OBJECTIVES: To investigate the clinical application of the digital-assisted reconstruction of the mandible and tumors with free fibula transplantation and immediate implantation via the intraoral approach. METHODS: Twelve patients with benign mandibular tumors were collected. Three-dimensional mandibular reconstruction was performed digitally before surgery to simulate mandibular tumor resection, fibula resection and reconstruction, and implant implantation. The intraoperative resection of the mandibular tumor was conducted through the intraoral approach under the guidance of a guide plate, and fibula resection, molding, reconstruction, and oral fixation were immediately performed. Implant implantation was performed during the second phase of implant surgery and denture restoration was performed 1-2 months after surgery. RESULTS: The types of mandibular defects were BrownⅠ (one case), Ⅰc (four cases), Ⅱ (one case), Ⅱc(three cases), and Ⅲ (three cases). The length of the fibular bone was 12-22 cm. The number of fibular molding amputations was as follows: two cases in two segments, six cases in three segments, three cases in four segments, and one case in five segments. All of these cases underwent folding fibular reconstruction of mandibular and alveolar bone defects. A total of 44 implants were implanted, and none failed after operation. CONCLUSIONS The intraoral approach is a reliable method for the resection of mandibular benign tumors, with few postoperative complications and the ability to position and fix accurately the reconstructed folded fibula under digital design. The immediate implantation of the transplanted fibula does not affect the blood supply and has a high success rate. It is an effective and reliable method for the resection and reconstruction of mandibular benign tumors.
Humans ; Fibula/transplantation* ; Mandibular Neoplasms/surgery* ; Mandibular Reconstruction/methods* ; Bone Transplantation/methods* ; Male ; Middle Aged ; Female ; Mandible/surgery* ; Adult ; Free Tissue Flaps ; Surgery, Computer-Assisted

The unilateral cleft lip repair surgery has undergone over a century of development, marked by achievements and difficulties. Although the development of the methods for cleft lip repair has passed the period of rapid advancement, there remains an urgent need in clinical practice to further improve these methods in order to enhance clinical outcomes. This article aims to improve cleft lip repair methods by analyzing and elaborating on various aspects, including the attributes of cleft lip repair, the shift in concepts of cleft lip repair, innovations in surgical techniques, technical improvements, and classifications and repair methods for correcting secondary deformities. The analysis is based on the author's research and experience.
Cleft Lip/surgery* ; Humans ; Plastic Surgery Procedures/methods* ; Surgical Flaps

OBJECTIVES: This retrospective study aimed to investigate factors influencing positional changes of the condyle and temporomandibular joint (TMJ) following mandibular defect reconstruction with bone flaps, and to evaluate the biomechanical impacts of flap reconstruction on condylar positioning, thereby providing evidence for optimizing surgical protocols and TMJ functional rehabilitation. METHODS: A retrospective study was conducted on 90 patients undergoing mandibular segmental resection with immediate bone flap reconstruction at Guizhou Medical University Affiliated Stomatological Hospital (June 2019 to May 2024). After strict screening, 50 cases with complete data were analyzed. Clinical parameters (defect size, location, reconstruction method) and craniofacial CT scans at four timepoints [preoperative (T0), 7-10 days (T1), 3 months (T2), and 6 months (T3) postoperatively] were collected. Mimics 20 software facilitated 3D reconstruction for measuring TMJ anterior/posterior/superior joint spaces (Kamelchuk method) and calculating condylar position via the Pullinger index [Ln (posterior/anterior space)]. Vitral and Krisjane methods quantified mandibular linear parameters (ramus length, condylar pole distances to the sagittal plane, angulation) and glenoid fossa morphology. Statistical analyses were performed using SPSS 21.0. RESULTS: Mandibular defect size and location were significant factors influencing postoperative condylar position changes (P<0.05). Compared to preoperative measurements, postoperative condylar anterior, posterior, and superior joint spaces were significantly increased (P<0.001). The most pronounced anterior condylar displacement occurred within 7-10 days postoperatively (P<0.05). In patients with condyle resection, postoperative joint space and angle changes were significant; in patients with condyle preservation, only superior and anterior joint space changes were statistically significant (P<0.05). Additionally, from T1 to T2, the changes in condylar medial-lateral distance, superior joint space, and anterior joint space were negatively correlated with the preoperative condylar position. Compared with preoperative,in the T0-T1 period, condylar medial-lateral distance, posterior joint space, and articular tubercle angle changes were significantly negatively correlated with time (P<0.05). Notably, the angle between the condylar long axis and the coronal axis showed a sustained negative trend from T1 to T3 (P<0.05). CONCLUSIONS Condylar position changes after mandibular defect repair with bone flap reconstruction are associated with the size and location of the defect. Additionally, adaptive remodeling of the temporomandibular joint (TMJ) joint space occurs postoperatively. The phenomenon of anterior displacement of the condyle in the early postoperative period (7-10 days) shows a trend of reduction with prolonged follow-up time, and further sample size research is needed.
Humans ; Retrospective Studies ; Temporomandibular Joint/surgery* ; Mandibular Condyle/surgery* ; Male ; Female ; Adult ; Middle Aged ; Mandibular Reconstruction/methods* ; Mandible/surgery* ; Surgical Flaps ; Tomography, X-Ray Computed ; Young Adult ; Biomechanical Phenomena ; Aged ; Adolescent ; Imaging, Three-Dimensional

OBJECTIVES: Color doppler flow imaging (CDFI) and cone-beam computed tomography (CBCT) were utilized to evaluate changes in mucosal vascular parameters and the osteogenic effects following guided bone regeneration (GBR) in the maxillary anterior region using trapezoidal or modified triangular flaps. METHODS: Patients undergoing single maxillary anterior dental implant surgery with GBR were randomly allocated into two groups: a trapezoidal flap group and a modified triangular flap group. After GBR surgery, the mucosal vascular parameters at the surgical site were assessed at various time intervals (preoperative, 2 h, 1 and 3 days, and 1, 2, and 4 weeks postoperative) using CDFI. In addition, the effects of bone augmentation were evaluated through the analysis of CBCT images obtained preoperatively, 2 h, and 6 months postoperative. RESULTS: The buccal mucosa in the edentulous area had a lower blood flow rate than the corresponding tooth in the same jaw, and the difference was statistically significant (P<0.001). The mucosal blood flow rate in the surgical area increased compared with that in the preoperative period. The peak flow rate was recorded at 2 weeks postoperatively and then decreased to levels comparable to those of the reference tooth. A statistically significant difference was observed between the two groups (P<0.05). The buccal alveolar ridge width of the implant platform was reduced by (1.3±0.9) mm in the trapezoidal flap group and (0.9±0.7) mm in the modified triangular flap group, respectively, at 6 months postoperatively, compared with 2 h postoperative. The buccal alveolar ridge width of the 5 mm from the implant platform was reduced by (0.9±0.6) mm and (0.3±0.6) mm, respectively. The buccal alveolar ridge width of the 10 mm from the implant platform was reduced by (0.6±0.8) mm and (0.2±0.6) mm, respectively. The height of the alveolar ridge was reduced by (1.9±1.4 ) mm and (1.4±1.3) mm. The change in graft volume was (136±78 ) mm³ and (114±85) mm³. However, the differences between the two groups were not statistically significant (P>0.05). CONCLUSIONS When a tooth is missing, blood flow to the buccal mucosa on the side of the missing tooth is reduced. The modified triangular flap group demonstrated superior microcirculation of blood flow in the operative area after GBR of the maxillary anterior teeth. Trapezoidal and modified triangular flaps achieved the anticipated bone augmentation during bone augmentation surgery in the maxillary anterior region, with no considerable effect on the changes in alveolar bone size parameters.
Humans ; Surgical Flaps/blood supply* ; Bone Regeneration ; Mouth Mucosa/blood supply* ; Cone-Beam Computed Tomography ; Osteogenesis ; Maxilla/surgery* ; Male ; Female ; Guided Tissue Regeneration, Periodontal/methods*

BACKGROUND AND OBJECTIVES

Mouth retractors are essential in ensuring efficient yet safe exposure of the oral cavity and oropharynx. However, when applied improperly or haphazardly, retractors can cause tissue injuries and compromise patient safety. In addition, there are gaps in the usability of existing designs. This study aimed to identify the issues encountered by otorhinolaryngology surgeons in the use of commercially available mouth retractors, design and fabricate an improved retractor, and explore the use of additive manufacturing (popularly known as 3D printing) for retractor prototyping.

The study used the United States Food and Drug Administration (US FDA) Design Control as its framework. End-user requirements from otorhinolaryngologists were collected through key informant interviews. Results were organized into a Design Input template which was used to guide the design and development process. Prototype designs were iteratively created using computer-aided design software and 3D printing. Once design specifications were satisfied, a beta prototype was fabricated and given to another cohort of otorhinolaryngologists. The participants assessed the usability of the beta prototype. System Usability Scale (SUS) was used to quantify participant's feedback.

Five designs were created in the course of the study. The final prototype was fabricated using a Stereolithography (SLA) 3D printer. Several features were developed to address user requirements. The primary modification was to make the retractor modular to facilitate easier and shorter mounting and assembly. Gingival injury was addressed with the replacement of the maxillary alveolus hook with support bars. Five participants evaluated the beta prototype which received a mean SUS score of 75, well above the 50th percentile threshold.

This study demonstrates the applicability of the US FDA Design Control Process in the local setting to improve the mouth retractor design. Clinical and ergonomic issues were identified and design solutions were proposed and some have been implemented in a low-fidelity prototype. Results of the small-scale usability test suggest that the present form factor can be the basis for further iterations. Future studies can implement the proposed features to address other clinical and ergonomic needs.

Prosthesis loosening is the leading cause of postoperative revision in unicompartmental knee arthroplasty (UKA). The deviation of medial and lateral translational installation of the prosthesis during surgery is a common clinical phenomenon and an important factor in increasing the risk of prosthesis loosening. This study established a UKA finite element model and a bone-prosthesis fixation interface micromotion prediction model. The predicted medial contact force and joint motion of the knee joint from a patient-specific lower extremity musculoskeletal multibody dynamics model of UKA were used as boundary conditions. The effects of 9 femoral component medial and lateral translational installation deviations on the Von Mises stress of the proximal tibia, the contact stress, and the micro-motion of the bone prosthesis fixation interface were quantitatively studied. It was found that compared with the neutral position (a/A of 0.492), the lateral translational deviation of the femoral component significantly increased the tibial Von Mises stress and the bone-prosthesis fixation interface contact stress. The maximum Von Mises stress and the maximum contact stress of the fixation interface increased by 14.08% and 143.15%, respectively, when a/A was 0.361. The medial translational deviation of the femoral component significantly increased the bone-prosthesis fixation interface micro-motion. The maximum value of micromotion under the conditions of femoral neutral and medial translation deviation was in the range of 20-50 μm, which is suitable for osseointegration. Therefore, based on considerations such as the micromotion range suitable for osseointegration reported in the literature, the risk of reducing prosthesis loosening, and factors that may induce pain, it is recommended that clinicians control the mounting position of the femoral component during surgery within the safe range of 0-4 mm medial translation deviation.
Humans ; Arthroplasty, Replacement, Knee/methods* ; Finite Element Analysis ; Biomechanical Phenomena ; Knee Prosthesis ; Tibia/surgery* ; Femur/surgery* ; Stress, Mechanical ; Prosthesis Failure ; Knee Joint/surgery* ; Prosthesis Design

Although metal blocks have been widely used for reconstructing uncontained tibial bone defects, the influence of their elastic modulus on the stability of tibial prosthesis fixation remains unclear. Based on this, a finite element model incorporating constrained condylar knee (CCK) prosthesis, tibia, and metal block was established. Considering the influence of the post-restraint structure of the prosthesis, the effects of variations in the elastic modulus of the block on the von Mises stress distribution in the tibia and the block, as well as on the micromotion at the bone-prosthesis fixation interface, were investigated. Results demonstrated that collision between the insert post and femoral prosthesis during tibial internal rotation increased tibial von Mises stress, significantly influencing the prediction of block elastic modulus variation. A decrease in the elastic modulus of the metal block resulted in increased von Mises stress in the proximal tibia, significantly reduced von Mises stress in the distal tibia, decreased von Mises stress of the block, and increased micromotion at the bone-prosthesis fixation interface. When the elastic modulus of the metal block fell below that of bone cement, inadequate block support substantially increased the risk of stress shielding in the distal tibia and fixation interface loosening. Therefore, this study recommends that biomechanical investigations of CCK prostheses must consider the post-constraint effect, and the elastic modulus of metal blocks for bone reconstruction should not be lower than 3 600 MPa.
Knee Prosthesis ; Humans ; Finite Element Analysis ; Tibia/surgery* ; Elastic Modulus ; Arthroplasty, Replacement, Knee/methods* ; Stress, Mechanical ; Metals ; Prosthesis Design ; Knee Joint/surgery* ; Biomechanical Phenomena

OBJECTIVE: To investigate the effectiveness of posterior lateral perforator flap in lower limb combined with free fibula for maxillary tissue defect repair. METHODS: Between December 2018 and December 2023, 16 patients with the maxillary malignant tumors were admitted. There were 10 males and 6 females, with an average age of 64.3 years (range, 54-75 years). There were 7 cases of maxillary gingival cancer, 5 cases of hard palate cancer, and 4 cases of maxillary sinus cancer. According to the 2017 American Joint Committee on Cancer (AJCC) TNM stage, there were 8 cases of stage Ⅲ, 6 cases of stage Ⅳa, and 2 cases of stage Ⅳb. After resection of the lesion, the remaining maxillary defects were classified into class Ⅱa in 3 cases, class Ⅱb in 5 cases, and class Ⅲb in 8 cases according to Brown's classification. The size of soft tissue defects ranged from 4 cm×3 cm to 8 cm×6 cm. The posterior lateral perforator flap in lower limb in size of 5 cm×4 cm-9 cm×7 cm were harvested to repair soft tissue defects, and free fibula in length of 6-11 cm were used to repair bone defects. The donor sites of the lower limb were sutured directly (6 cases) or repaired with free skin grafting (10 cases). Six patients with positive lymph node pathology were treated with radiotherapy after operation. At 6 and 12 months after operation, the self-assessment was performed by the University of Washington Quality of Survival Questionnaire Form (QUW-4) in five dimensions (facial appearance, swallowing function, chewing function, speech function, and mouth opening), and swallowing function was evaluated by using the Kubota water swallowing test. RESULTS: Postoperative pathological examination showed that all patients were squamous cell carcinoma. One patient who was treated with radiotherapy developed osteomyelitis and 1 patient developed venous crisis of skin flap. The rest of the flaps and all skin grafts survived, and the wounds healed by first intention. All patients were followed up 1-5 years (mean, 2.8 years). Two patients died of local recurrence of the tumor at the 4th and 5th years after operation, respectively. Except for the chewing function score and total score at 6 months after operation, which showed significant differences compared to preoperative scores ( P<0.05), there was no significant difference in other QUW-4 scale scores between different time points ( P>0.05). The patients' swallowing function evaluated by Kubota water swallowing test reached normal in 4 cases, suspicious in 9 cases, and abnormal in 3 cases at 6 months after operation, and 10, 6, and 0 cases at 12 months after operation, respectively. The swallowing function at 12 months was significantly better than that at 6 months ( Z=-2.382, P=0.017). CONCLUSION The posterior lateral perforator flap in the lower limb combined with free fibula to repair maxillary tissue defects can repair soft and hard tissue defects at the same time, so that the patient's facial appearance, swallowing function, chewing function, speech function, and mouth opening are satisfactorily restored and the mid-term effectiveness is good.
Humans ; Middle Aged ; Male ; Female ; Fibula/surgery* ; Aged ; Perforator Flap ; Plastic Surgery Procedures/methods* ; Maxilla/surgery* ; Maxillary Neoplasms/surgery* ; Free Tissue Flaps/transplantation* ; Lower Extremity/surgery* ; Bone Transplantation/methods* ; Treatment Outcome

OBJECTIVE: To investigate the effectiveness of digital three-dimensional (3D) printing osteotomy guide plate assisted total knee arthroplasty (TKA) in treatment of knee osteoarthritis (KOA) patients with femoral internal implants. METHODS: The clinical data of 55 KOA patients who met the selection criteria between July 2021 and October 2023 were retrospectively analyzed. Among them, 26 cases combined with femoral implants were treated with digital 3D printing osteotomy guide plate assisted TKA (guide plate group), and 29 cases were treated with conventional TKA (control group). There was no significant difference in gender, age, body mass index, side, Kellgren-Lawrence classification, preoperative visual analogue scale (VAS) score, Hospital for Special Surgery (HSS) knee score, knee range of motion, and other baseline data between the two groups ( P>0.05). The operation time, intraoperative blood loss, incision length, postoperative first ambulation time, surgical complications; VAS score, knee HSS score, knee range of motion before operation, at 1 week and 3 months after operation, and at last follow-up; distal femoral lateral angle, proximal tibial medial angle, hip-knee-ankle angle and other imaging indicators at last follow-up were recorded and compared between the two groups. RESULTS: The operation time, incision length, intraoperative blood loss, and postoperative first ambulation time in the guide plate group were significantly lower than those in the control group ( P<0.05). In the control group, there were 1 case of incision rupture and bleeding and 1 case of lower limb intermuscular venous thrombosis, which was cured after symptomatic treatment. There was no complication such as neurovascular injury, incision infection, or knee prosthesis loosening in both groups. Patients in both groups were followed up 12-26 months, with an average of 16.25 months. The VAS score, HSS score, and knee range of motion improved at each time point after operation in both groups, and further improved with time after operation, the differences were significant ( P<0.05). The above indicators in the guide plate group were significantly better than those in the control group at 1 week and 3 months after operation ( P<0.05), and there was no significant difference between the two groups at last follow-up ( P>0.05). At last follow-up, the distal femoral lateral angle, the proximal tibial medial angle, and the hip-knee-ankle angle in the guide plate group were significantly better than those in the control group ( P<0.05). CONCLUSION The application of digital 3D printing osteotomy guide plate assisted TKA in the treatment of KOA patients with femoral implants can simplify the surgical procedures, overcome limitations of conventional osteotomy guides, reduce surgical trauma, achieve individualized and precise osteotomy, and effectively restore lower limb alignment and knee joint function.
Humans ; Arthroplasty, Replacement, Knee/instrumentation* ; Osteoarthritis, Knee/surgery* ; Osteotomy/instrumentation* ; Male ; Retrospective Studies ; Female ; Printing, Three-Dimensional ; Femur/surgery* ; Middle Aged ; Bone Plates ; Range of Motion, Articular ; Aged ; Treatment Outcome ; Surgery, Computer-Assisted/methods* ; Knee Prosthesis ; Knee Joint/surgery* ; Operative Time

OBJECTIVE: To explore the feasibility of reconstruction of phonatory function by using a tubular free flap from upper-lateral upper arm to repair the laryngotracheal circumferential defect after near-total laryngectomy for laryngeal cancer. METHODS: A retrospective study was conducted on 7 patients who underwent near-total laryngectomy between June 2021 and October 2023, aged from 48 to 70 years (median, 59 years), 6 males and 1 female. The disease duration ranged from 1 to 11 months, with a median of 6 months. Pathological diagnosis of preoperative biopsy was squamous cell carcinoma. Tumor classification: glottic type in 5 cases, supraglottic type in 1 case, transglottic type in 1 case; TNM staging: T ₄N ₀M ₀ in 6 cases, T ₄N ₂M ₀ in 1 case; American Joint Committee on Cancer (AJCC) staging in 2017 was stage Ⅳ. Preoperative MRI angiography of upper arm was performed to investigate the blood supply in the upper and lateral regions of the upper arm. After near-total laryngectomy and bilateral neck lymph node dissection, the area of the laryngotracheal defect was measured. A free flap measuring 7.0 cm×5.0 cm to 8.0 cm×7.0 cm was harvested from the upper-lateral upper arm, rolled into a tube shape, and connected between the stump of the cervical trachea in the neck root and that of the epiglottis at the tongue base. Four patients received adjuvant radiochemotherapy, 1 patient received radiochemotherapy and targeted therapy, 2 patients adopted no further adjuvant treatment. RESULTS: All 7 patients were followed-up 1-2 years (mean, 1 year and 3 months). Four patients had primary wound healing, 2 patients had minor pharyngeal fistulas that healed after dressing change, 1 patient experienced pharyngeal fistula because of flap necrosis and the wound still healed without secondary surgery. All patients took food orally within 1 month after operation, and the tracheal cannula was retained. Six patients with survived flap gradually adapted to their new pronunciation mode and obtained satisfactory phonatory function from 15 days to 2 months after operation. Four patients had slight aspiration after operation. Till the end of the follow-up, all patients survived and no local recurrence or distant metastasis had been observed. The motor function of the upper arm was not affected, only partial sensory loss occurred in the area near the incision. The scar of the incision could be covered by the short sleeve so as to obtain a better aesthetic effect. CONCLUSION Using a tubular free flap from upper-lateral upper arm to repair the laryngotracheal circumferential defect after near-total laryngectomy for laryngeal cancer can achieve satisfactory phonatory restoration while preserve the motor function and aesthetics of the donor site.
Humans ; Laryngectomy/methods* ; Male ; Middle Aged ; Female ; Laryngeal Neoplasms/surgery* ; Aged ; Free Tissue Flaps ; Retrospective Studies ; Plastic Surgery Procedures/methods* ; Carcinoma, Squamous Cell/surgery* ; Phonation ; Arm/surgery* ; Neck Dissection