Maxillary Sinus Augmentation and Implant Installation in Patients With Pseudocysts and Mucous Retention Cysts.

This case study systematically assessed diverse approaches to sinus augmentation in the presence of sinus pathology. Three patients were carefully selected and categorized as pseudocyst (PsC) (type 1), mucous retention cyst (MRC) smaller than 20 mm (type 2), and MRC larger than 20 mm in size (type 3). All patients underwent sinus augmentation procedures, with each case utilizing a unique surgical approach. Spontaneous drainage was performed for the patient with PsC (type 1), followed by uncomplicated sinus augmentation. For the patient with an MRC smaller than 20 mm (type 2), aspiration of the cyst contents preceded sinus augmentation. Conversely, the patient with a larger MRC (type 3) underwent cyst enucleation followed by sinus augmentation after complete recovery of the sinus membrane. No complications were noted in any of the cases, and follow-up revealed stable implant installation at the site of sinus augmentation. Within the constraints of this study, the choice of surgical procedure, whether involving spontaneous drainage, aspiration, or enucleation, should be guided by an anticipated pathologic diagnosis and the size of the sinus cyst. This informed approach empowers clinicians to make well-informed decisions for the best possible outcomes and sustained results. Overall, this study offers valuable insights for clinicians seeking to optimize sinus augmentation procedures in the presence of sinus pathology.

Three-Dimensional Analysis of Bone Remodeling After Closed Treatment for Mandibular Condylar Head Fracture.

Closed treatment of mandibular condylar fractures has been used for its indications based on the fracture site, fracture status, and patient age. Posttreatment mandibular condyle size is associated with mandibular function; however, a few studies have reported bone remodeling patterns and volume changes in the condyle and glenoid fossa after mandibular condylar head fractures (CHFs). Therefore, volumetric changes in the mandibular condyle and glenoid fossa were analyzed in the present study, and bone remodeling patterns were evaluated after mandibular CHFs. The present study included 16 condyles from 12 patients who received closed treatment for CHF. After reconstruction of a 3-dimensional skull model, including the mandible, using computed tomography data taken immediately after injury and 6 months after treatment, volume changes in the mandibular condyle and glenoid fossa were analyzed. The condylar volume increased by 0.32±0.66 cm3 during the 6-month healing period without statistical significance (P=0.093). Regarding the glenoid fossa, the fossa showed a statistically significant volume increase of 0.41±0.59 cm3 (P=0.021), and 12 glenoid fossae (75%) showed downward bone apposition; however, no change or only mild bone resorption was observed in 4 glenoid fossae (25%). The results of this study indicated that the volume changes in the mandibular condyle after closed treatment of a mandibular CHF are not significant, and the glenoid fossa adapts to the displaced mandibular condyle through downward growth accompanied by volume increase.

Metastasis of Renal Cell Carcinoma to the Mandible.

Renal cell carcinoma (RCC) is the most common tumor of the kidney. Although RCC often metastasizes to other organs, metastasis to the head and neck region is rare, and metastasis to the mandible is very unusual. Given the fact that metastasis of primary neoplasms is not always predictable, it is essential to rule out metastatic carcinoma in jaw lesions. We herein report a rare presentation of metastasis of RCC to the mandible, in which the metastatic lesion in the oral cavity was found first, followed by the primary lesion, in a 22-year-old girl who suffered from pain in the left temporomandibular joint on mouth opening and hypoesthesia of the left chin, left lower lip, and left lower gum.

Tapered, Sand-Blasted, Large-Grit, and Acid-Etched Surfaced Internal Dental Implant in the Diverse Pathologic Jaw.

PURPOSE: The treatment of pathologic lesions in jaws either through conservative or radical approaches, frequently leads to a loss of teeth. As a result, patients will experience diminished masticatory and phonetic function as well as esthetic deficits. In this manuscript, we report multiple cases of successful implant rehabilitation after the conservative treatment of pathologic lesions in jaws utilizing allogeneic bone grafts and the installation of implant fixtures. MATERIALS AND METHODS: In this study, we examined 8 patients with 8 different kinds of pathologic lesions in their jaws, who were treated with a conservative approach and rehabilitated with bone grafts and implant installations using internal dental implant type with tapered, sand-blasted, large-grit, acid-etched surfaces. Marginal bone loss was analyzed through radiograms, and the implant survival rates and graft outcome evaluations were recorded. RESULTS: No significant difference was found in the mean marginal bone loss throughout the follow-up period. The survival rate of the implant and the success rate of graft were recorded as 100%. CONCLUSIONS: The results of this study suggest that conservative surgical management for pathologic lesions based on the understanding of the pathologies can be helpful for successful oral rehabilitation. In bone grafting, it is necessary to determine an appropriate timing and method considering the risk of recurrence and the vascularity of the recipient site. For subsequent implant placement, selecting an implant system suitable for the site of placement and placing it within 3 to 6 months after bone grafting can help the long-term maintenance of the grafted bone and dental implant.

Accurate Mandible Reconstruction by Mixed Reality, 3D Printing, and Robotic-Assisted Navigation Integration.

ABSTRACT: Mandibular reconstruction is one of the most complex procedures concerning the patient's postoperative facial shape and occlusion condition. In this study, the authors integrated mixed reality, three-dimensional (3D) printing, and robotic-assisted navigation technology to complete the mandibular reconstruction in a novel and more accurate way. Mixed reality can visualize the significant anatomical structures of the operative area, but only be used in simulated operation by now. Three-dimensional printing surgical guide plate makes it easy to separate tissue, while imprecision often occurs due to the potential of displacement and deformation. In recent years, most robotic-assisted navigation surgery technology can only achieve precise position by 2D view on the screen but not realistic 3D navigation. in this study, the integrated 3 technologies were used in mandibular reconstruction. Preoperative imaging examination was performed, and the data were imported into the digital workstation before operation. First, the original data was edited and optimized to reconstruct the digital model and formulate the surgical plan. Then MR was used to output the visualized project and matched the 3D reconstruction model in reality. The 3D plate was printed for surgical guidance. Last, robotic-assisted navigation was used to guide and position the vascularized fibula autograft and the immediate dental implantation. In conclusion, the authors integrated the 3 technologies and constructed a new digital surgical procedure to improve surgical accuracy and simplify the procedure comparing with traditional surgery.

Anatomical Characteristics of the Accessory Maxillary Ostium in Three-Dimensional Analysis.

Background and Objectives: The accessory maxillary ostium (AMO) can interfere with ventilation and drainage of the maxillary sinus, and therefore the importance of evaluating the anatomical features of the AMO has been emphasized. This study aimed to evaluate anatomical characteristics of the AMO together with the natural ostium (NO) using three-dimensional (3D) analysis and to assess the relationship between the AMO and maxillary sinus pathologies. Materials and Methods: This retrospective study included 394 sinuses in 197 patients. Using 3D computed tomography images, the prevalence of the AMO and concurrent sinus pathologies were examined. For patients with an AMO, 3D spatial positions of the AMO and NO related to adjacent anatomic structures and dimensions of the AMO and NO were evaluated. Results: A total of 84 sinuses showed single or multiple AMO, with a prevalence of 21.3%. The AMO was located superiorly by 30.1 mm from the maxillary sinus floor, inferiorly by 1.3 mm from the orbital floor, and posteriorly by 22.4 mm from the anterior sinus wall. The AMO was located 5.4 mm posteriorly and 0.7 mm inferiorly from the NO. On the same coronal plane as the NO or AMO, height from the maxillary sinus floor to the NO and AMO ranged from 19.4 to 45.8 mm and 14.5 mm to 41.9 mm, respectively. The mean horizontal and vertical dimensions were 5.9 mm and 4.6 mm for the NO and 2.8 mm and 3.0 mm for the AMO. We detected a significant association between the presence of the AMO and the mucosal thickening (p = 0.029). Conclusions: The results of this study suggest that, although the AMO and NO are mostly located in positions that do not limit sinus-related surgeries, such as maxillary sinus floor augmentation, the AMO and NO are also found in lower positions, which may be a detriment to the postoperative physiological function of the maxillary sinus and affect treatment outcomes.

Effect of Bone Buttressing at the Vertical Osteotomy Site on Postoperative Stability After Mandibular Setback Surgery.

ABSTRACT: This study aimed to assess the effect of bone buttressing at the vertical osteotomy site on postoperative stability after mandibular setback surgery and determine factors contributing to postoperative relapse. This retrospective study was conducted on patients who received mandibular setback surgery using bilateral sagittal split ramus osteotomy. Patients were divided into two groups: group I, intimate bony contact, and group II, bony gap of 2 mm or more. Using lateral cephalograms taken before surgery, 1 week after surgery, and 6 months after surgery, surgical changes, and postoperative relapse were compared between 2 groups. To assess associations between postoperative relapse and other variables, Pearson correlation analysis and multiple linear regression analysis were performed. Twenty-eight patients were evaluated (17 in group I and 11 in group II). Mean relapse was greater in group II (1.8 mm) than in group I (1.2 mm), although there were no significant differences between 2 groups (P = 0.203). Postoperative relapse was significantly associated with intraoperative clockwise rotation of the proximal segment (P < 0.001) and the amount of mandibular setback (P = 0.038). Bony gap was only correlated with postoperative counterclockwise rotation of the proximal segment (P = 0.014). In the regression analysis, intraoperative clockwise rotation of the proximal segment significantly predicted postoperative relapse (P < 0.001, R2 = 0.388). The absence of bone buttressing at the vertical osteotomy site may not significantly affect postoperative stability after mandibular setback surgery, and it is important to minimize intraoperative clockwise rotation of the proximal segment for better postoperative stability.

Evaluation of Bone Remodeling After Simultaneous Sagittal Split Ramus Osteotomy and Mandibular Angle Ostectomy in Patients With Mandibular Prognathism.

PURPOSE: The present study assessed the postoperative bone remodeling after simultaneous sagittal split ramus osteotomy (SSRO) and mandibular angle ostectomy using a 3-dimensional analysis of computed tomography (CT) data. MATERIALS AND METHODS: We designed and implemented a retrospective study that included patients who had undergone SSRO with (study group) or without (control group) mandibular angle ostectomy. Using CT data taken immediately after (T1) and 6 months (T2) after surgery, the vertical and horizontal morphologic changes of the mandibular angle were evaluated and compared between the 2 groups. In the study group, the volumetric changes of the mandibular angle were assessed, and the bone regeneration rate was calculated. RESULTS: A total of 58 mandibular angles were evaluated (32 in the study group and 26 in the control group). The study group exhibited significantly greater vertical bone regrowth at the middle and posterior regions of the mandibular angle ostectomy line compared with that in the control group (middle, P < .001; posterior, P < .001). Both groups showed significant horizontal bone regrowth at 6 months postoperatively (P < .01). In the study group, the postoperative vertical bone regrowth was significantly associated with the extent of exposed bone below the angle ostectomy line at T1 for all regions (P < .001). The percentage of postoperative regenerated bone volume relative to the volume of bone removed intraoperatively was 41.8%. CONCLUSIONS: The present findings suggest that significant bone regrowth could occur after mandibular angle ostectomy with simultaneous SSRO. Therefore, it is necessary to consider bone remodeling patterns in the treatment planning stage for better and more predictable surgical outcomes.

Evaluation of Postoperative Mandibular Positional Changes After Mandibular Setback Surgery in a Surgery-First Approach: Isolated Mandibular Surgery Versus Bimaxillary Surgery.

PURPOSE: The aim of this study was to compare postoperative positional changes in the mandible after isolated mandibular surgery (IMS) or bimaxillary surgery (BMS) in a surgery-first approach (SFA). MATERIALS AND METHODS: The authors designed and implemented a retrospective cohort study composed of patients who underwent mandibular setback surgery using the SFA. Surgical and postoperative changes were evaluated using lateral cephalograms taken 1 month before surgery (T0), 1 week after surgery (T1), and immediately after debonding of orthodontic appliances (T2; 16.6 ± 8.7 months after surgery). To predict postoperative mandibular positional changes from the increase in vertical dimension (VD) in surgical occlusion, the mandible was rotated counterclockwise to the preoperative VD on the lateral cephalogram at T1, and resultant mandibular positional changes were measured. To evaluate actual postoperative mandibular positional changes between each time point and compare them between the 2 groups, independent t test, paired t test, and repeated-measures analysis of variance were performed. RESULTS: Thirty patients were evaluated (16 in IMS group and 14 in BMS group). The 2 groups showed significant time-course mandibular positional changes from T0 to T1 and from T1 to T2 within each group (point B, P < .001), although no statistically significant differences were observed between groups. There was no statistically relevant difference between groups in the predicted and actual postoperative rotational movements. In addition to the mandibular forward movement that resulted from postoperative mandibular counterclockwise rotation, additional horizontal relapse occurred. CONCLUSION: The present findings suggest that the mandible exhibits notable postoperative forward movement during postoperative orthodontic treatment, regardless of the extent of the orthognathic surgery in the SFA, and it is necessary to consider mandibular forward movement from the VD increase in surgical occlusion and additional relapse during the treatment planning stage.

Maxillary Expansion and Mandibular Setback Surgery With and Without Mandibular Anterior Segment Osteotomy to Correct Mandibular Prognathism With Obstructive Sleep Apnea.

Mandibular prognathism is usually treated with mandibular setback surgery. However, this approach reduces the pharyngeal airway space, and can aggravate obstructive phenomena in patients with obstructive sleep apnea (OSA). While maxillary expansion is known to lead to an increase in the pharyngeal airway volume (PAS), its effect on the PAS in mandibular setback surgery has not yet been reported. The authors report a surgical approach with maxillary expansion in 2 patients with mandibular prognathism that was accompanied by OSA: maxillary midsagittal expansion with minimum maxillary advancement and minor mandibular setback without mandibular anterior segmental osteotomy (ASO) or major mandibular setback with mandibular ASO. Preoperative and postoperative computed tomography and polysomnography indicated that OSA was improved and pharyngeal airway space was increased or sustained, and the prognathic profile could be corrected to an acceptable facial esthetic profile. In summary, maxillary transversal expansion and mandibular setback with or without mandibular ASO can be successfully applied to treat mandibular prognathism with OSA.