ABSTRACT: ObjectivesMagnetic resonance (MR) imaging may provide some information as to the extent and tissue characteristics of a cancerous mass,
but the imaging features of lesions in the floor of the mouth have not been sufficiently clarified. MR imaging features of
tumescent lesions in this region were characterized, and the differential diagnoses are discussed.
MethodsMR images of 12 patients with tumescent lesions in the floor of the mouth (three patients with squamous cell carcinoma, two
with adenoid cystic carcinoma, one with hemangioma, one with schwannoma, one with lipoma, and four with ranula) were reviewed.
The literature on the imaging features of tumescent disease in the floor of the mouth was searched using the Medline database.
ResultsSix types of tumescent lesions in the floor of the mouth are presented. The differential diagnosis through a review of the
references is discussed. Malignant tumors were demonstrated as ill-defined masses. MR images were good at showing the internal
structures, such as fluid, hemorrhage, fat, nerves, calculus (phlebolith), cholesterol, and keratin, as different signal intensities.
Therefore, MR images gave clues for the differential diagnosis.
ConclusionMR images presented the distinctive features or the extent of the lesions and were therefore considered useful for a more
accurate diagnosis prior to treatment.
Oral Radiology 04/2012; 22(1):18-26. · 0.27 Impact Factor
ABSTRACT: ObjectivesThe purposes of this study were to analyze the CT anatomy of the mandibular first and second molars in uninfected subjects
and to clarify the pathway of odontogenic infection originating from the mandibular first and second molars.
MethodsCT anatomies, especially for bucco-lingual aspects and the surrounding soft tissues, were investigated in 100 uninfected subjects
and 17 infected patients.
ResultsAt the level of bifurcation, disappearance of the cortical plates was frequently observed on the buccal and lingual sides
of the first molars, and it was reduced on the buccal side in the second molar. In the first molar, the bony width was thinner
on the buccal than the lingual side. The lingual cortices were thinner in the second molar. All medial pterygoid and 88% of
masseter muscles were situated posteriorly, without horizontally overlapping the second molar, whereas the mylohyoid muscle
(MhM) overlapped horizontally with the first and second molars. The MhM was positioned superior to the root apices in 10 and
39% of first and second molars, respectively. All patients with first molar infection showed involvement of buccal structures,
and one showed lingual side involvement. In contrast, six of nine patients with second molar infection showed involvement
on the lingual side.
ConclusionsInfection originating from the second molar was more likely to spread to the lingual side than infection originating from
the first molar. CT anatomy surrounding the causal teeth supported the spread pathways of mandibular first and second molar
Oral Radiology 04/2012; 25(2):99-107. · 0.27 Impact Factor
ABSTRACT: ObjectivesThis study determined suitable conditions for masseter and temporal muscle massage using a specially fabricated robot and
evaluated its effects on patients with TMJ dysfunction associated with myofascial pain.
MethodsThe robot was designed with two arms with six degrees-of-freedom, and equipped with plungers. A phase-1 trial examined 22
healthy volunteers to determine its safety and suitable massage pressure, examining three different pressures. The volunteers
evaluated their comfort, warmth, and ease of mouth opening by use of a visual analogue scale (VAS). A phase-2 trial examined
the safety, suitable dose regimen, and efficacy in 12 patients. Maximal mouth opening was measured, and muscle pain and massage
were evaluated subjectively.
ResultsThe robot was safe in the phase-1 trial, except for two massages in which the pressure was excessive. Massages at 6–10N were
given the highest VAS scores. In phase 2, the massage pressure was arbitrary and each muscle was massaged seven times for
1min, three times every two weeks. After evaluating the efficacy, additional treatments were performed at a greater pressure
or for longer. The massage treatment was very effective for most patients.
ConclusionThe massage treatment was safe and effective for most patients when administered at a pressure of 6–10N seven times for 1min
per muscle every two weeks. The robot may constitute a useful tool for treating TMJ dysfunction associated with myofascial
Oral Radiology 04/2012; 25(1):53-59. · 0.27 Impact Factor
ABSTRACT: ObjectiveWe compared the relationship between anatomical structures analyzed by panoramic radiographs and CT images of uninfected impacted
maxillary third molars and investigated the pathway of infection originating from pericoronitis of maxillary third molars.
MethodsPatients (n=62) with uninfected impacted maxillary third molars and patients (n=8) with odontogenic infection originating from pericoronitis of the maxillary third molars were selected from an image
database. CT and panoramic images were evaluated separately by an oral surgeon and a radiologist for the vertical position
of the tooth, the presence of bone around the crown, proximity to the maxillary sinus, visibility of masticatory muscles,
and mesiodistal and buccopalatal inclinations.
ResultsIn uninfected patients, a significant correlation was observed between the vertical positions evaluated by the two methods.
Of the third molars, 79 (63.7%) were identified as vertical type on both panoramic and CT images. Regarding the maxillary
sinus, of the 19molars classified as the separate type on panoramic images, 2 (10.5%) were identified as the close type on
CT. CT examination revealed the involvement of buccal cortical plates and the buccal space in the majority of infected patients.
ConclusionsCT images revealed that 94molars (75.8%) showed vertical type on the buccopalatal inclination and that 45 impacted molars
(36.3%) showed bone defects in the buccal area. Infections originating from pericoronitis of the maxillary third molar showed
involvement of the buccal cortical plates, the buccal space, and other spaces, which were clearly depicted on CT images.
Oral Radiology 04/2012; 25(2):108-117. · 0.27 Impact Factor
ABSTRACT: ObjectivesWe sought to develop a method for evaluating dysphagia using videofluorography (VF) by analyzing the time course of changes
in pharyngeal wall movement and to assess patients with head-and-neck cancer before and after surgery.
MethodsThe subjects were 14 patients diagnosed with head-and-neck cancer. We obtained VF images before and after surgery and analyzed
them with two-dimensional video measurement software. Then, we calculated dysfunction scores based on the remaining or aspiration
amount of sample by interpreting the VF images.
ResultsWe found dysmotility of the posterior pharyngeal wall in some postoperative cases. Inter- and intrarater reproducibility was
high in the evaluation of posterior pharyngeal wall movements. A significant difference was found in the scores between the
patients showing dysmotility of the posterior pharyngeal wall and no dysmotility.
ConclusionsWe developed a reproducible method for evaluating movements of the posterior pharyngeal wall during swallowing using VF. This
may become a useful tool for objectively evaluating VF data.
Oral Radiology 04/2012; 25(2):123-128. · 0.27 Impact Factor
ABSTRACT: ObjectivesThis study clarified ultrasonography (US) changes after splint therapy and investigated the use of this modality for evaluating
treatment of the masseter muscle in temporomandibular disorder (TMD) patients with myofascial pain.
MethodsTwenty-five female TMD patients with myofascial pain were examined with US before and after splint therapy. The thickness
and internal appearance of the masseter muscle were evaluated.
ResultsNo differences in thickness were found before and after treatment in either “Improved” or “Not improved” patients. Twelve
patients showed changes in the internal appearance. A significant difference was observed in the distributions of types of
internal appearance before and after treatment. Three representative cases are presented.
ConclusionsUS has potential for evaluating the masseter muscle in TMD patients with myofascial pain, especially muscles that appear edematous
Oral Radiology 04/2012; 22(2):52-57. · 0.27 Impact Factor
ABSTRACT: ObjectivesTo demonstrate the imaging characteristics of a patient with myoepithelial carcinoma (MEC) of the mandible accompanied by
submandibular lymph node metastases, and to discuss the differential image-based diagnoses.
Patients and resultsThe patient was a 57-year-old woman who had suffered from a dull pain in her left lower molar region for 3months and had
an elastic-soft mass in her submandibular region for 2months. Computed tomography (CT) images showed permeative destruction
of the bone trabecula and intermittent absorption of the cortical plates in the left mandible. The bone marrow of this area
showed low signal intensity in a T1-weighted magnetic resonance (MR) image, slightly low signal intensity in a T2-weighted
image, and marked contrast enhancement. A tumor was confirmed outside the buccal and lingual cortical plates. The left submandibular
mass was shown as a well-defined, water-density mass by CT, low signal intensity in the T1-weighted MR image, and markedly
high signal intensity in the T2-weighted image. The histopathological diagnosis was MEC of the mandible with submandibular
lymph node metastasis.
ConclusionsWe demonstrated the imaging characteristics of MEC, showing permeative destruction of the bone trabecula, intermittent absorption
of the mandible, and cystic degeneration of the metastatic cervical lymph node.
KeywordsMyoepithelial carcinoma-Jaw-Lymph node metastasis-MRI
Oral Radiology 04/2012; 26(1):29-35. · 0.27 Impact Factor
ABSTRACT: The aim of this study was to clarify the sonographic features of the masseter muscle as indices for judging the efficacy of massage treatment.
Fifteen patients with temporomandibular disorder (10 with unilateral and 5 with bilateral muscle pain) underwent massage treatment alternately on the bilateral masseter and temporal muscles with an oral rehabilitation robot. Sonography was performed before and after treatment, and the masseter thickness and existence of anechoic areas were evaluated.
The thickness on the symptomatic side in the unilateral group significantly decreased after treatment. Anechoic areas were shown in 20 muscles (66.7%) before treatment, and disappeared or were reduced in size in 17 muscles (85.0%) after treatment. The pretreatment thickness was significantly related to visual analog scale (VAS) scores regarding posttreatment muscle pain and massage impression. The existence of anechoic areas was relevant to VAS scores regarding muscle pain.
Masseter thickness and existence of anechoic areas might be related to the therapeutic efficacy regarding muscle pain.
Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics 10/2010; 110(4):517-26. · 1.50 Impact Factor
ABSTRACT: The aim of this study was to clarify the changes, using magnetic resonance (MR) images, in the masseter muscles caused by low-level static contraction.
Ten healthy male volunteers were enrolled in the study. The MR scans were performed before, immediately after, and 10 minutes after low-level static contraction. Two imaging sequences were acquired: a diffusion-weighted image and an iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) image. The apparent diffusion coefficient (ADC), the signal-to-noise ratio (SNR), and the thicknesses of the right and left masseter muscles were examined.
The ADC and SNR immediately after exercise were significantly higher than those before exercise and 10 minutes after exercise. The muscles were significantly thicker immediately after exercise than before exercise and 10 minutes after exercise.
We confirmed the presence of edema in the masseter muscles caused by low-level static contraction using MR images.
Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics 03/2010; 109(6):908-16. · 1.50 Impact Factor
ABSTRACT: The aims of this study were (1) to assess the diagnostic power of magnetic resonance imaging (MRI) for mandibular osteomyelitis through comparison with conventional techniques and (2) to establish practical MRI diagnostic criteria in relation to treatment and clinical outcome.
In 55 subjects, clinically suspected as mandibular osteomyelitis, signal intensities (SI) were evaluated on T1-weighted/short T1 inversion recovery (STIR) images.
Forty-seven subjects were definitively diagnosed as having osteomyelitis by pathology studies or clinical course. For the acute or subacute stage, positively associated appearances were low SI on T1-weighted image and extensive high or focal high SI on the STIR image. For chronic stage, appearances of low SI on both T1-weighted and STIR images should be added to those for the acute or subacute stage. These findings support the at-present accepted imaging diagnostic criteria based on bony changes for detection of osteomyelitis.
This study confirms that T1-weighted/STIR images are useful for the detection of mandibular osteomyelitis.
Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics 05/2008; 105(4):503-11. · 1.50 Impact Factor
ABSTRACT: The purpose of this study was to determine the means and the ranges of the thresholds of cephalometric indexes by which orthodontists subjectively differentiate patients needing treatment for facial asymmetry from those who do not. The study was performed at the Departments of Orthodontics and Oral and Maxillofacial Radiology, Aichi-Gakuin University School of Dentistry in Nagoya, Japan, in 2004.
Ten orthodontists subjectively evaluated the frontal photographs of 100 subjects and classified them into 2 groups. The subjects in group A showed good or clinically acceptable levels of asymmetry and did not require treatment. Those in group B showed marked asymmetry, and treatment was recommended. The frontal cephalographs were also analyzed with 5 indexes related to the mandible. For each orthodontist, the threshold was determined by means of the discriminant analysis.
As the number of subjects who were judged to require treatment increased, the threshold of cephalometric indexes became smaller, and the discriminant accuracy was reduced. Among the 5 indexes evaluated, the distance of menton (mean, 4.28 mm), maxillomandibular midline angle (mean, 4.31 degrees ), and the distance of L1 (mean, 2.78 mm) showed relatively high accuracy in all observers.
The distance of menton, the maxillomandibular midline angle, and the distance of L1 appeared to be relevant indexes for the subjective evaluation of facial asymmetry. The thresholds determined in this study could contribute to the planning and evaluation of orthodontic treatments.
American journal of orthodontics and dentofacial orthopedics: official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics 06/2007; 131(5):609-13. · 1.33 Impact Factor
ABSTRACT: ObjectivesWe evaluated the clinical utility of a three-dimensional computed tomography (3D-CT) system to assess changes in the symmetry
of patients undergoing sagittal split ramus osteotomy (SSRO) for mandibular prognathism.
MethodsNine patients who underwent SSRO for mandibular prognathism were analyzed before and after their treatment using a 3D-CT system
that we developed for evaluating maxillofacial skeletal asymmetry. Asymmetry indices for selected landmarks were calculated
before and after treatment and compared with those of normal controls. Three regions were assessed: the maxillary, mandibular
body, and mandibular ramus regions. Based on these regional assessments before and after treatment, changes in asymmetry types
were determined for each patient.
ResultsThe asymmetry index was frequently improved for tooth-related landmarks, whereas no changes were observed in the anterior
nasal spine, orbitale, or porion. In the maxillary and mandibular body regions, all nine patients showed improvement or no
change in asymmetry. Deterioration was observed only in the mandibular ramus region of three patients who had preoperative
asymmetry in the maxillary region.
ConclusionOur 3D-CT system is effective for postoperative evaluation of facial asymmetry in patients with mandibular prognathism.
Oral Radiology 05/2007; 23(1):10-15. · 0.27 Impact Factor
ABSTRACT: The location and configuration of mandibular canal variations are important in surgical procedures involving the mandible, such as extraction of an impacted third molar, dental implant treatment, and sagittal split ramus osteotomy. We report 3 Japanese patients with bifid mandibular canals using panoramic radiograph and multi-slice helical computed tomography (CT) images. In 2 of the 5 sides, the bifid mandibular canal was suggested on panoramic radiograph. The bifid mandibular canal had a short and narrow upper canal toward the distal area of the second molar in 4 sides, and a short and narrow lower canal toward the distal area of second molar in 1 side, as revealed on reconstructed CT images. Since the location and configuration of mandibular canal variations are important in surgical procedures involving the mandible, they should be carefully observed using reconstructed CT images.
Implant Dentistry 04/2007; 16(1):24-32. · 1.05 Impact Factor
ABSTRACT: The aims of this study were to characterize the symmetrical features of patients with facial deformities and to suggest a classification system for facial asymmetry based on 3-dimensional-computed tomography (3D-CT) evaluation.
Preoperative CT images were investigated for 49 patients with maxillofacial deformities. Asymmetry indices were calculated for some landmarks in the maxilla, mandibular body and the mandibular ramus regions.
Asymmetry was observed most frequently in the mandibular body region. The subjects were divided into 3 groups. Subjects without any asymmetry in the 3 regions were classified as Group I (44.9%). Groups II or III were defined for subjects without or with maxillary region asymmetry, respectively, and they were subcategorized. In Group IIA (8.2%), asymmetry was shown solely in the mandibular body region, and in Group IIB (18.4%), additional asymmetry was shown in the mandibular ramus region. Group IIIA (6.1%) showed asymmetry only in the maxillary region, and Group IIIB (22.4%) showed asymmetry in all 3 regions.
The 3D-CT classification for facial asymmetry has the potential to replace the conventional cephalometric classification.
Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics 10/2006; 102(3):382-90. · 1.50 Impact Factor
ABSTRACT: Condylar remodeling, which develops after mandibular setback osteotomy, was evaluated and compared in CT, plain film radiographs, and MR images acquired postoperatively.
Thirty-nine patients treated with sagittal split ramus osteotomy (SSRO) and 46 patients treated with intraoral vertical ramus osteotomy (IVRO) were studied. Remodeling as seen in the images and the diagnostic agreement between imaging modalities was evaluated.
A newly formed bone layer in the posterior part of the condylar head was identified as a sign suggestive of remodeling. This sign was seen predominantly at periods over 6 months postoperatively. IVRO subjects had a higher incidence of remodeling than did the SSRO group. The diagnostic agreement between the 3 imaging modalities was substantial. There was a positive correlation between postoperative condylar displacement and the incidence of remodeling.
The incidence of postoperative condylar head remodeling may be predictable. High-dose postoperative imaging studies to assess the TMJ should be restricted to those cases having a clear need for such studies.
Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics 05/2006; 101(4):505-14. · 1.50 Impact Factor
ABSTRACT: The purposes of this study were to investigate the horizontal relationship of the roots of maxillary molars with the cortical plates and the maxillary sinus and to investigate the influence of these relationships on the spread of odontogenic infection. Computed tomography images of 120 control subjects and 49 patients with infection originating in the maxillary first or second molar were investigated. In the control group, more than 60% of the first molar roots contacted both palatal and buccal cortical plates (type A), while such contact was not seen in more than 60% of second molars. The floor of maxillary sinus was most frequently observed at the level between the bifurcation and apices of roots in both first and second molars. In patients with infection, cortical changes were more frequently seen on the buccal side than on the palatal side, and 80% of patients with buccal cortical change showed the position in which the buccal roots were close to the buccal cortical plate. Mucosal thickening of the maxillary sinus was found in 87.8%. The buccopalatal spread of odontogenic infection originating in the maxillary first and second molars was influenced by the horizontal root position in relation to the cortices.
Clinical Oral Investigations 04/2006; 10(1):35-41. · 2.36 Impact Factor
ABSTRACT: The purpose of this study was to investigate the relationship between the subjective evaluation of facial asymmetry and seven cephalometric indices. Ten orthodontists subjectively evaluated the frontal photographs of 100 subjects and categorized them into three categories, ie, category I--symmetrical view; category II--a little asymmetry not requiring treatment; and category III--marked asymmetry requiring treatment. Seven indices that were used to evaluate facial asymmetry were determined using frontal cephalographs of these patients. Interobserver agreement was assessed using Cohen's kappa statistic. Agreement among the observers for category III was higher than for categories I and II. To define the characteristics of each category, the cephalometric indices, which at least eight observers agreed on, were compared between the categories. No differences were found in any of the indices between categories I and II. Five indices showed differences between category III and the other categories. Among them, the distance of Me from the vertical reference line was the most relevant index for the subjective evaluation of facial asymmetry. When a discrepancy is found between skeletal measurements and a subjective evaluation, the influence of soft tissue structures should be considered in facial asymmetry.
The Angle Orthodontist 08/2005; 75(4):651-5. · 1.21 Impact Factor
ABSTRACT: Recently, 3-dimensional-computed tomography (3D-CT) imaging has been used in the diagnosis and surgical treatment planning of patients with craniofacial deformities. The present authors have developed a 3D-CT imaging procedure for a 3-dimensional coordinate point evaluation system to assess and diagnose patients with facial asymmetry.
The CT data of 16 subjects was selected retrospectively as the control group from patients who had undergone CT examinations to diagnose conditions other than maxillofacial deformities. Anatomical landmarks modified from orthodontic craniometric (cephalometric) points were defined on the 3D-CT images and the asymmetry index of each point was calculated in millimeters. A diagrammatic chart with a baseline indicating the mean asymmetry indices plus the standard deviation in the control group was designed. The resulting diagrammatic chart was used to evaluate the degree of deformity in facial asymmetry patients.
The topography of facial asymmetry was assessed. The 3D-CT imaging technique as described herein is a practical method of evaluating the morphology of facial asymmetry.
Oral Surgery Oral Medicine Oral Pathology Oral Radiology and Endodontics 03/2005; 99(2):212-20. · 1.46 Impact Factor
ABSTRACT: To reveal computed tomography (CT) features of patients with coronoid process hyperplasia without interference between the process and the zygomatic bone.
A case-control study was designed. Thirteen cases without interference (2 male and 11 female, 28-56 years old) and 65 controls were sampled from a patient database. Differences in CT features were analyzed between the 2 groups regarding the following 7 points of 5 regions: configuration of the coronoid process, vertical level of the coronoid process, the distance between the bilateral zygomatic arches, thickness of the temporal muscle, anteroposterior width of the temporal muscle, thickness of the temporal muscle tendon, and thickness of the masseter muscle. Cluster analysis was applied to differentiate between individuals.
All cases had bilateral hyperplastic change of the coronoid process. Differences were found between the cases and controls in 6 of 7 CT features with the exception of temporal muscle thickness. All incidences of significant difference showed larger values in the cases. All cases were clustered into the same group and were differentiated from the controls.
CT features appeared to be effective for diagnosis of this condition, and these patients should be put into the same category under the diagnosis of coronoid process hyperplasia.
Oral Surgery Oral Medicine Oral Pathology Oral Radiology and Endodontics 02/2005; 99(1):93-100. · 1.46 Impact Factor
ABSTRACT: The aims of the present study were to clarify the anatomy of impacted mandibular third molars in relation to surrounding structures and to investigate the pathway of infection originating from pericoronitis of this tooth.
Computed tomography (CT) images were evaluated in 87 patients with uninfected mandibular third molar impaction and in 12 patients with infection originating from an impacted mandibular third molar. In uninfected patients, bony features around the impacted crown were investigated together with the relationship between the crown and surrounding muscles. In infected patients, involvements of bony and soft tissue structures were evaluated according to the disappearance of cortices and lateral asymmetry of density and shape in the spaces and muscles.
In uninfected patients, the disappearance of the lingual cortical plate was observed in 48 (35.3%) impacted molars, while only in 11 (8.1%) teeth for buccal cortices. The cortical thickness was thinner on the lingual side than the buccal side. Sixty-five percent of the masseter muscle horizontally overlapped the crown, while almost all of the medial pterygoid muscle was posteriorly situated apart from the crown. The mylohyoid muscle horizontally overlapped the crown at below or intermediate vertical positions. In infected patients, the involvement of lingual structures was more frequently observed than that of buccal structures. The mylohyoid muscle was involved in 10 (83.3%) of 12 patients. Among them, 8 showed submandibular space involvement.
CT findings supported the clinical observations of infection spread in patients with pericoronitis of the impacted mandibular third molar. CT appeared to be an effective tool for investigating the pathway of infection originating from the pericoronitis of impacted mandibular third molars.
Oral Surgery Oral Medicine Oral Pathology Oral Radiology and Endodontics 12/2004; 98(5):589-97. · 1.46 Impact Factor