A comparison of accuracy among different approaches of static-guided implant placement in patients treated with mandibular reconstruction: A retrospective study.

OBJECTIVE: This study aimed to evaluate the differences in the accuracy of immediate intraoral, immediate extraoral, and delayed dental implant placement with surgical guides (static computer-aided implant surgery) in patients treated with mandibular reconstruction. METHODS: This was a retrospective study. The patients were divided into three groups: immediate intraoral placement (IIO), immediate extraoral placement (IEO), and delayed placement (DEL). Four variables were used to compare the planned and actual implant positions: angular deviation, three-dimensional (3D) deviation at the entry point of the implant, 3D deviation at the apical point of the implant, and depth deviation. RESULTS: The angular deviation was significantly higher in the IIO group than in the IEO (p < .05) and DEL (p < .05) groups. The 3D deviation at the entry point was significantly higher in the IIO group than in the IEO (p < .05) and DEL (p < .01) groups. The 3D deviation at the apical point was significantly higher in the IIO group than in the IEO (p < .01) and DEL (p < .01) groups. The depth deviation was significantly higher in the IIO group than in the IEO (p < .05) and DEL (p < .05) groups. There was no statistical difference between the IEO and DEL group in angular and 3D deviation. CONCLUSION: With surgical guides, among the different approaches for implant placement, delayed implant placement remains the most accurate approach for patients treated with mandibular reconstruction.

A study on the morphology of iliac crest based on the objectives of jaw bone defect reconstruction.

OBJECTIVES: to understand the morphological characteristics of iliac crest and provide advice and assistance for jaw bone reconstruction with iliac bone flap by evaluating the thickness and curvature of iliac crest. MATERIALS AND METHODS: 100 patients who had taken Spiral CT of the Abdominal region before surgeries between 2020 and 2022 were included in this study. 3D reconstruction images of the iliac bones were created. 5 vertical planes perpendicular to the iliac crest were made every 2 cm along the centerline of the iliac crest (VP2 ~ VP10). On these vertical planes, 4 perpendicular lines were made every 1 cm along the long axis of the iliac crest (D1 ~ D4). The thicknesses at these sites, horizontal angle (HA) of iliac crest and the distance between inflection point and the central point of anterior superior iliac spine (DIA) were measured. RESULTS: The thickness of iliac bone decreased significantly from D1 ~ D4 on VP6 ~ VP10 and from VP2 ~ VP10 on D3 and D4 level (P<0.05). HA of iliac crests was 149.13 ± 6.92°, and DIA was 7.36 ± 1.01 cm. Iliac bone thickness, HA and DIA had very weak or weak correlation with patient's age, height and weight. CONCLUSIONS: The average thicknesses of iliac crest were decreased approximately from front to back, from top to bottom. The thickness and curvature of the iliac crest were difficult to predict by age, height and weight. CLINICAL RELEVANCE: Virtual surgical planning is recommended before jaw bone reconstruction surgery with iliac bone flap, and iliac crest process towards alveolar process might be a better choice.

Iliac crest towards alveolar processes or mandibular inferior margin in mandibular reconstruction with a vascularized iliac bone flap: which is better?

OBJECTIVE: The study aims to compare differences among iliac bone flaps with different iliac crest orientations for the repair of mandibular defects with an aim to analyze their advantages, disadvantages, and effects. MATERIAL AND METHODS: Clinical data and computed tomography scans of all patients who underwent iliac bone flap repair of the mandible in Peking University School and Hospital of Stomatology from January 2016 to April 2021 were collected. Patients were divided into the iliac crest towards alveolar process (Group A) and the iliac crest towards mandibular inferior margin (Group B). Software was used to measure corresponding indicators. The results obtained for the groups were statistically analyzed. RESULTS: The study included 78 patients (25 and 53 in groups A and B, respectively). The symmetry of the LC-type defect was better in group A (p < 0.05). The all-bone width of the alveolar process side in group A was greater than 6 mm; in 15 cases of group B, the width was less than 6 mm (p < 0.05). The intermaxillary distance of two sites were higher in group B (p < 0.05). The bone cortical thickness was significantly thicker in group A (p < 0.05). CONCLUSION: One year after the mandibular body defect was reconstructed with a vascularized iliac bone flap, the iliac crest towards alveolar process group showed better bone symmetry, width, intermaxillary distance, and cortical thickness to meet the planting requirements. CLINICAL RELEVANCE: The use of an iliac crest towards alveolar process may be a better approach for mandible reconstruction.

Clinical Characterization of Oral and Maxillofacial Tumors and Tumor-Like Lesions in Children and Adolescents.

PURPOSE: To investigate the clinical characteristics of oral and maxillofacial tumors in children and adolescents. METHODS: This is a retrospective study of patients who had oral and maxillofacial tumors under the age of 18 years and were treated at the Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology from January 1990 to July 2021 (31 y). Their general conditions, pathological diagnosis, gender, age, and anatomical location were counted to analyze their morbidity and composition characteristics. RESULTS: This study contained 5405 cases, including 2903 male patients and 2502 female patients, with a median age of 9 years. Peak incidence was observed in the 14 to 18 years age group. The mandible (22.15%), maxilla (11.75%), and tongue (9.25%) were the most common sites of incidence. Malignant and intermediate type tumors accounted for 13.04%, benign tumors and tumor-like lesions for 55.67%, most often occurs in the maxillofacial bone, of which fibro-osseous lesions constitute an important part. Cysts accounted for 31.29%. Among the tumors occurring in the jaws, the most common malignant type was sarcoma, and ameloblastoma was the most common benign tumor. Malignant jaw tumors were mostly treated by resection, 10.64% by fibular flap reconstruction. While benign jaw tumors and tumor-like lesions were mostly treated by resection or curettage. CONCLUSIONS: The distribution of anatomical location and pathological types of oral and maxillofacial tumors in children has certain characteristics, so that the selection of their treatment options is different from that of adults due to the consideration of the growth and developmental characteristics of children.

Vascularized Free Fibular Flap in Oral and Maxillofacial Reconstruction: A 20-year Experience at a Single Institution Using 2640 Flaps.

BACKGROUND: This retrospective study reviewed all patients who underwent oral and maxillofacial reconstruction with fibular flaps in the last 2 decades at a single hospital. MATERIALS AND METHODS: We reviewed all patients with fibular flaps from 1999 to 2018. The following data were collected: sex; age; reconstruction region; diagnosis; the number of days spent in the hospital after surgery; time spent using a tourniquet for harvesting a fibula flap; vessels at the recipient site; the prevalence of unplanned reoperations; the prevalence of flap failure; history of preoperative radiotherapy; virtual surgical planning; segments of the fibula. RESULTS: In total, 2640 patients were included. The mean age was 45.5 years. The most prevalent region of reconstruction was the mandible (n=2347, 88.9%). The most common diagnosis was squamous cell carcinoma (n=1057, 40.0%). The mean number of days spent in the hospital after surgery decreased year-by-year from 18.3 days to 10.4 days. The first choice of recipient artery was the facial artery (n=1643, 62.2%) and that of the recipient vein was the external jugular vein (n=1196, 45.3%). The prevalence of surgical success was 97.6%. Prevalence of unplanned reoperations was 7.5%. CONCLUSIONS: The fibular flap was a good choice for oral and maxillofacial bony reconstruction in most cases.

Mandibular Reconstruction Using Iliac Flap Based on Occlusion-Driven Workflow Transferred by Digital Surgical Guides.

PURPOSE: The current standard for mandibular reconstruction is a contour-based approach using a fibular flap offering good cosmetic results but challenging to reconstruct using dental implants. An iliac flap is more amenable to implant placement and better suited for occlusion-driven reconstruction. We aimed to describe an occlusion-driven workflow that involves the use of digital surgical guides to perform mandibular reconstruction using an iliac flap; we also aimed to compare our results to those we achieved with conventional contour-based reconstruction. METHODS: This was a retrospective cohort study. All patients who underwent mandibular reconstruction with an iliac flap at our university hospital between September 2017 and December 2019 were considered eligible for the study. The inclusion criteria included mandibular defects after tumor ablation and stable preoperative occlusal relationship. The exclusion criteria were as follows: defects involving the condyle and ramus, temporomandibular joint disease, and obvious preoperative nontumor-related facial asymmetry. To evaluate surgical outcomes, patients were assigned to 2 groups based on the implemented surgical workflow: the occlusion-driven and traditional contour-driven groups. The intermaxillary distance, intermaxillary angle, surface deviation, and implantation rates were compared between the 2 groups. The operating time, length, and number of iliac bone segments were recorded. Intergroup differences were investigated using an independent samples t test and Fisher exact test. RESULTS: Overall, 24 patients were included (13 in the occlusion-driven group and 11 in the contour-driven group). Implantation rate was higher in the occlusion-driven group (61.5%) compared with the contour-driven group (18.2%; P = .047). The average acceptable intermaxillary distance was greater in the occlusion-driven group (92.3 ± 27.7%) than in the contour-driven group (47.0 ± 47.6%; P = .01). The average intermaxillary angle was 88.2 ± 8.4° in the occlusion-driven group and 76.4 ± 10.3° in the contour-driven group (P < .01). CONCLUSIONS: Digital surgical guides can precisely transfer virtual surgical planning to real-world mandibular surgery. An occlusion-driven workflow might provide a better intermaxillary jaw relationship than traditional contour-driven surgical procedures, resulting in improved mastication.

Prospective Trial of Near-Infrared Spectroscopy for Continuous Noninvasive Monitoring of Free Fibular Flaps.

INTRODUCTION: Some free flaps develop postoperative vessel thrombosis, which influences the flap survival rate. Early discovery and identification of vascular crisis are critical to the success rate of flap salvage. The primary aims of this study were to determine the features of postoperative blood supply changes in fibular flaps with normal and abnormal blood flow, using near-infrared spectroscopy (NIRS), to monitor oxygenation and blood flow, and to characterize the probable risk factors for vascular crisis. METHODS: Sixty-three consecutive patients undergoing reconstruction of unilateral mandibular defects with free fibular flaps at the Peking University School of Stomatology were included. Patients were divided into 2 groups, A (n = 38) and B (n = 25); fibular flaps in group A underwent continuous NIRS monitoring from immediately postoperatively until 7 days postoperatively (approximately 150 hours), whereas fibular flaps and opposite mandibles in group B underwent intermittent monitoring: once every 4 hours during the first 24 hours postoperatively and once every 12 hours from 24 to 168 hours postoperatively. RESULTS: Six fibular flaps developed vascular thromboses: 4 were venous thromboses and 2 were arterial thromboses; 5 were rescued after exploration. Of 6 regional oxygen saturation (rSO2) values in the continuous monitoring group, 4 showed no significant differences at any time point compared with the intermittent monitoring group (P > 0.05). The rSO2 of the fibular flap was significantly different from that in the opposite mandible in the first 36 hours postoperatively (P < 0.05). This difference decreased over time. During the initial period of venous thrombosis, rSO2, deoxyhemoglobin, and oxygenated hemoglobin all rose slightly, then showed simultaneous rapid reduction. However, the magnitude of reduction was smaller for deoxyhemoglobin than for oxygenated hemoglobin. CONCLUSIONS: Near-infrared spectroscopy can be used for noninvasive and reliable assessment of oxygenation and blood flow in free flaps through continuous, real-time monitoring. It is also portable, inexpensive, and simple to operate. In addition, the detection depth of NIRS is up to 2.0 cm, so it can be used to monitor buried flaps with depths <2.0 cm.

Changes in Condylar Position After Mandibular Reconstruction With Condylar Head Preservation by Computed Tomography.

PURPOSE: Condylar position can change after mandibular reconstruction using the free fibula flap. The present study evaluated changes in condylar position using computed tomography (CT) after mandibular reconstruction with condylar head preservation. MATERIALS AND METHODS: This retrospective study consisted of 16 patients. CT data of 32 temporomandibular joints (TMJs) were recorded before surgery (T0), 7 to 10 days after surgery (T1), and 16.8 ± 7.4 months after surgery (T2). The anteroposterior condylar position was evaluated using the method of Pullinger and Hollender (Oral Surg Oral Med Oral Pathol 62:719, 1986). Repeated-measures analysis of variance (P = .05) was performed. RESULTS: Data of 16 patients were obtained for statistical analysis. Condylar position changed over time after mandibular reconstruction. The ipsilateral condyles moved anteroinferiorly after surgery (T0 to T1) and tended to move anterosuperiorly during follow-up (T1 to T2). No major changes were noted in the contralateral condyles. CONCLUSION: Condylar positions showed obvious changes over time after mandibular reconstruction with condylar preservation. Nevertheless, additional studies are warranted to further evaluate the relation between condylar position and TMJ function.

Parasympathectomy increases resting salivary secretion in normal and irradiated submandibular glands of rats.

Fluid and ion secretion from the submandibular gland (SMG) is mainly regulated by parasympathetic nerves. This study evaluated the effect of parasympathectomy on salivary secretion from normal and irradiated rat SMGs from 1 to 24 wk after denervation. Although stimulated salivary secretion was significantly lower in denervated SMGs compared with contralateral self-controls, the resting salivary flow rates were markedly higher in the denervated SMGs at 1, 12, and 24 wk after denervation. The levels of muscarinic acetylcholine M1 and M3 receptors, as well as of aquaporin 5, were up-regulated. Notably, although irradiated SMGs showed significantly lower resting and stimulated salivary secretion rates than non-irradiated SMGs, the resting salivary secretion rates of the irradiated and denervated SMGs were markedly higher than seen in the irradiated self-control SMGs at 1, 12, and 24 wk after parasympathectomy, and were even higher than seen in the non-irradiated sham-operated rats. The expression of M1 and M3 receptors was similarly elevated. Taken together, our results suggest that parasympathetic denervation increases resting salivary secretion of both normal and irradiated SMGs. This approach might provide a potential modality for relieving radiation-induced xerostomia, which is a common complication following treatment of head and neck cancer.

Surgical Reconstruction of Maxillary and Mandibular Defects Using a Printed Titanium Mesh.

PURPOSE: To reconstruct maxillary and mandibular defects with printed titanium mesh using computer-assisted surgery (CAS) for the achievement of structural, esthetic, and functional goals. PATIENTS AND METHODS: The authors designed and implemented this prospective study of patients with maxillary or mandibular defects who underwent reconstruction with printed titanium mesh using CAS. After surgery, the preoperative design and postoperative outcome were evaluated using Geomagic Studio software. RESULTS: The sample was comprised of 2 patients with maxillary defects and 2 with mandibular defects. A satisfactory contour was achieved in all patients. The rate of concordance between the preoperative design and the postoperative outcome was higher than 81 and 94% within 3 mm for the mandibular and maxillary reconstructions, respectively. CONCLUSION: The results of this study suggest that complicated maxillary and mandibular defects can be satisfactorily reconstructed with customized printed titanium meshes using CAS.

Fibular free flap reconstruction for the management of advanced bilateral mandibular osteoradionecrosis.

Fibular osteoseptocutaneous flap has been widely used for unilateral mandibular reconstruction. However, reports about the effects of fibular osteoseptocutaneous flap for the reconstruction of bilateral mandibular defects are limited. In this study, we used free vascularized fibular flaps to successfully manage bilateral mandibular osteoradionecrosis(ORN) in 5 patients. Functional aspects were evaluated during the reconstruction process. All 5 patients had bilateral refractory ORN of the mandible and underwent radical resection between 2003 and 2011. The reconstruction surgery was performed in 2 stages using 2 free fibular flaps in 3 patients. In the other 2 patients, reconstruction was performed in a single stage using 2 separate flaps prepared from a single fibula. All patients had a healthy mandibular symphysis and meniscus of the temporomandibular joint, and these structures were preserved during the reconstruction.Of the 10 defects involving the mandible sides, 9 were successfully reconstructed. One microvascular composite flap failed because of radiation injury to the arterial endothelium at the recipient site. After the treatments, all patients had good esthetic and functional outcomes. Preoperative clinical features such as trismus and dysphagia were also markedly improved. Our surgical method may be an effective alternative for the clinical management of advanced bilateral mandibular ORN.

Evaluation of foot perfusion after fibula flap surgery.

Fibula flap is widely used in reconstruction work, whereas the low extremity blood supply alteration was unclear. This study would observe the blood oxygen saturation change of foot after harvesting fibula flap. The regional tissue oxygen saturation (rSO2) of the lateral side and inner side of feet was measured using near-infrared spectroscopy oxygen monitoring system (NIRS) before operation and in postoperative day 1 to 7, and the foot of the control side was measured as control. The rSO2 of the donor side foot decreased less than 5% (P < 0.05) in the first 8 hours after operation and recovered to the level of the control side later. NIRS is ideal for measuring rSO2 of donor side foot after fibula flap. The rSO2 of the donor side foot decreased less than 5% after fibula flap harvesting.

Reconstruction of the anterior maxillary defect using a vascularized bone flap with residual teeth in the posterior maxilla.

BACKGROUND: Microsurgical bone reconstruction is challenging in cases of anterior maxillary defects because of the presence of residual teeth. The study analyzed the method and feasibility of using vascularized bone flaps to reconstruct anterior maxillary defects. METHODS: We retrospectively analyzed 15 patients treated at the Department of Oral and Maxillofacial Surgery, Peking University School, and Hospital of Stomatology between November 2017 and January 2023. RESULTS: A total of 14 patients were successfully reconstructed using the digital technique: 6 deep circumflex iliac artery (DCIA) flaps and 8 fibular free flaps. Palatal and buccal pedicle paths were used in 4 and 10 cases, respectively, for vascular anastomosis. The implant coverage rates of the DCIA and fibular free flaps were 87.2% and 92.6%, respectively (p > 0.05). CONCLUSION: Anterior maxillary defects reconstructed with the DCIA and fibular free flaps are reliable methods. Furthermore, the palatal and buccal paths are recommended for vascular anastomosis.

Retrospective study of the deep circumflex iliac artery flap and the vascularized fibula free flap for maxillary defect repair.

OBJECTIVES: The deep circumflex iliac artery flap (DCIA) and vascularized fibular free flap (FFF) are mainstay flaps for maxillary defect reconstruction. This study compared the functional outcomes and success rates of these flaps to provide midface reconstruction strategies. MATERIALS AND METHODS: Maxillary defects reconstructed with DCIA or FFF at the Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology between May 2016 and May 2023 were retrospectively analyzed. The length, width, and height of the grafted bone segments; intermaxillary distance; buttress reconstruction rate (BRR); dental arch reconstruction rate (DAR); success rate; and dental implantation rate were compared. RESULTS: The DCIA and FFF groups had 33 and 27 patients, respectively. Success rate in the DCIA group was 93.94 % and 100 % in the FFF group. The DCIA length was less than that of FFF; however, the width and height were significantly larger. 87.10 % of cases in the DCIA group were classified as Brown class b and c, 51.85 % of cases in the FFF group were classified as Brown class d. The average BRR in the DCIA group was 69.89 % ± 16.05 %, which was significantly higher than that in the FFF group. A total of 38.7 % and 11.1 % patients in the DCIA and FFF groups, respectively, had completed implantation. CONCLUSION: DCIA has a greater width and height, and is more suitable for repairing Brown class b and c defects, providing sufficient bone for implantation, while the FFF is longer and more suitable for Brown class d defect reconstruction.

One-stage jaw reconstruction and prosthetic rehabilitation with an iliac flap: a case report and literature review.

BACKGROUND: One-stage jaw reconstruction with fibular flap and prosthetic rehabilitation restores bony and dental continuity simultaneously. It was also called as "jaw-in-a-day (JIAD)" technique. However, bone volume and height of fibular flap may be insufficient for dental implant insertion. The provision of a considerable amount of bone makes an iliac flap the ideal choice in these cases. We present the first case report to document the use of one-stage jaw reconstruction and prosthetic rehabilitation with the iliac flap. CASE PRESENTATION: We modified the conventional JIAD workflow to make it suitable for iliac flap. Two cases were presented who both underwent segmental mandibulectomy for ameloblastoma. Virtual surgical planning was performed in all cases. The iliac crest was positioned upward to provide cortical bone for achieving primary stability of dental implants. Similar to the "all-on-4" procedure, the iliac bone was placed 12 to 15 mm below the occlusal plane to create adequate space for the implant-retained prosthesis. Immediate implant-based dental rehabilitation was performed at same stage. The surgery was successful in all cases without any short-term complications. In the first postoperative week, patients were given a liquid diet through a nasal feeding tube. The liquid diet is advised until 1 month after the surgery. Thereafter, a soft diet is recommended. Patients were advised to resume routine mastication and normal diet 3 months after the surgery. Peri-implantitis occurred in one patient, and additional gingival graft was required. Postoperative function and esthetics were satisfactory at the last follow-up visit. CONCLUSIONS: One-stage jaw reconstruction and prosthetic rehabilitation with the iliac flap are safe and useful for restoring postoperative function and esthetics. It should be used in more cases with a longer follow-up in further studies.

Virtual Surgical Planning of Deep Circumflex Iliac Artery Flap for Midface Reconstruction.

OBJECTIVE: Midface reconstruction is challenging for functional and esthetic reasons. The present study analyzed the effect of virtual surgical planning (VSP) of the deep circumflex iliac artery (DCIA) flap for midface reconstruction. PATIENTS AND METHODS: Thirty-four patients who underwent midface reconstruction with the DCIA flap were included in this retrospective study. Of the 34 patients, 16 underwent preoperative VSP, which used a three-dimensionally printed surgical guide, computer-assisted navigation system, and pre-bent titanium implants to transfer VSP into real-world surgery. The other 18 patients underwent traditional midface reconstruction. The following were compared between the two groups: bony contact rate in the buttress region (BCR), dental arch reconstruction rate (DAR), surgical approach, position of vascular anastomosis, and dental implantation rate. The independent-samples t-test and Fisher's exact test were used for analysis. P < 0.05 was considered statistically significant. RESULTS: In total, 12 males and 22 females were included in this study. All patients underwent midface reconstruction using the DCIA flap at the same institution. The median age of patients was 33 years (range: 16-68 years). The average BCR and DAR values in the VSP group were 59.4% ± 27.9% and 87.5% ± 18.9%, respectively, which were significantly higher compared with the non-VSP group (P = 0.049 and P = 0.004, respectively). The dental implantation rate in the VSP group (50.0%) was significantly higher compared with the non-VSP group (11.1%; P = 0.023). The intraoral approach for tumor ablation and vascular anastomosis was the most frequent choice in both groups. There was no significant difference between the two groups. All patients were satisfied with facial symmetry postoperatively. CONCLUSIONS: VSP could effectively augment the effect of midface reconstruction with the DCIA flap. Stronger bone contact in the buttress region and higher DAR provide more opportunity for dental implantation, which might be the best solution to improve masticatory function in patients with midface defects.

Orbital floor symmetry after maxillectomy and orbital floor reconstruction with individual titanium mesh using computer-assisted navigation.

PURPOSE: The present study aimed to evaluate the symmetry of the orbital floor after maxillectomy and orbital floor reconstruction with individual titanium mesh using a computer-assisted navigation system. PATIENTS AND METHODS: Nineteen patients who underwent orbital floor reconstruction with individual titanium mesh were included in this study. Postoperative computed tomography scans recorded after three-dimensional (3D) reconstruction were used to evaluate the symmetry of the orbital floor, including orbital floor height, orbital floor eminence, globe projection, orbital volume, and surface deviation. RESULTS: The average orbital floor height of the reconstructed and the unaffected side was 37.7 ±â€¯2.3 and 37.8 ±â€¯2.7 mm, respectively (P = .47). The average orbital floor eminence of the reconstructed and the unaffected side was 40.1 ±â€¯5.5 and 39.6 ±â€¯5.3 mm, respectively (P = .17). The average globe projection of the reconstructed and the unaffected side was 15.5 ±â€¯3.2 and 15.3 ±â€¯3.0 mm, respectively (P = .27). The average orbital volume of the reconstructed and the unaffected side was 25.9 ±â€¯4.4 and 26.3 ±â€¯4.4 cm3, respectively (P = .29). Repeatability between the reconstructed and the unaffected side was 88.3% ± 2.6% at within 1 mm and 98.6% ± 0.9% at within 2 mm. The average of maximum deviation was 2.4 ±â€¯0.2 mm. CONCLUSION: Individual titanium mesh is one of the best techniques for orbital floor reconstruction, as it can be placed precisely and helps achieve desirable esthetic outcomes through virtual surgical planning and using a computer-assisted navigation system.

Improvement of the patient early mobilization protocol after oral and maxillofacial free flap reconstruction surgery.

OBJECTIVE: There is lack of standardized management and mobilization strategies after oral and maxillofacial reconstruction surgery. We used prospective randomized controlled trials to explore improvements in postoperative mobilization protocol in such patients. METHODS: A total of 149 patients were randomly divided into tracheotomy control group A (38 cases) and test group A (37 cases), nontracheotomy control group B (38 cases) and test group B (36 cases). Test group patients sat up in bed on the 2nd day after surgery and performed off-bed activity on the 3rd day, whereas control group patients sat up in bed on the 4th day postoperatively and performed off-bed activity on the 6th day. Objective evaluation included free flap success rate, postoperative complications, sleep time, and catheter removal time, among other parameters. Subjective evaluation included postoperative pain and comfort evaluation. RESULTS: The success rate of free flaps was 97.3% in test group A and 100% in the other groups. In terms of mean sleep time, 4.6 ± 1.0 h in test group A, which was longer than 4.1 ± 1.0 h in control group A (P = 0.034); 5.7 ± 1.4 h in test group B, which was longer than 4.9 ± 1.7 h in control group B (P = 0.026). Early activity makes catheter removal time (tracheal incision, nasogastric tube, urethral catheter) shorter and gets higher comfort evaluation scores in both test groups versus control groups (P < 0.05). CONCLUSIONS: The early mobilization protocol for patients undergoing free flap reconstruction was safe, and can effectively improve sleep, shorten the catheter indwelling time, and increase the patient's comfort level.

Navigation Guidance During Free Flap Mandibular Reconstruction: A Cadaveric Trial.

Importance: Segmental mandibulectomy for tumors that distort the buccal surface of the mandible present a reconstructive challenge. Objective: To determine whether mandible alignment after navigation-guided mandible reconstruction is better than alignment after non-template-assisted freehand reconstruction and as good as template-assisted reconstruction in a cadaveric trial. Design, Setting, and Participants: A cadaveric trial using 10 specimens was conducted at a tertiary academic center. Fiducials were created on the ramus to compare alignment with each intervention. Segmental mandibulectomy was performed on each cadaver. Each cadaver underwent navigation-guided reconstruction, template-assisted reconstruction using a manually shaped plate, and non-template-assisted freehand reconstruction with plate contouring performed after mandibulectomy. The study was conducted from October 1, 2015, to January 1, 2016; data analysis was performed from February 1, 2016, to March 1, 2016. Interventions: Segmental mandibulectomy, navigation-guided reconstruction, template-assisted reconstruction using a manually shaped plate, and non-template-assisted freehand reconstruction. Main Outcomes and Measures: Ramus fiducial coordinates were recorded at baseline and after each intervention. Mandible dimensions were measured using cephalometric landmarks. Postintervention and baseline differences in ramus and mandible position were calculated. Results: Ramus alignment was not significantly different between navigation-guided and template-assisted reconstruction, differing by 0.54 mm (98.3% CI, -0.38 to 1.47 mm). Non-template-assisted freehand reconstruction was associated with a 3.14-mm difference in alignment compared with template-assisted reconstruction (98.3% CI, 1.09 to 5.19 mm). Navigation-guided alignment resulted in a 3.69-mm improvement in alignment compared with non-template-assisted freehand reconstruction (98.3% CI, 1.79 to 5.58 mm). There was some improvement in the gonion-gonion and lingula mandibulae-lingula mandibulae (Lm-Lm) alignment for navigation-assisted compared with non-template-assisted freehand reconstruction by 1.97 mm (98.3% CI, -0.65 to 4.58 mm) and 1.39 mm (98.3% CI, -0.17 to 2.95 mm), respectively. There was marginal evidence of better Lm-Lm alignment for navigation-guided than template-assisted reconstruction (0.44 mm; 98.3% CI, -0.06 to 0.95 mm). Conclusions and Relevance: Mandible alignment following navigation-guided reconstruction is similar to template-assisted reconstruction. Navigation-guided alignment is likely better than non-template-assisted freehand reconstruction, and navigation guidance offers a reliable technique for real-time adjustment when reconstructing complex surgical defects, such as tumors effacing the buccal cortex of the mandible.

Preliminary clinic study on computer assisted mandibular reconstruction: the positive role of surgical navigation technique.

BACKGROUND: The objectives of the present study were to investigate the reliability and outcomes of computer-assisted techniques in mandibular reconstruction with a fibula flap and verify whether the surgical navigation system was feasible in mandible reconstructive surgery. METHODS: Eight cases were enrolled in the computer assisted surgery (CAS) group and 14 cases in the traditional group. The shaping and fixation of the fibula grafts were guided by computer assisted techniques, which could be monitored with the BrainLAB surgical navigation system. The variation of mandible configuration was evaluated by CT measurement in the Mimics software, including the variation of length, width, height and gonial angle of the mandible. The 3D facial soft tissue alteration was also analyzed in 3D chromatogram by Geomagic software. RESULTS: All 22 fibula flaps survived. The mandibular configurations and facial contours had a better clinic result in the CAS group. The length, width, height and gonial angle of the reconstructive mandible were more similar to the original one. The Wilcoxon rank sum test analysis suggested significant differences in the measurements. The chromatographic analysis also visually showed superiority over the traditional group. CONCLUSIONS: The computer assisted surgical navigation method used in mandibular reconstruction is feasible and precise for clinical application. The contour of the reconstructed mandible and facial symmetry are improved with computer techniques.