Comparison of Posttreatment Stability Between Mandibular Setback Surgery-Early and Conventional Surgery in Class III Patients: A 4.6-Year Follow-Up.

OBJECTIVES: This retrospective study aims to compare long-term stability between the mandibular setback surgery-early (MSE) approach, involving minimal orthodontics, and the mandibular setback conventional surgery (MCS) approach, involving sufficient orthodontics, in Class III patients with mandibular prognathism. METHODS: Among 210 patients who underwent orthognathic surgery, a total of 40 subjects were enrolled based on standardized inclusion criteria: only mandibular surgery, <5 mm setback difference between right and left of the mandible, orthodontics with fixed appliances, and more than 2 years of follow-up after treatment. These patients were allocated to the MSE (n = 20) and MCS groups (n = 20) according to the duration of presurgical orthodontics. Changes in cephalometric measurements were compared between the MSE and MCS groups before surgery (T0), 1 month after surgery (T1), at the end of treatment (T2), and posttreatment retention (T3). RESULTS: The MSE and MCS groups had a mean presurgical orthodontic duration of 2 and 9.5 months, respectively. From T1 to T2, the MSE group showed a significantly larger forward movement of the mandible than the MCS group (2.1 versus 0.7 mm; P < 0.001). In addition, from T2 to T3 (average 4.6 years), the MSE group presented anterior relapse of 0.6 mm in the mandible, but there were no statistically significant intergroup differences. CONCLUSION: Although the MSE group showed greater postsurgical forward mandibular relapse than the MCS group, the two groups exhibited similar skeletal and dental stability during the posttreatment retention.

Survival analysis of implants after surgical treatment of peri-implantitis based on bone loss severity and surgical technique: a retrospective study.

BACKGROUND: Few trials have compared the results of surgical treatment for peri-implantitis based on severity of peri-implantitis and surgical method. This study investigated the survival rate of implants based on type of surgical method used and initial severity of peri-implantitis. Classification of severity was determined based on bone loss rate relative to fixture length. METHODS: Medical records of patients who underwent peri-implantitis surgery from July 2003 to April 2021 were identified. Classification of peri-implantitis was divided into 3 groups (stage 1: bone loss < 25% (of fixture length), stage 2: 25% < bone loss < 50%, stage 3: bone loss > 50%) and performance of resective or regenerative surgery was investigated. Kaplan-Meier survival curves and Cox hazards proportional models were used to analyze the cumulative survival rate of implants. Median survival time, predicted mean survival time, hazard ratio (HR), and 95% confidence interval (CI) were calculated. RESULTS: Based on Kaplan-Meier analysis, 89 patients and 227 implants were included, and total median postoperative survival duration was 8.96 years. Cumulative survival rates for stage 1, 2, and 3 were 70.7%, 48.9%, and 21.3%, respectively. The mean survival time for implants in stage 1, 2, and 3 was 9.95 years, 7.96 years, and 5.67 years, respectively, with statistically significant difference (log-rank p-value < 0.001). HRs for stage 2 and stage 3 were 2.25 and 4.59, respectively, with stage 1 as reference. Significant difference was not found in survival time between resective and regenerative surgery groups in any peri-implantitis stage. CONCLUSIONS: The initial bone loss rate relative to the fixture length significantly correlated with the outcome after peri-implantitis surgery, demonstrating a notable difference in the long-term survival rate. Difference was not found between resective surgery and regenerative surgery in implant survival time. Bone loss rate could be utilized as a reliable diagnostic tool for evaluating prognosis after surgical treatment, regardless of surgical method used. TRIAL REGISTRATION: Retrospectively registered. (KCT0008225).

Low Bone Density Predictability of CBCT and Its Relation to Primary Stability of Tapered Implant Design: A Pilot Study.

Research regarding bone density assessment using cone beam computed tomography in low bone density regions is sparse. This in vitro study aimed to evaluate the predictability of cone beam computed tomography for low bone density regions and its correlations with primary implant stability when placing tapered design implants with a stepped osteotomy. Eighteen porcine mandibular condyles were used as simulated low bone density regions. Hounsfield units (HU), obtained via multislice computed tomography, and gray values (GV), obtained via cone beam computed tomography, were measured three times at one-month intervals. The maximum implant insertion torque (MIT) and implant stability quotient (ISQ) were recorded as the taper design implants were placed using a stepped osteotomy. HU and GV were measured as 335.05-803.07 and 389.98-906.40, respectively. For repeated measurements of HU and GV, the intraclass correlation coefficients were 0.989 and 0.980; the corresponding value for mean HU and GV was 0.768. Bland-Altman plots showed a mean difference between HU and GV of -78.15. Pearson correlation coefficients revealed a strong correlation between HU and GV (r=0.91, p<0.01). The mean ± standard deviation values for MIT and ISQ were 36.44 ± 6.64 Ncm and 80.85 ± 2.03, respectively, but no statistically significant correlations were found with GV and HU. Within the study's limitations, GV showed similar bone density estimation compared to HU in soft bones. Tapered implant placement with a stepped osteotomy achieved stable primary implant stability in soft bones. However, these in vitro results need to be approved in further clinical studies.

Accuracy of dental implant placement with computer-guided surgery: a retrospective cohort study.

BACKGROUND: The aim of this study was to assess the accuracy of virtual planning of computer-guided surgery based on the actual outcomes of clinical dental implant placement. METHODS: This retrospective study enrolled patients among whom implant treatment was planned using computer-guided surgery with cone beam computed tomography (CBCT). The patients who received implant according to the guide with the flapless and flapped approach were classified as group 1 and 2, respectively, and the others who could not be placed according to the guide were allocated to the drop-out group. The accuracy of implant placement was evaluated with the superimposition of CBCT. RESULTS: We analyzed differences in the deviated distance of the entrance point and deviated angulation of the insertion of implant fixtures. With regard to the surgical approach, group 2 exhibited greater accuracy compared to group 1 in deviation distance (2.22 ± 0.88 and 3.18 ± 0.89 mm, respectively, P < 0.001) and angulation (4.27 ± 2.30 and 6.82 ± 2.71°, respectively, P = 0.001). The limitations of guided surgery were discussed while considering the findings from the drop-out group. CONCLUSIONS: Computer-guided surgery demonstrates greater accuracy in implant placement with the flapless approach. Further research should be conducted to enhance the availability of guides for cases with unfavorable residual bone conditions.

Soft Tissue Changes After Clockwise Rotation of Maxillo-Mandibular Complex in Class III Patients: Three-Dimensional Stereophotogrammetric Evaluation.

OBJECTIVES: To evaluate the linear, angular, and volumetric changes of soft tissue after clockwise repositioning of the maxillo-mandibular complex in skeletal class III patients using three-dimensional (3D) stereophotogrammetry and to determine the correlation between changes in the skeletal and soft tissue variables. METHODS: This study included 18 skeletal class III patients who underwent two-jaw surgery; superior impaction and clockwise rotational movement of the maxilla with the rotation center at upper incisors, and setback of the mandible. Lateral cephalograms and 3D photographs taken before and 6 months after surgery were compared. RESULTS: After maxillary impaction of anteriorly 1.7 mm and posteriorly 3.1 mm, and mandibular setback of 8.7 mm, the volume of lower lip and chin region decreased significantly by 33.6 cm3 (13% net change, P < 0.001), while paranasal and upper lip region volume increased by 3.2 cm3 (2%) and 7.2 cm3 (4%), respectively. CONCLUSION: The clockwise rotation of maxillo-mandibular complex in class III patients significantly reduced lower lip and chin volume with minimal increase in paranasal and upper lip volumes. 3D stereophotogrammetry can provide quantitative evaluation of facial soft tissue volumetric changes.

Cisplatin Plus Cetuximab Inhibits Cisplatin-Resistant Human Oral Squamous Cell Carcinoma Cell Migration and Proliferation but Does Not Enhance Apoptosis.

Cisplatin is among the most widely used anticancer drugs used in the treatment of several malignancies, including oral cancer. However, cisplatin treatment often promotes chemical resistance, subsequently causing treatment failure. Several studies have shown that epidermal growth factor receptors (EGFRs) play a variety of roles in cancer progression and overcoming cisplatin resistance. Therefore, this study focused on EGFR inhibitors used in novel targeted therapies as a method to overcome this resistance. We herein aimed to determine whether the combined effects of cisplatin and cetuximab could enhance cisplatin sensitivity by inhibiting the epithelial-to-mesenchymal transition (EMT) process in cisplatin-resistant cells. In vitro analyses of three cisplatin-resistant oral squamous cell carcinoma cells, which included cell proliferation assay, combination index calculation, cell cytotoxicity assay, live/dead cell count assay, Western blot assay, propidium iodide staining assay, scratch assay, and qRT-PCR assay were then conducted. Our results showed that a cisplatin/cetuximab combination treatment inhibited cell proliferation, cell motility, and N-cadherin protein expression but induced E-cadherin and claudin-1 protein expression. Although the combination of cisplatin and cetuximab did not induce apoptosis of cisplatin-resistant cells, it may be useful in treating oral cancer patients with cisplatin resistance given that it controls cell motility and EMT-related proteins.

Prognosis of single tooth implants following alveolar ridge preservation with two recombinant human bone morphogenetic protein-2 delivery systems.

BACKGROUND: We previously reported similar efficacies of alveolar ridge preservation (ARP) on single extraction socket with two different E. coli derived recombinant human bone morphogenetic protein-2 (rhBMP-2) delivery systems (Cowell BMP, Cowell medi Co, Busan, Korea; ß-tricalcium phosphate and hydroxyapatite particle & O-BMP, Osstem Implant Co, Busan, Korea; absorbable collagen sponge). After the trial, we completed implant therapy and observed over an average of 3 years. This follow-up study was performed retrospectively to compare result of implant treatment at the preserved alveolar ridge site. METHODS: Patients who underwent extraction of single tooth and received ARP with one of two rhBMP-2 delivery systems from October 2015 to October 2016 were enrolled. Twenty-eight patients (Group 1: Cowell BMP 14; Group 2: O-BMP 14) who underwent implant therapy and prosthetic treatment were included in study. Stability and marginal bone loss (MBL) of each implant were collected from medical charts and radiographs, and analyzed. The survival and success rates of implants were calculated. RESULTS: The primary implant stability represented by implant stability quotient (ISQ) for Groups 1 and 2 was 69.71 and 72.86, respectively. The secondary implant stability for Groups 1 and 2 was 78.86 and 81.64, respectively. Primary and secondary stabilities were not statistically different (P = 0.316 and 0.185, respectively). MBL at the latest follow-up was 0.014 mm in Group 1 over 33.76 ± 14.31 months and 0.021 mm in Group 2 over 40.20 ± 9.64 months, with no significant difference (P = 0.670). In addition, the success rate of implants was 100% (14/14) in Group 1 and 92.9% (13/14) in Group 2, with survival rate of 100% (14/14) in Group 1 and 92.9% (13/14) in Group 2. CONCLUSIONS: We confirmed good prognosis in both groups as a result of implant therapy after ARP with each of two rhBMP-2 carriers.

Associations between mandibular torus and types of temporomandibular disorders, and the clinical usefulness of temporary splint for checking bruxism.

BACKGROUND: Occlusal stress from oral parafunctional habits is one of the causes of temporomandibular disorders (TMD) and mandibular torus (MT). Although some studies have investigated the correlation between TMD and MT, understanding of the relationships between types of TMD and MT is insufficient. Therefore, we conducted this study to investigate the associations between presence of MT and TMD types. METHODS: This study included 77 patients diagnosed with TMD who first visited our clinic for TMD between March 2019 and July 2020. Among them, 30 (38.9%) had MT, and 54 (70.1%) had oral parafunction. Parafunctional activity during sleep was confirmed using a temporary splint for checking bruxism (TSCB). RESULTS: The relationship between prevalence of MT and oral parafunction in TMD patients was not statistically significant (P = 0.131), but the odds ratio was relatively high at 2.267. An analysis of TMD type revealed that Type I, which is classified as myalgia of the masticatory muscles, and MT had a significant association (P = 0.011). We fabricated a TSCB for 27 patients to wear during sleep and confirmed that 23 (85.2%) had nocturnal bruxism. The TSCB results and presence of MT showed a significant relationship (P = 0.047). CONCLUSION: Through the results of this study, clinicians may consider the hyperactivity of masticatory muscles in the presence of MT when treating TMD patients. In addition, TSCB has a great diagnostic value as it can be easily manufactured and be useful for discovering pre-existing oral parafunctions that patients are not aware of.

Improved oral hygiene care attenuates the cardiovascular risk of oral health disease: a population-based study from Korea.

AIMS: Oral health problems such as periodontal disease, dental caries, and tooth loss have been suggested to have associations with cardiovascular disease. This study aimed to evaluate whether oral hygiene behaviour can alleviate cardiovascular risk associated with oral health status using a nationwide population-based cohort. METHODS AND RESULTS: The data of 247 696 healthy adults aged 40 years or older who underwent an oral health screening programme and had no history of major cardiovascular events were extracted from the National Health Insurance System-National Health Screening Cohort. After a median follow-up of 9.5 years, 14 893 major cardiovascular events occurred including cardiac death, myocardial infarction, stroke, and heart failure. The risk of cardiovascular events was higher when a subject had periodontal disease, a higher number of dental caries, or more tooth loss. Performing one more tooth brushing a day was associated with a 9% significantly lower risk of cardiovascular events after multivariable adjustment. Regular dental visits (once a year or more) for professional cleaning were also shown to reduce cardiovascular risk by 14%. Improved oral hygiene behaviours were shown to attenuate the cardiovascular risk originating from periodontal disease, dental caries, and tooth loss. CONCLUSION: Oral hygiene care such as frequent tooth brushing and regular dental visits for professional cleaning reduced the risk of future cardiovascular events in healthy adults. This study also suggests that improved oral hygiene behaviour may modify the association between oral health and cardiovascular diseases.

Increased FOXM1 Expression by Cisplatin Inhibits Paclitaxel-Related Apoptosis in Cisplatin-Resistant Human Oral Squamous Cell Carcinoma (OSCC) Cell Lines.

Cisplatin and paclitaxel are commonly used to treat oral cancer, but their use is often limited because of acquired drug resistance. Here, we tested the effects of combined cisplatin and paclitaxel on three parental (YD-8, YD-9, and YD-38) and three cisplatin-resistant (YD-8/CIS, YD-9/CIS, and YD-38/CIS) oral squamous cell carcinoma (OSCC) cell lines using cell proliferation assays and combination index analysis. We detected forkhead box protein M1 (FOXM1) mRNA and protein expression via real-time qPCR and Western blot assays. Cell death of the cisplatin-resistant cell lines in response to these drugs with or without a FOXM1 inhibitor (forkhead domain inhibitory compound 6) was then measured by propidium iodide staining and TdT dUTP nick end labeling (TUNEL) assays. In all six OSCC cell lines, cell growth was more inhibited by paclitaxel alone than combination therapy. Cisplatin-induced overexpression of FOXM1 showed the same trend only in cisplatin-resistant cell lines, indicating that it was associated with inhibition of paclitaxel-related apoptosis. In summary, these results suggest that, in three cisplatin-resistant cell lines, the combination of cisplatin and paclitaxel had an antagonistic effect, likely because cisplatin blocks paclitaxel-induced apoptosis. Cisplatin-induced FOXM1 overexpression may explain the failure of this combination.

The role of p53 status on the synergistic effect of CKD-602 and cisplatin on oral squamous cell carcinoma cell lines.

The purpose of this study was to evaluate the synergistic apoptotic effect of CKD-602 in combination with cisplatin on different p53 statuses of oral squamous cell carcinoma (OSCC) cell lines, YD-8, YD-9, and YD-38. MTT assays were used to evaluate the inhibitory effect of the treatments modality on cell growth. The combination index was calculated using CompuSyn software. Detection of cell death was carried out using the propidium iodide (PI)/RNase staining assay, Annexin V/PI double staining assay, and Western blotting. Combination treatment using CKD-602 and cisplatin inhibited proliferation and increased the apoptotic effect on the three OSCC cell lines. Apoptotic cell death was detected in the cell lines, and significant synergistic effects of CKD-602 in combination with cisplatin were observed despite the differences in p53 status. From these results, it was suggested that the combination of CKD-602 with cisplatin might be a potential therapeutic strategy for OSCC. In particular, cell line-specific therapy is necessary because of the differences in treatment response based on p53 status.

Factors Related to Relapse After Mandibular Setback Surgery With Minimal Presurgical Orthodontics.

PURPOSE: The aims of this study were to compare the presurgical conditions, surgical changes, and postsurgical changes in patients with skeletal Class III malocclusion with different degrees of horizontal relapse after mandibular setback surgery (MS) with minimal presurgical orthodontics (MPO) and to identify the factors contributing to this relapse. MATERIALS AND METHODS: For this retrospective study, 33 consecutive patients who underwent MS-MPO were selected. Lateral cephalograms were taken preoperatively (T0), 1 month after surgery (T1), and at orthodontic debonding (T2). Patients were divided into low relapse (LR; n = 18; relapse, <1 mm) and high relapse (HR; n = 15; relapse, >2 mm) groups based on the cephalometric distance of mandibular horizontal relapse. Paired t test, independent t test, and Pearson correlation analysis were used to evaluate surgical (T0 to T1) and postsurgical (T1 to T2) changes in the skeletodental variables and to explore the relation between surgical changes and horizontal relapse. RESULTS: Compared with the LR group, the HR group exhibited more upward movement with counterclockwise rotation of the mandible from T1 to T2. The HR group presented at T0 with a more prognathic mandible, greater vertical facial height, and a positive overbite. In addition, the HR group presented more posterior movement with clockwise rotation of the mandible, increased overjet, and decreased overbite from T0 to T1. Horizontal relapse of the mandible was positively correlated with the amount of setback and clockwise rotation of the mandible and the change in overjet and was negatively correlated with the change in overbite. CONCLUSIONS: Mandibular instability was related to the extent of setback and clockwise rotation of the mandible, decreased overbite, and increased overjet during MS-MPO.

Upregulation of MDR- and EMT-Related Molecules in Cisplatin-Resistant Human Oral Squamous Cell Carcinoma Cell Lines.

Cisplatin is one of the major drugs used in oral cancer treatments, but its usage can be limited by acquired drug resistance. In this study, we established three cisplatin-resistant oral squamous cell carcinoma (OSCC) cell lines and characterized them using cell viability assays, qPCR, Western blotting, FACS, immunofluorescence, and wound healing assays. Three OSCC cell lines (YD-8, YD-9, and YD-38) underwent long-term exposure to cisplatin, eventually acquiring resistance to the drug, which was confirmed by an MTT assay. In these three newly established cell lines (YD-8/CIS, YD-9/CIS, and YD-38/CIS), overexpression of multidrug resistance (MDR)-related genes was detected by qPCR and Western blotting. The cell lines displayed an increase in the functional activities of breast cancer resistance protein (BCRP) and multidrug resistance protein1 (MDR1) by rhodamine 123 and bodipy FL prazosin accumulation assays. Moreover, the cisplatin-resistant cells underwent morphological changes, from round to spindle-shaped, increased expression of epithelial-to-mesenchymal transition (EMT)-related molecules such as N-cadherin, and showed increased cell migration when compared with the parental cell lines. These results suggest that these newly established cell lines have acquired drug resistance and EMT induction.

Comparing Stability of Mandibular Setback Versus 2-Jaw Surgery in Class III Patients With Minimal Presurgical Orthodontics.

PURPOSE: The aim of this study was to compare treatment time and skeletal stability between mandibular setback surgery (MS) and 2-jaw surgery (2J) with minimal presurgical orthodontics (MPO) in patients with skeletal Class III. MATERIALS AND METHODS: One hundred ninety-five patients who underwent orthognathic surgery were enrolled in this retrospective cohort study. Consecutive patients were selected based on standardized inclusion criteria: Class III malocclusion with mandibular prognathism, surgery type, and presurgical orthodontics with non-extraction for less than 6 months (MPO). Lateral cephalograms were taken before surgery (T0), 1 month after surgery (T1), and at debonding (T2). To evaluate surgical changes (T0 to T1) and postsurgical changes (T1 to T2) in skeletodental tissue, linear, angular, and dental measurements were analyzed using paired t test and independent t test. RESULTS: Thirty-one patients were allocated to the MS-MPO group (n = 16) and the 2J-MPO group (n = 15). The 2J-MPO group showed a shorter duration of postsurgical orthodontic and total surgical and orthodontic treatment than the MS-MPO group. Although the 2J-MPO group exhibited advancement and superior impaction of the maxilla from T0 to T1, posterior movement with clockwise rotation of the mandible between the 2 groups did not show a statistical difference. In addition, from T1 to T2, the MS-MPO and 2J-MPO groups presented forward and upward movement and counterclockwise rotation of the mandible, but no intergroup difference was found. CONCLUSIONS: The MS-MPO and 2J-MPO groups showed similar horizontal and vertical mandibular stability. However, the 2J-MPO group presented a shorter surgical and orthodontic treatment time than the MS-MPO group.

Maximum Standardized Uptake Value of (99m)Tc Hydroxymethylene Diphosphonate SPECT/CT for the Evaluation of Temporomandibular Joint Disorder.

Purpose To evaluate the diagnostic accuracy of the quantitative parameter standardized uptake value (SUV) at single photon emission computed tomography (SPECT)/computed tomography (CT) for the evaluation of temporomandibular joint (TMJ) disorder (TMD). Materials and Methods This study was approved by the institutional review board, and the need for informed consent was waived. Forty-four TMJs in 22 patients with TMD (five men and 17 women; mean age ± standard deviation, 30.0 years ± 12.1) were evaluated. The patients underwent planar bone scintigraphy and SPECT/CT 3-4 hours after injection of technetium 99m hydroxymethylene diphosphonate. The planar scintigraphy parameter of relative ratio (RR) and SPECT/CT parameters mean SUV (SUVmean) and maximum SUV (SUVmax) were compared for the visual assessment of TMD on planar scintigraphy images and for the presence of TMJ arthralgia. Group comparisons, receiver operating characteristic analysis, and Pearson correlation analysis were conducted. Results SUVmax gradually increased from normal (2.82 ± 0.73) to mild or moderately abnormal (3.56 ± 0.76, P < .05) and then to severely abnormal (4.86 ± 1.25, P < .05). However, RR and SUVmean did not vary significantly according to visual grade (P > .05). On the other hand, SUVmax was significantly greater in arthralgic TMJs (4.15 ± 1.11) than in nonarthralgic TMJs (2.97 ± 0.75, P < .001), as was SUVmean (1.63 ± 0.42 vs 1.30 ± 0.31, respectively; P = .005). However, there was no significant difference in RR (3.61 ± 0.57 vs 3.76 ± 0.68, P = .45). In receiver operating characteristic curve analyses for arthralgic TMJ, SUVmax had the greatest area under the curve (area of 0.815). Conclusion SUVmax derived from bone SPECT/CT may be useful for the evaluation of TMD. (©) RSNA, 2016 Online supplemental material is available for this article.

Comparison of the Stability After Mandibular Setback With Minimal Orthodontics of Class III Patients With Different Facial Types.

PURPOSE: Most studies on the surgery-first approach focused on skeletal relapse compared with conventional surgery. The objective of this study was to compare the stability of skeletal Class III patients with 2 different vertical facial types after mandibular setback surgery (MS) with minimal orthodontic preparation (MO). MATERIALS AND METHODS: In this retrospective study, the patients were recruited from a population that had undergone MS. Consecutive patients were selected based on the following inclusion criteria: skeletal Class III malocclusion with mandibular prognathism, MO without extraction for less than 6 months, and sagittal split ramus osteotomy. The vertical facial types of the patients were classified based on the Frankfort mandibular-plane angle (FMA). Lateral cephalograms were taken at the presurgical stage, at 1 month after surgery (T1), and at the debonding stage (T2). To evaluate surgical changes (T1 - presurgical stage) and relapse (T2 - T1), the linear, angular, and dental measurements were analyzed using a paired t test and an independent t test. RESULTS: The 26 patients were divided into 2 groups: normal-angle group (n = 14; mean FMA, 23.58°) and high-angle (HA) group (n = 12; mean FMA, 30.26°). From T1 to T2, the normal-angle and HA groups showed significant forward and counterclockwise rotation of the mandible (distance between pogonion and perpendicular line to Frankfort horizontal plane from sella, 1.71 mm and 1.51 mm, respectively; distance between menton and perpendicular line to Frankfort horizontal plane from sella, 1.91 mm and 1.60 mm, respectively; angle between articulare-menton line and Frankfort horizontal plane, -0.55° and -0.89°, respectively). The HA group showed a significant upward movement of the mandible (distance from Frankfort horizontal plane to pogonion, -1.13 mm; distance from Frankfort horizontal plane to menton, -0.78 mm). However, there was no significant difference in the skeletal-dental changes between the 2 groups from T1 to T2. CONCLUSIONS: The vertical facial types of Class III patients with similar prognathic mandible and dental patterns may not cause any differences in the relapse pattern after MS-MO.

Evaluation of Soft Tissue Changes Around the Lips After Mandibular Setback Surgery With Minimal Orthodontics Using Three-Dimensional Stereophotogrammetry.

PURPOSE: Most reports on the surgery-first approach in skeletal Class III malocclusion have focused on the skeletal changes. The present study evaluated the soft tissue changes around the lips over time after mandibular setback surgery (MS) with minimal orthodontics (MO) using 3-dimensional (3D) stereophotogrammetry. MATERIALS AND METHODS: We performed a retrospective study of patients with mandibular prognathism who had undergone MS-MO. Lateral cephalograms and 3D photographs were taken before (T0) and 1 (T1) and 6 months (T2) after surgery and were superimposed. A paired t test, independent t test, and simple linear regression analysis were used to evaluate the hard and soft tissue changes and their correlation. RESULTS: The sample included 15 patients (7 males and 8 females). The soft tissue landmarks on the X-axis (left-right) showed no significant positional changes. The landmarks of the lips and oral commissure on the Y-axis (vertical) moved downward until T2; however, most of these changes did not differ significantly over time (T1 compared with T0 and T2 compared with T0). The landmarks in the lower lip, oral commissure, and soft tissue chin on the Z-axis (anterior-posterior) showed posterior movement at T1 and T2. In contrast, the lower lip (labiale inferius, 1.67 mm) and soft tissue chin (soft tissue B point, 1.28 mm; soft tissue pogonion, 1.61 mm) moved significantly forward from T1 to T2, but had no correlation with the anterior relapse of the mandible. CONCLUSIONS: Protrusion of the lower lip and soft tissue chin with forward and upward relapse of the mandible during postoperative orthodontics was observed. The results from the present study suggest that 3D stereophotogrammetry can be useful for evaluating the perioral soft tissue changes over time in orthognathic surgery patients.

Adenotonsillar hypertrophy as a risk factor of dentofacial abnormality in Korean children.

No studies for the role of adenotonsillar hypertrophy in development of dentofacial abnormalities have been performed in Asian pediatric population. Thus, we aimed to investigate the relationship between adenotonsillar hypertrophy and dentofacial abnormalities in Korean children. The present study included consecutive children who visited a pediatric clinic for sleep-disordered breathing due to habitual mouth breathing, snoring or sleep apnea. Their palatine tonsils and adenoids were graded by oropharyngeal endoscopy and lateral cephalometry. Anterior open bite, posterior crossbite, and Angle's class malocclusions were evaluated for dentofacial abnormality. The receiver-operating characteristic curve analysis was used to identify age cutoffs to predict dentofacial abnormality. A total of 1,083 children were included. The presence of adenotonsillar hypertrophy was significantly correlated with the prevalence of dentofacial abnormality [adjusted odds ratio = 4.587, 95% CI (2.747-7.658)] after adjusting age, sex, body mass index, allergy, and Korean version of obstructive sleep apnea-18 score. The cutoff age associated with dentofacial abnormality was 5.5 years (sensitivity = 75.5%, specificity = 67%) in the children with adenotonsillar hypertrophy and 6.5 years (sensitivity = 70.6%, specificity = 57%) in those without adenotonsillar hypertrophy. In conclusion, adenotonsillar hypertrophy may be a risk factor for dentofacial abnormalities in Korean children and early surgical intervention could be considered with regards to dentofacial abnormality.

Influencing factors on the effect of mandibular advancement device in obstructive sleep apnea patients: analysis on cephalometric and polysomnographic parameters.

BACKGROUND: The purposes of this study were to evaluate clinical outcome of mandibular advancement device (MAD) for obstructive sleep apnea (OSA) patients and to estimate influencing factors on MAD effect. METHODS: From the patients who were diagnosed as OSA by polysomnography at Seoul National University Bundang Hospital from January 2007 to February 2009, the patients who chose MAD as initial treatment option were included. All the patients' data were collected by reviewing and analyzing medical record and radiograph retrospectively. RESULTS: Eighty-six patients (76 males and 10 females; mean age of 51.5 ± 9.8 years) with OSA were included in this study. Total success rate of MAD treatment was 47.7% (41/86 patients). Among cephalometric parameters, lower facial height (35.61 ± 4.26 vs. 38.19 ± 4.89) showed significant difference between success group and non-success group. From the polysomnographic parameters, apnea index (19.79 ± 17.32 vs. 30.08 ± 23.28), average oxygen saturation (95.03 ± 1.42 vs. 94.32 ± 1.56), lowest oxygen saturation (81.44 ± 6.64 vs. 76.87 ± 7.98), oxygen saturation under 90% (4.47 ± 5.90 vs. 9.01 ± 9.29), and oxygen desaturation index (23.58 ± 17.46 vs. 37.16 ± 22.35) showed significant difference between groups. CONCLUSIONS: From the results, it was proved that MAD was an effective treatment option for the OSA patients. Some cephalometric and polysomnographic parameters including posterior lower facial height, apnea index, average oxygen saturation, lowest oxygen saturation, oxygen saturation under 90 %, and oxygen desaturation index could be influencing factors on MAD effect.