Buccal nerve schwannoma mimicking a salivary gland tumor:a rare case report

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 functionof the buccal nerve was recovered without complications.

Effect of a vertical incision on postoperative swelling after an impacted mandibular third molar extraction: two cases with split-mouth designed magnetic resonance imaging analysis

This study examined the effects of a vertical incision on postoperative edema after third molar extraction. The study design was that of a comparative split-mouth approach. Evaluation was performed via magnetic resonance imaging (MRI). Two patients with homogeneous bilateral impacted mandibular third molars were enrolled. These patients underwent facial MRI within 24 hours after simultaneous extraction surgery. Modified triangular flap and enveloped flap incisions were made. Postoperative edema was evaluated by MRI and was assessed according to anatomical space. The two pairs of homogeneous extractions demonstrated that vertical incisions were associated qualitatively and quantitatively with extensive postoperative edema. The edema associated with these incisions spread toward the buccal space, beyond the buccinator muscle. In conclusion, a vertical incision with mandibular third molar extraction was related to edema in the buccal space and the fascial space, which contributed to clinical facial swelling.

Acute Myeloid Leukemia Identified Incidentally in Patient with Infected Extraction Socket through Preoperative Screening Blood Test: A Case Report

Leukemia is a neoplastic disease with an excessive proliferation of immature white blood cells and their precursors. Common oral manifestations of acute myeloid leukemia (AML) include ulceration, petechiae, spontaneous bleeding, and gingival hyperplasia. The estimated prevalence of AML is 19 per 100,000 populations, the median age of diagnosis is over 65 years, and of all the subtypes of leukemia, AML accounts for the highest percentage of leukemic deaths. The purpose of this study is to report the case of a 77-year-old female patient, who visited our outpatient clinic due to consistent inflammatory findings. Though she received surgical treatment, she was diagnosed with AML by chance after a preoperative blood test. We also discuss the necessity of performing a preoperative blood test prior to invasive dental procedures such as tooth extraction or biopsy.

Effect of initial placement level and wall thickness on maintenance of the marginal bone level in implants with a conical implant-abutment interface: a 5-year retrospective study

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.

Modified difficult index adding extremely difficult for fully impacted mandibular third molar extraction

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.

Effect of bisphosphonate on temporomandibular joint in osteopenia-induced rats by botulinum toxin A injection on masticatory muscle: a preliminary study / 대한악안면성형재건외과학회지

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.

Modified difficult index adding extremely difficult for fully impacted mandibular third molar extraction

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.

Subcutaneous emphysema related to dental procedures

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.

Three-dimensional analysis of the anterior loop of the inferior alveolar nerve in relation to the growth pattern of the mandibular functional subunit / 대한악안면성형재건외과학회지

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.

Expression of collagenases (matrix metalloproteinase-1, 8, 13) and tissue inhibitor of metalloproteinase-1 of retrodiscal tissue in temporomandibular joint disorder patients

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.

Three-dimensional computed tomography evaluation of craniofacial characteristics according to lateral deviation of chin / 대한악안면성형재건외과학회지

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.

Temporomandibular joint synovial chondromatosis extending to the temporal bone: a report of two cases

Synovial chondromatosis is a rare benign lesion originating from the synovial membrane. It presents as adhesive or non-adhesive intra-articular cartilaginous loose bodies. Although the causes of synovial chondromatosis have not been fully elucidated, inflammation, external injury, or excessive use of joints have been suggested as possible causes. Synovial chondromatosis has been reported to occur most frequently at large joints that bear weights, with a rare occurrence at the temporomandibular joint (TMJ). When synovial chondromatosis develops at TMJ, clinical symptoms, including pain, joint sounds, and mouth opening may common. Moreover, synovial chondromatosis rarely spreads to the mandibular condyle, glenoid cavity, or articular eminence of TMJ. The goal of this study was to discuss the methods of surgery and other possible considerations by reviewing cases of patients who underwent surgery for synovial chondromatosis that extended to the temporal bone.

Temporomandibular joint synovial chondromatosis extending to the temporal bone: a report of two cases

Synovial chondromatosis is a rare benign lesion originating from the synovial membrane. It presents as adhesive or non-adhesive intra-articular cartilaginous loose bodies. Although the causes of synovial chondromatosis have not been fully elucidated, inflammation, external injury, or excessive use of joints have been suggested as possible causes. Synovial chondromatosis has been reported to occur most frequently at large joints that bear weights, with a rare occurrence at the temporomandibular joint (TMJ). When synovial chondromatosis develops at TMJ, clinical symptoms, including pain, joint sounds, and mouth opening may common. Moreover, synovial chondromatosis rarely spreads to the mandibular condyle, glenoid cavity, or articular eminence of TMJ. The goal of this study was to discuss the methods of surgery and other possible considerations by reviewing cases of patients who underwent surgery for synovial chondromatosis that extended to the temporal bone.

Progression of periapical cystic lesion after incomplete endodontic treatment

We report a case of large radicular cyst progression related to endodontic origin to emphasize proper intervention and follow-up for endodontic pathosis. A 25 yr old man presented with an endodontically treated molar with radiolucency. He denied any intervention because of a lack of discomfort. Five years later, the patient returned. The previous periapical lesion had drastically enlarged and involved two adjacent teeth. Cystic lesion removal and apicoectomy were performed on the tooth. Histopathological analysis revealed that the lesion was an inflammatory radicular cyst. The patient did not report any discomfort except for moderate swelling 3 days after the surgical procedure. Although the patient had been asymptomatic, close follow-ups are critical to determine if any periapical lesions persist after root canal treatment.

Bony window approach for a traumatic bone cyst on the mandibular condyle: a case report with long-term follow-up

Traumatic bone cyst (TBC) occurs preferentially on the mandibular symphysis and body, but rarely on the mandibular condyle. When TBC occurs in the condylar area, it can usually be related with or misdiagnosed as a temporomandibular joint disorder. A 15-year-old female patient visited the Temporomandibular Joint Clinic with a 5-year history of pain and noise localized in the left temporomandibular joint. On imaging, a well demarked oval-shaped radiolucent lesion was observed on the left condyle head. The patient underwent cyst enucleation and repositioning of the bony window on the lateral cortex of the affected condyle head under the impression of subchondral cyst or TBC; however, no cystic membrane was found. The bone defect resolved and showed no recurrence on the serial radiographic postoperative follow-up for 43 months after surgery.

Contralateral recurrence of necrotizing sialometaplasia of the hard palate after five months: a case report

Necrotizing sialometaplasia usually heals within 4 to 10 weeks with conservative treatment, and rarely recurs. When necrotizing sialometaplasia is present on the hard palate it may occur unilaterally or bilaterally. In this case, necrotizing ulceration occurred on the left hard palate of a 36-year-old woman after root canal treatment of the upper left first premolar under local anesthesia. After only saline irrigation the defect of the lesion completely healed and filled with soft tissue. After 5 months, however, a similar focal necrosis was found on the contralateral hard palate without any dental treatment having been performed on that side and progressed in similar fashion as the former lesion. We conducted an incisional biopsy and obtained a final pathological diagnosis for the palatal mass of necrotizing sialometaplasia. At the 3-year follow-up, the patient's oral mucosa of the hard palate was normal, without any signs and symptoms of the condition. We report a case of a second occurrence of necrotizing sialometaplasia on the contralateral side from the first, with a time lapse between the first and second occurrence.

Conservative condylectomy alone for the correction of mandibular asymmetry caused by osteochondroma of the mandibular condyle: a report of five cases

We describe our experience with conservative condylectomy for the correction of facial asymmetry in five patients with osteochondroma of the mandibular condyle. All five patients presented with malocclusion and facial asymmetry, which are common clinical findings of osteochondroma involving the mandibular condyle. We performed conservative condylectomy without additional orthognathic surgery for all five patients, preserving the vertical height of the condylar process as much as possible. Following surgery, intermaxillary traction using a skeletal anchorage system with rubber elastics was performed on all patients to improve occlusion, and, when necessary, additional minimal orthodontic treatment was performed. The mean follow-up period was 42 months. At the last follow-up visit, all patients exhibited satisfactory facial symmetry and remodeling of the remaining condyle, with stable health and no signs of recurrence. In conclusion, conservative condylectomy alone, without subsequent orthognathic surgery, is adequate for the restoration of facial symmetry and the preservation of vertical condylar height in select patients with condylar osteochondroma.

Mouth opening limitation caused by coronoid hyperplasia: a report of four cases

Coronoid process hyperplasia is a rare condition that causes mouth opening limitation, otherwise known as trismus. The elongated coronoid processes impinge on the medial surfaces of the zygomatic arches when opening the mouth, which limits movement of the mandible and leads to trismus. Patients with trismus due to coronoid process hyperplasia do not have any definite symptoms such as temporomandibular joint pain or sounds upon clinical examination, and no significant abnormal signs are observed on panoramic radiographs or magnetic resonance images of the temporomandibular joint. Thus, the diagnosis of trismus is usually very difficult. However, computed tomography can help with the diagnosis, and the condition can be treated by surgery and postoperative physical therapy. This paper describes four cases of patients who visited our clinic for trismus and were subsequently diagnosed with coronoid process hyperplasia. Three were successfully treated with a coronoidectomy and postoperative physical therapy.

Characteristics of bony changes and tooth displacement in the mandibular cystic lesion involving the impacted third molar

OBJECTIVES: The purpose of this retrospective study is to find the differentiating characteristics of cystic and cystic-appearing lesions that involve the impacted mandibular third molar by analyzing panoramic radiographs and computed tomography images, and to aid the preoperative diagnosis. MATERIALS AND METHODS: Eighty-one patients who had a mandibular cystic or cystic-appearing lesion that involved impacted mandibular third molar and underwent cyst enucleation were included in the study. The preoperative panoramic radiograph and computed tomography findings were analyzed in accordance to the histopathologic type. RESULTS: Most of the cystic lesions containing the mandibular third molar were diagnosed as a dentigerous cyst (77.8%). The occurrence of mesio-distal displacement of the third molar was more frequent in the odontogenic keratocyst (71.4%) and in the ameloblastoma (85.7%) than in the dentigerous cyst (19.1%). Downward displacement was primarily observed in each group. Odontogenic keratocyst and ameloblastoma showed more aggressive growth pattern with higher rate of bony discontinuity and cortical bone expansion than in dentigerous cyst. CONCLUSION: When evaluating mandibular cystic lesions involving the impacted mandibular third molar, dentigerous cyst should first be suspected. However, when the third molar displacement and cortical bone absorption are observed, then odontogenic keratocyst or ameloblastoma should be considered.

Misdiagnosis of florid cemento-osseous dysplasia leading to unnecessary root canal treatment: a case report

This case report demonstrates an unnecessary endodontic treatment of teeth with florid cemento-osseous dysplasia (FCOD) due to a misdiagnosis as periapical pathosis and emphasizes the importance of correct diagnosis to avoid unnecessary treatment. A 30-year-old woman was referred to our institution for apicoectomies of the mandibular left canine and both the lateral incisors. The periapical lesions associated with these teeth had failed to resolve after root canal treatment over a 3-year period. Radiographic examinations revealed multiple lesions on the right canine, the second premolar, and both first molars as well as the anterior region of the mandible. Based on clinical, radiographic and histological evaluations, the patient condition was diagnosed as FCOD. The patient has been monitored for 2 years. To avoid unnecessary invasive treatment, accurate diagnosis is essential before treatment is carried out in managing FCOD.