Integrating lipid metabolite analysis with MRI-based transformer and radiomics for early and late stage prediction of oral squamous cell carcinoma.

BACKGROUND: Oral Squamous Cell Carcinoma (OSCC) presents significant diagnostic challenges in its early and late stages. This study aims to utilize preoperative MRI and biochemical indicators of OSCC patients to predict the stage of tumors. METHODS: This study involved 198 patients from two medical centers. A detailed analysis of contrast-enhanced T1-weighted (ceT1W) and T2-weighted (T2W) MRI were conducted, integrating these with biochemical indicators for a comprehensive evaluation. Initially, 42 clinical biochemical indicators were selected for consideration. Through univariate analysis and multivariate analysis, only those indicators with p-values less than 0.05 were retained for model development. To extract imaging features, machine learning algorithms in conjunction with Vision Transformer (ViT) techniques were utilized. These features were integrated with biochemical indicators for predictive modeling. The performance of model was evaluated using the Receiver Operating Characteristic (ROC) curve. RESULTS: After rigorously screening biochemical indicators, four key markers were selected for the model: cholesterol, triglyceride, very low-density lipoprotein cholesterol and chloride. The model, developed using radiomics and deep learning for feature extraction from ceT1W and T2W images, showed a lower Area Under the Curve (AUC) of 0.85 in the validation cohort when using these imaging modalities alone. However, integrating these biochemical indicators improved the model's performance, increasing the validation cohort AUC to 0.87. CONCLUSION: In this study, the performance of the model significantly improved following multimodal fusion, outperforming the single-modality approach. CLINICAL RELEVANCE STATEMENT: This integration of radiomics, ViT models, and lipid metabolite analysis, presents a promising non-invasive technique for predicting the staging of OSCC.

Root canal narrowing patterns of mandibular first premolars on panoramic radiographs according to the number of root canals diagnosed on cone beam computed tomographic images.

Understanding the variations in root canal morphology is important for successful endodontic treatment. Mandibular first premolars have a single root in 98% of cases, and multiple root canals are found in approximately 20% of cases. However, the details of these characteristic findings in panoramic radiography and their diagnostic accuracy are unknown. This study aimed to investigate the characteristic radiographic findings of mandibular first premolars possessing multiple root canals and determine the diagnostic accuracy using panoramic radiography. Four radiologists evaluated 347 mandibular first premolars in 186 patients who underwent panoramic radiography and dental cone beam computed tomography (CBCT). Two radiologists confirmed the existence of single or multiple root canals using CBCT. The remaining two radiologists evaluated the imaging findings of the root canal morphology and classified them into two patterns: gradual narrowing and sudden narrowing. In the case of the sudden narrowing pattern, the location of sudden narrowing was also evaluated. A gradual narrowing pattern was observed in 56% of teeth with a single root canal, and a sudden narrowing pattern was observed in 83% of teeth with multiple root canals. When sudden narrowing between the cervical and apical 1/4 of the root canal was used as the diagnostic criterion for multiple root canal teeth, the highest diagnostic performance was observed (sensitivity, 76.1%; specificity, 73.9%). The sudden narrowing between the cervical level and the apical 1/4 level of the root canal is a practical diagnostic criterion for mandibular first premolar with multiple root canals.

Evaluation of radiation dose and image quality for dental cone-beam computed tomography in pediatric patients.

Children are sensitive to radiation; therefore, it is necessary to reduce radiation dose as much as possible in pediatric patients. In addition, it is crucial to investigate the optimal imaging conditions as they considerably affect the radiation dose. In this study, we investigated the effect of different imaging conditions on image quality and optimized the imaging conditions for dental cone-beam computed tomography (CBCT) examinations to diagnose ectopic eruptions and impacted teeth in children. To achieve our aims, we evaluated radiation doses and subjective and objective image quality. The CBCT scans were performed using 3D Accuitomo F17. All combinations of a tube voltage (90 kV), tube currents (1, 2, 3 mA), fields of view (FOVs) (4 × 4, 6 × 6 cm), and rotation angles (360°, 180°) were used. Dose-area product values were measured. SedentexCT IQ cylindrical phantom was used to physically evaluate the image quality. We used the modulation transfer function as an index of resolution, the noise power spectrum as an index of noise characteristics, and the system performance function as an overall evaluation index of the image. Five dentists visually evaluated the images from the head-neck phantom. The results showed that the image quality tended to worsen, and scores for visual evaluation decreased as tube currents, FOVs and rotation angles decreased. In particular, image noise negatively affected the delineation of the periodontal ligament space. The optimal imaging conditions were 90 kV, 2 mA, 4 × 4 cm FOV and 180° rotation. These results suggest that CBCT radiation doses can be significantly reduced by optimizing the imaging conditions.

Influence of oestrogen deficiency and excessive mechanical stress on condylar head of mandible.

OBJECTIVE: We assessed the aetiology of idiopathic condylar resorption by examining the effects of oestrogen and compressive mechanical stress under a low systemic oestrogen condition in temporomandibular joints (TMJ) caused by an ovariectomy. MATERIALS AND METHODS: Female rabbits were divided into non-ovariectomy (non-OVX) and ovariectomy (OVX) groups. A cortical osteotomy was performed with a custom device that was increased in length by 0.25 mm every 12 hr for 1 week after the operation, during which the TMJs in the rabbits received compressive mechanical stress. Samples from both groups were examined with micro-computed tomography and histological staining. RESULTS: Area and depth of bone resorption were both greater in the OVX group. Furthermore, a significantly earlier and greater prevalence of sub-condylar bone resorption was noted in that group, while cells positive for tartrate-resistant acid phosphatase were increased in the OVX group. CONCLUSIONS: The present findings suggest that oestrogen induced a much greater amount of bone resorption on the anterior surface of the condylar head at an earlier stage in the TMJs of the present model rabbits. Thereafter, restoration of TMJ function appeared to occur in a normal manner.

The effectiveness of an actuator-driven pulsed water jet for the removal of artificial dental calculus: a preliminary study.

BACKGROUND: While hand and ultrasonic scalers are the primary tools used for the removal of dental calculus in periodontal treatment, many studies have shown that they also damage the enamel surface. We have developed a novel actuator-driven pulsed water jet (ADPJ) system, which has the ability to selectively remove materials depending on their stiffness. Considering the different material properties between teeth and dental calculus, it might be possible to develop the ADPJ to remove dental calculus without damage to the tooth's enamel surface using a suitable jet pressure. Therefore, the aim of this study was to assess the effectiveness of the ADPJ in removing dental calculus, and the surface features of the teeth after its use. METHODS: A total of 93 artificial teeth coated with artificial dental calculus were examined in this study. The weights of 90 teeth were measured before and after the use of ADPJ, which had an applied voltage setting of 150, 200, or 240 V. The three remaining teeth were instrumented with a conventional hand scaler, ultrasonic scaler, or ADPJ (set at 240 V). Damage to the artificial tooth surfaces was evaluated using 5% Evans blue dye under an optical microscope. Furthermore, apatite pellets, which are utilized as experimental substitutes for natural teeth, were assessed after the use of ADPJ and both conventional scalers. RESULTS: The ADPJ significantly reduced the amount of artificial calculus, and the removal rate was dependent on the applied voltage. No damage was observed on the surface of the artificial tooth and apatite pellet following the use of ADPJ, in contrast to the conventional scalers. CONCLUSIONS: The results of this study demonstrate the in vitro effectiveness of ADPJ in the removal of dental calculus, without causing damage to tooth surfaces.

Relationship of MR imaging of submandibular glands to hyposalivation in Sjögren's syndrome.

OBJECTIVE: We analysed the correlation between magnetic resonance images of the parotid and submandibular glands and the salivary flow rate in patients with Sjögren's syndrome. METHODS: We retrospectively reviewed magnetic resonance images (heterogeneous signal-intensity distribution and gland volume on T1- and fat-suppressed T2-weighted images, and multiple high-signal-intensity spots on magnetic resonance sialograms in the parotid and submandibular glands) obtained from 66 patients who were diagnosed with Sjögren's syndrome. We evaluated the relationship between these imaging features and their salivary flow rates in stimulated and unstimulated conditions. RESULTS: We found that as the disease progressed, both the heterogeneous signal-intensity distribution and the volumes of the parotid and the submandibular glands were significantly related to the stimulated and the unstimulated salivary flow rate. These imaging features were more highly correlated in assessments of the submandibular gland than in those of the parotid gland for both stimulated and unstimulated salivary flow rates. CONCLUSIONS: Magnetic resonance image features of heterogeneity and smaller volume in the submandibular gland are reliable for predicting hyposalivation related to the progression of Sjögren's syndrome.

Dentin hypersensitivity-like tooth pain seen in patients receiving steroid therapy: An exploratory study.

To ascertain whether steroid therapy evokes dentin hypersensitivity (DH)-like tooth pain, we performed a study based on compelling evidence from patients receiving steroid therapy. An exploratory study was conducted using a questionnaire for 220 patients prescribed steroids who attended the Department of Hematology and Rheumatology of Tohoku University Hospital. Group comparisons between patients with and without steroid pulse therapy were analysed by statistical means. In this study, any DH-like tooth pain that commenced subsequent to steroid treatment was defined as steroid-derived (SD) tooth pain. The prevalence of SD tooth pain was 17.7% (39/220 patients). SD tooth pain was triggered in many vital teeth by cold and/or hot water (84.2% and 23.7%, respectively) with the pain characterised as continuous, in contrast to typical DH tooth pain. SD tooth pain was significantly more frequent in pulse therapy patients than in non-pulse therapy patients (p < 0.05). Logistic regression analysis adjusted for age and sex showed similar results (odds ratio = 3.74, p = 0.013). Moreover, a positive correlation was observed between the steroid dose and pain score (ρ = 0.642). Dose reduction or discontinuation of steroid therapy relieved SD tooth pain in all cases. Thus, steroid therapy can evoke DH-like tooth pain during treatment.

Prednisolone induces microglial activation in the subnucleus caudalis of the rat trigeminal sensory complex.

Prednisolone is a member of synthetic glucocorticoids which are widely used to treat chronic inflammatory diseases. In this study, neuronal degeneration and cell death, and glial reaction were investigated in the rat trigeminal ganglion (TG) and brainstem after subcutaneous injection of prednisolone for 7 days. Expression of c-Jun activating transcription factor 3 and caspase-3 was absent or infrequent in the TG, and cranial sensory and motor nuclei of saline- and prednisolone-treated animals. In these animals, distribution of calcitonin gene-related peptide-immunoreactive (-IR) neurons and nerve fibers was similar in the brainstem. In addition, the number of Iba1- and glial fibrillary acidic protein (GFAP)-IR cells with some processes in the brainstem was barely affected by prednisolone treatment. However, the treatment increased ramification of Iba1-IR processes in the subnucleus caudalis of the trigeminal sensory complex. Prednisolone scarcely influenced the morphology of GFAP-IR cells in the brainstem. Expression of p38 mitogen-activated protein kinase was very rare in the brainstem of saline- and prednisolone-treated animals. The present study suggests that microglia are activated by prednisolone in the subnucleus caudalis of the trigeminal sensory complex. The glucocorticoid may affect nociceptive transmission in the brainstem.

The clinical efficacy of powder air-polishing in the non-surgical treatment of peri-implant diseases: A systematic review and meta-analysis.

Peri-implant diseases, characterized by inflammatory conditions affecting peri-implant tissues, encompass peri-implant mucositis and peri-implantitis. Peri-implant mucositis is an inflammatory lesion limited to the mucosa around an implant, while peri-implantitis extends from the mucosa to the supporting bone, causing a loss of osseointegration. For non-surgical treatments, we tested the null hypothesis that the presence or absence of air-polishing made no difference. The study focused on randomized controlled trials (RCTs) comparing air-polishing with mechanical or ultrasonic debridement, evaluating outcomes such as bleeding on probing (BOP), probing depth (PD), plaque index/plaque score (PI/PS), clinical attachment level (CAL), bone loss, and mucosal recession (MR). Two independent reviewers conducted data extraction and quality assessments, considering short-term (<6 months) and long-term (≥6 months) follow-up periods. After screening, ten articles were included in the meta-analysis. In nonsurgical peri-implant disease management, air-polishing moderately mitigated short-term PI/PS for peri-implant mucositis and showed a similar improvement in long-term BOP and bone loss for peri-implantitis compared to the control group. The Egger test found no evidence of publication bias except for the long-term PI/PS of peri-implant mucositis. Leave-one-out analysis confirmed the stability of the results. The findings highlight the need for future research with longer-term follow-up and high-quality, multi-center, large-sample RCTs.

Temporomandibular joint ankylosis suspected to be associated with ankylosing spondylitis based on cervical computed tomography images: A pictorial essay.

This report showed a case of temporomandibular joint (TMJ) ankylosis suspected to be associated with ankylosing spondylitis based on the observation of bony ankylosis of the cervical spine on computed tomography (CT) images. A 53-year-old man presented with a chief complaint of difficulty in opening his mouth. His medical history indicated that in his 20s, he became aware of the difficulty in moving his neck. CT revealed marked osteoarthritic changes in the right mandibular condyle, suggesting fibrotic TMJ ankylosis. In addition, bony ankylosis of the cervical vertebral body and facet joints from the axis (C2) to C5 in continuity was observed. CT of the entire spine also showed bony deformity of the sacroiliac joints and bony ankylosis. Based on these findings, ankylosing spondylitis was suspected. The possibility of an ankylosing spondylitis complication should be considered in cases of TMJ ankylosis if bony ankylosis of the cervical spine is observed.

Detection of oral cancer and oral potentially malignant disorders using artificial intelligence-based image analysis.

BACKGROUND: We aimed to construct an artificial intelligence-based model for detecting oral cancer and dysplastic leukoplakia using oral cavity images captured with a single-lens reflex camera. SUBJECTS AND METHODS: We used 1043 images of lesions from 424 patients with oral squamous cell carcinoma (OSCC), leukoplakia, and other oral mucosal diseases. An object detection model was constructed using a Single Shot Multibox Detector to detect oral diseases and their locations using images. The model was trained using 523 images of oral cancer, and its performance was evaluated using images of oral cancer (n = 66), leukoplakia (n = 49), and other oral diseases (n = 405). RESULTS: For the detection of only OSCC versus OSCC and leukoplakia, the model demonstrated a sensitivity of 93.9% versus 83.7%, a negative predictive value of 98.8% versus 94.5%, and a specificity of 81.2% versus 81.2%. CONCLUSIONS: Our proposed model is a potential diagnostic tool for oral diseases.

Evaluation of optimal length and insertion torque for miniscrews.

INTRODUCTION: The purpose of this article was to test the theory that short miniscrews will decrease the possibility of damaging the root, but the failure rate will increase. METHODS: One hundred eighty-six miniscrews (diameter, 1.3 × 5 mm, n = 63; 6 mm, n = 62; 7 mm, n = 61) were placed in 105 consecutive patients. Multislice computed tomography and cone-beam computed tomography scans were taken before and after miniscrew placement. Insertion torque was measured at miniscrew placement. RESULTS: The success rate of the miniscrews in the maxilla (93.4%) was higher than that in the mandible (70.3%). A significantly lower success rate with 5-mm miniscrews was observed compared with 6-mm and 7-mm miniscrews in the mandible. Miniscrews placed in less than approximately 3.8 mm of bone and those within 1.4 mm of the root had significantly higher failure rates. Miniscrews placed with insertion torque greater than 10 Ncm had a tendency for a lower success rate. CONCLUSIONS: The optimum lengths of miniscrews of a diameter of 1.3 mm are 5 mm in the maxilla and 6 mm in the mandible. They should be placed at a distance from the root with insertion torque less than 10 Ncm for safe orthodontic anchorage without failure.

Imaging findings of arrested pneumatisation and differentiation from other skull base lesions.

OBJECTIVES: Arrested pneumatisation (AP) is an anatomic variant of the sphenoid sinus. Since AP remains underrecognised, otolaryngologists and radiologists may mistake AP for a lesion and perform follow-up imaging studies. We investigated the imaging findings of CT, MRI, and F-18 fludeoxyglucose (FDG)-positron emission tomography (PET) for AP, and discussed the differences between AP and other skull base lesions. METHODS: We reviewed multidetector low CT imaging of 442 patients (285 men and 157 women; age range, 19-93 years; mean age, 67.8 years) who underwent FDG-PET/CT for head and neck tumours between January 2019 and December 2019. The imaging findings of AP were reviewed on CT, MRI, FDG-PET/CT, and compared with those of fibrous dysplasia, chordoma, chondrosarcoma, multiple myeloma, and bone invasion of nasopharyngeal carcinoma. RESULTS: AP was identified in 22 patients (14 men and 8 women; age range, 24-93 years; mean age, 67.0 years) based on criteria from previous reports. AP manifested with well-circumscribed sclerotic margins on CT, without evidence of expansion. AP showed high-signal intensity on T1-/T2 weighted MRI. FDG-PET revealed non-significant uptake [maximum standardised uptake value (SUVmax): 0.85 (range, 0.4-1.27)] in AP. Contrastingly, skull base lesions showed expansion, poorly circumscribed boundaries without osteosclerotic margins, and moderate-to-severe FDG uptake (SUVmax: 1.8-8.4). CONCLUSIONS: The characteristic imaging findings of AP, namely non-expansile on CT and non-uptake on FDG-PET, may aid in its differentiation from other skull base lesions.

Molecular imaging in masseter muscle observed by muscle function magnetic resonance imaging and 31 P-magnetic resonance spectroscopy in patients with a jaw deformity.

BACKGROUND: Skeletal mandibular protrusion would influence to the muscle fatigue of the masticatory muscles. Establishing a diagnostic procedures combining physiological and biochemical information is necessary for quantitative evaluation of masticatory muscle fatigue. OBJECTIVE: The transverse relaxation time (T2 time) of muscle functional magnetic resonance imaging (mfMRI), and 31 P-magnetic resonance spectroscopy (MRS) were used to investigate the reliability as parameters for measuring the masseter muscle in patients with skeletal mandibular prognathism. METHOD: The subjects were 19 patients diagnosed as skeletal mandibular protrusions and 19 healthy subjects as a control group. Transverse relaxation time (T2 value) determined by mfMRI along with creatine phosphate (PCr) and inorganic phosphorus (Pi) determined by 31 P-MRS before, during, and after clenching were used for molecular imaging of muscle fatigue. RESULTS: The average T2 value of the patient group was significantly higher than that of the healthy control group at rest. Furthermore, the average T2 value transiently increased in both groups during experimental clenching. The PCr and Pi showed a tendency toward a transient decrease and increases, respectively. The pH in the masseter muscle showed a transient decrease in both groups prior to and following experimental clenching. The pH in the masseter muscle of the patient group was significantly lower than that in the healthy control group at rest and recovery. CONCLUSION: We showed mfMRI and 31 P-MRS are useful for evaluating masseter fatigue during clenching, and the masseter muscle in the prognathic patients showed more severe fatigue than the healthy controls.

Dental care using an oral appliance to support hematopoietic stem cell transplantation for NK/T cell lymphoma, nasal type, with palatal perforation.

PATIENT: A 33-year-old man diagnosed with extranodal natural killer cell/T-cell lymphoma, nasal type (ENKTCL-NT) inducing palatal perforation was referred to the perioperative oral care support center of Tohoku University Hospital for dental care to support cancer treatment including chemotherapy and hematopoietic stem cell transplantation (HSCT). Dental review during chemotherapy revealed mucositis suspected to be caused by mucosal trauma from altered jaw function (chewing and speech) due to palatal perforation. Although the patient was already in the cleanroom, an oral appliance as well as conservative care as recommended in oral management guidelines for HSCT were used to prevent worsening of oral mucositis at subsequent HSCT including High-dose chemotherapy and total body irradiation. After HSCT, a prosthodontist fitted a palatal obturator made by a dental technician and an oral surgeon reviewed the necrotic bone and removed the sequestra according to the changes in the palate. This approach involving a multidisciplinary team including a hematologist improved the impaired oral function and minimized oral complications. DISCUSSION: ENKTCL-NT and its treatment have a significant impact on patients' oral status. Hence, it is important to provide customized dental care based on previously endorsed guidelines according to the type of disease, treatment requirements, and oral and systemic status. CONCLUSION: This report indicated the importance of dental care with a customized plan before, during, and after HSCT for ENKTCL-NT with multidisciplinary supportive care for cancer patients to improve the impaired oral function and to minimize oral complications.

High diagnostic accuracy for lymph node metastasis of oral squamous cell carcinoma using PET/CT with a silicon photomultiplier.

OBJECTIVE: The higher sensitivity of the new-generation positron emission tomography/computed tomography (PET/CT) with silicon photomultiplier (SiPM) may increase false-positive rates in detecting metastatic lymph nodes (LNs). This study aimed to clarify the usefulness of the SiPM PET scanner in diagnosing LN metastasis of oral squamous cell carcinoma (SCC). METHODS: We retrospectively reviewed consecutive F-18 fluorodeoxyglucose PET/CT images of 39 SCC patients using SiPM PET and 31 SCC patients using non-SiPM PET. We measured the maximum standardized uptake value (SUVmax) of the LNs on PET images and maximum short-axis diameter on transverse CT images. RESULTS: The sensitivity and specificity of SiPM PET were 86.2% and 95.6%, respectively (cut-off SUVmax, 4.6). The area under the curve (AUC) of SiPM PET (0.977; 95% confidence interval [CI], 0.958-0.995) was significantly higher than that of non-SiPM PET (0.825; 95% CI 0.717-0.934) (P < 0.01). In a size-limited analysis of diameter, the AUC of SiPM PET (≥ 0.96 for all diameters) was significantly higher than that of non-SiPM PET (tended to decrease as the LN diameter decreased) for the diagnosis of LN metastasis by SUVmax. CONCLUSION: SiPM PET had higher diagnostic accuracy for LN metastasis of oral SCC than non-SiPM PET, even for small LN metastasis without increasing false-positives.

Perfusion defects in non-enlarged metastatic lymph nodes using vessel wall magnetic resonance imaging: Detection performance and diagnostic value.

A perfusion defect (PD) in non-enlarged lymph nodes (LNs) of oral squamous cell carcinoma (OSCC) is the most reliable radiological criterion for the diagnosis of metastasis. However, conventional contrast-enhanced (CE) T1 weighted images using turbo spin echo (TSE) sequence is limited in detecting PD in non-enlarged LNs due to flow artifacts from cervical blood vessels. Vessel wall (VW) MR imaging with blood vessel flow suppression and high spatial resolution may provide new insights into the detection of PD. However, there are no reports in the literature on the usefulness of VW MR imaging for the diagnosis of LN metastasis. It is demonstrated that PD of non-enlarged LNs in CE VR MR imaging of OSCC patients is useful for the diagnosis of metastatic LNs. VW MR imaging was significantly more sensitive in detecting PD of non-enlarged metastatic LNs than conventional TSE imaging on visual evaluation. Furthermore, it was found that the image contrast between PD and surrounding intranodal tissue in CE VW MR images was higher than that in conventional CE TSE images. In the correlation between imaging and histopathological findings of metastatic LNs, all LNs that exhibited PD on CE VW MR images were at an advanced histopathological metastatic stage. The pathology of PD was necrotic tissue with keratinization. The results indicated that PD in CE VW imaging is useful in diagnosing non-enlarged LNs at an advanced metastasis stage. The addition of VW MR imaging to conventional MR examination achieves higher diagnostic performance for non-enlarged metastatic LNs.

Effectiveness of an actuator-driven pulsed water jet for removal of softened carious dentin.

The aim of this study was to assess the utility of an actuator-driven pulsed water jet (ADPJ) as a hardness-dependent carious dentin removal device by using different outputs. Thirty-six plane surface dental caries samples were treated with the ADPJ at 150, 200, and 250 voltage (12 teeth each). The Knoop hardness number (KHN) and Ca/P mass ratio were measured at 70 µm from the deepest point of the removing groove. Furthermore, three other teeth samples were manually treated with the ADPJ at the three above mentioned voltages (one tooth each) for 1 min. The KHN and Ca/P mass ratio were measured at 70 µm from the surface of the residual dentin part. In both the KHN and Ca/P mass ratio, higher residual dentin depended on the applied voltage of ADPJ. The ADPJ enabled the removal of softened carious dentin in an applied voltage-dependent manner.

A comparative study on cephalometric differences in maxillofacial morphology between skeletal Class III cases with and without acromegaly: a pilot study.

OBJECTIVES: The most typical maxillofacial feature of patients with acromegaly is mandibular protrusion. This study aimed to determine differences in maxillofacial morphology between skeletal Class III patients with and without acromegaly using cephalometric analysis. METHODS: Cephalograms of 37 patients with acromegaly (Acro), 37 age-matched non-acromegalic patients with skeletal Class III malocclusion (C-III), and 37 age-matched Class I malocclusion patients (C-I; control) were retrospectively collected. The skeletal and dental morphology of each group was analyzed using cephalometric analysis, which included linear and angular measurements and facial profilograms. In addition, we analyzed diagnostic performance and cutoff values for discriminating acromegaly from skeletal Class III malocclusion using receiver operating characteristic (ROC) curve analysis. RESULTS: The mandibular ramus height was larger in the Acro group than in the other groups. The increase in L1/MP in the Acro group, which represented labial inclination of the mandibular central incisors, was the most characteristic feature in this study. ROC curve analysis indicated that a cutoff value of 88.4° for L1/MP had the highest diagnostic performance in discriminating acromegaly from non-acromegalic Class III malocclusion. CONCLUSIONS: Acromegaly was characterized by a greater degree of bimaxillary prognathism than was non-acromegalic Class III malocclusion. Focusing on labial inclination of the mandibular central incisors would be the most useful way to differentiate acromegaly from non-acromegalic Class III malocclusion.