The effect of tongue reduction for preventing adverse effects in patients undergoing class III orthognathic surgery: a three-dimensional comparative analysis.

OBJECTIVES: This study aims to evaluate the potential benefits of combining tongue reduction with mandibular setback surgery in patients undergoing class III orthognathic surgery. Specifically, we investigated whether this combined approach reduced the risk of surgical relapse, condylar resorption, and airway space reduction by mitigating tongue pressure on the mandible. MATERIAL AND METHODS: The study retrospectively enrolled patients who had undergone bilateral sagittal split ramus osteotomy (BSSRO) with at least 5 mm of setback and met the criteria of a body mass index > 20 kg/m2 and tongue volume > 100 mm3. The study included 20 patients with 10 in the tongue reduction group (TR, n = 10) and 10 in the BSSRO only group (SO, n = 10). RESULTS: The volumetric changes of the total airway space were significantly different between the TR and SO groups (p = 0.028). However, no significant differences were observed in the condylar resorption and postoperative relapse between the groups (p = 0.927 and 0.913, respectively). The difference between the resorption of the anterior and posterior segments of the condyle was also statistically insignificant (p = 0.826). Postoperative counterclockwise rotation of the proximal segment only demonstrated a significant correlation with postoperative relapse (p = 0.048). CONCLUSIONS: The reduction in tongue volume demonstrated a preventive effect on the reduction of the airway space after mandibular setback, although it did not yield statistical significance concerning surgical relapse and condylar volume. The counterclockwise rotation of the proximal segment might be responsible for the forward displacement of the distal segment and postoperative relapse. However, the clinical implications of this finding should be interpreted with caution owing to the limited sample size CLINICAL RELEVANCE: Tongue reduction could potentially serve as a preventive measure in preserving the airway space and might be beneficial in mitigating the risk of obstructive sleep apnea in patients with class III deformity.

Volume stability of hydroxyapatite and ß-tricalcium phosphate biphasic bone graft material in maxillary sinus floor elevation: a radiographic study using 3D cone beam computed tomography.

OBJECTIVES: The purpose of this study was to confirm volume stability of biphasic calcium phosphate (BCP) through the changes of grafted volume over the time by 3D CT analyzing software program. PATIENTS AND METHODS: Fifteen patients, 16 sinuses who were scheduled a staged implantation through sinus floor elevation (SFE)-lateral window technique from 2009 to 2011 were included in the study. Of the 15 patients, eight were male and seven were female (mean age 50.1). For sinus floor augmentation, BCP with local blood was packed loosely into the maxillary sinus and the grafted site was covered with a collagen membrane. For the evaluation of volume change, 3D CBCT scans were taken five times at pre-operatively (To), post-op 1 week (T1), 1 month (T2), 3 months (T3), and 6 months (T4). 3D image processing software (OnDemand3DTM software) was used for this study. The time sequential change was statistically evaluated. RESULT: 84.32% grafted BCP is maintained until post-op 6 month (T4), and the average volume loss is 207.7 mm(3) (about 0.21 cc). Statistically, a significant volume change (decreasing) was observed in three groups (T2-T1, T3-T2, T4-T3). CONCLUSION: Biphasic calcium phosphate, as a synthetic material, has high volume stability and is a predictable graft material for the successful SFE. Although some limitations of the 3D analyzing software program, it is a fast, simple, relatively accurate and promising approach to quantifying long-term changes in the grafted area.

Effect of low-level laser therapy on orthodontic tooth movement into bone-grafted alveolar defects.

INTRODUCTION: The objective of this study was to investigate the effect of low-level laser therapy (LLLT) on the rate of orthodontic tooth movement (OTM) into bone-grafted alveolar defects based on different healing states. METHODS: Ten male beagles were randomly allocated to 3 groups: group C, OTM alone as a control; group G, OTM into the grafted defects; group GL, OTM into the grafted defects with LLLT. The maxillary second premolars were protracted into the defects for 6 weeks, immediately (G-0 and GL-0) and at 2 weeks (G-2 and GL-2) after surgery. The defects were irradiated with a diode laser (dose, 4.5 J/cm(2)) every other day for 2 weeks. The rates of OTM and alveolar bone apposition, and maturational states of the defects were analyzed by histomorphometry, microcomputed tomography, and histology. RESULTS: The total amounts of OTM and new bone apposition rates were decreased by LLLT, with increased bone mineral density and trabecular maturation in the defects. Group GL-2 had the slowest movement with root resorption in relation to less woven bone in the hypermatured defect. CONCLUSIONS: LLLT significantly decreased the rate of OTM into the bone-grafted surgical defects by accelerating defect healing and maturation, particularly when the start of postoperative OTM was delayed.

Differences in bone remodeling using demineralized bone matrix in bilateral sagittal split ramus osteotomy: a study on volumetric analysis using three-dimensional cone-beam computed tomography.

PURPOSE: The aim of this study was to examine the effects of demineralized bone matrix (DBM) grafts on bone remodeling during sagittal split ramus osteotomy by measuring 3-dimensional (3D) reconstructed images. PATIENTS AND METHODS: Forty-eight patients were selected for this study. In the control group, no grafts were performed. In the DBM group, DBX grafts were placed between the proximal and distal segments. Three-dimensional cone-beam computerized tomographic (3D-CBCT) images were obtained within 1 week, after 3 months (T2), and after 6 months (T3) postoperatively. By measuring the total skeletal volume from the right condylar head to the right mandibular first molar, the volume of the graft site was measured indirectly. Using the data thus obtained, a volume-increasing ratio (percentage) was computed. SimPlant analytical software was used to analyze the 3D reconstructed volumes. RESULTS: The 2 groups showed a significant increase in volume. However, in the same period, the volume-increasing ratios of the 2 groups showed significant differences. In the control group, a significant increase in volume was seen until T2, after which a negligible increase was seen. Conversely, in the DBM group, a significant volume increase continued until T3. CONCLUSION: In orthognathic surgeries, grafting using DBM is a favorable procedure that accelerates bone formation. Therefore, in cases with inevitable large bony gaps, DBM grafts can play a positive role in the stable healing of segments and the prevention of postoperative complications. Moreover, because volumetric analysis using 3D-CBCT analyzing software is a fast and simple method, future studies using this technique are expected to increase.

Salvage of the condylar fracture: complication management of mandibular angle ostectomy.

A prominent mandibular angle is considered to be unattractive in Asians because it gives the face a square, coarse, and muscular appearance. Mandibular angle ostectomy has been known to be effective and to satisfy both surgeons and patients. However, a narrow surgical field hinders direct view of the site, making a procedure that is rather difficult to perform. Despite thorough presurgical planning and attention, there can be many complications and unfavorable results. A 21-year-old woman with right condyle process fracture was referred to Kyung Hee University Hospital at Gangdong. The patient was previously treated with mandibular angle reduction surgery at a local clinic. Via an extraoral approach, the condyle process was replaced and fixed using 1 long metal screw and one 2 × 2 square metal plate. We overcame the condylar fracture caused by mandibular angle ostectomy with reasonable reduction of the right condyle.

Timing of force application affects the rate of tooth movement into surgical alveolar defects with grafts in beagles.

INTRODUCTION: The purpose of this study was to investigate the influence of the timing of orthodontic force application on the rates of orthodontic tooth movement into surgical alveolar defects with bone grafts in beagle dogs. METHODS: Twelve beagles were randomly divided into 2 groups according to the surgical procedure: alveolar osteotomy alone (control) or osteotomy with bone graft (experimental group). The maxillary second premolars were protracted for 6 weeks into the surgical sites: immediately, at 2 weeks, and at 12 weeks after surgery. The orthodontic tooth movement rates and alveolar remodeling concomitant with surgical defect healing were evaluated by model measurements and histomorphometry as well as microcomputed tomography and histology. One-way analysis of variance and the Scheffé post hoc comparison were performed for investigating the rates of orthodontic tooth movement and mineralized bone formation. RESULTS: Both the orthodontic tooth movement rate and the mean appositional length of mineralized bone in the tension side of teeth were significantly accelerated when force was applied at 2 weeks in the control group and immediately in the experimental group (P <0.001). The 2-week control group showed a dramatic increase in apposition rate during 4 to 6 weeks after force application, whereas the immediate protraction experimental group did within the first 3 weeks (P <0.001). Decreased orthodontic tooth movement rates and reduced bone remodeling activities were apparent in the 12-weeks groups, especially in nongrafted defects. CONCLUSIONS: A bone graft into the surgical defect can not only allow immediate force application for accelerating orthodontic tooth movement with favorable periodontal regeneration, but also decrease the risk of inhibited orthodontic tooth movement in case of delayed force application after surgery.

A clinical retrospective study of implant as a risk factor for medication-related osteonecrosis of the jaw: surgery vs loading?

BACKGROUND: Risk factors for developing medication-related osteonecrosis of the jaw (MRONJ) include the general condition of the patient, smoking habit, poor oral hygiene, and the type, duration, and administration route of the drug, dentoalveolar surgery, such as implant placement. This study aimed to discuss whether implants may induce osteonecrosis in older patients receiving long-term medication and to analyze the radiological pattern of the bone necrosis. METHODS: This study included 33 patients diagnosed with dental implant-associated medication-related osteonecrosis of the jaw. Data regarding the medical history, type of medication used, durations of administration, laboratory test results, onset of bone necrosis since implant placement, type of opposing teeth, and radiological pattern of the bone necrosis on cone-beam computed tomography were recorded in patients with and without implants. RESULTS: The most commonly used drug was bisphosphonate, with an average duration of use of 61.37 (± 53.72) months. The laboratory results showed average serum C-terminal cross-linking telopeptide (CTX) level of 0.23 ng/mL, vitamin D, 23.42 ng/mL, and osteocalcin, 4.92 ng/mL. Osteonecrosis occurred after an average of 51.03 (± 39.75) months following implant placement. Radiological evaluation revealed obvious sequestration in the implant-absent group, and the formation of a unit sequestration with an implant fixture (en bloc) was observed in the implant-present group. The patients underwent surgical treatment of sequestrectomy and explantation. CONCLUSION: Implant placement, especially loading, may be considered a potential risk factor for the development of osteonecrosis in patients undergoing antiresorptive treatment.

Usefulness of a Low-Dose Sclerosing Agent for the Treatment of Vascular Lesions in the Tongue.

Hemangiomas and vascular malformations are common benign lesions of vessels in the cervical region. However, the lesions may not completely disappear and may require surgical or nonsurgical intervention. Several treatment options, including surgical excision, steroid injection, laser therapy, and sclerotherapy, are available. Surgical excision is a commonly used treatment; however, in cases of hemangiomas of the tongue, excision of the lesion may cause esthetic or functional impairments, including speech and swallowing. Sclerotherapy is a simple and safe method for treating vascular lesions conservatively. In this case report, two patients with a vascular lesion of the tongue underwent conservative sclerotherapy without surgical excision using a sclerosing agent (sodium tetradecyl sulfate). Both patients showed regression of the lesion without complications. As presented in these cases, repeated injections of low-dose 1% sodium tetradecyl sulfate as a sclerosing agent were safe and showed satisfactory outcomes.

Setback genioplasty with rotation for aesthetic mentolabial soft tissue: a case report.

The mentum plays an important role in the aesthetics of the face, and genioplasty is performed to improve an unbalance of the mentum. Among the various surgical approaches, setback genioplasty is used to create an aesthetic jaw-end appearance by moving the mentum backward when it protrudes more than normal. However, conventional setback genioplasty may be aesthetically disadvantageous because the profile of the mentum could become flat. This case study attempted to overcome the limitations of conventional setback genioplasty by rotating the position of the menton and pogonion. We devised a new method for setback genioplasty by rotating the segment anteroinferiorly. Using virtual surgery, we were able to specify the range of surgery more accurately and easily, and the surgery time was reduced. This case report showed the difference in chin soft tissue responses between conventional setback genioplasty and setback genioplasty with rotation.

The Efficacy of the Partial Glossectomy for Prevention of Airway Volume Reduction in Orthognathic Surgery of Class III Patients.

The aim of this study was to evaluate the effects of a partial glossectomy on volumetric changes of pharyngeal airway space (PAS) in patients with mandibular setback surgery. Overall, 25 patients showing clinical features related to macroglossia treated with mandibular setback surgery were included in this retrospective study. Subjects were divided into two groups: the control group (G1, n = 13, with BSSRO) and the study group (G2, n = 12, with both BSSRO and partial glossectomy). The PAS volume of both groups was measured by the OnDemand 3D program on CBCT taken shortly before operation (T0), 3 months post-operative (T1), and 6 months post-operative (T2). A paired t-test and repeated analysis of variance (ANOVA) were used for statistical correlation. Total PAS and hypopharyngeal airway space were increased after operation in Group 2 compared to Group 1 (p < 0.05), while oropharyngeal airway space showed no significant statistical difference with the tendency of increasing. The combination of partial glossectomy and BSSRO surgical techniques had a significant effect on increasing the hypopharyngeal and total airway space in class III malocclusion patients (p < 0.05).

Comparison of vertical bone resorption following various types of autologous block bone grafts.

BACKGROUND: This study aims to measure and compare the differences in vertical bone resorption after vertical augmentation using different types of autologous block bone. METHODS: Data were collected from 38 patients who had undergone vertical ridge augmentation using an autologous block bone before implant insertion. The patients were divided into three groups based on the donor sites: ramus bone (RB), chin bone (CB), and iliac crestal bone (IB). RESULTS: The surgical outcome of the augmentation was evaluated at the follow-up periods up to 60 months. In 38 patients, the mean amount of vertical bone gain was 8.36 ± 1.51 mm in the IB group, followed by the RB group (4.17 ± 1.31 mm) and the CB group (3.44 ± 1.08 mm). There is a significant difference in vertical bone resorption between the groups (p < 0.001), and the RB group demonstrated significantly lower resorption than the CB and IB groups (p = 0.011 and p < 0.001, respectively). The most common postoperative complications included neurosensory disturbance in the CB graft and gait disturbance in the IB graft. Out of the 92 implants inserted after augmentation, four implants were lost during the study period, resulting in an implant success rate of 95.65%. CONCLUSIONS: The RB graft might be the most suitable option for vertical augmentation in terms of maintaining postoperative vertical height and reducing morbidity, although the initial gain was greater with the IB graft compared to other block bones.

Bisphosphonates modulate the expression of OPG and M-CSF in hMSC-derived osteoblasts.

Bisphosphonates have been known to suppress osteoclast activity, survival, and recruitment. In this study, we tested effects of BPs on expression of two critical genes for osteoclastogenesis, M-CSF, and OPG in the process of osteoblast differentiation from hMSC. (1) The cells were cultured in osteogenic induction medium together with 0 (control group) and 10-8 M alendronate, pamidronate for up 2 and 3 weeks (for real-time PCR) and 3 and 4 weeks (for ELISA). (2) The real-time PCR protocol for M-CSF, OPG, and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) consist of 40 cycles. (3) Enzyme-linked immunosorbent assay (ELISA): the amounts of M-CSF and OPG in the culture medium were determined using commercially available ELISA kits for M-CSF and OPG. Treatment of differentiating cells with alendronate or pamidronate, nitrogen-containing BPs increase the expression of OPG, which suppresses osteoclastogenesis, whereas it decreases the expression of M-CSF, which enhances preosteoclast formation. These results suggest a new mechanism by which BPs inhibit osteoclastogenesis. Results support hypothesis that progressive accumulation of bisphosphonate in jaws causes imbalance in osteogenesis and bone absorption and collateral osteoclast-osteoblast interaction. Bisphosphonate-related osteonecrosis of jaw (BPONJ) is one of the most serious complications of bisphosphonate (BP) therapy. However, the mechanism behind the this process of BPONJ is still unclear and there are so many hypotheses. Among many hypotheses, we focused on osteoclast-osteoblast interaction in this study. The findings of this study show new light on the present BPONJ occurrence theory based on the osteoclastic activity of BPs. Also, a more advanced and developed theory for BRONJ occurrence may be obtained by combining the osteoclast inhibition mechanism and the effects on osteoblastic differentiation by BPs.

Postoperative stability of 2-jaw surgery with clockwise rotation of the occlusal plane.

OBJECTIVE: The objective of this study was to investigate the skeletal stability after Le Fort I osteotomy with clockwise rotation and bilateral sagittal split osteotomy. MATERIALS AND METHODS: The sample consisted of 31 young Korean patients who were treated with Le Fort I osteotomy with clockwise rotation and setback bilateral sagittal split osteotomy. The lateral cephalographs were obtained before surgery (T1), right after surgery (T2), and on an average of 6.23 months after the operation (T3). The horizontal and vertical relations of landmarks to the reference line and soft tissue changes were evaluated. RESULT: During the T2 - T1 period, there was superior and anterior movement of the posterior part (PNS, UMD) and advancement and impaction of the anterior part (ANS, A point, UIE) of the maxilla. The mandible was moved superiorly and posteriorly. During the T3 - T2 period, maxillary segment showed counterclockwise rotational relapse. The posterior part was relatively stable especially in the vertical position and the anterior part moved in the posterior and superior directions. Mandibular landmarks showed forward relapse in the horizontal aspect and superior relapse in the vertical aspect. The posterior part (PNS and UMD) showed a significantly higher stability rate (>70%) in the vertical aspect and the anterior part of the maxilla (ANS, A point) demonstrated a significantly lower value (<30%) in the vertical aspect. According to the skeletal changes, the soft tissue of the lower facial profile is rotated clockwise. CONCLUSIONS: Two-jaw surgeries involving clockwise rotation of the occlusal plane showed stable results especially in the maxillary posterior landmarks. The clockwise rotational movement can be beneficial to increase skeletal stability and facial aesthetics in Asians.

Osteochondroma of the mandibular condyle: surgical excision followed by occlusal stabilization.

Osteochondroma of the mandibular condyle in adults can be treated by surgical excision, condylectomy followed by costochondral graft or orthognathic surgery. Such complex treatment plan may not be appropriate for patients with old age, affected with chronic osteochondroma of the condyle. In this clinical report, we present a patient with osteochondroma of the condyle treated by surgical excision. The patient's postoperative occlusion was a contraindication for orthognathic surgery because of the severe abrasion of the teeth and the chronic compensation of the dentition to the deviated mandible. Surgical excision of the lesion was carried out under general anesthesia, and the remaining condylar head was salvaged as much as possible. No graft materials or posthodontic condyle reconstruction was carried out. Because there was no occlusal stop to secure the mandible in a centric relation position of the condyle, a stabilization splint was delivered to position the condyle in a relatively stable position. The stability of the condyle position was evaluated by follow-up cone beam computed tomographic scans of the pathologic and the contralateral condyle, along with clinical factors such as occlusal contact points and mandible movements assayed by ARCUSdigma (KaVo). After significant condylar position was achieved, full prosthodontic reconstruction was performed to both the patient's and the dentist's satisfaction.

Sinus mucosal healing pattern according to pterygomaxillary disjunction type after Le Fort I osteotomy.

Objectives: During Le Fort I osteotomy, the separation of the pterygomaxillary junction (PMJ) is a difficult procedure for most surgeons because it is invisible. In this process, damage to the posterior structures constituting the sinus or those adjacent to it, including the maxillary sinus posterior wall and pterygoid plate, may occur. We would like to investigate the effects of this on the inside of the maxillary sinus after surgery and whether there are complications. Materials and Methods: One-hundred patients who underwent Le Fort I osteotomy from 2013 to 2020 using cone-beam computed tomography images were classified into two groups (clean-cut type and fractured type) according to the PMJ cutting pattern. In addition, the mucosal thickness in the maxillary sinus was divided into preoperative, postoperative three months, one year, and the change over the course of surgery was evaluated retrospectively. Results: Of the total 100 cases, the clean-cut type numbered 28 cases and the fractured type totaled 72 cases. Among the fracture types, part of the sinus wall and the pterygoid plate were broken in 69 cases, and the maxillary sinus posterior wall was detached in three cases. There was no statistically significant difference in sinus mucosal thickening between the clean-cut type and fractured type of the PMJ, three months and one year after surgery between the two groups. However, there was a significant difference in sinus mucosal thickness at postoperative one year in the case where a partial detachment of the maxillary sinus posterior wall occurred compared to not. Conclusion: Even if there is some damage to the structures behind the PMJ, it may not be reasonable to spend some time on the PMJ separation process considering the overall postoperative complications, if there is no significant difference inside the sinus, or increased probability of postoperative complications.

Retrospective clinical study of mandible fractures.

BACKGROUND: As society becomes more complex, the incidence of mandibular fractures is increasing. This study aimed to analyze the incidence and type and identify etiological factors of mandibular fractures to use them in future treatments. MATERIAL AND METHODS: Data were collected from 224 patients who visited the department of oral and maxillofacial surgery at the Kyung Hee Medical Center dental hospital during a 6-year period (2016 to 2021). A logistic regression model was used for data analysis. RESULTS: In a total of 224 patients, 362 fractures were appeared. The average age of the patients was 34.1 years, with the highest incidence in the 20s. And the ratio between male and female was 4.09:1. Symphysis fractures were the most prevalent of all patients (52.7%), followed by unilateral condyle (37.1%), angle (36.2%), bilateral condyle (9.4%), body (8%), and coronoid (2.2%). The most common cause of fracture was daily-life activity (57.6%), followed by violence (30.4%), traffic accidents (8.5%), and syncope (3.6%). Patients with symphysis fracture were at low risk (OR < 1) of angle, body, and unilateral condyle fractures. Similarly, patients with unilateral fracture were at low risk (OR < 1) of symphysis, angle, body, and others site fractures. In contrast, patient with bilateral condyle fracture were at high risk (OR > 1) of coronoid fractures. And younger patients were high risk of mandibular angle fractures. CONCLUSION: Through this study, it was confirmed that etiological factors of mandibular fractures were like those of previous studies.

Retrospective study of two biochemical markers for the risk assessment of oral bisphosphonate-related osteonecrosis of the jaws: can they be utilized as risk markers?

PURPOSE: the purpose of this retrospective study was to examine the possibility of utilizing serum C-terminal telopeptide cross-link of type I collagen (s-CTX) and serum osteocalcin (s-OC) as risk markers for oral bisphosphonate-related osteonecrosis of the jaws (BRONJ). PATIENTS AND METHODS: the s-CTX values and the s-OC values were measured from 23 patients (one male, 22 females) diagnosed with BRONJ using clinical and radiographic examinations. The two biochemical markers were evaluated during a regular checkup for osteoporosis management. For the control group of s-CTX study, s-CTX values were obtained from 61 independently recruited postmenopausal women who have been on bisphosphonate therapy for >6 months. The s-CTX values of the ONJ group and the control group were compared. Because of retrospective nature of this study, the control group for s-OC study could not be established. A single sample t-test was performed for the s-OC value from the ONJ group. RESULT: twenty-three ONJ patients had taken alendronate for osteoporosis treatment, and the s-CTX testing results were low levels of 10-192 pg/ml (mean: 93.2 ± 49.4 pg/ml). Mean of s-CTX of the control (n=61) was 125 ± 85.7 pg/ml. The duration of BP therapy ranged between 1 and 10 years (4.82 ± 2.6). The s-OC level was estimated between 0.2 and 5.4 ng/ml (1.91 ± 1.51 ng/ml). The mean s-CTX value of the control group was higher but without significance (P=0.12). The s-OC values of the ONJ group were significantly lower than the lowest value of the reference range (P<0.001). CONCLUSION: as a result of the s-CTX and s-OC testings at the diagnosis of BRONJ, the values of the two markers were decreased. The decrease of the s-OC values implies a problem during the bone-formation process. Therefore, we can assume that in this patient group, invasive dental surgery contributes to an increase in the risk of BRONJ incidence. This result may imply that, during bisphosphonate therapy, simultaneous consideration of s-CTX showing inhibition of bone resorption and s-OC indicating the degree of bone formation might be a set of risk markers assessing risk prediction for BRONJ before invasive dental surgery.

Effect of lower third molars on the incidence of mandibular angle and condylar fractures.

PURPOSE: Numerous previous studies already have proven that mandibles with a third molar are significantly more susceptible to angle fracture by external force. Similarly, other data suggest that the absence of a third molar increases the risk of condylar fracture, while concurrently decreasing the risk of angular fracture. We attempt to characterize the effect of a third molar on the incidence of mandibular angle and condylar fractures. METHODS: This retrospective study reviews data from 385 patients, all of whom were seen in our clinics between February 2006 and November 2009. All data were collected from clinical examination notes and panoramic radiographs, with third-molar state evaluated by the Pell and Gregory classification system. RESULTS: Our results mirror those of previous studies. The incidence of mandibular angle fracture was significantly greater on sides with a third molar, whereas the condylar fracture rate significantly increased in mandibles lacking a third molar or without a fully erupted third molar. The rate of symphysis and mandibular angle fracture was also high in cases of multiple comorbid fractures. CONCLUSIONS: Both the presence and the state of the lower third molar affect the risk of future mandibular angle and condylar fracture.

Posterior bending osteotomy: An effective measure to secure facial symmetry in orthognathic surgery.

This study aimed to compare the effectiveness of posterior bending osteotomy and grinding techniques for orthognathic surgery in patients with facial asymmetry. Patients who had undergone Le Fort I osteotomy and bilateral sagittal split ramus osteotomy, and who presented with a menton shift and setback difference exceeding 4 mm, were enrolled. Cone-beam computed tomography was performed before surgery (T0), immediately after surgery (T1), and 6 months after surgery (T2). Overall, 38 patients were included and divided into posterior bending osteotomy (n = 23) and grinding (n = 15) groups. Significant differences were observed between the posterior bending osteotomy and grinding groups on the treated side. In the grinding group, the gonion on the treated side was displaced slightly outward, resulting in a significant difference between both sides (non-treated side: 50.52 ± 4.20 [T0] and 48.67 ± 4.37 [T2]; treated side: 50.88 ± 4.55 [T0] and 51.00 ± 3.95 [T2]; p = 0.038). In the posterior bending osteotomy group, bilateral inward movements of the gonion were observed, and the distance from the midsagittal plane to the gonion did not differ significantly between the sides (non-treated side: 46.74 ± 4.41 [T0] and 45.54 ± 3.95 [T2]; treated side: 47.43 ± 4.93 [T0] and 45.18 ± 3.52 [T2]; p = 0.224). The yawing movement of the proximal segment was greater in the grinding group than in the posterior bending osteotomy group (non-treated side: p = 0.839; treated side: p = 0.025). Posterior bending osteotomy is recommended over the grinding method for patients with severe facial asymmetry, in order to ensure a symmetric and esthetic facial profile by allowing passive adaptation between the mandibular segments.

Removal of a suture needle: a case report.

BACKGROUND: Foreign bodies may be embedded or left behind in the oral cavity during oral surgical procedure. The loss of instruments such as impression material, surgical gauze, and broken injection needles are commonly reported in the dental field. These complications are generally symptomatic and show signs of inflammation, pain, and purulent discharge. Accidental breakage of suture needles is a rare but potentially dangerous event. CASE PRESENTATION: In this report, we present one case of lost suture needle during the procedure of flap operation at local dental clinic and its successful removal under local/general anesthesia administration via CBCT with a help of two reference needles to localize the 6-0 nylon needle and consulting with the clinician. CONCLUSION: CT scanning taken while mouth-closing may not be accurate with regard to real location measurement performed while mouth-opening. If so, other up-to-date radiographic devices and methods to retrieve a needle are recommended.