Treatment of anterior open bite by posterior maxillary segmental osteotomy and miniplates: a case report.

BACKGROUND: Anterior open bite is a challenging malocclusion to correct orthodontic treatment. Anterior open bite associated with over-erupted posterior teeth and long lower facial height should be treated by reduction of posterior dimension for esthetic results. Although the possibility of orthodontic treatment of an anterior open bite has increased with the introduction of skeletal anchorage, there are still cases requiring surgery for various reasons. CASE PRESENTATION: This case report covers an anterior open bite of a 25-year-old man successfully treated with the posterior maxillary segmental osteotomy (PMSO) and miniplates. After the pre-surgical orthodontic treatment, the PMSO between canines and first premolars was performed under local anesthesia and miniplates were placed on the zygomatic buttress. As a result of 28 months of treatment, an impaction amount of 3.5 mm was obtained in the maxillary posterior teeth, and the facial esthetics improved at rest and smile. CONCLUSION: The impaction of the posterior dentoalveolar segment using the PMSO can be a good treatment option in patients with anterior open bite showing long lower facial height.

Clinical study on screw loosening in dental implant prostheses: a 6-year retrospective study.

OBJECTIVES: In this study, we determined the incidence and pattern of screw loosening in patients who received dental implants. MATERIALS AND METHODS: Patients who received implants between January 2008 and October 2013 and completed their prosthetic rehabilitation were evaluated for the incidence, frequency, and onset of screw loosening using dental charts and radiographs. The association between each factor and screw loosening was analyzed using the chi-square test and a multivariate analysis with binary logistic regression models (P<0.05). RESULTS: Total 1,928 implants were placed in 837 patients (448 males, 389 females), whose follow-up period after loading varied from 0.25 to 70 months (mean period, 31.5 months). Screw loosening occurred in 7.2% of implants. Most cases occurred less than six months after loading. Among those, 22.3% experienced recurrent screw loosening. Screw loosening was most common in the molar region (8.5%) and frequently associated with an implant diameter of ≥5 mm (14.2%). External implant-abutment connections (8.9%) and screw-retained implant prostheses (10.1%) showed higher incidence of problems than internal implant-abutment connections and cement-retained implants, respectively. Screw loosening was most common in implant prostheses with single crowns (14.0%). CONCLUSION: Within the limits of the current study, we conclude that the incidence of screw loosening differs significantly according to the position of implant placement, the type of implant and manufacturer, implant diameter, the type of implant-abutment connection, the type of retention in the implant prosthesis, and the type of implant prosthesis.

Application of botulinum toxin in maxillofacial field: Part III. Ancillary treatment for maxillofacial surgery and summary.

Botulinum toxin (BTX) has various therapeutic indications: bruxism, square jaw, facial wrinkle, oral ulcer and maxillofacial pain, etc. In this paper, we will discuss the effectiveness of using BTX in dental implant surgery and orthognathic and orthodontic treatment. We summarized the clinical application of botulinum toxin in the maxillofacial field at the finale.

Application of botulinum toxin in maxillofacial field: part I. Bruxism and square jaw.

The application of botulinum in oral and maxillofacial surgery begins in 1982, where Jan Carruthers started using it for reducing the muscle mass and smoothing the skin, and since then it has been used for cosmetic purposes. In Korea, it is already being used by various specialties including dentistry (oral and maxillofacial surgery, oral medicine), plastic surgery, dermatology, ophthalmology, general surgery, and orthopedic surgery, etc. Each specialty approaches to Botox with its own medical indications. In this article, we will discuss the maxillofacial application of botulinum toxin, which includes theoretical and practical aspects of such as bruxism and square jaw.

Application of botulinum toxin in maxillofacial field: Part II. Wrinkle, intraoral ulcer, and cranio-maxillofacial pain.

Botulinum toxin (BTX) is used in various ways such as temporarily resolving muscular problems in musculoskeletal temporomandibular disorders, inducing a decrease in bruxism through a change in muscular patterns in a patient's bruxism, and solving problems in patients with tension headache. And also, BTX is widely used in cosmetic applications for the treatment of facial wrinkles after local injection, but conditions such as temporomandibular joint disorders, headache, and neuropathic facial pain could be treated with this drug. In this report, we will discuss the clinical use of BTX for facial wrinkle, intraoral ulcer, and cranio-maxillofacial pain with previous studies and share our case.

Recording natural head position using an accelerometer and reconstruction from computed tomographic images.

OBJECTIVES: The concept of natural head position (NHP) was first introduced by Broca in 1862, and was described as a person's stable physiologic position "when a man is standing and his visual axis is horizontal." NHP has been used routinely for clinical examination; however, a patient's head position is random during cone-beam computed tomography (CBCT) acquisition. To solve this problem, we developed an accelerometer to record patients' NHP and reproduce them for CBCT images. In this study, we also tested the accuracy and reproducibility of our accelerometer. MATERIALS AND METHODS: A total of 15 subjects participated in this study. We invented an accelerometer that measured acceleration on three axes and that could record roll and pitch calculations. Recorded roll and pitch data for each NHP were applied to a reoriented virtual image using three-dimensional (3D) imaging software. The data between the 3D models and the clinical photos were statistically analyzed side by side. Paired t-tests were used to statistically analyze the measurements. RESULTS: The average difference in the angles between the clinical photograph and the 3D model was 0.04° for roll and 0.29° for pitch. The paired ttests for the roll data (P=0.781) and the pitch data (P=0.169) showed no significant difference between the clinical photographs and the 3D model (P>0.05). CONCLUSION: By overcoming the limitations of previous NHP-recording techniques, our new method can accurately record patient NHP in a time-efficient manner. Our method can also accurately transfer the NHP to a 3D virtual model.

Comparison of the efficacy and safety of 2% lidocaine HCl with different epinephrine concentration for local anesthesia in participants undergoing surgical extraction of impacted mandibular third molars: A multicenter, randomized, double-blind, crossover, phase IV trial.

BACKGROUND: The most commonly impacted tooth is the third molar. An impacted third molar can ultimately cause acute pain, infection, tumors, cysts, caries, periodontal disease, and loss of adjacent teeth. Local anesthesia is employed for removing the third molar. This study aimed to evaluate the efficacy and safety of 2% lidocaine with 1:80,000 or 1:200,000 epinephrine for surgical extraction of bilateral impacted mandibular third molars. METHODS: Sixty-five healthy participants underwent surgical extraction of bilateral impacted mandibular third molars in 2 separate visits while under local anesthesia with 2% lidocaine with different epinephrine concentration (1:80,000 or 1:200,000) in a double-blind, randomized, crossover trial. Visual analog scale pain scores obtained immediately after surgical extraction were primarily evaluated for the 2 groups receiving different epinephrine concentrations. Visual analog scale pain scores were obtained 2, 4, and 6 hours after administering an anesthetic. Onset and duration of analgesia, onset of pain, intraoperative bleeding, operator's and participant's overall satisfaction, drug dosage, and hemodynamic parameters were evaluated for the 2 groups. RESULTS: There were no statistically significant differences between the 2 groups in any measurements except hemodynamic factors (P >.05). Changes in systolic blood pressure and heart rate following anesthetic administration were significantly greater in the group receiving 1:80,000 epinephrine than in that receiving 1:200,000 epinephrine (P ≤.01). CONCLUSION: The difference in epinephrine concentration between 1:80,000 and 1:200,000 in 2% lidocaine liquid does not affect the medical efficacy of the anesthetic. Furthermore, 2% lidocaine with 1:200,000 epinephrine has better safety with regard to hemodynamic parameters than 2% lidocaine with 1:80,000 epinephrine. Therefore, we suggest using 2% lidocaine with 1:200,000 epinephrine rather than 2% lidocaine with 1:80,000 epinephrine for surgical extraction of impacted mandibular third molars in hemodynamically unstable patients.

Diseases having an influence on inhibition of angiogenesis as risk factors of osteonecrosis of the jaw.

OBJECTIVES: The objective of this study was to retrospectively investigate the association of diseases having an influence on inhibition of angiogenesis such as hypertension, diabetes mellitus type II, hypercholesterolemia, and rheumatoid arthritis (RA) with the development of osteonecrosis of the jaws. MATERIALS AND METHODS: The 135 patients were allocated into 4 groups of bisphosphonate-related osteonecrosis of the jaw (BRONJ) group (1A); non-BRONJ group (1B); osteonecrosis of the jaw (ONJ) group (2A); and control group (2B), according to histologic results and use of bisphosphonate. This retrospective study was conducted with patients who were treated in one institute from 2012 to 2013. Fisher's exact test and logistic regression analysis were used to analyze the odds ratios of diseases having an influence on inhibition of angiogenesis for development of ONJ. RESULTS: The effects of diabetes and hypertension were not statistically significant on development of ONJ. When not considering bisphosphonate use, RA exhibited a high odds ratio of 3.23 (P=0.094), while hyperlipidemia showed an odds ratio of 2.10 (P=0.144) for development of ONJ. More than one disease that had an influence on inhibition of angiogenesis showed a statistically significant odds ratio of 2.54 (P=0.012) for development of ONJ. CONCLUSION: Patients without diseases having an influence on inhibition of angiogenesis were at less risk for developing ONJ.

Correlations between anatomic variations of maxillary sinus ostium and postoperative complication after sinus lifting.

OBJECTIVES: The maxillary sinus mucosa is reported to recover to preoperative sterility after sinus floor elevation. However, when drainage of maxillary sinus is impaired, recovery can be delayed and maxillary sinusitis can occur. Therefore, in this study, we investigated the correlations between anatomic variants that can interrupt the ostium of the maxillary sinus and incidence of complication after sinus lifting. MATERIALS AND METHODS: The subjects are 81 patients who underwent sinus lifting in Wonkwang University Dental Hospital (Iksan, Korea). Computed tomography (CT) images of the subjects were reviewed for presence of nasal septum deviation, anatomic variants of the middle turbinate, and Haller cells. Correlations between anatomic variations and occurrence of maxillary sinusitis were statistically analyzed. RESULTS: Patients with anatomic variants of ostio-meatal units, such as deviated nasal septum, concha bullosa or paradoxical curvature of the middle turbinate, or Haller cells, showed a higher rate of complication. However, only presence of Haller cell showed statistically significant. CONCLUSION: Before sinus lifting, CT images are recommended to detect anatomic variants of the ostio-meatal complex. If disadvantageous anatomic variants are detected, the use of nasal decongestants should be considered to reduce the risk of postoperative sinusitis.

Advantages of intraoral and transconjunctival approaches for posterior displacement of a fractured zygomaticomaxillary complex.

BACKGROUND: Fracture of the zygomaticomaxillary complex (ZMC) is one of the most common facial injuries. A previous study has performed 3D analyses of the parallel and rotational displacements that occur in a fractured ZMC. However, few studies have investigated adequate fixation methods according to these displacements. Here, we assessed whether specific approaches and fixation methods for displacement of ZMC fractures produce esthetic results. METHODS: Hospital records and pre- and post-surgical computed tomographic scans of patients treated for ZMC fractures at the Department of Oral and Maxillofacial Surgery, College of Dentistry, Wonkwang University, between January 2010 and December 2015, were selected. Data were analyzed according to the direction of displacement and post-reduction prognosis using a 3D software. RESULTS: With ZMC fractures, displacement in the posterior direction occurred most frequently, while displacement in the superior-inferior direction was rare. A reduction using a transconjunctival approach and an intraoral approach was statistically better than that using an intraoral approach, Gillies approach, and lateral canthotomy approach for a posterior displacement (P < 0.05). CONCLUSIONS: When posterior displacement of a fractured ZMC occurs, use of an intraoral approach and transconjunctival approach simultaneously is recommended for reducing and fixing the displaced fragment accurately.

Changes of lip morphology following mandibular setback surgery using 3D cone-beam computed tomography images.

BACKGROUND: The aims of this study are to evaluate the lip morphology and change of lip commissure after mandibular setback surgery (MSS) for class III patients and analyze association between the amount of mandibular setback and change of lip morphology. METHODS: The samples consisted of 14 class III patients treated with MSS using bilateral sagittal split ramus osteotomy. Lateral cephalogram and cone-beam CT were taken before and about 6 months after MSS. Changes in landmarks and variables were measured with 3D software program Ondemand™. Paired and independent t tests were performed for statistical analysis. RESULTS: Landmarks in the mouth corner (cheilion, Ch) moved backward and downward (p < .005, p < .01). However, cheilion width was not statistically significantly changed. Landmark in labrale superius (Ls) was not altered significantly. Upper lip prominence angle (ChRt-Ls-ChLt °) became acute. Landmarks in stomion (Stm), labrale inferius (Li) moved backward (p < .005, p < .001). Lower lip prominence angle (ChRt-Li-ChLt °) became obtuse (p < .001). Height of the upper and lower lips was not altered significantly. Length of the upper lip vermilion was increased (p =< 0.01), and length of the lower lip vermilion was decreased (p < .05). Lip area on frontal view was not statistically significantly changed, but the upper lip area on lateral view was increased and change of the lower lip area decreased (p > .05, p < .005). On lateral view, upper lip prominent point (UP) moved downward and stomion moved backward and upward and the angle of Ls-UP-Stm (°) was decreased. Lower lip prominent point (LP) moved backward and downward, and the angle of Stm-LP-Li (°) was increased. Li moved backward. Finally, landmarks in the lower incisor tip (L1) moved backward and upward, but stomion moved downward. After surgery, lower incisor tip (L1) was positioned more superiorly than stomion (p < .05). There were significant associations between horizontal soft tissue and corresponding hard tissue. The posterior movement of L1 was related to statistically significantly about backward and downward movement of cheilion. CONCLUSIONS: The lip morphology of patients with dento-skeletal class III malocclusion shows a significant improvement after orthognathic surgery. Three-dimensional lip morphology changes in class III patients after MSS exhibited that cheilion moved backward and downward, upper lip projection angle became acute, lower lip projection angle became obtuse, change of upper lip area on lateral view was increased, change of lower lip area decreased, and morphology of lower lip was protruding. L1 was concerned with the lip tissue change in statistically significant way.

Bisphosphonate-related osteonecrosis of the jaw in a multiple myeloma patient: A case report with characteristic radiographic features.

A 59-year-old male who had suffered from multiple myeloma for nine years and had been administered bisphosphonates for seven years visited a dental hospital for pain relief due to extensive caries in his left maxillary molars. The molars were extracted, leaving an exposed wound for three months. The radiograph showed sequestra formation and irregular bone destruction in the left maxilla. Sudden pain and gingival swelling in the right mandibular molar area occurred six months later. The interseptum of the right lower second molar was observed to be necrotic during surgery. These findings coincided with the features of bisphosphonate-related osteonecrosis of the jaw (BRONJ). In this case, the long intravenous administration of bisphosphonates and tooth extraction were likely the etiologic factors of BRONJ in a patient with multiple myeloma; moreover, the bilateral occurrence of BRONJ is a characteristic feature.

Glandular odontogenic cyst mimicking ameloblastoma in a 78-year-old female: A case report.

Glandular odontogenic cyst (GOC) is a rare, potentially aggressive jaw lesion. The common radiographic features include a well-defined radiolucency with distinct borders, presenting a uni- or multilocular appearance. A cystic lesion in the posterior mandible of a 78-year-old female was incidentally found. Radiographs showed a unilocular lesion with a scalloped margin, external root resorption of the adjacent tooth, and cortical perforation. This lesion had changed from a small ovoid shape to a more expanded lesion in a period of four years. The small lesion showed unilocularity with a smooth margin and a well-defined border, but the expanded lesion produced cortical perforation and a lobulated margin. The provisional diagnosis was an ameloblastoma, whereas the histopathological examination revealed a GOC. This was a quite rare case, given that this radiographic change was observed in the posterior mandible of an elderly female. This case showed that a GOC can grow even in people in their seventies, changing from the unilocular form to an expanded, lobulated lesion. Here, we report a case of GOC with characteristic radiographic features.

Evaluation of soft tissue asymmetry using cone-beam computed tomography after open reduction and internal fixation of zygomaticomaxillary complex fracture.

OBJECTIVES: In this study, we assessed soft tissue asymmetry that occurred after open reduction of unilateral zygomaticomaxillary complex (ZMC) fractures. We proposed a simple method to assess soft tissue asymmetry after reduction surgery by evaluating the symmetry between the affected and the unaffected sides. The factors affecting soft tissue contour after surgery were also analyzed. MATERIALS AND METHODS: Subjects included patients admitted to Wonkwang University Dental Hospital from 2008 to 2013. Cone-beam computed tomography (CBCT) images of asymmetric patients who underwent open reduction at least 3 months prior were compared with healthy patients. RESULTS: The degree of asymmetry was measured in both the open reduction and control groups. Landmarks that showed a statistically significant difference between the two groups were zygion (1.73±0.24 mm), bucclae (1.08±0.26 mm), point of cheek (2.05±0.33 mm) and frontozygomatic point (1.30±0.31 mm). CONCLUSION: When compared with the normal group, asymmetry can occur in the affected side, which usually shows depression of overlying soft tissue and is statistically significantly different. Evaluation of soft tissue asymmetry with CBCT images after open reduction of ZMC fracture is useful.

3-Dimensional analysis for class III malocclusion patients with facial asymmetry.

OBJECTIVES: The aim of this study is to investigate the correlation between 2-dimensional (2D) cephalometric measurement and 3-dimensional (3D) cone beam computed tomography (CBCT) measurement, and to evaluate the availability of 3D analysis for asymmetry patients. MATERIALS AND METHODS: A total of Twenty-seven patients were evaluated for facial asymmetry by photograph and cephalometric radiograph, and CBCT. The 14 measurements values were evaluated and those for 2D and 3D were compared. The patients were classified into two groups. Patients in group 1 were evaluated for symmetry in the middle 1/3 of the face and asymmetry in the lower 1/3 of the face, and those in group 2 for asymmetry of both the middle and lower 1/3 of the face. RESULTS: In group 1, significant differences were observed in nine values out of 14 values. Values included three from anteroposterior cephalometric radiograph measurement values (cant and both body height) and six from lateral cephalometric radiographs (both ramus length, both lateral ramal inclination, and both gonial angles). In group 2, comparison between 2D and 3D showed significant difference in 10 factors. Values included four from anteroposterior cephalometric radiograph measurement values (both maxillary height, both body height) and six from lateral cephalometric radiographs (both ramus length, both lateral ramal inclination, and both gonial angles). CONCLUSION: Information from 2D analysis was inaccurate in several measurements. Therefore, in asymmetry patients, 3D analysis is useful in diagnosis of asymmetry.