Evaluation of expansion forces of five pure bone-borne maxillary expander designs anchored with orthodontic mini-implants: An in vitro study.

AIM: This in vitro study investigates the limit of expansion forces and torque wrench forces developed by five skeletal bone expander designs (MICRO 2/4 expanders™) for clinical application. MATERIAL AND METHODS: A total of 30 skeletal expanders were placed in artificial bone blocks and mechanically tested, simulating maxillary expansion. Differences in jackscrew (Dentaurum™ [D], Superscrew™ [S] and Powerscrew™ [P]), number of orthodontic mini-implants (OMIs; two or four) and their placement inclinations (parallel 0° or 10° inclination) form five designs (D4/10°, S4/0°, S4/10°, P4/10° and P2/10°). Expansion forces and torque wrench values were registered, and radiographs were made initially and after 4 mm of expansion. Stress-strain curves were obtained after successive activations and the statistical analysis was performed as appropriate. RESULTS: Plastic deformations in the OMIs and jackscrew occurred around the activation numbers 11-13, with torque wrench values in the range of 500-700 cN. The maximum expansion forces in expanders with four OMIs varied from 93.0 (D4/10°) to 166.6 N (P4/10°) whereas two OMI expanders (P2/10°) registered forces of 79.4 N. Radiographs revealed during loads bending forces (S4/00°, S4/10°) with jackscrew and OMIs deformation in a convex shape, and shear forces (P4/10°, P2/10°) demonstrated only OMIs deformation in a concave shape, providing 15% more expansive force. The jackscrew D4/10° did not have any deformation, but its wire key did not allow reliable activations from activation number 10 and compared to S4/10° and P4/10°, these expanders provided greater expansion forces (P = 0.000 and P = 0.032, respectively). CONCLUSION: The different results obtained in stability and expansion forces indicate that if the activations are carried out under extreme conditions, they may have clinical importance with deformations and non-working expansion mechanics. Jackscrew designs play an important role in expansive forces and expander stability. Torque wrench values can be used clinically as a tool to asses the expansion forces and to avoid deformations.

Success and complication rate of miniscrew assisted non-surgical palatal expansion in adults - a consecutive study using a novel force-controlled polycyclic activation protocol.

INTRODUCTION: Bone-borne miniscrew assisted palatal expansion (MAPE) is a common technique to improve maxillary transverse deficiency in young adolescents. Adult patients usually present a challenge, as they often require additional surgical assisted maxillary expansion (SARPE). There is still no clear statement about non-surgical expansion in adult patients using this technique. The aim of this study was to evaluate the success and complication rate of non-surgical palatal expansion in adults utilizing MAPE with a novel force-controlled polycyclic expansion protocol (FCPC). METHODS: This consecutive study consisted of 33 adult patients with an average age of 29.1 ± 10.2 years (min. 18 years, max. 58 years), including one dropout patient. First, four miniscrews were inserted and after 12-weeks latency, the expander was placed and the FCPC protocol was applied (MAPE group). In case of missing expansion, a SARPE was performed (SARPE group). After maximum expansion, a cone beam CT was made and widening of the midpalatal suture was measured. The outcome variables were successful non-surgical expansion and, with sample size power above 80%, the odds of failed non-surgical expansion and associated complications were evaluated. The primary predictor variable was age. Statistical analysis was performed using R (Version 3.1) to calculate power, to construct various models for measuring the odds of requiring surgical intervention/complications, and others. RESULTS: Successful non-surgical expansion was achieved in 27 patients (84.4%), ranging from 18 to 49 years. Mean age differed significantly between both groups (26.8 ± 8.2 years vs. 41.3 ± 9.9 years; p < 0.001). Mean expansion at the anterior and posterior palate for the MAPE group was 5.4 ± 1.5 mm and 2.5 ± 1.1 mm, respectively. Among these subjects' complications were observed in 18.5%. Age significantly increased the odds of complications (p = 0.019). CONCLUSIONS: 1. The success rate of MAPE among individuals aged 18 to 49 years was 84.4%. 2. A V-shaped expansion pattern in the antero-posterior dimension was mostly observed. 3. Complications were significantly associated with age. 4. A careful expansion protocol seems to be beneficial to prevent unfavorable results in adult patients. TRIAL REGISTRATION: Consecutive cohort study, Review Board No. EK-2-2014/0016.

Is There a Significant Difference in Relapse and Complication Rate of Surgically Assisted Rapid Palatal Expansion Using Tooth-Borne, Bone-Borne, and Orthodontic Mini-Implant-Borne Appliances?

PURPOSE: For surgically assisted rapid palatal expansion (SARPE), studies comparing different devices are missing. The aim was to evaluate expansion, relapse, and the complication rates for 3 different appliances. PATIENTS AND METHODS: In this retrospective cohort study, tooth-borne (TB, n = 29), bone-borne (BB, n = 12), or orthodontic mini-implant (OMI)-borne (n = 13) appliances were used for SARPE in 2 clinical centers. Patients presenting with a maxillary width discrepancy greater than 5 mm were included. Measurements of cast models and radiographs were performed preoperatively, immediately after consolidation, and at 1 year postoperatively. All distances were measured between canines, premolars, and molars. Complications (tooth damage, infection, technical failure) were evaluated. The outcome variables were expansion, relapse, and complications. Type of appliance was selected as predictor variable. Within- and between-group differences regarding expansion, relapse, and complications for the 3 appliances were statistically analyzed. RESULTS: In 54 patients (aged 28.8 ± 8.6 years), mean expansion (±standard deviation) for the TB, BB, and OMI appliances immediately after consolidation was 5.29 ± 1.39 mm, 5.22 ± 1.72 mm, and 3.81 ± 2.19 mm, respectively, at the dental level, and 5.51 ± 1.40 mm, 4.66 ± 2.03 mm, and 3.51 ± 1.66 mm, respectively, at the bone level. Mean (±standard deviation) relapse for the TB, BB, and OMI appliances at 1 year postoperatively measured 1.44 ± 1.01 mm, 0.76 ± 1.37 mm, and 0.27 ± 1.63 mm, respectively, at the tooth level and 1.19 ± 0.93 mm, 0.71 ± 0.96 mm, and 0.12 ± 1.56 mm, respectively, at the bone level. Analysis of variance and the Tukey test showed significant differences between the TB and OMI appliances for expansion and relapse (P = .034 and P = .024, respectively). The overall complication rate differed significantly (P < .001), with rates of 17.2%, 66.7%, and 15.4% for the TB, BB, and OMI appliances, respectively. CONCLUSIONS: BB and OMI appliances resulted in less relapse. Owing to the high complication rate, the further use of BB appliances is questionable.

The Effect of Orthognathic Surgery on Temporomandibular Joint Function and Symptoms: What are the Risk Factors? A Longitudinal Analysis of 375 Patients.

PURPOSE: The effects of orthognathic surgery (OGS) on the temporomandibular joint (TMJ) are still controversial. Based on a high-volume uniform collective, the function and clinical symptoms of the TMJ and the dysfunction index (Di) by Helkimo were evaluated prior and up to 2 years after OGS. METHODS: A longitudinal cohort study was performed between 2006 and 2016. A comprehensive examination focusing on TMJ function, temporomandibular disorder (TMD) symptoms, and the Di had been performed preopertaively (T0) and postoperatively at 6 weeks (T1), 6 months (T2), 1 year (T3), and 2 years (T4). The predictor variables used were sex, age, skeletal class, type of surgery, and amount of dysfunction or number of TMD complaints before treatment. The outcome of this study was TMD symptoms and the Di. Descriptive and bivariate statistics were computed, and the significance level was set at P < .05. RESULTS: The sample consisted of 375 patients (247 women, 128 men, mean age 28.1 ± 9.4 years), 269 with skeletal Class II (71.7%) and 106 with skeletal Class III (28.3%) treated with sagittal split osteotomy bilateral sagittal split osteotomy (n = 173) or Le Fort I and bilateral sagittal split osteotomy (n = 202). Severe signs of dysfunction (Di 2/3) were seen in 5.9% of the patients before OGS and in 2.1% of the patients 2 years after OGS. The difference in Di (Di0/1 and Di2/3) between T0 and T1/T2 was statistically significant (P = .028; P = .011, respectively). TMD symptoms were significantly reduced 2 years after OGS (P = .028). Female gender (P = .013), skeletal Class II (P < .001), and counterclockwise rotation (P < .001) were the only risk factors significantly associated with the occurrence of TMD at T1. CONCLUSIONS: The results of this study suggest that in most cases TMD symptoms can be significantly reduced and only a few can be induced with OGS. No risk factors were found for long-term effects on the TMJ.

Skeletal-versus soft-tissue-based cephalometric analyses: is the correlation reproducible?

OBJECTIVES: Dentofacial deformities can be analyzed by skeletal and soft tissue cephalometric analysis (CA). The aim was to evaluate the difference in reproducibility between both methods. MATERIALS AND METHODS: Lateral cephalograms of 112 patients (65 females and 47 males, 27.7 ± 9.0 years) were oriented in natural head position (NHP) and digitized. The distances of skeletal (SNA, SNB, SnPog) and soft tissue (A', B' and Pog') landmarks relative to the respective norm values and the angles between the Nasion Sella line (NSL) and Frankfurt horizontal (FH) to NHP were measured for statistical evaluation and compared with respective data of an adult control group (CG) with class I occlusion and harmonic facial balance. RESULTS: The mean differences (mm ± SD) of skeletal and soft tissue landmarks were -2.4 ± 4.4 (A), -7.0 ± 9.3 (B), -6.3 ± 11.2 (Pog), -0.9 ± 1.8 (A'), -4.7 ± 6.2 (B'), and -6.1 ± 7.8 (Pog'), respectively. Pearsons's correlation (r) between the measurements of SNA/A', SNB/B' and SNPog/Pog' were r = .158 (p = .092), r = .662 (p < .001) and r = .655 (p < .001), respectively. The mean (±SD) angles between NSL and FH to NHP were -9.8° ± 5 and 0.0° ± 3.9, respectively. CONCLUSION: Variability of cranial-based measurements could give a possible explanation for the high variation and the low reproducibility of skeletal cephalometric analysis with soft tissue measurements. Soft-tissue cephalometric analysis would probably improve facial analysis and treatment planning.

Is Virtual Surgical Planning in Orthognathic Surgery Faster Than Conventional Planning? A Time and Workflow Analysis of an Office-Based Workflow for Single- and Double-Jaw Surgery.

PURPOSE: The purpose of this study was to measure and compare the working time for virtual surgical planning (VSP) in orthognathic surgery in a largely office-based workflow in comparison with conventional surgical planning (CSP) regarding the type of surgery, staff involved, and working location. MATERIALS AND METHODS: This prospective cohort study included patients treated with orthognathic surgery from May to December 2016. For each patient, both CSP with manual splint fabrication and VSP with fabrication of computer-aided design-computer-aided manufacturing splints were performed. The predictor variables were planning method (CSP or VSP) and type of surgery (single or double jaw), and the outcome was time. Descriptive and analytic statistics, including analysis of variance for repeated measures, were computed. RESULTS: The sample was composed of 40 patients (25 female and 15 male patients; mean age, 24.6 years) treated with single-jaw surgery (n = 18) or double-jaw surgery (n = 22). The mean times for planning single-jaw surgery were 145.5 ± 11.5 minutes for CSP and 109.3 ± 10.8 minutes for VSP, and those for planning double-jaw surgery were 224.1 ± 11.2 minutes and 149.6 ± 15.3 minutes, respectively. Besides the expected result that the working time was shorter for single-versus double-jaw surgery (P < .001), it was shown that VSP shortened the working time significantly versus CSP (P < .001). The reduction of time through VSP was relatively stronger for double-jaw surgery (P < .001 for interaction). All differences between CSP and VSP regarding profession (except for the surgeon's time investment) and location were statistically significant (P < .01). The surgeon's time to plan single-jaw surgery was 37.0 minutes for CSP and 41.2 minutes for VSP; for double-jaw surgery, it was 53.8 minutes and 53.6 minutes, respectively. CONCLUSIONS: Office-based VSP for orthognathic surgery was significantly faster for single- and double-jaw surgery. The time investment of the surgeon was equal for both methods, and all other steps of the workflow differed significantly compared with CSP.

Piezosurgery for Sagittal Split Osteotomy: Procedure Duration and Postoperative Sensory Perturbation.

PURPOSE: To evaluate piezosurgery for bilateral sagittal split osteotomy (BSSO) for its duration and inferior alveolar nerve (IAN) perturbation. PATIENTS AND METHODS: In this prospective randomized study, the authors evaluated 100 BSSO procedures in 50 patients. Piezoelectric (group I) and conventional (group II) osteotomies were carried out on each side of the mandible of a patient by 2 specialists. The surgeons had at least 1 year of experience using piezosurgery. The period from incision to complete splitting of the mandibular bone was recorded (ie, procedure duration). The intraoperative status (visibility and relocation) of the IAN also was recorded. The neurosensory function of the IAN was measured by the 2-point discrimination threshold and static light touch methods before surgery and postoperatively (1, 3, and 6 weeks and 6 and 12 months). Parameters were compared between the test groups by the paired t, nonparametric Wilcoxon, or χ2 test. RESULTS: Intergroup comparison showed the mean duration of osteotomy was significantly shorter for group I (17 ± 6 vs 25 ± 9 minutes; P < .001). The rate of intraoperative exposures of the IAN was slightly lower for group I (68%) compared with group II (81%). However, the difference was not relevant. Neurosensory disturbance and recovery of the IAN did not differ between groups. CONCLUSION: Piezoelectric osteotomy requires considerably less time than conventional mechanical approaches, but shows no advantage in preventing neurosensory perturbation.

Comparison of two preoperative protocols for mandibular symphyseal distraction osteogenesis to reduce the risk of tooth damage.

Two techniques to separate the lower incisors prior to mandibular symphyseal distraction osteogenesis (MSDO) were evaluated with respect to avoiding tooth damage. METHODS: Fifty patients (20.2 ± 7.0 years) requiring MSDO were treated with a tooth-borne appliance by utilizing two preoperative protocols to separate the central incisors: i) brackets and a V-bent wire with an open coil spring (two-step; TS; n = 24) and ii) a wire attached from the appliance to the central incisors with subsequent dento-alveolar expansion prior to surgery (one-step; OS; n = 26). The distance between the lower incisors was measured preoperatively on radiographs and measurements at the cast models were performed. Complications and radiographs were analyzed. RESULTS: The mean distance (±SD) between the lower central incisors for OS and TS prior to surgery was 3.44 ± 1.05 and 3.18 ± 1.13 mm, respectively. The mean expansion for OS and TS was 4.3 ± 2.9 and 4.3 ± 2.7 mm at the dental level and 3.8 ± 3.2 and 4.0 ± 2.1 mm at the bone level, respectively. Four patients undergoing the TS and one patient undergoing the OS showed transient dental complications. CONCLUSION: Pre-surgical dento-alveolar expansion by utilizing a one-step technique to separate the lower central incisors reduces the risk of permanent tooth damage and weakens the mandibular bone in the midline.

Stability determinants of bone-borne force-transmitting components in three RME hybrid expanders-an in vitro study.

BACKGROUND: The aim was to test which component [wire arm, connecting abutment attachment, and orthodontic mini-implant (OMI)] of the force-transmitting system (FTS) in the anterior palate of three commonly used hybrid expanders (HEs; WILMES-HE, LUDWIG-HE, and WINSAUER-HE) deforms under increasing load. MATERIALS AND METHODS: Crude single and double wire arms were tested individually. Non-opening of the maxillae halves was simulated in artificial bone blocks with single wire and double wire FTS specimens. OMIs were inserted 8mm and underwent 6mm of continuous static lateral loading. Deformation angles were measured (X-ray, n = 6) at 0, 3 and 6mm feed. OMIs and abutments were scan electron microscope (SEM) evaluated. RESULTS: After 1.0mm of loading, the single wire arm of all FTS deformed between 63.4 (16.5) N and 76.2 (18.4) N, and the double wire arm of reinforced FTS (wires positioned 'side by side') deformed after 1.0mm between 110.0 (18.4) N and 134.8 (22.3) N. The crude single wire resisted 89 (5.1) N until plastic deformation, whereas the crude double wire positioned 'on top of each other' resisted 438 (21.3) N. At 6mm loading, the reinforced WINSAUER-HE FTS withstood a maximum load of 320.9 (31.1) N and the reinforced LUDWIG-HE FTS 19% less, both under great deformation of double wires and OMIs. The screw-fixated WILMES-HE FTS abutment attachment (overlapping OMI head 34%) detached around 250N. The bonded WINSAUER-HE and LUDWIG-HE abutment attachments did not detach. Nor did the modified bonded plus the modified screw-fixated WILMES-HE abutment attachment when overlapping 100%. CONCLUSION: Early OMI and single wire arm deformation in HEs are crucial for unsuccessful RME in more mature maxillae. Double wire arms should be obligatory. OMIs with inner diameter greater 1.36mm are recommended. One hundred per cent overlapping abutment attachments do not detach.

Are Biodegradable Osteosyntheses Still an Option for Midface Trauma? Longitudinal Evaluation of Three Different PLA-Based Materials.

The aim was to evaluate three different biodegradable polylactic acid- (PLA-) based osteosynthesis materials (OM). These OM (BioSorb, LactoSorb, and Delta) were used in 64 patients of whom 55 (85.9%) had fractures of the zygoma, five (7.8%) in the LeFort II level, two of the frontal bone (3.1%), and two of the maxillary sinus wall (3.1%). In addition to routine follow-up (FU) at 3, 6, and 12 months (m) (T1, T2, and T3) all patients were finally evaluated at a mean FU after 14.1 m for minor (e.g., nerve disturbances, swelling, and pain) and major (e.g., infections and occlusal disturbances) complications. Out of all 64 patients 38 presented with complications; of these 28 were minor (43.8%) and 10 major (15.6%) resulting in an overall rate of 59.4%. Differences in minor complications regarding sensibility disturbance at T1 and T3 were statistically significant (P = 0.04). Differences between the OM were not statistically significant. Apart from sufficient mechanical stability for clinical use of all tested OM complications mostly involved pain and swelling probably mainly related to the initial bulk reaction attributable to the drop of pH value during the degradation process. This paper includes a review of the current aspects of biodegradable OM.

Can dual-energy CT improve the assessment of tumor margins in oral cancer?

OBJECTIVES: The aim was to investigate the image quality of dual-energy computed-tomography (DECT) compared to single-energy images at 80 kV and 140 kV in oral tumors. MATERIALS AND METHODS: Forty patients underwent a contrast-enhanced DECT scan on a definition flash-CT. Four reconstructions (80 kV, 140 kV, mixed (M), and optimum-contrast (OC)) were assessed by four blinded readers for subjective image quality (10-point scale/10=best). For objective quality assessment, linear attenuation measurements (line density profiles (LDP)) were positioned at the tumor margin, and the difference between minimum and maximum was calculated. Signal-to-noise ratios (SNR) were measured in the tongue. RESULTS: The mean image quality for all readers was 5.1±0.3, 8.4±0.3, 8.1±0.2, and 8.3±0.2 for the 140 kV, 80 kV, M, and OC, respectively (P<001 between 140 kV and all others). The mean difference between the minimum and maximum within the LDP was 139.4±59.0, 65.7±29.5, 105.1±46.5, and 118.7±59.4 for the 80 kV, 140 kV, M, and OC, respectively (P<001). The SNR for the tongue was 3.8±2.1, 3.8±2.1, 4.2±2.4, and 4.1±2.3 for the 80 kV, 140 kV, M, and OC, respectively. DISCUSSION: DECT of oral tumors offers high image quality, with subjectively rated image quality and attenuation contrast at the tumor margin similar to that of 80 kV; DECT, however, provides a significantly higher SNR compared to 80 kV.

Osteoporosis and bisphosphonates-related osteonecrosis of the jaw: not just a sporadic coincidence--a multi-centre study.

INTRODUCTION: Bisphosphonates (BPs) are powerful drugs that inhibit bone metabolism. Adverse side effects are rare but potentially severe such as bisphosphonate-related osteonecrosis of the jaw (BRONJ). To date, research has primarily focused on the development and progression of BRONJ in cancer patients with bone metastasis, who have received high dosages of BPs intravenously. However, a potential dilemma may arise from a far larger cohort, namely the millions of osteoporosis patients on long-term oral BP therapy. PATIENTS AND METHODS: This current study assessed 470 cases of BRONJ diagnosed between 2004 and 2008 at eleven different European clinical centres and has resulted in the identification of a considerable cohort of osteoporosis patients suffering from BRONJ. Each patient was clinically examined and a detailed medical history was raised. RESULTS: In total, 37/470 cases (7.8%) were associated with oral BP therapy due to osteoporosis. The majority (57%) of affected individuals did not have any risk factors for BRONJ as defined by the American Association of Oral and Maxillofacial Surgery. The average duration of BP intake of patients without risk factors was longer and the respective patients were older compared to patients with risk factors, but no statistical significant difference was found. In 78% of patients the duration of oral BP therapy exceeded 3 years prior to BRONJ diagnosis. DISCUSSION: The results from this study suggest that the relative frequency of osteoporosis patients on oral BPs suffering from BRONJ is higher than previously reported. There is an urgent need to substantiate epidemiological characteristics of BRONJ in large cohorts of individuals.

Preoperative radiochemotherapy in the treatment of advanced oral cancer: outcome of 276 patients.

INTRODUCTION: The aim of this study was to review survival and locoregional control in patients with advanced oral and oropharyngeal squamous cell carcinoma treated by multimodal therapy with preoperative radiochemotherapy and radical surgery. MATERIAL: Retrospective cohort study. METHODS: Included in this analysis are 276 consecutive patients with UICC disease stages III and IV (T2: 13.0%; T3: 16.7%; T4: 70.3%; N0: 29.7%; N1: 20.3%; N2: 45.3%; N3: 4.7%; stage III: 16.3%; stage IV: 83.7%). All patients received preoperative radiochemotherapy (50Gy, Mitomycin and 5-Fluorouracil) and radical locoregional resection. RESULTS: Median surveillance period was 101.4 months (24-202 months). 5-year overall survival probability was 53.9%. 5-year local control probability was 70.2%. CONCLUSION: These results underline the reliability of preoperative treatment of patients with oral and oropharyngeal cancer.

Three-dimensional measurement of the mandible after mandibular midline distraction using a cemented and screw-fixated tooth-borne appliance: a clinical study.

PURPOSE: The aim of this study was to analyze the 3-dimensional movement of the mandible segments after distraction of the mandibular midline by use of a cemented and screw-fixated tooth-borne appliance. PATIENTS AND METHODS: Twenty patients with transverse deficiencies of the lower arch were included in a consecutive study. Before surgical intervention, a custom-made appliance was cemented to the teeth and also fixed with 2 screws between the teeth on each side. The distraction appliance was activated after 5 days at a rate of 0.6 mm/d. After a consolidation period of 6 weeks, the appliance was removed and an orthodontic retainer was applied. Radiographs and cast models were taken preoperatively and postoperatively, and direct linear measurements were performed at the same intervals. RESULTS: Mean expansion (+/- SD) of the osteotomy line measured on the radiographs for the superior, middle, and inferior part of the mandible was 5.1+/-2.4, 5.9+/-2.8, and 5.7+/-2.9 mm, respectively. The mean overall expansion was 5.6+/-2.6 mm. The width increase of the models between the canines, first premolars, second premolars, first molars, and second molars was 4.2+/-1.8, 5.0+/-2.0, 4.7+/-2.0, 4.3+/-1.7, and 3.6+/-1.3, respectively, at the tooth level and 3.4+/-2.0, 3.6+/-1.8, 3.3+/-1.4, 3.2+/-1.5, and 2.2+/-1.8, respectively, at the bone level. CONCLUSIONS: Expansion of the osteotomy line in the vertical dimension showed a uniform pattern. Lateral movements of the mandibular segments decreased from the symphysis to the gonial angles. The positional changes of the teeth and the bone segments were proportionate. Minimal dental movement was observed.

High resolution magnetic resonance imaging with an orbital coil as an alternative to computed tomography scan as the primary imaging modality of pediatric orbital fractures.

PURPOSE: The computed tomography (CT) scan is currently the gold standard in the imaging of orbital fractures. The weak points of this imaging modality, however, include restricted soft tissue depiction as well as the radiation. Both attributes are of particular importance in children because of the high rate of trapdoor fractures and the radiation to the lens. Although magnetic resonance imaging (MRI) is not associated with these drawbacks, it has not been established in the primary diagnosis of pediatric orbital fractures. The aim of our study was to establish the use of MRI with a special orbital coil for the primary diagnosis of pediatric orbital trauma. PATIENTS AND METHODS: In our retrospective study, 14 pediatric patients presented to our department with a blunt orbital trauma from 2003 to 2007. Twelve of 14 patients with orbital floor fractures required surgical reconstruction. Until 2004, imaging was carried out by plain x-rays and CT scan for a decision regarding the necessity of surgery. Since introducing the MRI microscopy orbital coil in 2004, CT scans have been replaced by MRI for the primary fracture diagnosis in 8 pediatric cases. Kappa statistics have been applied to assess inter- and intraobserver reliability for CT scans and MRI. This study shows our experiences using MRI in combination with conventional x-rays to determine the operative approach in 2 of the 8 pediatric cases suffering from blunt orbital trauma. RESULTS: The most common causes for pediatric orbital trauma in our collective were accidents. In 8 cases using MRI as the primary imaging modality, depiction of the fracture dislocation and differentiation of the adjacent fatty and muscle tissue was excellent and indication for surgery was distinct. MRI reached a high intra- and inter-rater agreement level (kappa=0.80). CONCLUSION: MRI combined with a microscopy orbital coil is a valuable alternative to the CT scan in the primary diagnosis of pediatric orbital fractures. Floor fractures, and particularly muscle incarceration, should be diagnosed by high resolution MRI combined with a microscopy coil instead of CT to avoid radiation to the lens and to obtain a better soft tissue depiction.

Maxillomandibular fixation using intraoral cortical bone screws and specially designed metal hooks (Ottenhaken) in the conservative treatment of mandibular fractures.

PURPOSE: The present work evaluated the success of maxillomandibular fixation (MMF) by intraoral cortical bone screws and specially designed metal hooks (Ottenhaken) in nondislocated or slightly dislocated mandibular fractures. PATIENTS AND METHODS: A total of 44 patients who sustained various types of mandibular fractures were treated at the University Hospital for Craniomaxillofacial and Oral Surgery, Vienna Medical School by MMF with Ottenhaken only. The patients were evaluated by preoperative and postoperative radiography, and clinical testing was performed by thermal testing with a cold spray and by assessing the degree of tooth mobility adjacent to the inserted screws. To determine the success of the treatment, various parameters, including screw or hook fracture, screw loosening, local infection of the punctured mucosa, and iatrogenic tooth damage, were considered. RESULTS: The screws and hooks were successfully inserted and MMF was engaged with tight elastics in all cases. The most frequent complication was rupturing of the elastics, necessitating replacement. In 5 patients, local infection of the mucosa around the screw led to severe pain that was treated successfully with analgesics. The screws could be left in place in all 5 cases. Hook fracture and screw loosening each occurred in 1 patient. No iatrogenic injuries of the dental roots were noted. After screw removal, all wounds healed uneventfully. CONCLUSION: The use of intraoral cortical bone screws and specially designed metal hooks (Ottenhaken) for MMF is a useful, valid alternative to arch bars that carries only rare, mild complications.

Secondary post-traumatic enophthalmos: high-resolution magnetic resonance imaging compared with multislice computed tomography in postoperative orbital volume measurement.

PURPOSE: Multislice computed tomography (MSCT) was the modality of choice for orbital volume measurement. This first prospective study compares MSCT with high-resolution magnetic resonance imaging (MRI) combined with micro (MRImc) and headcoil (MRIhc) in volumetric evaluation of the postsurgical enophthalmic orbit. PATIENTS AND METHODS: Morphologic and dimensional changes of the orbit, eyebulb, and fat content were investigated 3 to 4 months after reconstruction of complex orbital fractures in 36 patients. Image analysis and volumetric assessment from 2-dimensional and 3-dimensional-MRImc and MRIhc were compared with MSCT. The volume segmentation algorithm operated on multispectral, 3-dimensional MR data acquired at isotropic proton density weighted acquisitions. RESULTS: CT and MRI volume data correlated significantly (P < .01). Enlargement of the posterior segment often resulted in orbital geometry change from conical to convex. Even cases of correct orbital reconstruction presented significant volume enlargement compared to the contralateral side (P < .01). The retro bulbar fat showed itself fragmented and was dislocated in the medial posterior region mostly. We found reduced sagittal eye projection, increased width of the orbital rim, and dislocation of the posteromedial orbital floor (P < .01). High correlation was detected between orbital volume increment and degree of enophthalmos (0.93 mm per 1 cm3 orbital volume enlargement diameter) (P < .01). CONCLUSIONS: As MRI orbital volume measurement permitted prediction of postsurgical enophthalmos, which is related to possible failure in orbital volume correction and reduction of the posterior medial bulge and not to fat content changes, it is suited for planning secondary correction.

Mortality and causes of death after multimodality treatment for advanced oral and oropharyngeal cancer.

PURPOSE: To analyze mortality and causes of death in patients who received preoperative radiochemotherapy and underwent radical surgery for advanced oral or oropharyngeal cancer. PATIENTS AND METHODS: A total of 222 patients who underwent multimodality treatment from 1990 to 2000 were included in the study. The inclusion criterion was International Union Against Cancer (UICC) disease stage II to IV (T2, 33.3%; T3, 12.6%; T4, 54.1%). Patients received preoperative radiotherapy 50 Gy and concomitant chemotherapy with mitomycin and 5-fluorouracil. Radical local-regional en bloc resection was performed in all patients. Survival status and causes of death were ascertained from the National Health Registry. Death certificates and autopsy reports were consulted when hospital files failed to provide reliable data. RESULTS: After a median surveillance period of 72.3 months (range, 24 to 152 months), 59% of patients were alive, 21% had died of recurrence, 5% had died perioperatively, and 15% had died from other causes. Of these, a second cancer in the head and neck region or the lower respiratory tract or the upper digestive tract was found in 7.3%. Although 93% of deaths related to recurrent disease occurred within the first 36 months after surgery, the remaining causes of death did not reveal a specific temporal pattern. CONCLUSION: Favorable survival data were registered for patients with advanced squamous cell carcinoma of the oral cavity who underwent combined treatment protocols. These patients frequently die of comorbidities. Because recurrent disease is a less common cause of mortality than are other causes, the latter should receive attention during surveillance.