatment for a fractured mandibular condyle are inconvenient to patients and lead to lowered quality of life (QOL). To overcome these inconveniences, IMF-screws (IMFS) to facilitate intermaxillary fixation during surgery have been developed. The purpose of the present study is to investigate and compare QOL for patients treated for a fractured mandibular condyle with either IMFS or arch bars. MATERIAL AND METHODS: This research trial was conducted from 2010 to 2014 as part of an earlier prospective, multicenter, randomized clinical trial in which the use of IMFS was compared to the use of arch bars in the treatment of mandibular condylar fractures. RESULTS: In total, 50 patients were included: 30 (60%) male patients and 20 (40%) female patients (mean age: 31.8 years, standard deviation [SD] = 13.9 years, range = 18-64 years). A total of 24 (48%) patients were allocated in the IMFS group, and 26 (52%) patients were assigned to the arch-bars control group. Significant results were observed in the subscales social isolation, possibility to eat and vary diet, influence on sleep, and satisfaction with the given treatment, all in favour of IMFS. CONCLUSION: In conclusion, using IMFS as a method for conservative treatment of condylar fractures led to a higher QOL during the 6-week period of fracture healing. In comparison to arch bars, patients treated with IMFS experienced less social isolation, had fewer problems with eating, and express the feeling they are able to continue their normal diet. Furthermore it seems that the use of IMFS has a lower negative impact on social and financial aspects of the patient.

Conservative treatment of a mandibular condyle fracture: Comparing intermaxillary fixation with screws or arch bar. A randomised clinical trial.

INTRODUCTION: A mandibular condyle fracture can be treated conservatively by intermaxillary fixation (IMF) or by open reposition and internal fixation (ORIF). Many IMF-modalities can be chosen, including IMF-screws (IMFS). This prospective multi-centre randomised clinical trial compared the use of IMFS with the use of arch bars in the treatment of mandibular condyle fractures. RESULTS: The study population consisted of 50 patients (mean age: 31.8 years). Twenty-four (48%) patients were allocated in the IMFS group. Twenty-six (52%) patients were assigned to the arch bars group. In total 188 IMF-screws were used (5-12 screws per patient, mean 7.83 screws per patient). All pain scores were lower in the IMFS group. Three patients developed a malocclusion (IFMS-group: one patient, arch bars-group: two patients). Mean surgical time was significantly shorter in the IMFS group (59 vs. 126 min; p<0.001). There were no needlestick injuries (0%) in the IMFS group and eight (30.7%) in the arch bars group (p=0.003). One IMF-screw fractured on insertion (0.53%), one (0.53%) screw was inserted into a root. Six (3.2%) screws loosened spontaneously in four patients. Mucosal disturbances were seen in 22 patients, equally divided over both groups. CONCLUSION: Considering the advantages and the disadvantages of IMFS, and observing the results of this study, the authors conclude that IMFS provide a superior method for IMF. IMFS are safer for the patients and surgeons.

Complications of mandibular distraction osteogenesis for acquired deformities: a systematic review of the literature.

A systematic review on complications in all forms of mandibular distraction osteogenesis (MDO) for acquired deformities was performed. Search terms expressing distraction osteogenesis were used in 'AND' combination with search terms comprising 'mandible' and terms for complication, failure, and morbidity. A search using PubMed (National Library of Medicine, NCBI), EMBASE, and the Cochrane Controlled Trials Register yielded 644 articles published between 1966 and mid October 2013. Three hundred and twenty-one eligible articles were screened in detail. Complications related to MDO in acquired deformities were reported in 105 clinical articles, involving 1332 patients. Treatments included alveolar distraction osteogenesis (ADO), mandibular lengthening, DO in bone grafts, and bi-/trifocal transport disc DO (TDDO) for segmental mandibular defects. A high incidence of complications was seen in MDO for acquired deformities (ADO 44.4%; residual group 43.9%). An index for classifying complications in MDO, based on the impact and further treatment or final results, was used. In the ADO group, soft tissue complications (8.0%), insufficient vector control (7.6%), temporary inferior alveolar nerve (IAN) neurosensory disturbances (6.5%), device-related problems (3.5%), mandible fractures (2.8%), insufficient bone formation (2.5%), and fracture of the transport disc (1.3%) were seen. In the residual group, temporary IAN neurosensory disturbances (13.4%), minor infection (5.3%), DO failure (4.0%), and device-related problems (3.8%) were reported.

Panoramic imaging is not suitable for quantitative evaluation, classification, and follow up in unilateral condylar hyperplasia.

Patients with suspected unilateral condylar hyperplasia are often screened radiologically with a panoramic radiograph, but this is not sufficient for routine diagnosis and follow up. We have therefore made a quantitative analysis and evaluation of panoramic radiographs in a large group of patients with the condition. During the period 1994-2011, 132 patients with 113 panoramic radiographs were analysed using a validated method. There was good reproducibility between observers, but the condylar neck and head were the regions reported with least reliability. Although in most patients asymmetry of the condylar head, neck, and ramus was confirmed, the kappa coefficient as an indicator of agreement between two observers was poor (-0.040 to 0.504). Hardly any difference between sides was measured at the gonion angle, and the body appeared to be higher on the affected side in 80% of patients. Panoramic radiographs might be suitable for screening, but are not suitable for the quantitative evaluation, classification, and follow up of patients with unilateral condylar hyperplasia.

Do the changes in muscle mass, muscle direction, and rotations of the condyles that occur after sagittal split advancement osteotomies play a role in the aetiology of progressive condylar resorption?

Changes in cross-sectional area (CSA), volume (indicating muscle strength), and direction of the masseter and medial pterygoid muscles after surgical mandibular advancement were measured, along with the rotation of the condyles after bilateral sagittal split osteotomies (BSSOs) to advance the mandible. Measurements were done on magnetic resonance images obtained before and 2 years after surgery. CSA and volume were measured in five short-face and seven long-face patients (five males, seven females). Muscle direction was calculated in eight short-face and eight long-face patients (eight males, eight females). Short-face patients underwent BSSO only; long-face patients underwent combined BSSO and Le Fort I osteotomies. The CSA and volume decreased significantly (mean 18%) in all patients after surgery. The postoperative muscle direction was significantly more vertical (9°) in long-face patients. Rotations of the proximal segments (condyles) were minimal after 2 years. The results of this study showed that, after BSSO advancement surgery, changes in the masseter and medial pterygoid muscles are not likely to cause increased pressure on the condyles and nor are the minimal rotations of the condyles. It is concluded that neither increased muscle traction nor condylar rotations can be held responsible for progressive condylar resorption after advancement BSSO.

Complications of mandibular distraction osteogenesis for developmental deformities: a systematic review of the literature.

A systematic review of English and non-English articles on the complications of mandibular distraction osteogenesis (MDO) for patients with developmental deformities was performed, in accordance with the PRISMA statement. Search terms expressing distraction osteogenesis were used in 'AND' combination with search terms comprising 'mandible' and terms for complication, failure, and morbidity. A search using PubMed (National Library of Medicine, NCBI), EMBASE, and Cochrane Controlled Trials Register yielded 644 articles published between 1966 and mid October 2013. Clinical articles that reported complications related to MDO in developmental deformities were included. Two hundred and fifty articles were eligible and were screened in detail. A total of 32 articles reporting the cases of 565 patients were finally included. Patients underwent mandibular lengthening and transverse widening. A total of 211 complications were reported (37.4%); these were classified according to an index that indicates the clinical impact. Inferior alveolar nerve (IAN) neurosensory disturbances, minor infection, device failure, anterior open bite, permanent dental damage, and skeletal relapse were most represented. Complications that resolved spontaneously (type I) were seen in 11.0%, medically or technically manageable complications, without hospitalization, were seen in 10.8% (type II), and permanent complications (type VI) were seen in 9.6%.

Microcomputed tomographic analysis of human condyles in unilateral condylar hyperplasia: increased cortical porosity and trabecular bone volume fraction with reduced mineralisation.

Unilateral condylar hyperplasia or hyperactivity is a disorder of growth that affects the mandible, and our aim was to visualise the 3-dimensional bony microstructure of resected mandibular condyles of affected patients. We prospectively studied 17 patients with a clinical presentation of progressive mandibular asymmetry and an abnormal single-photon emission computed tomographic (SPECT) scan. All patients were treated by condylectomy to arrest progression. The resected condyles were scanned with micro-CT (18 µm resolution). Rectangular volumes of interest were selected in 4 quadrants (lateromedial and superoinferior) of the trabecular bone of each condyle. Variables of bone architecture (volume fraction, trabecular number, thickness, and separation, degree of mineralisation, and degree of structural anisotrophy) were calculated with routine morphometric software. Eight of the 17 resected condyles showed clear destruction of the subchondral layer of cortical bone. There was a significant superoinferior gradient for all trabecular variables. Mean (SD) bone volume fraction (25.1 (6) %), trabecular number (1.69 (0.26) mm(-1)), trabecular thickness (0.17 (0.03) mm), and degree of mineralisation (695.39 (39.83) mg HA/cm(3)) were higher in the superior region. Trabecular separation (0.6 (0.16) mm) and structural anisotropy (1.84 (0.28)) were higher in the inferior region. The micro-CT analysis showed increased cortical porosity in many of the condyles studied. It also showed a higher bone volume fraction, greater trabecular thickness and trabecular separation, greater trabecular number, and less mineralisation in the condyles of the 17 patients compared with the known architecture of unaffected mandibular condyles.

Efficacy of antidepressants on orofacial pain: a systematic review.

Orofacial pain is a common complaint with multiple diagnoses. There is controversy about the effectiveness of antidepressants for the management of orofacial pain disorders. In order to be able to make a best evidence choice between available antidepressants for the treatment of orofacial pain, a systematic review was conducted of existing randomized controlled trials of antidepressants. Trials were identified from the Pubmed database up to March 2012, from references in retrieved reports and from references in review articles. Six articles were found and included in this review. Four studies were randomized placebo-controlled trials and two studies were randomized active-controlled trials. Two independent investigators reviewed these articles using a 15-item checklist. All six trials were of high quality according to the 15-item criteria. Nevertheless there was limited evidence to support the effectiveness of antidepressants in orofacial pain disorders, because of the heterogeneity of treatment modalities and the low number of randomized controlled trials per diagnose. More randomized controlled trials are needed to come to a firm conclusion for the use of antidepressants for orofacial pain disorders.

Static and dynamic loading of mandibular condyles and their positional changes after bilateral sagittal split advancement osteotomies.

This study analysed the effects of change of direction of masseter (MAS) and medial pterygoid muscles (MPM) and changes of moment arms of MAS, MPM and bite force on static and dynamic loading of the condyles after surgical mandibular advancement. Rotations of the condyles were assessed on axial MRIs. 16 adult patients with mandibular hypoplasia were studied. The mandibular plane angle (MPA) was <39° in Group I (n=8) and >39° in Group II (n=8). All mandibles were advanced with a bilateral sagittal split osteotomy (BSSO). In Group II, BSSO was combined with Le Fort I osteotomy. Pre and postoperative moment arms of MAS, MPM and bite force were used in a two-dimensional model to assess static loading of the condyles. Pre and postoperative data on muscle cross-sectional area, volume and direction were introduced in three-dimensional dynamic models of the masticatory system to assess the loading of the condyles during opening and closing. Postsurgically, small increases of static condylar loading were calculated. Dynamic loading decreased slightly. Minor rotations of the condyles were observed. The results do not support the idea that increased postoperative condylar loading is a serious cause for condylar resorption or relapse.

Positional changes of the masseter and medial pterygoid muscles after surgical mandibular advancement procedures: an MRI study.

This study evaluated whether surgical mandibular advancement procedures induced a change in the direction and the moment arms of the masseter (MAS) and medial pterygoid (MPM) muscles. Sixteen adults participated in this study. The sample was divided in two groups: Group I (n=8) with a mandibular plane angle (mpa) <39° and Group II (n=8) with an mpa >39°. Group I patients were treated with a bilateral sagittal split osteotomy (BSSO). Those in Group II were treated with a BSSO combined with a Le Fort I osteotomy. Pre- and postoperative direction and moment arms of MAS and MPM were compared in these groups. Postsurgically, MAS and MPM in Group II showed a significantly more vertical direction in the sagittal plane. Changes of direction in the frontal plane and changes of moment arms were insignificant in both groups. This study demonstrated that bimaxillary surgery in patients with an mpa >39° leads to a significant change of direction of MAS and MPM in the sagittal plane.

[The pursuit of facial harmony]. / Het streven naar faciale harmonie.

In the treatment of patients with an oro-facial anomaly the functioning of the masticatory system and aesthetic aspects play a role. Recently, the software programme 'Facial Harmony', which analyzes the soft tissue contour of the face, appeared. Using this programme, a research project was carried out to find out if the result of the surgical treatment of 40 patients with an oro-facial anomaly satisfied the,facial harmony requirements. Only 65% of the treatment results met the requirements. It was especially the patients who had been treated for mandibular deficiency with mandibular and horizontal lines meeting at a wide angle who showed no facial harmony. Only 30% of those patients demonstrated facial harmony postoperatively. If the surgical treatment had been completed by a genioplasty, this percentage would very probably have risen to 85.

Comparison of different analytical methods used for analyzing SPECT scans of patients with unilateral condylar hyperactivity.

This study aimed to compare different analytical methods and identify the optimal analysis method to distinguish patients with unilateral condylar hyperactivity (UCH) from those with inactive condyles. Single-photon emission computed tomography (SPECT) scans of patients with progressive and nonprogressive mandibular asymmetry (each group, n=26), were analyzed using the region of interest technique. Sensitivity, specificity and receiver operating characteristic (ROC) curves were calculated for the different analytic methods. The ROC curve illustrates that UCH can be diagnosed significantly better by determining the percentile bone activity in both condyles. The area under the curve (AUC) of the percentile comparison between the affected and contralateral condyles was 0.93+/-0.04, that for the condyle/clivus ratio was 0.75+/-0.07 and for the condyle/cervical spine (CS) ratio 0.57+/-0.08. Sensitivity for the condyle/clivus ratio was 65% and specificity 61%. Sensitivity for the condyle/CS ratio was 85% and specificity 31%. For the percentile difference of the condyles, sensitivity and specificity were 88%. For UCH patients, direct comparison of bone activity between the affected and contralateral condyle in SPECT scans is the analysis method of choice. Comparison of condylar bone activity to reference bone activity does not have additional value in the diagnosis of UCH.

[Dysgnathia complex, a rare deviation]. / Dysgnathia complex, een zeldzame afwijking.

Dysgnathia complex is a rare disorder characterized by a hypoplastic or absent mandible (micro- or agnathia), a limited mouth opening (trismus), a small tongue (microglossia) and ear anomalies. Since 1961 only 21 cases of isolated dysgnathia complex are reported in literature. Diagnosis of this disorder is difficult due to the general unfamiliarity of the disorder as well as the less apparent disparity with other known developmental syndromes of the head and neck area. A case of a female recently diagnosed with dysgnathia complex is discussed.

A comparison of human jaw muscle cross-sectional area and volume in long- and short-face subjects, using MRI.

OBJECTIVE: In humans, the vertical craniofacial dimensions vary significantly with the size of the jaw muscles, which are regarded as important controlling factors of craniofacial growth. The functional relevance of the maximum cross-sectional area (CSA), indicating maximum muscle strength, is questionable since peak forces are generated only a fraction of the day. Alternatively, muscle volume (indicating the generated loads) might be a more meaningful functional variable. Therefore, the aim of this study was to investigate if jaw muscle volume is stronger related with vertical craniofacial dimensions than with jaw muscle CSA. DESIGN: Thirty-one adult healthy subjects with varying vertical craniofacial morphology participated in this study. Axial magnetic resonance imaging (MRI) scans were used for segmentation of the masseter (Mas) and medial pterygoid muscles (MPM). This enabled measurements of the muscle CSA and volume. Cephalometric analysis was performed using lateral radiographs. With factor analysis, the number of cephalometric variables was reduced into two factors that represented the anterior face height and the posterior face height (PFH), respectively. Subsequently, mutual relationships between these factors and muscular variables were assessed using a multiple regression analysis. RESULTS: It was found that vertical craniofacial dimensions were significantly better (up to 12%) related with muscle volume rather than with CSA. Furthermore, it was shown that especially the PFH factor was significantly correlated with the Mas and MPM. CONCLUSION: Vertical craniofacial dimensions are stronger related with jaw muscle volume than with CSA. Tentatively, it can be assumed that the generated muscle loads, rather than maximum forces, influence vertical craniofacial growth.

[Two patients with progressive nasal obstruction due to a dentigerous cyst and a nasolabial cyst]. / Twee patiënten met progressieve neuspassageklachten door respectievelijk een dentogene en een niet-dentogene cyste.

Slowly progressing nasal obstructions are usually caused by otorhinolaryngological abnormalities but are sometimes caused by maxillofacial disorders. Two patients, a boy aged 13 years and a man aged 56 years, had unilateral nasal obstruction. The boy was diagnosed with a dentigerous cyst in the maxillary sinus and the man had a nasolabial cyst (Klestadt's cyst). Both patients were treated with trans-oral enucleation and fully recovered.

[Disturbances of growth and development of the maxillofacial skeleton]. / Groei- en ontwikkelingsstoornissen van het aangezichtsskelet.

Due to many developments in oral and maxillofacial surgery, the contribution of oral and maxillofacial surgeons in the diagnostics and treatment of growth and development disorders of the craniomandibulo-maxillofacial skeleton has become more and more important. Many disorders are treated by multidisciplinary teams including orthodontists and prosthodontists. Arbitrarily, 3 categories of growth and developmental disorders can be distinguished: dento-alveolar, dento-maxillofacial, and dento-maxillo-craniofacial disorders. In addition to classic bony reconstruction methods, new methodologies have been developed, such as distraction osteogenesis and simultaneous skin and soft tissue corrections. For many decades, the treatment of growth and development disorders has been a frequent subject of doctoral dissertations in The Netherlands. Attention is currently being paid to developing methods for three-dimensional planning and correction of these disorders, and methods which are minimally invasive.

[Dissertations 25 years after the date 6. Orthognathic surgery]. / Proefschriften 25 jaar na dato 6. Kaakosteotomieën.

In 1979 a thesis on orthognathic surgery was published. Progress of research concerning the surgical orthodontic treatment of dento-facial deformities is discussed with emphasis on the stability of the results, the behavior of the tongue, the temporomandibular joint and the psycho-social aspects. Also some aspects of distraction osteogenesis are mentioned.

Outcome of treatment of Class II malocclusion by intraoral mandibular distraction.

Our aim was to find out long-term results of treatment in patients treated orthodontically and by mandibular distraction osteogenesis. Data on duration of treatment, costs, and results of 26 patients (13 girls and 13 boys) with a mean age of 15 years were analysed. The preoperative cephalograms were compared with those taken at the last follow-up visit. There was a significant reduction in duration of treatment when patients were treated without a first phase that included functional appliances. The differences in costs of orthodontic treatment were not significant. The costs of the operation for distraction were significantly higher compared to BSSO, mainly because of the costs of the distraction devices. Comparison of the cephalograms showed a significant increase in SNB angle, Wits value, ANB angle, overjet, and overbite. The Y-axis, MP/S, and SpP/MP angle increased. Orthodontic treatment and distraction of the mandible was a successful, but more expensive, treatment.

Stability after distraction osteogenesis to lengthen the mandible: results in 50 patients.

PURPOSE: The purpose of this study was to investigate mandibular stability after lengthening the mandible by means of distraction. MATERIALS AND METHODS: Fifty patients (mean age, 14.7 years; range, 11.2 to 37.3 years) with Angle Class II mandibular hypoplasia were treated by bilateral distraction osteogenesis to lengthen the mandible. Patients were divided into a high-angle group, with a high mandibular angle (sella/nasion-mandibular plane [SN-MP] >38 degrees), and a normal-to-low mandibular angle group (SN-MP