Transoral Endoscopy-Assisted Tongue-Lip Adhesion With Modified Tongue Base Suspension in a Pierre-Robin Sequence: A Safe and Effective Technique.

Life-threatening airway obstruction is a major concern in patients with Pierre-Robin sequence. Tongue-lip adhesion (TLA) has been used to manage airway obstruction. The authors present the case of a female neonate with Pierre-Robin sequence who presented with airway obstruction and a cleft palate. She underwent a TLA procedure with modified tongue base suspension (TBS). Endoscopy was used to check and control the traction of the tongue base to enable unobstructed self-ventilation. Positive outcomes including improved O2 saturation and weight gain were noted. The effectiveness of TLA was enhanced by using TBS with real-time endoscopy to evaluate the oropharyngeal airway space required to alleviate airway obstruction. The use of endoscopy enabled us to check and determine how much the tongue base should be tracted by manipulating the tongue anteriorly and posteriorly. The authors report transoral endoscopy-assisted TLA and modified TBS.

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.

Redox-Sensitive Delivery of Doxorubicin from Nanoparticles of Poly(ethylene glycol)-Chitosan Copolymer for Treatment of Drug-Resistant Oral Cancer Cells.

Reactive oxygen species (ROS)-sensitive polymer nanoparticles were synthesized for tumor targeting of an anticancer drug, doxorubicin (DOX). For this purpose, chitosan-methoxy poly(ethylene glycol) (mPEG) (ChitoPEG)-graft copolymer was synthesized and then DOX was conjugated to the backbone of chitosan using a thioketal linker. Subsequently, the chemical structure of the DOX-conjugated ChitoPEG copolymer (ChitoPEGthDOX) was confirmed via 1H nuclear magnetic resonance (NMR) spectra. Nanoparticles of the ChitoPEGthDOX conjugates have spherical shapes and a size of approximately 100 nm. Transmission electron microscopy (TEM) has shown that ChitoPEGthDOX nanoparticles disintegrate in the presence of hydrogen peroxide and the particle size distribution also changes from a monomodal/narrow distribution pattern to a multi-modal/wide distribution pattern. Furthermore, DOX is released faster in the presence of hydrogen peroxide. These results indicated that ChitoPEGthDOX nanoparticles have ROS sensitivity. The anticancer activity of the nanoparticles was evaluated using AT84 oral squamous carcinoma cells. Moreover, DOX-resistant AT84 cells were prepared in vitro. DOX and its nanoparticles showed dose-dependent cytotoxicity in both DOX-sensitive and DOX-resistant AT84 cells in vitro. However, DOX itself showed reduced cytotoxicity against DOX-resistant AT84 cells, while the nanoparticles showed almost similar cytotoxicity to DOX-sensitive and DOX-resistant AT84 cells. This result may be due to the inhibition of intracellular delivery of free DOX, while nanoparticles were efficiently internalized in DOX-resistant cells. The in vivo study of a DOX-resistant AT84 cell-bearing tumor xenograft model showed that nanoparticles have higher antitumor efficacy than those found in free DOX treatment. These results may be related to the efficient accumulation of nanoparticles in the tumor tissue, i.e., the fluorescence intensity in the tumor tissue was stronger than that of any other organs. Our findings suggest that ChitoPEGthDOX nanoparticles may be a promising candidate for ROS-sensitive anticancer delivery against DOX-resistant oral cancer cells.

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.

Clear Aligner Use Following Surgery-First Mandibular Prognathism Correction.

This case report introduces a treatment in mandibular prognathism correction by combining the surgery-first (SF) approach and clear aligners. An intraoral scanner (TRIOS 3, 3Shape, Copenhagen, Denmark) and a virtual setup program (OrthoAnalyzer, 3Shape) were used for treatment simulation. All clear aligners were fabricated using a 3-dimensional printer. The total treatment was completed within 3 months after surgery. An immediate improvement of the facial profile was obtained using the SF approach, and rapid and esthetic tooth movement was achieved using clear aligners. This case report demonstrated that the combination of the SF approach and clear aligners could be a patient-oriented surgical-orthodontic treatment method.

Oxygen and Acrylic Acid Plasma Treatment on Titanium Mesh for Improving the Hydroxyapatite Formation.

Customized titanium (Ti) meshes were treated with O2 plasma and acrylic acid plasmapolymerization (PPAAc). The optimum conditions for PPAAc were as follows: 20 W, 15 mTorr, and 5 min. Hydroxyapatite formation increased in Ti meshes treated with O2 and PPAAc compared with that in untreated Ti meshes. Moreover, MC3T3-E1 cells exhibited improved cell spreading, attachment, proliferation in PPAAc treated Ti mesh than in untreated Ti mesh. This result revealed that O2 and PPAAc surface treatment on Ti mesh was potential tool for improving the bone formation on the Ti mesh clinically application.

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.

Surgery-first approach in correcting skeletal Class III malocclusion with mandibular asymmetry.

This case report describes a surgical orthodontic case that used the recently introduced surgery-first approach to correct a severe skeletal Class III malocclusion. A 19-year-old woman presented with severe mandibular prognathism and facial asymmetry; she had been waiting for growth completion in order to pursue surgical correction. After prediction of the postsurgical tooth movement and surgical simulation, 2-jaw surgery that included maxillary advancement and differential mandibular setback was performed using a surgery-first approach. Immediate facial improvement was achieved and postsurgical orthodontic treatment was efficiently carried out. The total treatment time was 16 months. The patient's facial appearance improved significantly and a stable surgical orthodontic outcome was obtained.

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.

Anatomical Studies of the Orbital Cavity Using Three-Dimensional Computed Tomography.

OBJECTIVE: This study was designed to analyze the morphometric characteristics of the orbital cavity using three-dimensional computed tomography in Asians. METHODS: Two hundred seventy-six orbits in 142 Asians (74 men and 68 women) were examined and compared according to age, sex, and laterality (right and left). RESULTS: Mean orbital morphometric values were as follows. Orbital cavity depth was 49.60 mm from optic foramen to orbitale (inferior) and 41.32 mm from optic foramen to lacrimal crest (medial). Anterior and posterior orbital medial wall heights were 17.73 and 12.76 mm, respectively. Medial, middle, and lateral orbital floor lengths were 39.08, 29.56, and 20.08 mm, respectively. Anterior and posterior orbital floor width was 21.87 and 12.00 mm, respectively. For the orbital inferior-medial angle, anterior, middle, and posterior value was 132.11°, 126.24°, and 136.88°, respectively. Inferior orbital cavity depth, anterior orbital medial wall height, and orbital floor length tended to increase with aging, whereas orbital floor width tended to decrease with aging. No significant differences were found in terms of laterality, and values were greater in men than in women. CONCLUSIONS: This quantitative analysis of orbital measurements will allow surgeons to plan operations more accurately and will help predict outcomes.

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.

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.

Effect of periosteum attached to autogenous iliac block bone graft on bone resorption in rabbits.

The purpose of this study was to evaluate the effect of the periosteum attached to an iliac block bone graft on resorption of the grafted bone. Twenty-one rabbits were used. Iliac bone was harvested with (experimental group) or without a periosteum (control group) and grafted on the rabbit calvarium and fixed with miniscrews. The animals were killed, and specimens were harvested at 1, 4, and 8 weeks after the surgery. Histologic examination and histomorphometry were done. Grafted bones were severely resorbed, and the overall shapes were changed in the control group. On the contrary, the overall shape of the grafted bone was maintained, although the grafted bone was resorbed in the experimental group. Moreover, there were no osteoclasts adjacent to the periosteum of the graft. These results suggest that the periosteum attached to grafted bone can help establish early revascularization and prevent the resorption of grafted bone.

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.

Transcutaneous approach for the removal of parotid gland stones.

Salivary stones in the parotid gland can be treated with a wide range of methods. Stones close to the opening of the duct can be easily removed through the oral cavity, whereas the entire salivary gland may need to be removed if stones are located close to the parotid gland. In such cases, surgical removal of the parotid gland may be lengthy and may produce facial nerve injury. We report a simple extraoral approach used for the removal of parotid gland stones located close to the parotid gland by precisely identifying the location of stones in 2 patients with parotid sialolithiasis.

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).