Michael R. Markiewicz

Accuracy of a computer-aided surgical simulation protocol for orthognathic surgery: A prospective multicenter study

PURPOSE The purpose of this prospective multicenter study was to assess the accuracy of a computer-aided surgical simulation (CASS) protocol for orthognathic surgery. MATERIALS AND METHODS The accuracy of the CASS protocol was assessed by comparing planned outcomes with postoperative outcomes of 65 consecutive patients enrolled from 3 centers. Computer-generated surgical splints were used for all patients. For the genioplasty, 1 center used computer-generated chin templates to reposition the chin segment only for patients with asymmetry. Standard intraoperative measurements were used without the chin templates for the remaining patients. The primary outcome measurements were the linear and angular differences for the maxilla, mandible, and chin when the planned and postoperative models were registered at the cranium. The secondary outcome measurements were the maxillary dental midline difference between the planned and postoperative positions and the linear and angular differences of the chin segment between the groups with and without the use of the template. The latter were measured when the planned and postoperative models were registered at the mandibular body. Statistical analyses were performed, and the accuracy was reported using root mean square deviation (RMSD) and the Bland-Altman method for assessing measurement agreement. RESULTS In the primary outcome measurements, there was no statistically significant difference among the 3 centers for the maxilla and mandible. The largest RMSDs were 1.0 mm and 1.5° for the maxilla and 1.1 mm and 1.8° for the mandible. For the chin, there was a statistically significant difference between the groups with and without the use of the chin template. The chin template group showed excellent accuracy, with the largest positional RMSD of 1.0 mm and the largest orientation RMSD of 2.2°. However, larger variances were observed in the group not using the chin template. This was significant in the anteroposterior and superoinferior directions and the in pitch and yaw orientations. In the secondary outcome measurements, the RMSD of the maxillary dental midline positions was 0.9 mm. When registered at the body of the mandible, the linear and angular differences of the chin segment between the groups with and without the use of the chin template were consistent with the results found in the primary outcome measurements. CONCLUSIONS Using this computer-aided surgical simulation protocol, the computerized plan can be transferred accurately and consistently to the patient to position the maxilla and mandible at the time of surgery. The computer-generated chin template provides greater accuracy in repositioning the chin segment than the intraoperative measurements.

Imaging Findings in Bisphosphonate-Related Osteonecrosis of Jaws

PURPOSE Bisphosphonate-related osteonecrosis of the jaws (BRONJ) is a well-described clinical condition with consistent radiographic findings. The purpose of this report was to review these findings in an attempt to offer important diagnostic, prognostic, and therapeutic information associated with BRONJ. MATERIALS AND METHODS The findings of studies assessing the radiographic landmarks on plain films, intraoral films, orthopantograph, computed tomography, magnetic resonance imaging, and nuclear bone scans in patients with BRONJ were analyzed. RESULTS The radiographic findings in patients with BRONJ include osteosclerosis, osteolysis, dense woven bone, a thickened lamina dura, subperiosteal bone deposition, and failure of postsurgical remodeling. CONCLUSIONS Consistent imaging findings are noted in the BRONJ patient. Imaging is an essential part of the clinical assessment of the BRONJ patient and might be an additional tool for tracking the progression of the disease.

Corticosteroids Reduce Postoperative Morbidity After Third Molar Surgery: A Systematic Review and Meta-Analysis

PURPOSE The purpose of this study was to apply meta-analytical methods to measure the effect of corticosteroids (CS) on edema, trismus, and pain at early and late postoperative periods after third molar (M3) removal. MATERIALS AND METHODS A systematic search of the literature was carried out to identify eligible articles. The primary predictor variable was perioperative CS exposure (yes or no). The 3 outcome variables were edema, trismus, and pain assessed during the early (1-3 days) and late (>3 days) postoperative time periods. Standardized mean differences (SMD) for edema and weighted mean differences (WMD) for trismus and pain were pooled across studies. Differences between the 2 treatment groups were assessed using random effects models and metaregressions for both early and late postoperative assessments. RESULTS Twelve trials met the inclusion criteria. Subjects receiving CS had significantly less edema during both early (SMD, 1.4; 95% confidence interval [CI], 0.6, 2.2; P < .001) and late (SMD, 1.1; 95% CI, 0.1, 2.0; P = .03) time periods after surgery and less trismus than controls during the early and late postoperative periods (early WMD, 4.1 mm; 95% CI, 2.8 mm, 5.5 mm; P < .001; late WMD, 2.7 mm; 95% CI, 0.8 mm, 4.6 mm; P = .005). Average pain levels were not significantly different between the 2 groups (early WMD, 0.4 visual analog scale [VAS]; 95% CI, -0.04 VAS, 0.9 VAS; P = .07; late WMD, 0.5 VAS; 95% CI, -0.6 VAS, 1.5 VAS; P = .4). CONCLUSIONS The findings of this study suggest that perioperative administration of corticosteroids produces a mild to moderate reduction in edema and improvement in range of motion after M3 removal.

Morbidity Associated With Oral Mucosa Harvest for Urological Reconstruction: An Overview

PURPOSE To present a systematic review of the literature regarding complications associated with the donor site following oral mucosa harvest for urethral reconstruction. MATERIALS AND METHODS The authors conducted a database search for relevant literature during the time period January 1966 through January 1, 2007, regarding complications associated with oral mucosa graft harvest for use in urethral transplantation. Bibliographies of database hits were searched for pertinent papers. RESULTS The most common harvest sites were the buccal and mandibular labial mucosa. The most frequent complications at both mucosal harvest sites were scarring and contracture. These 2 complications limit jaw opening and have been found to last for as long as 4 weeks. Labial mucosa harvest is associated with the additional morbidity of perioral neurosensory defect because of the procedures proximity to the mental nerve. When nerve damage occurs, it usually subsides within 10 months postsurgery. Patients report relatively the same quality of life following harvest from both donor sites, although buccal mucosa harvest was associated with less postoperative discomfort, less neurosensory defect, and less salivary flow change. Following oral mucosa harvest, patients should be able to ingest oral fluids within 24 hours, solid foods within 2 days, and return to a normal dietary regimen within 1 week of harvest. CONCLUSION When harvesting oral mucosa for urethral reconstruction, sound surgical principles will ensure the patient the best chance of avoiding postoperative complications at the donor site. Oral and maxillofacial surgeons should advise both urologists and their patients of the potential complications associated with both oral mucosa harvesting sites.

The Use of 3D Imaging Tools in Facial Plastic Surgery

The authors present an overview of 3D computer-aided design and computer-aided modeling tools available to the facial plastic surgeon. They describe the role of 3D tools in all phases of computer-aided surgery including: data acquisition, planning, surgery, and assessment. Applications of these tools include obtaining 3D measurements, using mirror imaging to reconstruct missing areas of the head and neck, and 3D sizing or segmentation of bone and soft tissue. They review of clinical outcomes obtained from studies reviewing 3D tools. These systems have potential value for education, reducing operating room time, and improving clinical outcomes.

Does intraoperative navigation restore orbital dimensions in traumatic and post-ablative defects? ☆

BACKGROUND The outcomes of the reconstruction of post-ablative and post-traumatic orbital defects are often unpredictable when considering the restoration of the orbital dimensions. Intraoperative navigation offers the surgeon visualization of bony landmarks via comparison to preoperative computed tomography, aiding in bony reduction and implant placement. The purpose of this study was to assess whether intraoperative navigation-guided orbital reconstruction re-establishes orbital volume and globe projection in subjects with post-ablative and post-traumatic orbital defects. MATERIAL AND METHODS The investigators initiated a retrospective cohort study and enrolled a sample of subjects that underwent primary or secondary reconstruction for unilateral orbital deformities secondary to traumatic injury or tumour surgery. Pre- and post-operative orbital volume and globe projection were measured using Analyze (Mayo Clinic Biomedical Imaging Resource, Rochester, MN, USA). A matched pairs t-test was used to assess the difference in pre- and post-operative orbital volume and globe projection. RESULTS Twenty-three subjects underwent intraoperative navigation-guided orbital reconstruction. The mean difference in orbital volume and globe projection between the non-operated orbit and operated orbit in the post-operative period was -1.3 cm(3) and 2.4mm respectively. Both final measurements were within the margin of error of clinically noticeable enophthalmos. The mean absolute difference in orbital volume and globe projection between the pre- and post-operative period was 5.1 cm(3) (p=<0.001) and 4.1mm (p=<0.001) respectively. CONCLUSION The results of this study suggest that orbital reconstruction using intraoperative navigation is effective in establishing normal orbital volume and globe projection in post-traumatic and post-ablative defects, therefore restoring the orbit and globe to pre-traumatic and pre-ablative conditions.

Modern concepts in computer-assisted craniomaxillofacial reconstruction.

Purpose of reviewTo review the past years literature regarding current computer-assisted reconstruction techniques and their outcomes. Recent findingsCurrent computer-assisted craniofacial reconstruction research is focused on data acquisition, planning, surgical and assessment phases. The major areas of interest among researchers include cosmetic surgery; cleft and craniofacial surgery; traumatic reconstruction, head and neck tumor reconstruction; and orthognathic surgery and distraction osteogenesis. Recent advances in the fields include facial analysis and planning in rhinoplasty, facial surface and bone graft volume analysis in cleft surgery, computer-guided tumor ablation and osteocutaneous reconstruction in tumor surgery, and preoperative planning and surgical assistance in orthognathic and distraction osteogenesis surgery. SummaryResearch in computer-aided craniofacial surgery is progressing at a rapid rate. Rather than just the latest innovation, sound research studies are proving computer assistance to be invaluable in producing superior outcomes, especially in the fields of head and neck surgery, orthognathic surgery, and craniomaxillofacial trauma surgery. Further outcome studies and cost-benefit analyses are still needed to show the superiority of these methods to contemporary techniques.

Reliability of Intraoperative Navigation in Restoring Normal Orbital Dimensions

PURPOSE To assess the reliability and effectiveness of intraoperative navigation in restoring normal orbital and globe dimensions in traumatic and postablative orbital defects. MATERIALS AND METHODS To address the research purpose, the investigators initiated a retrospective cohort study and enrolled a sample of subjects that underwent primary or secondary reconstruction for unilateral orbital deformities secondary to traumatic injury or tumor surgery during the study enrollment period. Using computed tomographic datasets, pre- and postoperative orbital volume and globe projection were measured using Analyze software (Mayo Clinic Biomedical Imaging Resource, Rochester, MN). Intraclass correlation coefficient (ICC) was used to evaluate the reliability between preoperative unaffected orbit and the postoperative affected orbital and globe dimensions. A matched pairs t test was used to assess the difference in pre- and postoperative orbital volume and globe projection. RESULTS The sample was composed of 23 subjects that underwent orbital reconstruction secondary to traumatic of postablative defects. There was a linear and reliable relationship between preoperative unaffected and postoperative affected orbital volumes (ICC, 0.67; 95% CI, 0.37 to 0.86), and preoperative unaffected and postoperative affected globe projections was high (ICC, 0.87; 95% CI, 0.69 to 0.94). There was a significant difference in pre- and postoperative mean orbital volume (30.6 vs 25.5 cm(3), P ≤ 0.001), and pre- and postoperative globe projection (51.2 vs 53.6 mm, P ≤ 0.001). CONCLUSIONS The results of this study suggest that intraoperative navigation-assisted orbital reconstruction is reliable in restoring orbital volume and globe projection to pretraumatic and preablative conditions.

Low Prealbumin Level Is a Risk Factor for Microvascular Free Flap Failure

PURPOSE The purposes of this study were 1) to estimate and compare the 1-month survival rates of patients with acute malnutrition (low prealbumin level) and patients who are not malnourished (normal prealbumin level) and 2) to identify risk factors associated with microvascular free flap failure. MATERIALS AND METHODS To address the research purposes, we designed a retrospective cohort study and enrolled a sample composed of patients who underwent head and neck microvascular reconstruction and had prealbumin levels measured in the perioperative period. The primary predictor variable was nutritional status (low vs normal prealbumin level). The primary outcome variable was flap survival. One-month survival rates were estimated by use of Kaplan-Meier survival analyses. Risk factors for free flap failure were identified by use of multivariate marginal Cox proportional hazards modeling. RESULTS The sample was composed of 162 patients who underwent microvascular free tissue transfer during the study enrollment period. The 1-month survival estimates for patients who were and were not malnourished were 76.5% (95% confidence interval [CI], 48.8% to 90.5%) and 95.2% (95% CI, 90.1% to 97.7%), respectively (P = .002). In the adjusted Cox hazards proportions model, acute malnutrition was associated with a 4-fold increased risk of failure (P = .04) in comparison with those patients with a normal nutritional status. CONCLUSIONS Acute malnutrition in patients undergoing microvascular free flap reconstruction in the head and neck region was associated with an increased risk for free flap failure.

Computer-Aided Orthognathic Surgery

Computer-Aided Orthognathic Surgery Savannah Gelesko, DDS, Michael R. Markiewicz, DDS, MPH, MD, Katherine Weimer, MS, R. Bryan Bell, DDS, MD* Department of Oral and Maxillofacial Surgery, Oregon Health and Science University, Mail code: SDOMS, 611 Southwest Campus Drive, Portland, OR 97239, USA Virtual Surgical Planning, Medical Modeling Inc, 17301 West Colfax Avenue, Suite 300, Golden, CO 80401, USA Oral, Head, and Neck Cancer Program, Providence Cancer Center, Providence Portland Medical Center, 4805 NE Glisan Street, Portland, OR 97213, USA Trauma Service/Oral and Maxillofacial Surgery Service, Legacy Emanuel Medical Center, 2801 North Gantenbein, Portland, OR 97227, USA