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.

Can Fracture Reduction be Attempted Through a 3D-Printed Guide Template Without Maxillomandibular Fixation?

BACKGROUND: Computer-aided design and manufacturing (CAD/CAM) is widely used in clinical practice. This technology may change existing methods for mandibular fracture management. PURPOSE: The purpose of this in-vitro study was to determine if the reduction for mandibular symphysis fracture can be performed without maxillomandibular fixation (MMF) using 3-dimensional (3D)-printed template. STUDY DESIGN, SETTING, AND SAMPLE: This in-vitro study was designed as a proof-of-concept. The sample was composed of 20 existing pairs of intraoral scan and computed tomography (CT) data. A mandibular model stereolithography (STL) file was created by merging the STL file obtained for the bimaxillary dentitions with the CT DICOM file, and this was set as the original model. Using the original model, a STL file of a fracture model of the mandibular symphysis was created using CAD. A template similar to a wafer or an implant guide was manufactured to restore original occlusion, and the mandibular fracture model was reduced and fixed using the 3D-printed template and wire. This was set as the experimental group. The 3D coordinate system error was measured at 6 landmarks and statistically compared using scan data between models of the groups. PREDICTOR/EXPOSURE/INDEPENDENT VARIABLES: Reduction techniques with MMF or without MMF using guide template for mandibular fracture model. MAIN OUTCOME VARIABLE(S): The 3D coordinate system error (mm). COVARIATES: The position of landmarks. ANALYSES: The Mann-Whitney U test, student's t-test, and the Kruskal-Wallis test were used to analyze the coordinate errors between the landmarks. A P value of < .05 was considered statistically significant. RESULTS: The 3D error value of the control and experimental group were 1.06 ± 0.63 mm (range: 0.11 to 2.92 mm) and 0.96 ± 0.48 mm (range: 0.2 to 2.95 mm), respectively. There was no statistical difference between the control and experimental group. There was a statistically significant difference in the lower 2 and lower 3 landmarks compared to the upper 1 (P = .001 and .000, respectively) before and after the reduction in the experimental group. CONCLUSION AND RELEVANCE: This study demonstrates that the reduction using a 3D-printed guide template for the mandibular symphysis fracture could be possible even without the MMF.

Periodontal ligament preloading and rapid prototyping of the donor tooth in the autotransplantation of premolars with complete root formation.

This case report describes the successful orthodontic treatment of an 11-year-old girl with skeletal Class II malocclusion and congenitally missing mandibular second premolars. To resolve her upper lip protrusion and restore the missing mandibular premolars, extraction of the maxillary first premolars and subsequent autotransplantation of the extracted premolars onto the site of the missing mandibular second premolars were performed. To ensure the success of the autotransplantation and subsequent orthodontic treatment, an orthodontic force was preapplied on the donor teeth, and the recipient sockets were prepared with the aid of replica teeth. Thereafter, comprehensive orthodontic treatment was performed to close the extraction space in the maxilla and align the mandibular dentition, including the transplants. The patient achieved a functional occlusion with an improved facial profile. Results of the orthodontic treatment and autotransplantation were stable during the 5-year follow-up. On the basis of this report, a management protocol for a biomechanically enhanced autotransplantation procedure was suggested. This approach would enable an effective treatment procedure, thereby increasing the usefulness of autotransplantation.

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.

Changes of visualised Eustachian tube lengths by age and position: Radiologic study in sitting and supine positions using cone beam and conventional CT.

OBJECTIVES: Patulous eustachian tube (ET) has been characterised by the visualisation of full-length ET on computed tomography (CT) results. We wanted to investigate the changes of visualised ET lengths by age in supine and sitting positions. DESIGN: Retrospective study. SETTING: Tertiary care academic referral centre. PARTICIPANTS: One hundred subjects who underwent cone beam CT (CBCT) in a sitting position and conventional CT in a supine position for non-otitis-related or dental complaints. MAIN OUTCOME MEASURES: Visualised ET lengths from the nasopharyngeal orifice measured by different positions and ages. RESULTS: Subjects did not show visualisation of full-length ET throughout the study. The visualised ET lengths (9.0 ± 2.5 mm) of the CBCT group were significantly larger than those (6.8 ± 2.3 mm) of the conventional CT group (P < 0.0001).Women showed longer visualised ET lengths than men in CBCT group (P < 0.001). The visualised ET lengths of the CBCT group were consistent or slightly increasing as a function of age (P = 0.06); however, the visualised ET lengths of the conventional CT group decreased as a function of age (P = 0.001). The slopes of regression lines of the two groups were significantly different. CONCLUSIONS: When in the supine position, the ET lengths gradually shortened as the subjects got older, most likely due to venous engorgement and the collapse of surrounding tissues; this finding thus suggests that CT in a supine position is an inappropriate method to diagnose patulous ET. The visualised ET lengths by CBCT in a sitting position were consistent throughout the different ages of the subjects and may be used as a diagnostic test for patulous ET.

Transnasal Placement of a Balloon-Expandable Metallic Stent: Human Cadaver Study of the Eustachian Tube.

PURPOSE: To investigate the technical feasibility of stent placement in the cartilaginous portion of the Eustachian tube (ET). MATERIALS AND METHODS: Twelve ETs of 6 cadavers were used. Two different-sized stents were placed on either the right (2.5 mm in diameter) or left (3.5 mm in diameter) side of the ET. The procedural feasibility was assessed by subtraction Eustachian tubography, computed tomography before and after the procedure, and fluoroscopic and endoscopic images. The stent location, inner luminal diameter of the stented ET, radiation dose, procedural time, and fluoroscopy time were analyzed. RESULTS: Stent placement was successful in 11 of 12 cadaveric specimens without procedure-related complications. In the 1 specimen, the balloon catheter with crimped stent was passed into the bony canal of the ET without any resistance. The distal end of the stent was located in the middle ear cavity. Stents were located within the cartilaginous portion of the ET (n = 1), the proximal tip bridging the nasopharyngeal orifice of the ET (n = 5), or the proximal end of the stent protruded from the tubal orifice (n = 5). The mean luminal diameter in the outer segment was significantly smaller than in the middle (P < .001) and inner (P < .001) segments. The mean procedure time was 128 ± 37 seconds. The mean radiation dose and fluoroscopy time of each cadaver were 3235.4 ± 864.8 cGy/cm2 and 139 ± 49 seconds, respectively. CONCLUSIONS: Stent placement of the ET under endoscopic and fluoroscopic guidance is technically feasible in a human cadaver model.

Factors Influencing Perception of Facial Attractiveness: Gender and Dental Education.

PURPOSE: This study was conducted to investigate the gender- and dental education-specific differences in perception of facial attractiveness for varying ratio of lower face contour. METHODS: Two hundred eleven students (110 male respondents and 110 female respondents; aged between 20-38 years old) were requested to rate facial figures with alterations to the bigonial width and the vertical length of the lower face. We produced a standard figure which is based on the "golden ratio" and 4 additional series of figures with either horizontal or vertical alterations to the contour of lower face. The preference for each figure was evaluated using a Visual Analog Scale. The Kruskal Wallis test was used for differences in the preferences for each figure and the Mann-Whitney U test was used to evaluate gender-specific differences and differences by dental education. RESULTS: In general, the highest preference score was indicated for the standard figure, whereas facial figure with large bigonial width and chin length had the lowest score.Male respondents showed significantly higher preference score for facial contour that had a 0.1 proportional increase in the facial height-bigonial width ratio over that of the standard figure.For horizontal alterations to the facial profiles, there were no significant differences in the preferences by the level of dental education. For vertically altered images, the average Visual Analog Scale was significantly lower among the dentally-educated for facial image that had a proportional 0.22 and 0.42 increase in the ratio between the vertical length of the chin and the lip. CONCLUSION: Generally, the standard image based on the golden ratio was the most. Slender face was appealed more to males than to females, and facial image with an increased lower facial height were perceived to be much less attractive to the dentally-educated respondents, which suggests that the dental education might have some influence in sensitivity to vertical changes in lower face.

Clinical and Cephalometric Analysis of Facial Soft Tissue.

OBJECTIVE: This study aimed to provide average of standard values in planning orthognathic surgery in Asians. MATERIALS AND METHODS: Thirty-three Asians with well-balanced facial profile, combined with class I occlusion and stabilized condylar head were evaluated using lateral cephalograms. RESULTS: Facial length (Nasion'-Menton') was 138.8 and 127.0 mm in male and female, respectively. Upper and lower lip length were 24.5 and 49.8 mm for male, and 22.2 and 45.1 mm for female, and maxillary incisor exposure was 2.0 and 4.0 mm in male and female, respectively. Nasolabial angle was 77.7° and 84.1° in male and female, respectively. Alar base, A point', and maxillary incisor were placed posteriorly to true vertical line by 10.6, 1.0, and 8.0 mm for male and 9.0, 0.8, and 6.9 mm for female. The horizontal distance between upper lip anterior and lower lip anterior was 2.1 mm for male and 2.6 mm for female, and the horizontal distance between A point' and B point' was 5.3 mm for male and 3.9 mm for female. Orbital rim' to A-point' was 12.4 and 11.3 mm in male and female, respectively. Pogonion' located posteriorly to glabella' by 2.7 mm for male and anteriorly to glabella' by 3.2 mm for female, and facial angle was 156.7° and 147.0° in male and female, respectively. CONCLUSIONS: This quantitative analysis of facial profile in Asian will be helpful in evaluation of facial soft tissue and establishment of treatment plans for orthognathic surgery.

Comparison of Orthodontics-First and Surgery-First Approach in Positional Changes of the Condyle After Mandibular Setback Surgery Using Three-Dimensional Analysis.

PURPOSE: To examine and compare the 3-dimensional (3D) postoperative changes of the condylar position after mandibular setback surgery using the orthodontics-first approach (OFA) and surgery-first approach (SFA). MATERIALS AND METHODS: This retrospective cohort study included patients who had undergone bilateral sagittal split ramus osteotomy for mandibular prognathism using OFA or SFA. Computed tomography images were obtained and analyzed preoperatively (T0), postoperatively (T1), and at the 6-month follow-up visit (T2). The bodily shift of the condylar center and rotational movement of the condylar head were measured using the 3D coordinate system between each time point and compared between the OFA and SFA groups. Repeated measures analysis of variance with a Bonferroni post hoc test was used to compare the time course changes of the condylar position for the 2 surgical-orthodontic approaches. RESULTS: A total of 55 patients (mean age 21.9 years; 31 males, 24 females) were evaluated. Of the 55 patients, 29 had undergone OFA and 26, SFA. In both groups, the condyle showed perioperative lateral and inferior displacement with inward rotation, followed by returning to its preoperative position during the 6 months postoperatively. No significant difference was found between the 2 groups in the time course change of the condylar position. CONCLUSIONS: Regardless of the timing of the operation (OFA vs SFA), the perioperative and postoperative changes of the condylar position after mandibular setback surgery are equivalent.

Behavior of Osteoblast-Like Cells on a ß-Tricalcium Phosphate Synthetic Scaffold Coated With Calcium Phosphate and Magnesium.

OBJECTIVES: Tricalcium phosphate (TCP) is one of the most useful synthetic scaffolds for bone grafts and has several advantages. However, the rapid degradation of TCP makes it less osteoconductive than the other candidates, and represents a major shortcoming. To overcome this problem, the authors investigated magnesium (Mg) and/or hydroxyapatite (HA) coating on a ß-TCP substrate using a sputtering technique. METHODS: Biocompatibility tests were carried out on ß-TCP discs that were either uncoated (TCP), coated with HA by radio frequency magnetron sputtering (HA-TCP), coated with Mg by DC sputtering (Mg-TCP), or multicoated with Mg and HA by DC and radio frequency magnetron sputtering (MgHA-TCP). RESULTS: Cells showed similar morphology in all 4 groups, and were widely spread, had flattened elongated shapes, and were connected to adjacent cells by pseudopods. An MTT assay revealed higher cell proliferation on HA-TCP, Mg-TCP, and MgHA-TCP compared with TCP at 3 and 5 days. MgHA-TCP also showed significantly higher alkaline phosphatase activity levels compared with TCP, HA-TCP, and Mg-TCP (P < 0.05). CONCLUSIONS: Results suggest that Mg-coated ß-TCP could have great potential as a bone graft material for future applications in hard tissue regeneration.

Evaluation of Mandibular Anatomy Associated With Bad Splits in Sagittal Split Ramus Osteotomy of Mandible.

PURPOSE: This study aimed to identify risk factors associated with bad splits during sagittal split ramus osteotomy by using three-dimensional computed tomography. METHODS: This study included 8 bad splits and 47 normal patients without bad splits. Mandibular anatomic parameters related to osteotomy line were measured. These included anteroposterior width of the ramus at level of lingula, distance between external oblique ridge and lingula, distance between sigmoid notch and inferior border of mandible, mandibular angle, distance between inferior outer surface of mandibular canal and inferior border of mandible under distal root of second molar (MCEM), buccolingual thickness of the ramus at level of lingula, and buccolingual thickness of the area just distal to first molar (BTM1) and second molar (BTM2). RESULTS: The incidence of bad splits in 625 sagittal split osteotomies was 1.28%. Compared with normal group, bad split group exhibited significantly thinner BTM2 and shorter sigmoid notch and inferior border of mandible (P <0.05). However, for BTM1 and buccolingual thickness of the ramus at level of lingula, there was no statistical difference between the 2 groups. Mandibular angle, anteroposterior width of the ramus at level of lingula, external oblique ridge and lingula, and MCEM were not significantly different between the groups. CONCLUSION: This study suggests that patients with shorter ramus and low thickness of the buccolingual alveolar region distal to the second molar had a higher risk of bad splits. These anatomic data may help surgeons to choose the safest surgical techniques and best osteotomy sites.

17ß-Estradiol induces odontoblastic differentiation via activation of the c-Src/MAPK pathway in human dental pulp cells.

The present study is aimed at investigating the effects of the exogenous estrogen 17ß-estradiol (E2) on odontoblastic differentiation in human dental pulp cells (HDPCs) immotalized with hTERT gene and their molecular mechanism. Proliferation was detected by BrdU assay, and odontoblast differentiation induction was evaluated by the expression of dentin sialophosphoprotein (DSPP), dentin sialoprotein (DSP) and dentin matrix protein1 (DMP1), and alkaline phosphatase (ALP) activity and mineralization. Estrogen receptor-α (ER-α), c-Src, and mitogen-activated protein kinases (MAPKs) were examined and their inhibitors were used to determine the roles on odontogenic induction. E2 significantly promoted the HDPC proliferation, which was mediated by extracellular signal-related kinase 1/2. E2 upregulated DSPP, DSP, and DMP1 as the odontogenic differentiation markers and enhanced ALP activity and mineralization. E2 increased phosphorylation of ER-α and fulvestrant, an ER downregulator, significantly downregulated DSPP, DMP1, and DSP induced by E2. Moreover, E2 treatment activated c-Src and MAPKs upon odontogenic induction, whereas chemical inhibition of c-Src and MAPKs decreased expression of DSPP, DMP1, and DSP and mineralization augmented by E2. Moreover, fulvestrant reduced E2-induced phosphorylation of c-Src and MAPK and inhibition of c-Src by PP2 attenuated activation of MAPKs during E2-induced odontoblastic differentiation. Taken together, these results indicated that E2 stimulates odontoblastic differentiation of HDPCs via coordinated regulation of ER-α, c-Src, and MAPK signaling pathways, which may play a key role in the regeneration of dentin.

Surgical Enucleation of the Mucocele on the Inferior Orbit Using Transantral Approach.

The mucocele on the inferior orbit is infrequent. When there is occurrence on the inferior orbit, the infraorbital approach, such as transantral, subciliary approach is used commonly. But because of some side effects, the authors use transantral approach intraorally. A 26-year-old woman visited our department with complaint of palpable mass. Computed tomography (CT) disclosed cystic lesion on the left inferior orbit. Surgical approach to the lesion was established with bony window opening on the anterior maxillary wall intralorally. Medpor sheet was placed on orbital floor after the removal of the lesion. Histopathologically, the lesion was diagnosed as mucocele. Orbital volume was kept well after the operation and no ocular sequela was observed.

Surgical Correction of the Malpositioned Segment After Alveolar Distraction in the Edentulous Patient.

This study examined a female patient with a lower edentulous state, who had undergone a previous alveolar distraction. A lingually malpositioned segment was found after the alveolar distraction. Therefore, an osteotomy of the distracted segment was performed and the segment was corrected into the labial side and fixed with miniplates. Good results in correcting the malpositioned segment were achieved in this edentulous patient using the osteotomy and fixation after an alveolar distraction.

Comparative study of the sinus septa between dentulous and edentulous patients by cone beam computed tomography.

PURPOSE: The purpose of this study was to conduct radiographic comparison of maxillary septa in dentulous and edentulous patients using 3-dimensional cone-beam computed tomography (CBCT). MATERIALS AND METHODS: From November- 2008 to August 2010, the CBCT of full dentulous 100 patients was conducted randomly at the Department of Radiology, Chonnam National University Dental Hospital. Septa in the maxillary sinus were analyzed. Also, CBCT of 51 patients with partial or full edentulous dentition on maxillary posterior area was obtained. The height of the maxillary sinus septa was measured from the sinus floor, the location divided by the anterior, middle, and posterior portion, and the direction was determined to be the buccopalatal, sagittal, and transverse course. RESULTS: In dentulous patients, sinus septa were found in 27% with 6.01 ± 2.21 mm mean height. The mean age of these patients was 24 years and 9 months, and most septa were found in anterior portion with a buccopalatal course. In cases of edentulous patients, the prevalence of edentulous patients with septa was 25.8% with 5.30 ± 1.90 mm mean height. The mean age of the patients was 63 years and 4 months, and most of septa were in the middle portion with a buccopalatal direction. CONCLUSION: There was no significant difference in the prevalence, incidence, height, location, and direction of maxillary sinus septa between dentulous and edentulous patients (P > 0.05).

Does mandible ramus height asymmetry affect postoperative skeletal stability in orthognathic surgery patients?

BACKGROUND: Relapses following orthognathic surgery have been reported to exceed 2% to 50%, depending on multiple factors. This study aimed to analyze the stability after orthognathic surgery in patients with mandibular ramus height asymmetry through 3D reconstruction using Cone-beam CT. METHODS: This retrospective cohort study investigated patients who underwent mandibular setback surgery using bilateral sagittal split ramus osteotomy. Three-dimensional CT scans were taken at three different time points. Evaluation of the postoperative stability involved measuring changes in the x, y, and z axes as well as roll and yaw rotations of the mandible at specific landmarks (B point, mental foramen) on 3D CT scans obtained immediately after surgery and 6-12 months postoperatively. They were categorized into four groups based on bilateral mandibular height asymmetry through Asymmetry index (AI). The one-way ANOVA was implemented to compare the intergroup differences and Tukey's post hoc test was employed. Additionally, the Pearson correlation coefficient was also calculated. RESULTS: A total of 24 patients were included in this study. The corresponding AI, representing the degree of asymmetry in both mandibles, were calculated as Group 1 was 1.25 ± 0.64%, Group 2 was 2.89 ± 0.47%, Group 3 was 5.03 ± 0.51%, and Group 4 was 9.40 ± 1.99%. The x-axis change in Group 4 was significantly larger at 1.71 mm compared to Group 1 at 0.64 mm. The mandibular roll, Group 4 showed a statistically significant increase at 1.33° compared to Group 1 at 0.35°. And there was a significant positive correlation observed between x-axis change and AI (p = 0.019), as well as between mandibular roll and AI (p = 0.025). CONCLUSION: After orthognathic surgery, stability was influenced by numerous factors, with the findings of this study suggesting that the degree of ramus height asymmetry in the mandible can be considered one contributing factor.

Delayed closure of the palatal defect using buccal inversion and palatal rotation flaps after maxillectomy.

Maxillectomy leaves oronasal and oroantral defects that result in functional impairment of mastication, deglutition, and speech. Many treatment options are suggested and tried including the palatal flap as local flap. Although palatal flaps have been used to repair various oral cavity defects, they have certain limitations due to the dimensions. The amount and location of the palatal tissues available are important for palatal repair. Secondary intentional healing after maxillectomy will allow the epithelialization of the defect margin adjacent to remained palate, and there will be more mucosa that is available for closure of the defect. We delayed the closure of the palatal defect, while the patient underwent prosthetic treatment for functional recovery in 5 maxillectomy patients. Delayed closure of palatal defect with local flap was done at 10.8 ± 7.9 months after the maxillectomy. While delayed closure in hemimaxillectomy patients left postoperative fistula, it provided separation of the oral cavity and nasal/sinus cavity and adequate surface for prosthesis in partial maxillectomy patients.

Condylar volume and positional changes following a bilateral sagittal split ramus osteotomy in skeletal class II and III malocclusions.

BACKGROUND: Mandibular condyle remodeling and displacement are post-orthognathic surgery concerns that can potentially lead to occlusal issues after bilateral sagittal split ramus osteotomy. This retrospective study examined the relationship between condylar volume changes and position alterations after surgery in patients with skeletal class II and III malocclusions using cone-beam CT. METHODS: The study included 16 patients (6 with Class II malocclusion, 10 with Class III malocclusion) who underwent bilateral sagittal split ramus osteotomy at Chonnam National University Hospital. Cone-beam CT data were collected at three specific time points: before surgery, immediately after surgery, and approximately 6 months post-surgery. Mandibular movement was measured using InVivoDental 5.4.6. ITK-SNAP 3.8.0 was used to assessed condylar volume changes post-surgery. Condyle positions were evaluated in four parts with RadiAnt DICOM Viewer 4.6.9. Statistical analyses were performed using the SPSS version 23. RESULTS: Considering both Class II and III malocclusion, a 2.91% volume reduction was noted immediately and at 6 months after surgery. Both Class II and III cases demonstrated a decrease in superior joint space by -0.59 mm and medial joint space by -1.09 mm. No significant correlation was found between this process and condylar volume change. CONCLUSIONS: The mandibular condyle volume decreased, and superior-medial movement of the condyle was detected in patients with Class II and III malocclusion immediately and at 6 months after surgery with no volume-position correlation.