Do Surgical Intervention Type and Baseline Condylar Position Affect Spatial Dimension Changes of the Temporomandibular Joint in the Surgical Correction of Skeletal Class II Deformities?

BACKGROUND: One of the key features of orthognathic surgery is altering temporomandibular joint (TMJ) condylar positions. PURPOSE: This multivariate study aimed to identify surgical interventions and patient factors significantly associated with changes in TMJ spatial dimensions after the surgical correction of skeletal Class II deformities. STUDY DESIGN, SETTING, SAMPLE: This is a retrospective cohort study including patients who had undergone an isolated bilateral sagittal split ramus osteotomy (BSSO) or a bimaxillary osteotomy (BMO) for mandibular advancement and a control sample of patients treated with the removal of odontogenic cysts in the mandibular posterior region. Excluded were those who presented with specific radiographic signs of TMJ osteoarthrosis, severe facial asymmetry, or deformity secondary to trauma. PREDICTOR/EXPOSURE/INDEPENDENT VARIABLE: The primary predictors were condylar position at baseline (anterior, concentric, and posterior), time points (T0, preoperatively; T1, immediately after surgery; and T2, 1-year follow-up), and surgical intervention type (BSSO, BMO, and control group). MAIN OUTCOME VARIABLES: The primary outcomes were changes in posterior spatial dimension (PSD), superior spatial dimension, and medial spatial dimension assessed by cone-beam computed tomography preoperatively, immediately after surgery, and at 1-year follow-up. COVARIATES: Covariates included sex, age, and amount of mandibular advancement. ANALYSES: Estimations of independent effects of primary predictors on outcome variables were made by applying generalized estimation equation models. The value of statistical significance was P < .05. RESULTS: The study sample included 88 participants. The BSSO samples included 39 patients, and the BMO group included 22 patients; the control group comprised 27 subjects. The average age was 31.2 years; the majority were female (61.4%). Adjusted generalized estimation equation models yielded a significant time interaction between BSSO and spatial dimensions over time (PSD, P < .001). Key predictors of spatial dimension changes were the baseline posterior (PSD, P < .001) and the central condylar position (PSD, P < .001). CONCLUSION AND RELEVANCE: This controlled study, for the first time, provides scientific evidence on the effects of surgical intervention type and baseline condylar position on spatial dimension changes in the TMJ. It shows a more favorable outcome in long-term spatial dimension changes for patients treated by a BMO procedure.

Factors associated with voice-related quality of life among patients with temporomandibular disorders.

BACKGROUND: Research would be important for obtaining a better understanding of voice complaints among patients with temporomandibular disorders (TMD). OBJECTIVE: The identification of predictors of voice disorders associated with TMD pain was made according to Diagnostic Criteria for TMD (DC/TMD) Axis I. METHODOLOGY: Functional limitations were measured using the Jaw Functional Limitation Scales for mastication (JFLS-M), jaw mobility (JFLS-JM), and verbal and emotional expression (JFLS-VEE). Patients also completed the Hospital Anxiety and Depression Scale (HADS). The primary outcome was social-emotional and physical functioning as indicated by scores on the Voice-Related Quality of Life (V-RQOL) questionnaire. Multiple linear regression was used to model the relationship between the domains on the V-RQOL questionnaire and scores on the HADS and JFLS after adjusting for age, gender, DC/TMD diagnosis, pain intensity, and time since pain onset. RESULTS: The HADS-D (B=-1.15; 95% CI, -1.718 to -0.587; p<.001) and JFLS-VEE (B=-0.22; 95% CI, -0.40 to -0.06; p=.008) were significant predictors of scores on the V-RQOL questionnaire. CONCLUSION: Higher scores on depression measures and limitations in verbal and emotional expression could exacerbate voice problems among TMD pain patients. Future research should promote multidisciplinary treatments for TMD pain-related voice disorders.

Factors associated with voice-related quality of life among patients with temporomandibular disorders

Abstract Research would be important for obtaining a better understanding of voice complaints among patients with temporomandibular disorders (TMD). Objective The identification of predictors of voice disorders associated with TMD pain was made according to Diagnostic Criteria for TMD (DC/TMD) Axis I. Methodology Functional limitations were measured using the Jaw Functional Limitation Scales for mastication (JFLS-M), jaw mobility (JFLS-JM), and verbal and emotional expression (JFLS-VEE). Patients also completed the Hospital Anxiety and Depression Scale (HADS). The primary outcome was social-emotional and physical functioning as indicated by scores on the Voice-Related Quality of Life (V-RQOL) questionnaire. Multiple linear regression was used to model the relationship between the domains on the V-RQOL questionnaire and scores on the HADS and JFLS after adjusting for age, gender, DC/TMD diagnosis, pain intensity, and time since pain onset. Results The HADS-D (B=-1.15; 95% CI, -1.718 to -0.587; p<.001) and JFLS-VEE (B=-0.22; 95% CI, -0.40 to -0.06; p=.008) were significant predictors of scores on the V-RQOL questionnaire. Conclusion Higher scores on depression measures and limitations in verbal and emotional expression could exacerbate voice problems among TMD pain patients. Future research should promote multidisciplinary treatments for TMD pain-related voice disorders.

Modeling the effect of bilateral sagittal split osteotomy on posterior, superior and medial space dimensions of the temporomandibular joint: a retrospective controlled cohort study.

BACKGROUND: To model the effect of isolated bilateral sagittal split osteotomy (BSSO) on changes in posterior (PSD), superior (SSD), and medial space dimensions (MSD) of the temporomandibular joint. METHODS: Using a retrospective cohort study design, pre- and postoperative (immediately after surgery; 1 year follow-up) cone-beam computed tomography measurements of 36 patients who had undergone BSSO for mandibular advancement were compared with a control group of 25 subjects from whom a mandibular odontogenic cyst was removed under general anesthesia. Generalized estimation equation (GEE) models were used to examine the independent effects of study group, preoperative condylar position, and time points on PSD, SSD, and MSD adjusting for covariates (age, sex, and mandibular advancement). RESULTS: No significant differences were found regarding changes in PSD (p = 0.144), SSD (p = 0.607), or MSD (p = 0.565) between the BSSO and control groups. However, the preoperative posterior condylar position showed significant effects on PSD (p < 0.001) and MSD (p = 0.043), while the preoperative central condylar position demonstrated a significant effect on PSD (p < 0.001). CONCLUSION: The data suggest that preoperative posterior condylar position is a significant effect modifier of PSD and MSD over time in this cohort.

Implant-to-nasal floor dimensions projected by panoramic radiographs in the maxillary incisor-canine region: implications for dental implant treatment.

To make a comparison of panoramic radiography (PAN) and cone-beam computed tomography (CBCT) determinations of implant-to-nasal floor dimensions (INFD) in the anterior maxillary region, and to assist in determining in which tooth regions additional radiation exposure involved in CBCT scans is justifiable. Data related to INFD by PAN (PAN-D) at implant-to-nasal floor sites (central incisor, lateral incisor, canine) were gathered using 141 implant sites from 119 adult patients. INFD was estimated employing the CBCT technique as a reference method. PAN analysis equations were created for estimation of INFD by CBCT (CBCT-D) specific to implant sites. For assessment of the agreement between the PAN and CBCT methodologies, the Bland-Altman approach was employed. There were robust and significant odds ratios that implants in the canine region would fall into the underestimation groups of > 0 mm (4.5:1) (p = 0.003), > 0.5 mm (6.2:1) (p < 0.001), and > 1 mm (5.4:1) (p = 0.002). The root mean squared error (RMSE) and pure error (PE) were highest for the canine region (RMSE = 1.973 mm, PE = 2.20 mm). This research offers evidence of site-specific underestimations of available horizontal bone dimensions for implants when PAN is employed to assess the availability of vertical bone dimensions. The data suggest that it may be necessary to exclude canine regions when making assessment of INFD through PAN. Use of CBCT may, therefore, be recommended for all implant size and angulation estimations in this region.

Condylar erosion is predictive of painful closed lock of the temporomandibular joint: a magnetic resonance imaging study.

BACKGROUND: To assess whether magnetic resonance imaging (MRI) findings of condylar erosion (CE) are predictive of a specific clinical diagnosis of painful closed lock of the temporomandibular joint (TMJ), and to determine the strength of association between CE and types of internal derangement (ID). METHODS: Based upon sample size estimation, this retrospective paired-design study involved 62 patients, aged between 18 and 67 years. Inclusion criteria were the presence of a unilateral clinical diagnosis of arthralgia coexisting with disk displacement without reduction ('AR and DDwoR/wLO'), assigned according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) Axis I, and the absence of signs and symptoms of TMJ pain and dysfunction on the contralateral TMJ side. Bilateral sagittal and coronal MR images were obtained to establish the prevalence of CE and TMJ ID types of disk displacement with (DDR) and without reduction (DDNR). Logistic regression analysis was used to compute odds ratios for CE and ID types. Confounding variables adjusted for were age, sex, time since pain onset, pain intensity, and type of ID. RESULTS: In the regression analysis, the MRI items of DDR (p = 0.533) and DDNR (p = 0.204) dropped out as nonsignificant in the diagnostic clinical 'AR and DDwoR/wLO' group. Significant increases in the risk of 'AR and DDwoR' occurred with CE (3.1:1 odds ratio; p = 0.026). The presence of CE was significantly related to DDNR (adjusted OR = 43.9; p <  0.001). CONCLUSIONS: The data suggest CE as a dominant factor in the definition of painful closed lock of the TMJ, support the view that joint locking needs to be considered as a frequent symptom of osteoarthritis, and emphasize a strong association between the MRI items of CE and DDNR.

A logistic analysis prediction model of TMJ condylar erosion in patients with TMJ arthralgia.

BACKGROUND: In terms of diagnostic and therapeutic management, clinicians should adequately address the frequent aspects of temporomandibular joint (TMJ) osteoarthritis (OA) associated with disk displacement. Condylar erosion (CE) is considered an inflammatory subset of OA and is regarded as a sign of progressive OA changes potentially contributing to changes in dentofacial morphology or limited mandibular growth. The purpose of this study was to establish a risk prediction model of CE by a multivariate logistic regression analysis to predict the individual risk of CE in TMJ arthralgia. It was hypothesized that there was a closer association between CE and magnetic resonance imaging (MRI) indicators. METHODS: This retrospective paired-design study enrolled 124 consecutive TMJ pain patients and analyzed the clinical and TMJ-related MRI data in predicting CE. TMJ pain patients were categorized according to the research diagnostic criteria for temporomandibular disorders (RDC/TMD) Axis I protocol. Each patient underwent MRI examination of both TMJs, 1-7 days following clinical examination. RESULTS: In the univariate analysis analyses, 9 influencing factors were related to CE, of which the following 4 as predictors determined the binary multivariate logistic regression model: missing posterior teeth (odds ratio [OR] = 1.42; P = 0.018), RDC/TMD of arthralgia coexistant with disk displacement without reduction with limited opening (DDwoR/wLO) (OR = 3.30, P = 0.007), MRI finding of disk displacement without reduction (OR = 10.96, P < 0.001), and MRI finding of bone marrow edema (OR = 11.97, P < 0.001). The model had statistical significance (chi-square = 148.239, Nagelkerke R square = 0.612, P < 0.001). Out of the TMJs, 83.9% were correctly predicted to be CE cases or Non-CE cases with a sensitivity of 81.4% and a specificity of 85.2%. The area under the receiver operating characteristic curve was 0.916. CONCLUSION: The established prediction model using the risk factors of TMJ arthralgia may be useful for predicting the risk of CE. The data suggest MRI indicators as dominant factors in the definition of CE. Further research is needed to improve the model, and confirm the validity and reliability of the model.

Panoramic prediction equations to estimate implant- to-mandibular canal dimensions in the mandibular posterior region: implications for dental implant treatment.

BACKGROUND: To develop and cross-validate site-specific panoramic radiography (PAN) analysis prediction equations of implant-to-mandibular canal dimensions (IMCD) in mandibular regions posterior to the mental foramen, and to help determine in which instances CBCT technology will be a justified adjunct in clinical practice. METHODS: IMCD by PAN (Pan-D) from implant site-specific regions (first premolar, second premolar, first molar, and second molar sites) were collected from 40- to 70-year-old adolescents. They were randomly assigned to validation (n = 144) and cross-validation (n = 148) groups. The cone-beam computed tomography (CBCT) technique was used as the criterion method for the estimation of IMCD (CBCT-D). The PAN analysis equations were developed using stepwise multiple regression analysis and cross-validated using the Bland-Altman approach. RESULTS: There was a significant relationship between PAN-D and CBCT-D for both validation (R2 = 57.8 %; p < .001) and cross-validation groups (R2 = 52.5 %; p < .001). Root means-squared error (RMSE) and pure error (PE) were highest for the first molar (RMSE = 1.116 mm, PE = 1.01 mm) and the second molar region (RMSE = 1.162 mm, PE = 1.11 mm). CONCLUSIONS: PAN-D has the potential to be developed as an indirect measure of IMCD. However, the findings suggest to exclude scoring of the first and second molars when assessing IMCD via PAN. Use of CBCT may be justified for all IMCD estimations in the first and second molars regions. TRIAL REGISTRATION: This study has been registered and approved by the Ethics Committee of the Martin-Luther University, Halle, Germany (2020-034).

Implant-to-root dimensions projected by panoramic radiographs inthe maxillary canine-premolar region: implications for dental implant treatment.

BACKGOUND: This study aimed to compare panoramic radiography (PAN) and cone beam computed tomography (CBCT) determinations of implant-to-root dimensions (IRD) in anterior and posterior maxillary regions, and to help determine in which instances increased radiation exposure from CBCT scans may be justified. METHODS: IRD measured by PAN (PAN-D) from implant-to-root sites (central incisor, lateral incisor, canine, first premolar, and second premolar) was collected from 418 implant sites in 110 adults. The CBCT technique was used as the reference method for the estimation of IRD. The PAN analysis equations were developed using stepwise multiple regression analysis and the Bland-Altman approach was applied to assess the agreement between PAN and CBCT methods. RESULTS: The odds ratio that an implant at the canine-to-first premolar (9.7:1) (P = 0.000) or at the first premolar-to-second premolar region (4.5:1) (P = 0.000) belongs to the underestimation group was strong and highly significant. The root mean square error (RMSE) and pure error (PE) were highest for the canine-to-first premolar (RMSE = 0.886 mm, PE = 0.45 mm) and the first premolar-to-second premolar region (4.5:1) (RMSE = 0.944 mm, PE = 0.38 mm). CONCLUSIONS: This study provides evidence of site-specific underestimations of available horizontal bone dimensions for implants when assessed by PAN. These data suggest that the canines and first and second premolars may have to be excluded when assessing root angulations via PAN.

Assessment of Location of the Mandibular Canal: Correlation Between Panoramic and Cone Beam Computed Tomography Measurements.

PURPOSE: To compare panoramic and cone beam computed tomography (CBCT) determinations of implant-to-mandibular canal (MC) dimensions in mandibular regions posterior to the mental foramen and to investigate whether factors such as gender, age, region, and vertical dimension influence correlation between the two techniques. MATERIALS AND METHODS: A retrospective analysis was carried out in 64 consecutive adult patients (42 females, 22 males; average age 57.1 ± 13.3 years) in whom 126 implants were positioned in the posterior segment of the mandible. Implant sites (first premolar, second premolar, first molar, and second molar) were assessed on each panoramic and CBCT radiograph by measuring the distance from the inferior border of the implant to the superior border of the MC. Binary logistic regression analysis was used to compute the odds ratios (ORs) of each implant site for underestimation vs nonunderestimation. Linear regression analysis was performed with CBCT dimension as the dependent variable and panoramic dimension, gender, and age as the independent variables. RESULTS: The mean implant-to-MC dimension was 2.50 ± 1.31 mm in panoramic radiography and 2.91 ± 1.62 mm in CBCT. The OR that an implant at the second molar region belonged to the underestimation group was strong (15.1:1) and highly significant (P = .011). If a predictive value of .95 was demanded, the implant-to-MC dimensions had to be overestimated by 2 mm compared to the predicted CBCT dimension. CONCLUSION: This study provides evidence of an underestimation of available vertical bone dimensions for implants in the posterior regions of the mandible when assessed by panoramic radiography. Use of CBCT is therefore recommended for all implant size estimations in this region.

Association Between Missing Posterior Teeth and Occurrence of Temporomandibular Joint Condylar Erosion: A Cone Beam Computed Tomography Study.

PURPOSE: To determine a possible association between asymptomatic temporomandibular joint (TMJ) condylar erosion and the number of missing posterior teeth and their location, as well as the number of dental quadrants with missing posterior teeth. MATERIALS AND METHODS: This case-control study involved 210 patients (male to female ratio = 98:112) aged 16-74 years, with 105 asymptomatic patients with TMJ condylar erosion and a control group of 105 patients without TMJ condylar erosion. Cone beam computed tomography images were evaluated to classify the severity of TMJ condylar erosion as grade 0 (absence of erosion), grade I (slight erosion), grade II (moderate erosion), or grade III (extensive erosion). RESULTS: The number of missing posterior teeth (mean ± standard deviation [SD]; 2.7 ± 2.4 vs 0.7 ± 1.2) (P < .001), number of dental quadrants with missing posterior teeth (1.5 ± 1.3 vs 0.6 ± 0.9) (P < .001), and bilateral location of missing posterior teeth (41 ± 39.0 vs 10 ± 9.5) (P < .001) were all significantly higher in patients with erosion than in those without erosion. The condylar erosion grade was significantly associated with the number of missing posterior teeth (odds ratio [OR] = 1.24; P = .006), the number of dental quadrants with missing posterior teeth (OR = 1.36; P = .006), and the bilateral occurrence of missing posterior teeth (OR = 3.03; P = .002). CONCLUSION: The findings from this study suggest a possible association between TMJ condylar erosion grades and the number of missing posterior teeth, the number of quadrants with missing posterior teeth, and the bilateral occurrence of missing posterior teeth.

Association Between Chronic Tension-Type Headache Coexistent with Chronic Temporomandibular Disorder Pain and Limitations in Physical and Emotional Functioning: A Case-Control Study.

AIMS: To assess the association between chronic tension-type headache coexistent with chronic temporomandibular disorder (TMD) pain and severe limitations in physical and emotional functioning. METHODS: Sample size estimation was used to determine that this case-control study should include 126 subjects. Subjects suffering from chronic TMD who were aged between 18 and 68 were recruited in routine clinical practice. Of the 126 included subjects, 63 had TMD pain associated with chronic tension-type headache (cases) and 63 had TMD pain without a history of tension-type headache (controls). Clinical diagnosis of TMD was made according to the Research Diagnostic Criteria for TMD (RDC/TMD) Axis I criteria, and clinical diagnosis of headache was made according to the International Classification of Headache (ICHD-II). RDC/TMD Axis II criteria were applied to record the scores from the Graded Chronic Pain Scale (GCPS) and the Symptoms Checklist-90-Revised Depression (SCL-DEP) and Somatization (SCL-SOM) scales. A logistic regression analysis was used to assess the relationship between TMD pain with chronic tension-type headache and high levels of depression and somatization severity as scored on the SCLDEP and SCL-SOM scales, respectively, and high pain-related disability (GCPS grade III or IV). Data were adjusted to take into account age, gender, time since TMD pain onset, chronic TMD pain intensity, and characteristic pain intensity. RESULTS: The presence of chronic tension-type headache was significantly associated with severe SCL-DEP (odds ratio [OR] = 7.2; P < .001), severe SCLSOM (OR = 13.8; P < .001), and high pain-related disability (OR = 9.7; P < .001). CONCLUSION: This study provides evidence of associations between the clinical diagnosis of chronic tension-type headache coexistent with chronic TMD pain and key aspects of physical and emotional functioning reflected in severe depression, severe somatization, and high pain-related disability.

Condylar Erosion in Patients With Chronic Temporomandibular Joint Arthralgia: A Cone-Beam Computed Tomography Study.

PURPOSE: The objective of this study was to assess the association between temporomandibular joint (TMJ) condylar erosion and chronic TMJ arthralgia. MATERIALS AND METHODS: Based on a sample size estimation, this case-and-control study involved 198 patients 16 to 73 years old recruited from a routine clinical practice (99 cases, patients with chronic TMJ arthralgia and mean pain duration of 16.4 months; 99 controls, asymptomatic patients without a history of orofacial pain). The clinical diagnosis of arthralgia was made according to the Research Diagnostic Criteria for Temporomandibular Disorders. Cone-beam computed tomographic (CBCT) images were evaluated for the presence or absence of erosive osseous changes of the TMJ condyle. Severity of TMJ condylar erosion was classified as grade 0 (absence of erosion), grade I (slight erosion), grade II (moderate erosion), or grade III (extensive erosion). Logistic regression analysis was used to assess the association between chronic TMJ arthralgia and condylar erosion, adjusting for age, gender, number of missing posterior teeth, and number of dental quadrants with missing posterior teeth. RESULTS: TMJ condylar erosion was found in 59.6% of cases and 21.2% of controls. There was a significant association between TMJ arthralgia and degree of condylar erosion (P < .001). The odds ratio that a TMJ with condylar erosion grade II might belong to the TMJ arthralgia group was strong (3.1:1; 95% confidence interval [CI], 1.17 to 8.09) and significant (P = .023). Significant increases in risk of TMJ arthralgia occurred with condylar erosion grade III (7.7:1; 95% CI, 3.09 to 19.18; P < .001). CONCLUSIONS: The study provides evidence of an association between TMJ condylar erosion and chronic TMJ arthralgia.

Clinically important difference thresholds of the visual analog scale: a conceptual model for identifying meaningful intraindividual changes for pain intensity.

The aim of this study was to estimate a range of clinically important difference (CID) values of the visual analog scale for pain intensity (VAS-PI), and to assess the effect of patient baseline characteristics on VAS change scores. Data from a prospective cohort study with 678 patients with subacute and chronic temporomandibular disorder pain were analyzed. Patients were divided into 9 cohorts on the basis of the baseline VAS score and the duration of pain. The CID was estimated over a 12-week period, and 2 different methods were used: (1) mean change scores, and (2) optimal cutoff point in receiver operator characteristic curves. The patient's global impression of change was used as an external criterion. The general linear model univariate analysis was applied to assess the effect of baseline pain level and duration of pain on the raw VAS change scores, while adjusting for age and sex. The CID mean change ranged from 20.9 to 57.5 mm (64.1-76.3%), and the CID optimal cutoff point from 11.5 to 28.5 mm (29.9-47.7%). For the VAS change scores, the main effect of the variable baseline pain level was significant (F=107.09, P<.001). However, there was no significant baseline pain level by duration of pain interaction effect (F=1.13, P=.340). On the basis of the results, we advocate the choice of a single CID value according to the context of the patient's baseline level of pain.

Cephalometric variables discriminate among magnetic resonance imaging-based structural characteristic groups of the temporomandibular joint.

OBJECTIVE: The aim of this study was to assess retrospectively whether, in patients with temporomandibular joint (TMJ) arthralgia, commonly used cephalometric variables of dentofacial morphology can discriminate among magnetic resonanace imaging (MRI)-based TMJ structural characteristic groups of "uni- or bilateral disc displacement without reduction (DDwoR) associated with bilateral osteoarthrosis (OA)" and "uni- or bilateral disc displacement with reduction (DDwR) without OA." STUDY DESIGN: Bilateral MRI of the TMJ was performed in 56 consecutive TMJ arthralgia patients to identify individuals with specific structural characteristic of uni- or bilateral TMJ DDwoR, DDwR, and OA. Application of the criteria resulted in a study group of 31 patients with "uni- or bilateral DDwoR with bilateral OA" and 25 with "uni- or bilateral DDwR without OA." Linear and angular cephalometric measurements were taken from lateral cephalograms to apply selected criteria of dentofacial morphology. One-way analysis of variance was used to assess differences in cephalometric variables by MRI-based TMJ group. Then, discriminant function analysis predicted TMJ group membership. RESULTS: A-B plane to facial plane angle, palatal plane to occlual plane, and interincisal angle produced a significantly discriminant function that predicted TMJ group membership (P < .001). This function correctly classified 85.7% of original grouped cases. CONCLUSIONS: Cephalometric variables may discriminate among MRI-based TMJ structural characteristic groups. Additional diagnostic information related to MRI-based classification groups was generated.

Structural characteristics of bilateral temporomandibular joint disc displacement without reduction and osteoarthrosis are important determinants of horizontal mandibular and vertical ramus deficiency: a magnetic resonance imaging study.

PURPOSE: To estimate in patients with temporomandibular joint (TMJ) arthralgia whether magnetic resonance (MR) imaging findings of bilateral TMJ disc displacement without reduction (DDwoR) and/or osteoarthrosis (OA) are determinants of horizontal mandibular and vertical ramus deficiencies. PATIENTS AND METHODS: Bilateral MR imaging of the TMJ was performed in 68 consecutive patients with TMJ arthralgia to identify those with bilateral TMJ DDwoR and/or OA. Linear and angular cephalometric measurements were performed to apply selected criteria of horizontal mandibular (gonion-menton [Go-Me] <73 mm and articulare-pogonion [Ar-Pog] <105 mm) and vertical ramus (articulare-gonion [Ar-Go] <45 mm) deficiencies. Logistic regression analysis was used to estimate the association between selected MR imaging and cephalometric parameters. RESULTS: In the age- and gender-adjusted analysis, significant increases in the risk of horizontal mandibular (odds ratio, 7.5:1; P = .031) and vertical ramus (odds ratio, 9.5:1; P = .003) deficiencies occurred with bilateral DDwoR and OA. CONCLUSION: In patients with TMJ arthralgia, the MR imaging parameters of DDwoR and OA seem important determinants of horizontal mandibular and vertical ramus deficiencies.

Are temporomandibular joint disk displacements without reduction and osteoarthrosis important determinants of mandibular backward positioning and clockwise rotation?

OBJECTIVE: The aim of this study was to estimate whether, in patients with temporomandibular joint (TMJ) arthralgia, the magnetic resonanace imaging (MRI) findings of bilateral TMJ disk displacement without reduction (DDwoR) and/or osteoarthrosis (OA) are determinants of mandibular backward positioning and/or clockwise rotation. STUDY DESIGN: Bilateral MRI of the TMJ was performed in 50 consecutive TMJ arthralgia patients to identify individuals with bilateral TMJ DDwoR and/or OA. Linear and angular cephalometric measurements were taken to apply selected criteria of mandibular backward positioning (FH to Na-Pog <84°, Na-A-Pog >5°, and SNB <75°) and clockwise rotation (FH to OP >13°, MP to FH >35°, and S-Gn to FH >64°). Logistic regression analysis was used to estimate the association between selected MRI and cephalometric parameters. RESULTS: In the age- and gender-adjusted analyses, significant increases in risk of mandibular backward positioning and clockwise rotation occurred with bilateral DDwoR and OA (9.5:1; P = .040). CONCLUSION: In patients with TMJ arthralgia the MRI parameters of DDwoR and OA seem to be important determinants of mandibular backward positioning and clockwise rotation.

Estimation of clinically important change for visual analog scales measuring chronic temporomandibular disorder pain.

AIMS: To estimate the clinically important change (CIC) on a 100-mm visual analog scale for pain intensity (VAS-PI) by relating it to the patient's global impression of change (PGIC) in patients with chronic temporomandibular disorder (TMD) pain and to assess the dependency of the CIC on their baseline pain scores. METHODS: Data from a prospective cohort study with 588 patients with chronic TMD pain were analyzed. The CIC was estimated over a 3-month period, and receiver operating characteristic methods were used to assess the optimal cut-off point. The PGIC category of "much improved" served as an external criterion. Dependency of absolute and percent change on baseline VAS-PI scores was determined by linear regression analysis. RESULTS: A VAS-PI change score of -19.5 mm and a percent change score of -37.9% were best associated with the concept of CIC. Since patients with high baseline pain required greater absolute reductions in pain to reach a clinically important improvement, percent change scores performed better in classifying improved patients. CONCLUSION: Providing a standard definition of the CIC adds to the interpretability of study results, ie, the estimates will aid in understanding individual patient outcomes.

Mineralization density and apparent density in mandibular condyle bone.

OBJECTIVES: This study evaluated a method for determining the density and distribution of bone of mandibular condyles using proprietary computerized tomography (CT) software. STUDY DESIGN: Thirty-eight condylar specimens were investigated with a high-resolution multislice CT. The density was determined by using bone density analysis algorithms available within the proprietary software. Apparent density was estimated over the total cross-sectional area, the total trabecular bone area apart from the cortical fraction, and on individually selected points. Color-coded pictures were created to demonstrate density differences. RESULTS: The cortical bone presented significantly higher densities than the trabecular bone. The anterior cortical bone had significantly higher densities than the posterior. The central anterior cortical and the central trabecular areas showed significantly higher densities than the medial and lateral areas. CONCLUSION: This technique proved to be a valuable method for determination of the differences in density in the mandibular condyle. It shows potential in providing clinicians with an imaging modality for specific clinical use.

Outcomes of dental fracture injury as related to laser Doppler flow measurements of pulpal blood-flow level.

Laser Doppler flowmetry (LDF) is a non-invasive method to assess pulpal blood flow (PBF). Dental fracture injuries have been associated with significant PBF reduction The purpose of this study was: (i) to evaluate whether the severity of outcomes of dental fracture injuries may be related to LDF measurements of PBF, and (ii) to investigate whether outcomes of dental fracture injuries may predict PBF levels. The relationship between outcomes and PBF measurements was analyzed in 72 permanent maxillary incisors of 52 consecutive dental trauma patients. The diagnostic outcome group comprised 72 incisors with a type I (absence of sensitivity, periapical radiolucency, and grey discoloration of crown) (n = 42), type II (loss of sensitivity) (n = 16), or type III (loss of sensitivity, periapical radiolucency, and/or grey discoloration of crown) diagnosis. At each session, when an injured permanent maxillary incisor was recorded, a contralateral homologous tooth was used as a control. An ordinal stepwise regression was completed to assess the degree of association between PBF measurements and diagnostic outcomes. A logistic regression analysis was used to compute the odds ratios for the outcome features for incisor non-injury controls vs two outcome groups: type II (n = 16) and type III (n = 14). PBF measurements that were significantly associated with more severe outcome were PBF levels of