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Background: Although most impacted third molars (ITMs) are extracted in the teens and early 20s, some undergo extractions after their 40s. It is unclear whether the reasons for extraction, the degree of impaction, and complications differ in patients in an older age group compared with a younger age group., Purpose: The purpose of this study was to measure the association between age and 1) reason for extraction and 2) postoperative complications., Study Design, Setting, Sample: This was a retrospective cohort study of patients who had undergone surgical extraction of at least one mandibular ITM at a single institution. We excluded 1) age under 20 years, 2) follow-up period of less than 1 week, and 3) tooth extraction under general anesthesia., Predictor Variable: The primary predictor variable was age, classified into 3 groups (20s:20-29; 30s:30-39; over 40s: 40 and greater)., Main Outcome Variable(s): The primary outcome variables were the reason for extraction (prophylactic or symptomatic) and the presence of complications. The secondary outcome variable was type of complication (postoperative infection, dry socket, neurosensory disturbance, presenting pain over 1 month, retained root requiring secondary treatment)., Covariates: The covariates were sex, laterality of ITM, and difficulty of extraction as measured by the difficulty index, a measure based on depth, orientation, and ramus relationship/space available, with a higher score indicating greater difficulty., Analyses: χ 2 test was performed to analyze the association of categorical outcome variables and covariates. Level of statistical significance was set at P < .05., Results: Of a total of 831 eligible subjects, there were 555 (66.8%), 159 (19.1%), and 117 (14.1%) in the 20s, 30s, and over 40s age groups, respectively. The percentage of symptomatic extraction of ITM was significantly higher in the over-40 age group compared with the 20s group (92.3 vs 69.4%, (P < .001). Complication rate also significantly differed between over 40s group and the 20s group (7.7 vs 1.8%, P < .001). Difficulty index and indications for ITM extraction were significantly different between groups (P < .001)., Conclusion and Relevance: Symptoms, difficulty, and complications related to ITM increase at over 40 years of age. This should be taken into consideration during the joint clinical decision-making process with patients with ITM., (Copyright © 2024 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Objective: To investigate the highest opportunity skin puncture point and needle orientation according to facial asymmetry and classification., Methods: Computed tomography of 136 patients was analyzed. Horizontal and vertical angles and distances from the canthal-tragal line were investigated to determine the puncture point and needle's angle., Result: All patients' average points were 7.39 (±2.85) mm anterior to the tragus and 3.44 (±4.18) mm below the canthal-tragal line with an angle of 8.53 (±6.90)° anteriorly and 32.26 (±7.23)° superiorly. Regarding asymmetry, there was a statistical difference in horizontal angle, depth, and canthal-tragal distance between the deviated and non-deviated sides. Especially, vertical distances were 4.44 (±4.66) mm and 2.59 (±4.11) mm in the deviated and non-deviated sides, respectively ( p < 0.001)., Conclusion: In closed-mouth, the puncture point was closer to the tragus and lower than the conventional point. The point in the deviated side should be considered lower than the non-deviated side.

Temporomandibular joint disorders are prevalent causes of orofacial discomfort. Diagnosis predominantly relies on assessing the configuration and positions of temporomandibular joint components in magnetic resonance images. The complex anatomy of the temporomandibular joint, coupled with the variability in magnetic resonance image quality, often hinders an accurate diagnosis. To surmount this challenge, we developed deep learning models tailored to the automatic segmentation of temporomandibular joint components, including the temporal bone, disc, and condyle. These models underwent rigorous training and validation utilizing a dataset of 3693 magnetic resonance images from 542 patients. Upon evaluation, our ensemble model, which combines five individual models, yielded average Dice similarity coefficients of 0.867, 0.733, 0.904, and 0.952 for the temporal bone, disc, condyle, and background class during internal testing. In the external validation, the average Dice similarity coefficients values for the temporal bone, disc, condyle, and background were 0.720, 0.604, 0.800, and 0.869, respectively. When applied in a clinical setting, these artificial intelligence-augmented tools enhanced the diagnostic accuracy of physicians, especially when discerning between temporomandibular joint anterior disc displacement and osteoarthritis. In essence, automated temporomandibular joint segmentation by our deep learning approach, stands as a promising aid in refining temporomandibular joint disorders diagnosis and treatment strategies., (© 2024. The Author(s).)

This study measured and analyzed chronological changes in temporomandibular joint space volume by compartment following transoral vertical ramus osteotomy (TOVRO) using reconstructed 3-dimensional (3D) images of patients with mandibular prognathism. It included 70 joints of 35 patients who underwent TOVRO between January 2018 and December 2021. Computed tomography (CT) or cone-beam CT (CBCT) was performed before surgery (T0) and at 3 days (T1), 6 months (T2), and 12 months postoperatively (T3). These scans were then analyzed using 3D software. The volumes of the overall (Vjs), anterior (Vajs), posterior (Vpjs), medial (Vmjs), and lateral (Vljs) joint spaces were calculated at each time point. A linear mixed model and repeated-measures covariance pattern with unstructured covariance were used to evaluate significant changes in joint space volume over time. Vjs significantly increased to 134.54 ± 34.28 mm 3 at T3 compared to T0 (p < 0.001). Vpjas and Vljs increased by 130.72 ± 10.07 mm 3 and 109.98 ± 7.52 mm 3 at T3 compared to T0, respectively (p < 0.001). However, no significant difference was observed between T0 and T2 in Vajs and Vmjs (p = 0.9999). The observed volume increases in Vpjs and Vljs appeared to contribute to the overall Vjs increase., (© 2024. The Author(s).)

The clinical application of growth factors such as recombinant human bone morphogenetic protein-2 (rh-BMP-2), for functional bone regeneration remains challenging due to limited in vivo efficacy and adverse effects of previous modalities. To overcome the instability and short half-life of rh-BMP-2 in vivo, we developed a novel osteogenic supplement by fusing a protein transduction domain (PTD) with BMP-2, effectively creating a prodrug of BMP-2. In this study, we first created an improved PTD-BMP-2 formulation using lipid nanoparticle (LNP) micellization, resulting in downsizing from micrometer to nanometer scale and achieving a more even distribution. The micellized PTD-BMP-2 (mPTD-BMP-2) demonstrated improved distribution and aggregation profiles. As a prodrug of BMP-2, mPTD-BMP-2 successfully activated Smad1/5/8 and induced mineralization with osteogenic gene induction in vitro. In vivo pharmacokinetic analysis revealed that mPTD-BMP-2 had a much more stable pharmacokinetic profile than rh-BMP-2, with a 7.5-fold longer half-life. The in vivo BMP-responsive element (BRE) reporter system was also successfully activated by mPTD-BMP-2. In the in vivo rat tibia distraction osteogenesis (DO) model, micro-computed tomography (micro-CT) scan findings indicated that mPTD-BMP-2 significantly increased bone volume, bone surface, axis moment of inertia (MOI), and polar MOI. Furthermore, it increased the expression of osteogenesis-related genes, and induced bone maturation histologically. Based on these findings, mPTD-BMP-2 could be a promising candidate for the next-generation osteogenesis drug to promote new bone formation in DO surgery. STATEMENT OF SIGNIFICANCE: This study introduces micellized bone morphogenetic protein-2 (mPTD-BMP-2), a next-generation osteogenic supplement that combines protein transduction domain (PTD) and nano-sized micelle formulation technique to improve transduction efficiency and stability. The use of PTD represents a novel approach, and our results demonstrate the superiority of mPTD-BMP-2 over rh-BMP-2 in terms of in vivo pharmacokinetic profile and osteogenic potential, particularly in a rat tibial model of distraction osteogenesis. These findings have significant scientific impact and potential clinical applications in the treatment of bone defects that require distraction osteogenesis. By advancing the field of osteogenic supplements, our study has the potential to contribute to the development of more effective treatments for musculoskeletal disorders., Competing Interests: Declaration of Competing Interest Jong In Yook is an inventor on the patent related to this work filed by MET Life Sciences Co., Ltd. (Korean Patent application no. 10-2019-0076443, PCT application no. PCT/KR2020/007011). Nam Hee Kim, Hyun Sil Kim, and Jong In Yook are the founders and shareholders, and Jo Eun Um and Kyu Ho Hwang are employees of MET Life Sciences Co., Ltd. All the other authors declare that they have no competing interests., (Copyright © 2023. Published by Elsevier Ltd.)

This study aimed to evaluate the efficacy of deep learning (DL) for the identification and classification of various types of dental implant systems (DISs) using a large-scale multicenter data set. We also compared the classification accuracy of DL and dental professionals. The data set, which was collected from 5 college dental hospitals and 10 private dental clinics, contained 37,442 (24.8%) periapical and 113,291 (75.2%) panoramic radiographic images and consisted of a total of 10 manufacturers and 25 different types of DISs. The classification accuracy of DL was evaluated using a pretrained and modified ResNet-50 architecture, and comparison of accuracy performance and reading time between DL and dental professionals was conducted using a self-reported questionnaire. When comparing the accuracy performance for classification of DISs, DL (accuracy: 82.0%; 95% confidence interval [CI], 75.9%-87.0%) outperformed most of the participants (mean accuracy: 23.5% ± 18.5%; 95% CI, 18.5%-32.3%), including dentists specialized (mean accuracy: 43.3% ± 20.4%; 95% CI, 12.7%-56.2%) and not specialized (mean accuracy: 16.8% ± 9.0%; 95% CI, 12.8%-20.9%) in implantology. In addition, DL tends to require lesser reading and classification time (4.5 min) than dentists who specialized (75.6 ± 31.0 min; 95% CI, 13.1-78.4) and did not specialize (91.3 ± 38.3 min; 95% CI, 74.1-108.6) in implantology. DL achieved reliable outcomes in the identification and classification of various types of DISs, and the classification accuracy performance of DL was significantly superior to that of specialized or nonspecialized dental professionals. DL as a decision support aid can be successfully used for the identification and classification of DISs encountered in clinical practice.

Schwannomas are benign tumors originating from myelinating cells constituting nerve sheaths but rarely contain cellular elements of the nerve. The authors encountered a 47-year-old female patient with a schwannoma on the anterior mandibular ramus arising from the buccal nerve, measuring 3 cm×4 cm. Surgical resection was performed with preservation of the buccal nerve via microsurgical dissection. After one month, the sensory function of the buccal nerve was recovered without complications.

Background and Objective: MRI is considered the gold standard for diagnosing anterior disc displacement (ADD), the most common temporomandibular joint (TMJ) disorder. However, even highly trained clinicians find it difficult to integrate the dynamic nature of MRI with the complicated anatomical features of the TMJ. As the first validated study for MRI-based automatic TMJ ADD diagnosis, we propose a clinical decision support engine that diagnoses TMJ ADD using MR images and provides heat maps as the visualized rationale of diagnostic predictions using explainable artificial intelligence., Methods: The engine builds on two deep learning models. The first deep learning model detects a region of interest (ROI) containing three TMJ components (i.e., temporal bone, disc, and condyle) in the entire sagittal MR image. The second deep learning model classifies TMJ ADD into three classes (i.e., normal, ADD without reduction, and ADD with reduction) within the detected ROI. In this retrospective study, the models were developed and tested on the dataset acquired between April 2005 to April 2020. The additional independent dataset acquired at a different hospital between January 2016 to February 2019 was used for the external test of the classification model. Detection performance was assessed by mean average precision (mAP). Classification performance was assessed by the area under the receiver operating characteristic (AUROC), sensitivity, specificity, and Youden's index. 95% confidence intervals were calculated via non-parametric bootstrap to assess the statistical significance of model performances., Results: The ROI detection model achieved mAP of 0.819 at 0.75 intersection over union (IoU) thresholds in the internal test. In internal and external tests, the ADD classification model achieved AUROC values of 0.985 and 0.960, sensitivities of 0.950 and 0.926, and specificities of 0.919 and 0.892, respectively., Conclusions: The proposed explainable deep learning-based engine provides clinicians with the predictive result and its visualized rationale. The clinicians can make the final diagnosis by integrating primary diagnostic prediction obtained from the proposed engine with the patient's clinical examination findings., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests., (Copyright © 2023. Published by Elsevier B.V.)

Purpose: This retrospective study aimed to analyze the relationship between the volume of the fractured and the normal orbit in patients with unilateral orbital fractures with and without indirect traumatic optic neuropathy (TON)., Subjects: Data of 25 patients with unilateral orbital fractures who underwent computer tomography between January 2016 and December 2020 were investigated. Emergency imaging was performed within 2 hours of arrival at the emergency room. The subjects were categorized into two groups: unilateral orbital fractures with and without TON., Methods and Measures: The assessment of TON was performed during a comprehensive ophthalmologic examination by an ophthalmologist. The stereographic orbit was reconstructed, and the volume was calculated. Other variables examined included age, sex, and cause of orbital trauma. The variables were compared using paired t-tests. Statistical significance was set at p < 0.05., Results: The orbital volume of the non-fractured orbit was 27.50  ± 2.26 and 27.48  ±  2.64 cm 3 in the groups with and without TON, respectively. The average volume of the fractured orbit in the TON group was 27.78  ± 2.56 cm 3 , and there was no significant volumetric difference between the fractured and non-fractured sides in this group. However, the average volume of the fractured orbit without TON was 28.76  ±  3.18 cm 3 , larger than that of the non-fractured orbit (p = 0.016)., Conclusions: Non-expansion of the fractured orbit was a risk factor for indirect TON in patients with unilateral orbital fractures. Volumetric analysis from primary imaging would expedite the diagnosis and treatment of TON, resulting in optimal outcomes., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

This study aimed to evaluate the accuracy of automated deep learning (DL) algorithm for identifying and classifying various types of dental implant systems (DIS) using a large-scale multicenter dataset. Dental implant radiographs of pos-implant surgery were collected from five college dental hospitals and 10 private dental clinics, and validated by the National Information Society Agency and the Korean Academy of Oral and Maxillofacial Implantology. The dataset contained a total of 156,965 panoramic and periapical radiographic images and comprised 10 manufacturers and 27 different types of DIS. The accuracy, precision, recall, F1 score, and confusion matrix were calculated to evaluate the classification performance of the automated DL algorithm. The performance metrics of the automated DL based on accuracy, precision, recall, and F1 score for 116,756 panoramic and 40,209 periapical radiographic images were 88.53%, 85.70%, 82.30%, and 84.00%, respectively. Using only panoramic images, the DL algorithm achieved 87.89% accuracy, 85.20% precision, 81.10% recall, and 83.10% F1 score, whereas the corresponding values using only periapical images achieved 86.87% accuracy, 84.40% precision, 81.70% recall, and 83.00% F1 score, respectively. Within the study limitations, automated DL shows a reliable classification accuracy based on large-scale and comprehensive datasets. Moreover, we observed no statistically significant difference in accuracy performance between the panoramic and periapical images. The clinical feasibility of the automated DL algorithm requires further confirmation using additional clinical datasets., (© 2023. The Author(s).)

Purpose: To compare the clinical outcomes of autogenous and allogeneic demineralized dentin matrices loaded with recombinant human bone morphogenetic protein-2 (rhBMP-2; auto- and allo-DDM/rhBMP-2) by measuring the buccal marginal bone resorption around dental implants., Materials and Methods: This retrospective study included patients who underwent dental implant placement with auto-DDM/rhBMP-2 as the control group and allo-DDM/rhBMP-2 as the experimental group. The primary outcome was buccal marginal bone resorption on CBCT. The resorption was calculated during T0 (from surgery to prosthetic loading), T1 (during the first year after loading), and T2 (during the second year after loading). The secondary outcome was the histologic analysis of five specimens of each group, obtained during the prosthetic procedure., Results: Among the 103 implants, 61 and 42 implants were placed with auto- and allo-DDM/rhBMP-2 matrices, respectively. The resorptions of all periods were similar between the groups (T0: 0.65 ± 0.71 and 0.67 ± 0.81 mm, T1: 0.55 ± 0.60 and 0.59 ± 0.81 mm, and T2: 0.29 ± 0.45 and 0.20 ± 0.30 mm with auto- and allo-DDM/rhBMP-2, respectively). The histologic and histomorphometric analysis revealed similar osteoinductive aspects and proportions of new bone between the groups., Conclusion: Allo-DDM/rhBMP-2 showed comparable outcomes in terms of buccal marginal bone resorption to auto-DDM/rhBMP-2 during the second year after loading.

Objectives: This retrospective study aimed to analyze data on nerve damage in patients who complained of sensory changes after dental implant surgery, the clinical results according to proximity of the implant fixture to the inferior alveolar nerve (IAN) canal, and the factors affecting recovery of sensation., Materials and Methods: The electronic medical records of 64 patients who had experienced sensory change after implant surgery were reviewed. Patients were classified by sex, age, implant installation sites, recovery rate and the distance between the implant fixture and IAN canal on computed tomography (CT). The distance was classified into Group I (D>2 mm), Group II (2 mm≥D>0 mm), and Group III (D≤0 mm)., Results: The 64 patients were included and the mean age was 57.3±7.3 years. Among the 36 patients who visited our clinic more than two times, 21 patients (58.3%) reported improvement in sensation, 13 patients (36.1%) had no change in sensation, and 2 patients (5.6%) reported worsening sensation. In Group II, symptom improvement was achieved in all patients regardless of the removal of the implant fixture. In Group III, 8 patients (40.0%) had reported symptom improvement with removal of the implant fixture, and 2 patients (33.3%) of recovered patients showed improvement without removal. Removal of the implant fixture in Group III did not result in any significant difference in recovery ( P =0.337), although there was a higher possibility of improvement in sensation in removal cases., Conclusion: Clinicians first should consider removing the fixture when it directly invades the IAN canal. However, in cases of sensory change after dental implant surgery where the drill or implant fixture did not invade the IAN canal, other indirect factors such as flap elevation and damage due to anesthesia should be considered as causes of sensory change. Removal of the implant should be considered with caution in these situations.

The purpose of this study is to evaluate the degree of spontaneous bone healing after cyst enucleation as well as its contributing factors. Pre- and post-operative computed tomography (CT) scans of consecutive patients who had undergone jaw cyst enucleation were retrospectively analyzed. The outcome variable was healing ratio, which was calculated using the volume of the cyst before surgery and the volume of the defect in the bone after surgery. Predictor variables including duration of observation, pre-operative cyst size, age, gender, and involved jaw were analyzed to determine their influence. Forty-four subjects (30 Male and 14 Female, average 40.7 ± 15.7 years) were included in this study. Healing ratio was significantly lower during the first year (33.5 ± 32.8%) compared to the second (74.5 ± 24.2%) and subsequent years (74.2 ± 17.8%). In 35 patients who had follow-ups of over 1 year, the healing ratio was not affected by the pre-operative cyst size and upper/lower jaw except gender (p = 0.037, female &gt; male) and age (p = 0.021, younger than 30 years &gt; 30 years and older). The residual defect was significant larger in cysts 3 cc or larger (1.64 ± 1.54 cc) compared to smaller cysts (0.43 ± 0.42 cc, p = 0.006). The residual defect volume of large cysts was similar to those of the pre-operative volume of small cysts (1.47 ± 0.72 cc). In conclusion, spontaneous bone healing ratio of post-enucleation defects was about 73.5% after 12 months. Large cysts (&gt; 3 cc) had larger defect, comparable to the volume of small cysts, but with altered contour. Additional treatment such as a bone graft may be considered especially in large cysts., (© 2022. The Author(s).)

Purpose: The purpose of this study is to investigate whether there were differences in perception of facial profile esthetics at the upper lip, gnathic, and genial levels according to observer gender and age in the Korean layperson population., Methods: Ten male (M1 to M10) and 10 female (F1 to F10) silhouettes with differing facial profiles at the level of the upper lip, mandibular, and chin were created from a male and female facial profile deemed well-balanced and orthognathic by reviewer consensus. These silhouettes were presented to 288 participants who were asked to rank the 5 most attractive male and female profiles. The participants were composed of 144 males and 144 females divided into 4 age groups: group I (under 20 years), group II (20 to 39 years), group III (40 to 59 years), and group IV (over 60 years). The most preferred profile and observer scores were investigated and calculated. Descriptive analysis, χ 2 test, and analysis of variance were used for statistical analysis according to age and gender., Results: The most preferred male and female silhouettes were orthognathic profiles. There was no significant difference according to gender when rating male (P = .281) and female (P = .442) silhouettes. No statistically significant difference was observed even when analyzed according to age groups. Although the difference in observer scores among each ranking showed a statistical difference according to age groups, the overall rankings showed a similar pattern both in male and female silhouettes. In the same age group, no difference in rank scores according to gender was observed. Severe concave profiles were found to have the lowest rank., Conclusions: An orthognathic profile was rated as the most desirable in the Korean layperson population, with few differences in perception of esthetic facial profile according to age and gender., (Copyright © 2021 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Background/aims: A relationship between mandibular fractures and traumatic temporomandibular joint (TMJ) conditions has been suggested in many studies. Although magnetic resonance imaging (MRI) is the best option for a TMJ evaluation, few studies have evaluated the TMJ condition after a mandibular fracture using MRI follow-up. The aim of this study was to evaluate the TMJ for post-traumatic conditions following a mandibular fracture using follow-up MRI., Materials and Methods: Fourteen TMJs of seven young adult males (aged 19-21 years) with mandibular fractures were analyzed by MRI, and 12 TMJs of six patients were evaluated by follow-up MRI after the trauma. Regarding the intensity of MRI, the pathologic condition of TMJ was classified into acute joint inflammation, marrow edema, and joint space widening., Results: Thirteen joints (92.9%) showed pathologic conditions, including 11 with acute joint inflammation (84.6%), 10 with joint space widening (76.9%), and six with marrow edema (46.2%). Five out of 12 evaluated joints were injected with dexamethasone. Among these, four joints healed within one week, and one healed within one month. Among the seven untreated TMJs, four and one joint healed within one week and one month, respectively, but two joints of one patient did not improve until one month. Although that patient received arthrocentesis, the right joint showed osteoarthritis six months after the trauma., Conclusions: Most TMJs were acutely damaged due to mandibular trauma and healed within one week to one month. A follow-up examination could be considered at one month after the injury to confirm the possibility of traumatic TMJ disorder, such as osteoarthritis., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Wound dehiscence is a common complication following vertical bone augmentation of implant dentistry. If the implanted titanium mesh becomes exposed, the exposed titanium mesh should be removed with the contaminated grafts before a clinical graft infection develops. However, no generally accepted evaluation methods have been suggested to determine the removal timing or the extent of contaminated bone grafts to be removed. Quantitative light-induced fluorescence (QLF) technology has been used for various oral bacterial condition such as dental caries, plaque, peri-implantitis, and osteomyelitis. This paper reports two patients with wound dehiscence within the third week after vertical bone augmentation with autogenous particulate bone on the posterior maxilla. With conservative treatment, a QLF technology was applied to determine whether to remove the mesh. The exposed mesh of the first patient was removed when red-fluorescence was observed the red fluorescence by QLF. However, the other case did not show red fluorescence during the fifth week after dehiscence, and secondary healing was achieved without complications. The remaining bone grafts were well integrated into the sound cortico-cancellous complex sufficient to support the dental implant. Based on these clinical, radiological, and histological results, we discussed the rationale of QLF application on wound dehiscence after the bone graft in implant dentistry., (Copyright © 2021. Published by Elsevier B.V.)

Purpose: The aim of this study was to compare straight and tapered implant designs in terms of marginal bone loss, the modified plaque index (mPI), and the modified bleeding index (mBI) for 5 years after functional loading., Methods: Twelve patients were recruited. Two types of implants were placed adjacent to each other: 1 straight implant and 1 tapered implant. Marginal bone loss, mPI, and mBI were measured every year for 5 years after loading., Results: The straight implants showed 0.2±0.4 mm of marginal bone loss at 5 years after loading, while the tapered implants showed 0.2±0.3 mm of marginal bone loss; this difference was not statistically significant ( P= 0.833). Our analysis also showed no statistically significant differences in mPI (straight implants: 0.3±0.3 vs. tapered implants: 0.2±0.3; P= 0.414) or in mBI (straight implants: 0.3±0.4 vs. tapered implants: 0.2±0.3; P= 0.317) at 5 years after prosthesis delivery., Conclusions: Straight and tapered implants showed no significant differences with respect to marginal bone loss, mPI, and mBI for 5 years after loading., Competing Interests: No potential conflict of interest relevant to this article was reported., (Copyright © 2021. Korean Academy of Periodontology.)

This study examined the effects of general anesthesia on the postoperative pain level after third molar extractions compared to local anesthesia. This retrospective study included patients who underwent four simultaneous third molar extractions under general or local anesthesia and had records of their postoperative pain levels (visual analog scale, VAS). The pain level was determined in the early (Postoperative day; POD < #3) and late (POD #3-7) periods. The operation time and recently modified difficulty index were analyzed to validate the homogenous condition of the extraction. Of the 227 male inpatients (aged 20.9 ± 1.3 years), 172 and 55 patients underwent third molar extractions under local and general anesthesia, respectively. The age and difficulty index were distributed equally, but the operation time was longer in general anesthesia than in local anesthesia ( p < 0.001). The early and late periods featured similar pain outcomes. The operation time correlated with the total periods with a correlation coefficient of 0.271 ( p < 0.001). In conclusion, the postoperative pain following whole third molar extraction was related to the operation time rather than the anesthetic methods.

Background/aim: With the recent increased share of stand-up electric scooters (e-scooters), it is common to see people riding e-scooters on the roads in Korea. The aim of this study was to investigate traumatic injuries to the craniofacial region related to e-scooter accidents and to determine the role of dentists (especially oral and maxillofacial surgeons) in the evaluation of patients with trauma at the emergency department due to an e-scooter accident., Materials and Methods: This retrospective study investigated the medical records of patients who visited the Gangnam Severance Hospital Emergency Care Center for trauma related to e-scooter use from January 1, 2017 to March 31, 2020. Medical records were reviewed to determine the injuries sustained to the craniofacial region related to e-scooter use, including location of the injury (eg, cranium, craniofacial bone, teeth, soft tissue) and the type of trauma (eg, fracture, laceration, abrasion, contusion, concussion)., Result: A total of 256 patients' medical records were evaluated. Among them, 125 patients (48.8% of all patients) had sustained craniofacial trauma. Laceration (n = 56, 44.8%) was the most common type of craniofacial injury, followed by cerebral concussion (n = 49, 39.2%), dental injury (n = 27, 21.6%), and craniofacial bone fracture (n = 16, 12.8%)., Conclusion: Dentists should always consider the possibility of brain trauma and perform a complete craniofacial and oral examination when assessing patients after e-scooter accidents as outlined by the International Association of Dental Traumatology guidelines. Additionally, it is necessary to educate e-scooter riders about the importance of wearing protective devices, such as helmets, to reduce the risk of injuries to the craniofacial region., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The goal of this study was to develop a deep learning-based algorithm to predict temporomandibular joint (TMJ) disc perforation based on the findings of magnetic resonance imaging (MRI) and to validate its performance through comparison with previously reported results. The study objects were obtained by reviewing medical records from January 2005 to June 2018. 299 joints from 289 patients were divided into perforated and non-perforated groups based on the existence of disc perforation confirmed during surgery. Experienced observers interpreted the TMJ MRI images to extract features. Data containing those features were applied to build and validate prediction models using random forest and multilayer perceptron (MLP) techniques, the latter using the Keras framework, a recent deep learning architecture. The area under the receiver operating characteristic (ROC) curve (AUC) was used to compare the performances of the models. MLP produced the best performance (AUC 0.940), followed by random forest (AUC 0.918) and disc shape alone (AUC 0.791). The MLP and random forest were also superior to previously reported results using MRI (AUC 0.808) and MRI-based nomogram (AUC 0.889). Implementing deep learning showed superior performance in predicting disc perforation in TMJ compared to conventional methods and previous reports.

Background: The purpose of this study was to investigate the differences in configuration and dimensions of the anterior loop of the inferior alveolar nerve (ALIAN) in patients with and without mandibular asymmetry., Method: Preoperative computed tomography images of patients who had undergone orthognathic surgery from January 2016 to December 2018 at a single institution were analyzed. Subjects were classified into two groups as "Asymmetry group" and "Symmetry group". The distance from the most anterior and most inferior points of the ALIAN (IANant and IANinf) to the vertical and horizontal reference planes were measured (dAnt and dInf). The distance from IANant and IANinf to the mental foramen were also calculated (dAnt&#95;MF and dInf&#95;MF). The length of the mandibular body and symphysis area were measured. All measurements were analyzed using 3D analysis software., Results: There were 57 total eligible subjects. In the Asymmetry group, dAnt and dAnt&#95;MF on the non-deviated side were significantly longer than the deviated side (p < 0.001). dInf&#95;MF on the non-deviated side was also significantly longer than the deviated side (p = 0.001). Mandibular body length was significantly longer on the non-deviated side (p < 0.001). There was no significant difference in length in the symphysis area (p = 0.623). In the Symmetry group, there was no difference between the left and right sides for all variables., Conclusion: In asymmetric patients, there is a difference tendency in the ALIAN between the deviated and non-deviated sides. In patients with mandibular asymmetry, this should be considered during surgery in the anterior mandible.

Purpose: The position changing pattern of the condyles after intraoral vertical ramus osteotomy (IVRO) on the deviated and non-deviated sides is not clearly known. This study was conducted to evaluate the changes in condylar position after IVRO in patients with facial asymmetry and to compare the deviated and non-deviated sides using computed tomography imaging., Materials and Methods: This retrospective cohort study investigated patients with a diagnosis of mandibular prognathism with facial asymmetry who had undergone bilateral IVRO with Le Fort I osteotomy. Condylar positions were recorded on the non-deviated and deviated sides in the midaxial, midsagittal, and coronal planes at 3 time points using 3-dimensional analysis software: preoperatively (T1), at 6 months postoperatively (T2), and at 12 months postoperatively (T3). Linear and angular changes in condyle position were measured and analyzed between T1, T2, and T3. Reliability and comparative analyses were conducted., Results: Thirty-two patients were involved in this study. At T2, the most superior point of the condyle moved to 1.15 ± 0.24 mm (inferiorly) and 0.88 ± 0.23 mm (anteriorly) on the deviated side (P = .0002 and P = .0005, respectively) and to 0.99 ± 0.25 mm (inferiorly) and 1.08 ± 0.34 mm (anteriorly) on the non-deviated side, showing significant differences (P < .0001 and P = .0007, respectively) compared with T1. The condyle position showed a tendency to recover to its original position by T3. However, there were no statistically significant differences between T2 and T3 (P > .05). Furthermore, there were no statistically significant differences between the deviated and non-deviated sides over the entire follow-up period (P > .05)., Conclusions: The condyles did not completely recover to their preoperative positions until 12 months postoperatively. There was no significant difference between the deviated and non-deviated sides in mandibular prognathism with facial asymmetry., (Copyright © 2019. Published by Elsevier Inc.)

Background: The relationship between the lateral deviation of chin and the upper and middle facial third asymmetry is still controversial. The purpose of this study is to evaluate the correlation of upper and middle facial third asymmetry with lateral deviation of chin using 3-dimensional computed tomography. The study was conducted on patients who underwent orthognathic surgery from January 2016 to August 2017. A total of 40 patients were included in this retrospective study. A spiral scanner was used to obtain the 3-dimensional computed tomography scans. The landmarks were assigned on the reconstructed 3-dimensional images, and their locations were verified on the axial, midsagittal, and coronal slices. The Pearson correlation analysis was performed to evaluate the correlation between chin deviation and difference between the measurements of distances in paired craniofacial structures. Statistical analysis was performed at a significance level of 5%., Results: In mandible, the degree of chin deviation was correlated with the mandibular length and mandibular body length. Mandibular length and mandibular body length are shorter on the deviated-chin side compared to that on the non-deviated side (mandibular length, r = -0.897, p value < 0.001; mandibular body length, r = -0.318, p value = 0.045). In the upper and middle facial thirds, the degree of chin deviation was correlated with the vertical asymmetry of the glenoid fossa and zygonion. Glenoid fossa and zygonion are superior on the deviated-chin side than on the non-deviated side (glenoid fossa, r = 0.317, p value = 0.046; zygonion, r = 0.357, p value = 0.024)., Conclusion: Lateral deviation of chin is correlated with upper and middle facial third asymmetry as well as lower facial third asymmetry. As a result, treatment planning in patients with chin deviation should involve a careful evaluation of the asymmetry of the upper and middle facial thirds to ensure complete patient satisfaction., Competing Interests: Competing interestsThe authors declare that they have no competing interests., (© The Author(s). 2019.)

Objectives: The aim of this study was to evaluate the validity of the existing classification and difficulty index of impacted mandibular third molars in clinical situations and propose a more practical classification system., Materials and Methods: This study included 204 impacted mandibular third molars in 154 patients; panoramic x-ray images were obtained before tooth extraction. Factors including age, sex, and pattern of impaction were investigated. All impacted third molars were classified and scored for spatial relationship (1-5 points), depth (1-4 points), and ramus relationship (1-3 points). All variables were measured twice by the same observer at a minimum interval of one month. Finally, the difficulty index was defined based on the total points scored as slightly difficult (3-4 points), moderately difficult (5-7 points), very difficult (8-10 points), and extremely difficult (11-12 points)., Results: The strength of agreement of the total points scored and difficulty index were 0.855 and 0.746, respectively. Most cases were classified as moderately difficult (73.0%). Although only 13 out of 204 cases (6.4%) were classified as extremely difficult, patients classified as extremely difficult were the oldest ( P <0.05)., Conclusion: For difficulty classification, the authors propose one more difficult category beyond the existing three-step difficulty index: the clinician should consider the patient's age in the difficulty index evaluation., Competing Interests: Conflict of Interest: No potential conflict of interest relevant to this article was reported., (Copyright © 2019 The Korean Association of Oral and Maxillofacial Surgeons.)

Background: Animal studies are pivotal in allowing experimentation to identify efficacious treatment protocols for resolution of peri-implantitis. The purpose of this investigation was to characterize an expedited dog peri-implantitis model clinically, radiographically, and microbiologically., Methods: Eight hound dogs underwent extractions (week 0) and implant (3.3 × 8.5 mm) placement with simultaneous surgical defect creation and ligature placement for induction of peri-implantitis (week 10). Ligatures were replaced at 6 weeks (week 16) and removed after 9 weeks (week 19) when supporting bone loss involved approximately 50% of the peri-implant bone. Microbial samples from the defects and healthy control implant sites collected at week 19 were analyzed utilizing a microarray. Clinical measures of inflammation were obtained and radiographic bone loss was measured from periapical radiographs. Radiographic depth and width measurements of bony defect were repeated at weeks 10 (baseline), 16, and 19. Canonical analysis of principal coordinates was used to visualize overall differences in microbial abundance between peri-implantitis and healthy implants., Results: This accelerated disease protocol led to intrabony defect creation with a mean depth and width of 4.3 mm and 3.5 mm, respectively after 9 weeks of ligature placement. Microbial identification revealed 59 total bacteria in peri-implant sites, 21 of which were only present in peri-implant sites as compared to healthy controls. Overall microbial beta diversity (microbial between-sample compositional diversity) differed between peri-implantitis and healthy implants (p = 0.009)., Conclusions: Within the limitations of this study, this protocol led to expedited generation of peri-implant defects with a microbial profile indicative of a shift to disease and defect patterns conducive to regenerative treatment. However, the possibility of potential spontaneous resolution of lesions due to the lack of a chronicity interval as compared to chronic disease models need to be further clarified and considered during preclinical peri-implantitis model selection.

Objective: The relationship between bite force and torus palatinus or mandibularis remains to be explained. The major aim of this study was to determine the correlation between bite force and oral tori., Methods: The bite force of 345 patients was measured with a bite force recorder; impressions of the shape and size of the oral tori were taken on plaster models prior to orthodontic treatments. Subsequently, the relationship between oral tori and bite force was analyzed., Results: The size, shape, and incidence of torus palatinus was not significantly correlated with bite force. However, the size of torus mandibularis increased significantly in proportion to the bite force ( p  = 0.020). The occurrence of different types of oral tori was not correlated with the bite force., Discussion: The size of torus mandibularis provides information about bite force and can thus be used to clinically assess occlusal stress.

Purpose: Implant wall thickness and the height of the implant-abutment interface are known as factors that affect the distribution of stress on the marginal bone around the implant. The goal of this study was to evaluate the long-term effects of supracrestal implant placement and implant wall thickness on maintenance of the marginal bone level., Methods: In this retrospective study, 101 patients with a single implant were divided into the following 4 groups according to the thickness of the implant wall and the initial implant placement level immediately after surgery: 0.75 mm wall thickness, epicrestal position; 0.95 mm wall thickness, epicrestal position; 0.75 mm wall thickness, supracrestal position; 0.95 mm wall thickness, supracrestal position. The marginal bone level change was assessed 1 day after implant placement, immediately after functional loading, and 1 to 5 years after prosthesis delivery. To compare the marginal bone level change, repeated-measures analysis of variance was used to evaluate the statistical significance of differences within groups and between groups over time. Pearson correlation coefficients were also calculated to analyze the correlation between implant placement level and bone loss., Results: Statistically significant differences in bone loss among the 4 groups ( P <0.01) and within each group over time ( P <0.01) were observed. There was no significant difference between the groups with a wall thickness of 0.75 mm and 0.95 mm. In a multiple comparison, the groups with a supracrestal placement level showed greater bone loss than the epicrestal placement groups. In addition, a significant correlation between implant placement level and marginal bone loss was observed., Conclusions: The degree of bone resorption was significantly higher for implants with a supracrestal placement compared to those with an epicrestal placement., Competing Interests: Conflict of Interest: No potential conflict of interest relevant to this article was reported.

Background: Botulinum toxin injection on the masticatory muscle induces the osteopenic condition on the ipsilateral condyle. Bisphosphonate suppresses bone resorption and is used to treat osteopenic or osteoporotic condition. This study aimed to evaluate the effect of bisphosphonate administration on prevention of condylar resorption and botulinum toxin A-induced disuse osteopenia in rats., Results: The volume of the condyle and bone volume/tissue volume (BV/TV, %) showed a strong tendency towards statistical significance ( p  = 0.052 and 0.058). Trabecular thickness (Tb.Th, mm) and trabecular number (Tb.N, 1/mm) were significantly smaller in the Botox group than in the other groups ( p  < 0.05). The volume of the condyle and BV/TV in the bisphosphonate 100 and bisphosphonate 200 groups showed similar values when compared with the control group., Conclusion: Bisphosphonate administration after botulinum toxin A injection in the masticatory muscles appears to prevent condyle resorption and botulinum toxin-induced disuse osteopenia in rats., Competing Interests: This study was approved by and performed in accordance with the guidelines of the institutional animal research ethics committee (IACUC No. 2017-0083).Not applicableThe authors declare that they have no competing interests.Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Background: The purpose of the present study was to investigate the differences in the position and shape of the anterior loop of the inferior alveolar nerve (ALIAN) in relation to the growth pattern of the mandibular functional subunit., Methods: The study was conducted on 56 patients among those who had undergone orthognathic surgery at the Gangnam Severance Hospital between January 2010 and December 2015. Preoperative computerized tomography (CT) images were analyzed using the Simplant OMS software (ver.14.0 Materialise Medical, Leuven, Belgium). The anterior and inferior lengths of ALIAN (dAnt and dInf) and each length of the mandibular functional subunits were measured. The relationship between dAnt, dInf, and the growth pattern of the mandibular subunits was analyzed., Results: The length of the anterior portion of ALIAN (dAnt) reached 3.34 ± 1.59 mm in prognathism and 1.00 ± 0.97 mm in retrognathism. The length of the inferior portion of ALIAN (dInf) reached 6.81 ± 1.33 mm in prognathism and 5.56 ± 1.34 mm in retrognathism. The analysis of Pearson's correlation coefficiency on all samples showed that the lengths of functional subunits were positively correlated with the loop depth. The length of the symphysis area in prognathic patients was positively correlated with the anterior loop depth ( p  = 0.005)., Conclusions: Both the anterior and inferior length of ALIAN are longer in prognathic patients. Especially, it seems to be associated with the growth of the symphysis area., Competing Interests: This study had the approval of Yonsei Institutional Review board (IRB No.3-1015-0113).Not applicableThe authors declare that they have no competing interests.Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Objectives: The objective of this study was to analyze 11 cases of subcutaneous emphysema associated with dental procedures from a single hospital and discuss approaches for accurate diagnosis and treatment of the condition., Materials and Methods: The medical records of 11 patients who were treated for subcutaneous emphysema related to dental procedures between January 2009 and April 2017 were analyzed retrospectively. Patients with subcutaneous emphysema within the facial area or that spread to the neck and beyond, including the facial region, were assigned to two groups and compared in terms of age, sex, and durations of antibiotic use, hospitalization, and follow-up until improvement. The correlation between location of the origin tooth and range of emphysema spread was analyzed., Results: The average durations of antibiotic use during conservative treatment and follow-up until improvement were 8.55 days (standard deviation [SD], 4.46 days) and 1.82 weeks (SD, 1.19 weeks), respectively. There was no intergroup difference in duration of antibiotic use ( P =0.329) or follow-up ( P =0.931). Subcutaneous emphysema was more common after dental procedures involving the maxilla or posterior region than after those involving the mandible or anterior region. There was no significant difference in air distribution according to location of the air orifice (maxilla, mandible, or both; P =0.106)., Conclusion: Upon adequate conservative treatment accompanied by prophylactic antibiotic treatment considering the risk of infection, patients showed signs of improvement within a few days or weeks. There was no significant difference in treatment period between patients with subcutaneous emphysema localized to the facial region and those with subcutaneous emphysema spreading to the neck or beyond. These findings need to be confirmed by analysis of additional cases., Competing Interests: Conflict of Interest: No potential conflict of interest relevant to this article was reported.

Objective: The aim of this study was to analyze risk factors and establish a prediction model for temporomandibular joint (TMJ) disk perforation by constructing a nomogram., Study Design: The study included a total of 282 joints in 274 patients. All patients underwent open TMJ surgery after obtaining magnetic resonance imaging (MRI), from 2005 to 2015. The presence or absence of disk perforation was confirmed during the operation. Patients were classified into 2 groups: perforation and nonperforation groups. We investigated demographic data and the characteristics of the disk, joint space, and bone on MRI. A logistic regression analysis was performed to analyze risk factors. A nomogram was constructed and validated internally and externally., Results: Risk factors for disk perforation were increased age, disk shape (eyeglass or amorphous), low bone marrow signal, abnormal joint space, and 2 or more bony changes in the condyle and fossa. The area under the receiver operating characteristic curve of the nomogram was 0.908 (95% confidence interval [CI] 0.869-0.946) in the internal validation and 0.889 (95% CI 0.804-0.973) in the external validation with good suitability., Conclusions: We were able to predict the probability of disk perforation with analyzed risk factors and constructed a nomogram, which may be helpful in proper diagnosis and treatment., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Objectives: The aim of this study was to reveal how collagenases (matrix metalloproteinase [MMP]-1, 8, 13) and tissue inhibitor of metalloproteinase 1 (TIMP-1) are expressed in immunohistochemistry of retrodiscal tissue in temporomandibular joint disorder patients., Materials and Methods: This study was conducted on 39 patients who underwent discoplasty or discectomy. Immunohistochemical staining was undertaken and expression levels of MMP-1, 8, 13, and TIMP-1 were evaluated. The status of internal derangement of disc, osteoarthritis, and joint effusion were analyzed using magnetic resonance imaging (MRI). Disc status observed during operation was also categorized., Results: The more severe disc derangement was observed on MRI, the more increased expression of MMPs and TIMP-1 appeared. Regarding MMP-13 expression, 86.7% of late-stage disc displacement patients showed grade II or III. Expression level of MMPs or TIMP was not statistically significant associated with joint effusion level. In perforation and/or adhesion groups, all patients showed grade II or III expression of MMP-13. Once perforation occurred, MMP-13 showed increased expression with statistical significance., Conclusion: MMP-1 and MMP-13 expression seem to be related to progression of osteoarthritis whereas MMP-8 does not seem to have a specific role with regard to temporomandibular joint disorders. TIMP-1 is considered to be partly related to internal derangement rather than osteoarthritis, but it is not significant., Competing Interests: Conflict of Interest: No potential conflict of interest relevant to this article was reported.

Objective: To evaluate the volume and position of the temporomandibular joint structures, specifically the glenoid fossa and the condylar head, in patients with facial asymmetry., Study Design: Fifty-six adult patients were divided into two groups-asymmetry group and control group-based on the severity of the mandibular asymmetry, as seen on their orthopantomograms. The volumes and positions of the bilateral temporomandibular joint components were measured by using computed tomography images and a three-dimensional analysis program. Each of the variables was compared between and within the groups., Results: The volumes of the condyle and the glenoid fossa on the side of the smaller condyle were significantly smaller in the asymmetry group (P < .05) than in the control group. The volumetric ratios of the glenoid fossa and the joint space to the condyle were also significantly higher on that side (P < .001). The distance of the uppermost point of the glenoid fossa from the midaxial plane in the smaller condyle was significantly shorter (P < .05) only in the asymmetry group., Conclusions: When evaluating mandibular asymmetry, the volume of the glenoid fossa and the volume and vertical position of the condylar head need to be considered in addition to length or width of the condylar head., (Copyright © 2016 Elsevier Inc. All rights reserved.)

This study was performed to evaluate the long-term changes in mandibular width, lower facial width, and ramus angulation after intraoral vertical ramus osteotomy (IVRO) and to identify the factors influencing these changes. This retrospective study included 53 consecutive patients with mandibular prognathism who underwent IVRO with (n=33) or without (n=20) Le Fort I osteotomy. Postero-anterior cephalograms and frontal facial photographs obtained before, 1 month after, and at least 24 months after IVRO were used for measurements. A linear mixed model and paired t-tests were used to analyze temporal changes and the associated influencing factors. The mandibular width increased immediately after surgery (P<0.05), but decreased continuously thereafter. The ramus angulation showed negligible change within the first month (P>0.05) and decreased thereafter up to approximately 36 months. The amounts of mandibular setback and posterior impaction and the length of time postoperative influenced these changes. The lower facial width changed, although inconsistently, within 3mm over time (P>0.05). In conclusion, the mandibular width increased after IVRO but seemed to normalize within approximately 3 years. The lower facial width did not reflect underlying skeletal changes. Therefore, long-term transverse changes after IVRO can be considered clinically irrelevant., (Copyright © 2016 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Objectives: The aim of this animal study was to examine the effects of thread size in the implant neck area on peri-implant tissues in terms of BIC and hard- and soft-tissue dimensions., Materials and Methods: Six Beagle dogs received experimental implants in the mandible 3 month after the removal of premolars and first molars (P2, P3, P4, and M1). Two different types of implants were installed in each animal: Anyone microthread(®) as Group 1 and Anyone(®) as Group 2. Resonance frequency test, intraoral radiography, micro-CT, and histomorphometry were used to evaluate peri-implant tissue after implantation periods of 4 and 8 weeks., Results: No remarkable complication was observed during the healing period in either group. Resonance frequency testing revealed no significant difference between groups. In radiographic evaluation, Group 2 showed more bone loss than Group 1. However, this difference was not statistically significant. In the micro-CT analysis, BIC and BIV values and soft-tissue height were not significant in both groups. Histological analysis revealed no significant difference in BIC ratio, bone density, or bone loss between groups. However, soft-tissue height was significantly greater in Group 2 than in Group 1 (P = 0.0004)., Conclusion: No difference in peri-implant hard or soft tissues was observed according to thread size in the implant neck area., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

This case report describes the successful treatment of severely impacted mandibular second molars with severe apical root resorption of the mandibular first molars. The vertically impacted second molars were orthodontically moved (using orthodontic mini-implants) without additional root resorption of the first molars. The orthodontic treatment provided a satisfactory and stable outcome by improving the periodontium surrounding the first and second molars. The treatment also eliminated the need for prosthetic treatment by preserving the first and second molars., (Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Unilateral condylar overgrowth induces severe facial asymmetry. Therefore, treatment focuses on both elimination of the condyle lesion and correction of the facial asymmetry. The aim of this report is to present three patient cases, introducing a simpler surgical method, the indications for this surgical method, and a treatment planning flow that is consistently applicable regardless of the origin of the condylar lesion. Condylectomy was performed simultaneously with orthognathic surgery, with the vertical ramus osteotomy selected as the method of ramus surgery; ipsilateral ramus surgery was not performed on the condylectomy side. This method is applicable in cases in which facial asymmetry originates solely from unilateral condylar overgrowth, and the maxilla and mandible are presumed to have been in the normal class I anteroposterior position before the onset of condylar lesion growth. After surgery, temporomandibular joint pain and/or mouth limitations were resolved, the new condyle showed satisfactory bone remodelling, and favourable facial symmetry was attained. The postoperative results were maintained long-term and there was no recurrence on the condylectomy side. This simply modified surgical strategy for facial asymmetry due to unilateral condylar overgrowth may be used in selected patients, regardless of the origin of the condylar lesion., (Copyright © 2015 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Aim: Chondroblastoma is a rare, benign bone tumor that accounts for approximately 1% of all primary bone tumors. Chondroblastoma that occurs at the temporomandibular joint can exhibit symptoms similar to those associated with other temporomandibular disorders. This case study aims to present an eight-year followup of chondroblastoma occurring at the temporomandibular joint., Methodology: The patient presented swelling in the left temporomandibular joint and trismus. Based oncomputed tomography and magnetic resonance imaging findings, a provisional diagnosis of synovial chondromatosis was made. Complete excision of the lesion was performed under general anesthesia., Results: After histopathological examination, the lesion was finally diagnosed as chondroblastoma. Currently, 8 years after the operation, the patient has not experienced any symptoms or any notable complications., Conclusions: Although chondroblastoma is a benign tumor, it shows aggressive characteristics with bone invasion. Therefore, precise diagnosis and proper treatment planning is crucial for successful treatment of chondroblastoma.

Introduction: We report a case of successful autotransplantation of a premolar impacted with a dentigerous cyst and transplanted with collagen plugs for initial support., Methods: An 18-year-old man had an impacted premolar accompanied with a large dentigerous cyst. The tooth was extracted surgically and transplanted to an edentulous alveolar ridge, and a collagen sponge was inserted to ensure proper healing and initial support. Root canal treatment was performed 3 weeks after the surgery., Results: The previous lesion was healed, and the transplanted tooth was functional without any pathologic signs., Conclusions: Our protocol provides a viable option for saving an impacted tooth in the case of cyst enucleation., (Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)