Female predominance and effect of gender on unilateral condylar hyperplasia: a review and meta-analysis.

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

Evaluation of temporomandibular function after high partial condylectomy because of unilateral condylar hyperactivity.

PURPOSE: The purpose of this study was to assess temporomandibular function after condylectomy because of unilateral condylar hyperactivity (UCH) by means of standardized diagnostic criteria. The results were compared with those obtained in a control group. PATIENTS AND METHODS: In this study, 33 patients with UCH who underwent condylectomy and 31 controls matched for age and gender filled out a history questionnaire and underwent a clinical examination as part of the research diagnostic criteria for temporomandibular disorders. Data analysis was performed by use of the Fisher exact test for 2-by-2 tables. RESULTS: Patients and controls did not differ significantly regarding myofacial pain (P = .131), disc displacement (P = .516), and depression (P = .34). The groups differed significantly concerning arthralgia, osteoarthritis, and osteoarthrosis (P = .003), as well as pain with low disability (P = .022). CONCLUSIONS: In patients with UCH who underwent condylectomy because of progressive mandibular asymmetry, more joint-related temporomandibular problems as well as more postoperative pain developed when compared with age- and gender-matched controls. However, these problems did not lead to more severe disabilities in daily life.

Unilateral condylar hyperactivity: a histopathologic analysis of 47 patients.

PURPOSE: To perform a histopathologic analysis of condyles that were resected because of unilateral condylar hyperactivity and compare the results of the bone scan with the histopathologic findings. PATIENTS AND METHODS: A total of 47 resected condyles were histopathologically examined. In 29 cases, a single photon emission computed tomography (SPECT) bone scan was available. For all condylar specimens, a standardized histologic scoring system was used to assess the number of cartilage islands and the thickness of the cartilage layer. The SPECT scans were analyzed by calculating the difference in bone activity between the hyperactive and contralateral condyles. RESULTS: The number of cartilage islands was highly variable, ranging from almost absent in 37% of the patients to abundant in 35%. Furthermore, the relative thickness of the cartilage layer exhibited considerable variation, from less than one quarter of the total thickness of the condylar articular layer in 22% of the patients to one half of the total thickness in 35%. We found no significant relationship between the number of cartilage islands and bone activity using SPECT (P = .11) or between the relative thickness of the cartilage layer and bone activity using SPECT (P = .82). CONCLUSIONS: Unilateral condylar bone growth can occur without large numbers of cartilage islands and without abundant cartilage formation. The bone activity measured by bone scintigraphy was not related to the histologic results. The histopathologic findings of resected condyles in unilateral condylar hyperactivity cannot, therefore, be used as a reference standard. Nevertheless, histopathologic examination should always be performed to rule out other diseases.

No signs of metabolic hyperactivity in patients with unilateral condylar hyperactivity: an in vivo positron emission tomography study.

PURPOSE: The purpose of this study was to assess bone growth and blood flow in the condylar region in patients with unilateral condylar hyperactivity (UCH) by use of positron emission tomography (PET). PATIENTS AND METHODS: This prospective study included 7 patients with UCH and a control group of 6 volunteers. In addition to normal clinical investigations, labeled fluoride ((18)F(-)) and oxygen 15-labeled water (H(2)(15)O) PET scans were performed. RESULTS: In control subjects the net rate of fluoride influx, representing bone metabolism, was similar for left and right condylar sides. Interestingly, this was not significantly different from the affected condyles in UCH patients. Rather, the net rate of fluoride influx on the contralateral side of UCH patients was reduced significantly compared with the affected side (P= .02) and control subjects (P= .004). The mean blood flow on the left and right condylar sides in control subjects was not significantly different. The same was true for the hyperactive and contralateral condyles of UCH patients. Blood flow in the condylar region in UCH patients was similar to that in the control group. CONCLUSIONS: There was no evidence of an abnormally high rate of bone growth in the affected condylar region in UCH patients. Instead, the rate of bone growth appeared to be reduced in the contralateral condylar region. These PET results are in contrast to the characteristic clinical picture of UCH patients and suggest the possibility of subgroups in patients with a mandibular asymmetry caused by UCH. Furthermore, no evidence of hypervascularization of the condylar region in UCH patients was found.

Assessing the need for a protocol in monitoring weight loss and nutritional status in orthognathic surgery based on patients experiences.

BACKGROUND: To investigate retrospectively the orthognathic surgery (OGS) patients experience in weight loss and the influence of gender, age, duration of the surgical procedure, length of hospital stay, location of surgery and use of intermaxillary fixation (IMF) or without IMF on postoperative weight loss. MATERIAL AND METHODS: A total of 4487 patients treated by OGS where all patients visited the outpatient clinic one, three and six weeks after the surgical procedure. After six weeks, patients filled out a questionnaire in which weight loss was addressed. The patients were asked to give an estimate of their experiences weight loss. The population was first divided in two groups weight loss and no weight loss. RESULTS: In the weight loss group there is no significant difference in weight loss between patients with IMF and patients without IMF. In the weight loss group there were significantly more females then males. Further, in the subgroup IMF the operation time was significantly longer compared with the subgroup without IMF. The other parameters including age and hospital stay were not different in the groups. CONCLUSIONS: IMF in orthognathic treatment does not result in a difference self-reported loss of body weight compared to patients without IMF. Treatment protocols should include pre- and post-operative dietician consultations and possible indications for medical nutrition and vitamins. Key words:Assessing, protocol, weight loss, experiences, orthognathic surgery.

Symptomatic venous thromboembolism in orthognathic surgery and distraction osteogenesis: a retrospective cohort study of 4127 patients.

Venous thromboembolism is a common postoperative complication, and orthopaedic procedures are particularly at risk. We designed a retrospective, single centre, observational, cohort study of 4127 patients (mean (SD) age 27 (11) years) who had elective orthognathic operations or distraction osteogenesis between January 1970 and February 2012 at the VU University Medical Centre, Amsterdam, to investigate the incidence in this group over the 42-year period, 2 patients developed symptomatic venous thromboembolism (1 woman had a deep vein thrombosis (DVT) and 1 man had a DVT and pulmonary embolus) postoperatively. In relatively young patients with low to moderate risk factors and short hospital stay this type of operation is associated with a particularly low risk of developing thrombosis. It could be advisable to limit the use of thromboprophylaxis to patients at high risk or according to hospital guidelines.

Interobserver variation of single-photon emission computed tomography bone scans in patients evaluated for unilateral condylar hyperactivity.

OBJECTIVE: This study assessed the quantitative evaluation of the region of interest (ROI) by mean and maximum pixel counts of single-photon emission computed tomography (SPECT) scans in patients with clinical suspicion of unilateral condylar hyperactivity (UCH); the interobserver reliability and the correlation of condylar activity with patient age was determined. METHODS: Two independent observers analyzed 67 bone SPECT scans. Maximum and mean activity values within an ROI on the mandibular condyle were analyzed; a cutoff value of 55% was used to determine the qualitative outcome. RESULTS: Excellent interobserver agreement was seen for both maximum (kappa 1.0) and mean activity analysis (kappa 0.94). Maximum and mean condylar activities were strongly correlated (r > 0.98). Maximum and mean condylar activity of the normal condyle decreased significantly with increasing age. CONCLUSIONS: Maximum and mean condylar activity levels were highly correlated in patients with mandibular asymmetry. An excellent interobserver agreement was found with either maximum or mean condylar activity.

Bone scintigraphy as a diagnostic method in unilateral hyperactivity of the mandibular condyles: a review and meta-analysis of the literature.

Bone scan analyses and clinical assessment are used to diagnose unilateral condylar hyperactivity (UCH). This review compares the diagnostic accuracy of planar and SPECT bone scans. Studies diagnosing patients with possible UCH using bone scans, published between 1968 and 2008, were included in this review. Of 15 articles that met the inclusion criteria, 7 presented results in sufficient detail to calculate index test characteristics. Three control studies show that the difference in uptake values of the left and right condylar regions in the normal population does not exceed 10%. The pooled sensitivity of the planar bone scan (n=130) was 0.71 (95% confidence interval: 0.57-0.82), which was significantly lower (p=0.04) than that of the bone SPECT technique (n=88), which was 0.90 (0.79-0.97). The pooled specificity of the SPECT scan was 0.95 (0.82-0.99), which did not significantly differ (p=0.58) from that of the planar scan (0.92 (0.83-0.97)). Future studies should include a diagnostic analysis of the data, including two-by-two contingency tables, so the accuracy of the diagnostic test may be evaluated. Bone scans are best performed using SPECT, conducting a quantitative analysis by calculating the percentile differences between the left and right condylar regions.

Comparison of planar bone scintigraphy and single photon emission computed tomography in patients suspected of having unilateral condylar hyperactivity.

OBJECTIVE: A comparison is made of single photon emission computed tomography (SPECT) and planar bone scintigraphy in the diagnosis of patients with suspected unilateral condylar hyperactivity (UCH). STUDY DESIGN: The subjects comprised 56 patients with suspected UCH who underwent SPECT and regular planar bone scans. Accuracy of SPECT and planar scintigraphy were compared using left-right condylar activity. RESULTS: Of the 56 patients, 29 were diagnosed with active UCH and 27 without UCH. The mean relative activity of the hyperactive condylar region in the planar scans was 53.5% (SD +/- 2.3%), which was significantly higher in the SPECT scan with a mean value of 60.5% (SD +/- 5.4%), P < .005 (t = 8.951). Receiver operating curves (ROC) were clearly in favor of SPECT over the planar bone scan. The area under the curve (AUC) of the planar ROC was 0.87 +/- 0.049 while that of the SPECT ROC was 0.97 +/- 0.024. The optimal cut-off value for planar scanning was 52%, yielding a sensitivity of 67% and a specificity of 85%. For SPECT scanning, the optimal cut-off was 56%, resulting in a sensitivity of 93% and a specificity of 96%. CONCLUSIONS: It can be concluded that in patients with a clinically suspected active UCH, SPECT scanning is the preferred diagnostic tool rather than planar bone scanning. However, treatment planning should be done in combination with clinical assessment of progressive mandibular asymmetry as well as taking into account the patient history.