Three dimensional condylar positional and morphological changes following mandibular reconstruction based on CBCT analysis: a prospective study.

OBJECTIVE: This study aimed to evaluate the condylar positional changes following mandibular reconstruction with preservation of the condylar head using Cone-Beam Computed Tomography (CBCT). Also, to assess joint space changes and the overall volumetric space compared to the preoperative status. METHODOLOGY: This prospective study included 30 patients (60 joints) subjected to unilateral mandibular resection and reconstruction with preservation of the condylar head. The Helkimo index and preoperative (T1), two weeks postoperative (T2), and follow-up CBCTs (T3) after at least six months were gathered and processed to evaluate the condylar position and TMJ joint space using Anatomage Invivo 6. A student's t-test and repeated-measures ANOVA statistics were used. A P value of less than 0.05 was considered statistically significant. RESULTS: Thirty patients (14 males, 16 females) with a mean age of 40.01 ± 12.7 years (a range of 18.1-62.9 years) were included. On the tumor side, there were significant variances in the vertical and mediolateral condylar positions between the three-time points (T1, T2, T3). Immediately after the operation, the condyles were significantly displaced in a downward direction at T2, which became larger after the last follow-up period (T3) (p = 0.007). The condylar positions at the anteroposterior direction were relatively stable without significant differences between the three times points (p = 0.915). On the non-tumor side, the condylar positions were relatively stable in the mediolateral and anteroposterior positions. In the tumor side, all of the TMJ spaces were significantly increased in size following the mandibular reconstructions (T2 and T3). However, on the non-tumor side, the anterior, posterior, and medial joint spaces were significantly changed postoperatively. CONCLUSION: After mandibular reconstruction with condylar preservation, the condylar position and volumetric measurement immediately changed noticeably and continued to be a permanent change over time compared to relatively stable condyles on the non-tumor side. According to Helkimo index, patients become adapted to the postoperative changes without significant differences between the two sides.

Relationship between the condyle morphology and clinical findings in terms of gender, age, and remaining teeth on cone beam computed tomography images

Aim: This study aimed to evaluate the relationship between clinical findings and some factors such as age, gender, and remaining teeth on the anatomy of the temporomandibular joint in order to diagnose normal variations from abnormal cases. Methods: In this cross-sectional study, cone-beam computed tomography (CBCT) images of 144 patients referring to Tabriz Dental School for various reasons were selected and evaluated. The different aspects of the clinical parameters and the morphology of the condyle were evaluated on coronal, axial, and sagittal views. The CBCT prepared using the axial cross-sections had been 0.5 mm in thickness. The sagittal cross-sections had been evaluated perpendicular to the lengthy axis of the condyle at a thickness of 1 mm and the coronal cross-sections had been evaluated parallel to the lengthy axis of the condyle at a thickness of 1 mm. Data were analyzed with descriptive statistical methods and t-test, chi-squared test, using SPSS 20. The significance level of the study was p < 0.05. Results: There was a significant relationship between the condyle morphology, number of the teeth, and mastication side (p = 0.040). There were significant relationships between the condyle morphology, age between 20-40, and occlusion class I on the all the three views (coronal, axial, sagittal) (p = 0.04), (p = 0.006), (p = 0.006). Also, significant relationships were found in the condyle morphology and location of pain according to age, the number of remaining teeth, and gender. (p = 0.046) (p = 0.027) (p = 0.035). Conclusion:There are significant relationships between the clinical symptoms and condyle morphology based on age, gender, and the number of remaining teeth. The clinical finding that has the most significant relationship between the condyle morphology, remaining teeth (9-16 teeth), all of the age range (20-80 year), and gender was mastication side

Postoperative Anatomic Position of Mandibular Free Flap Neocondyles Affects Patient Symptoms.

Importance: Mandibular condyle reconstruction with vascularized free flaps can re-establish form and function after resection. However, no reports have been published regarding the postoperative anatomic seating of these reconstructions. Objective: To use postoperative axial imaging to determine whether condylar reconstructions migrate and correlate their ultimate location with postoperative symptoms. Design, Setting, and Participants: A prospectively maintained database of free flap cases performed between 2006 and 2019 at a single institution was queried. Twenty-one consecutive patients who underwent reconstructions that involved the mandibular condyle who also had postoperative axial imaging were selected for review. Distances were measured from the reconstructed condyle to the lateral, superior, and posterior aspect of the temporomandibular joint (TMJ), and correlated with postoperative symptoms and jaw function. Main Outcomes and Measures: Condyle displacement, postoperative diet, jaw pain, trismus, and malocclusion. Results: In total, 57% of patients had 1 cm or greater displacement of the condylar reconstruction from the TMJ in at least one vector. Anterior displacement of condyle by >1 cm was associated with jaw misalignment (42.8%) and clicking (14.3%) [odds ratio (OR) 37.3, 95% confidence interval (CI) 1.6-866.9, p = 0.024]. However, 83.3% of these patients were able to return to a normal diet and denied dysphagia. All edentulous patients had acceptable anteroposterior alignment, but 42.8% of dentulous patients had anterior displacement >1 cm (p = 0.12). Inferior displacement >1 cm was associated with dysphagia (OR 23, 95% CI 1.07-494.6, p = 0.04), but not pain or trismus. Eleven patients had multiple postoperative computed tomography scans, on average 21 months apart. The reconstructed location was stable in all 11 patients. Conclusions and Relevance: Patients undergoing free flap reconstruction of the mandibular condyle often return to normal diet, even when their reconstructions do not sit perfectly within the TMJ. Anterior displacement of the neocondyle may be more common in dentulous patients due to stress on the joint from chewing and produces some dysfunction and misalignment. Inferior displacement of the neocondyle may result in dysphagia. The reconstructed condyles are unlikely to migrate over time.

A panoramic study of the morphology of mandibular condyle in a sample of population from Basrah City / Estudio panorámico de la morfología del cóndilo mandibular en una muestra de población de la ciudad de Basora

SUMMARY: The study aims to evaluate the morphological variation of mandibular condyle This analysis was composed of 450 digital orthopantomograms taken for routine investigation to assess the morphology of 900 condylar heads. Condylar morphology was classified into four types (oval, bird beak, diamond and crooked finger). Most common occurring shape were evaluated, symmetry of condylar shape and most common combinations of the condylar shapes present in population were assessed. Out of 900 mandibular condyle, type 1(oval) of condyle was the most commonly appearing shape (56 %), followed by type 3 (diamond), type 2(bird beak) and finally type 4 (crooked finger). Symmetry was seen in 74.2 % of the total sample with the oval-oval was the most commonly occurring. Routine use of orthopantomography can assist dentist in assessment of condylar morphology alterations. Oval shape was the most common in all age groups in males and females. More studies on Iraqi population evaluating mandibular condyle are needed to provide standardized values for mandibular anatomical parts.

RESUMEN: El objetivo del presente estudio fue evaluar la variación morfológica del cóndilo mandibular. El análisis se realizó en 450 ortopantomogramas digitales en una investigación de rutina para evaluar la morfología de 900 cabezas condilares. La morfología condilar se clasificó en cuatro tipos (ovalada, pico de pájaro, diamante y dedo torcido). Se evaluó la forma más común de ocurrencia, la simetría de la forma condilar y las combinaciones más comunes en la población. De 900 cóndilos mandibulares, el tipo 1 (ovalado) de cóndilo apareció con mayor frecuencia (56 %), seguido del tipo 3 (diamante), el tipo 2 (pico de pájaro) y finalmente el tipo 4 (dedo torcido). Se observó simetría en el 74,2 % de la muestra total, siendo el óvalo-óvalo el que se presentó con mayor frecuencia. El uso rutinario de la ortopantomografía puede ayudar al dentista a evaluar las alteraciones de la morfología condilar. La forma ovalada fue la más común en todos los grupos etarios en hombres y mujeres. Se necesitan más estudios sobre la población iraquí que evalúen el cóndilo mandibular para proporcionar valores estandarizados para evaluar la anatomía mandibular.

Características anatómicas-funcionales que orientan la posición del cóndilo en la fosa mandibular en una relación céntrica: una descripción narrativa / Anatomical functional characteristics that guide the condylar position in mandibular fossa a centric relation: narrative description

RESUMEN: La Relación Céntrica (RC) es un concepto que busca definir la posición ideal del cóndilo de la mandíbula en la fosa mandibular, siendo esta posición muy discutida en la literatura y ha ido cambiado con los avances en conocimiento y tecnología. Tomándose en la actualidad en consideración elementos anatómicos esenciales que son utilizados como guía para el clínico. La importancia de poder reconocer esta posición radica en la correcta ejecución tanto de procedimientos diagnósticos como de tratamiento en diversas áreas de la odontología. Existen elementos anatómicos de la articulación temporomandibular (ATM) que nos ayudarían a comprender mejor el concepto de RC, entre estos destacan que la condensación ósea de las superficies articulares funcionales y su recubrimiento por fibrocartílago; la porción media del disco articular, desprovista de vasos y nervios; el techo de la fosa mandibular que puede llegar a ser extremadamente delgado por lo cual no se consideraría un área para soportar carga; la prolongación posterior del disco articular (DA) que es altamente vascularizada e inervada. El DA se encuentra íntimamente relacionado con estructuras como el ligamento temporomandibular o lateral y la cabeza superior del músculo pterigoideo lateral que permitirían junto a los elementos anteriormente mencionados el adecuado funcionamiento de la ATM. El correcto aprendizaje y utilización de estos conceptos contribuirá a lograr un mejor ejercicio del desarrollo profesional de estudiantes y profesionales del área de la odontología.

SUMMARY: The Central Relation (CR) is a concept that defines the ideal position of the mandibular condyle in the mandibular fossa. The position has been the subject of much discussion in the literature, noting changes as advancements in knowledge and technology are achieved. Thus, certain essential anatomical elements that are used as a guide for the clinician, are taken into account. The importance of being able to identify this position lies in the correct execution of both diagnostic and treatment procedures in various areas of dentistry. There are anatomical elements of the temporomandibular joint (TMJ) that improve understanding of the CR concept. These include: Bone condensation of the functional articular surfaces and their fibrocartilage coating; the middle portion of the joint disc, devoid of vessels and nerves. The roof of the mandibular fossa can become extremely thin, so it would not be considered an area to support load; the posterior prolongation of the articular disc (AD) Which is highly vascularized and innervated. The AD is also closely related to structures such as the temporomandibular or lateral ligament and the superior head of the lateral pterygoid muscle. Along with the previously described elements, this would allow proper functioning of the TMJ. The correct learning and use of these concepts contributes to a better exercise in the professional development of students and professionals in the area of dentistry.

Evaluation of 2 ultrasonic indicators as predictors of difficult laryngoscopy in pregnant women: A prospective, double blinded study.

BACKGROUND: Ultrasonic measurements of tongue thickness and condylar translation were recently introduced to predict difficult laryngoscopy in non-obstetric patients. We designed the present study to evaluate the performance of these two ultrasonic indicators in predicting difficult laryngoscopy in healthy parturients. METHODS: The 119 parturients undergoing elective cesarean delivery were enrolled. Tongue thickness and condylar translation measured by ultrasonography, and Modified Mallampati test (MMT) score, inter-incisor distance (IID) and modified Cormack-Lehane grading system (MCLS) were measured and recorded before anesthesia. The primary outcome was difficult laryngoscopy defined as MCLS 3 or 4. The association between these variables and difficult laryngoscopy were analyzed by using multivariable logistic regression and receiver operating characteristic (ROC) curve. RESULTS: Compared to the Easy Laryngoscopy Group, the tongue thickness was significantly higher and the condylar translation and IID were significantly lower in the Difficult Laryngoscopy Group. Tongue thickness and condylar translation but not MMT score and IID were proved to be two independent predictors for difficult laryngoscopy by multivariate logistic regression, with the odds ratios of 2.554 (95% confidence interval (CI), 1.715 to 3.802) and 0.457 (95% CI, 0.304 to 0.686). The area under the ROC curve to predict difficult laryngoscopy for tongue thickness was 0.93 (95% CI, 0.88-0.98) and for condylar translation was 0.77 (95% CI, 0.67-0.86), which were significantly higher than those for MMT score (0.67, 95% CI, 0.56-0.77) and IID (0.65, 95% CI, 0.55-0.76). CONCLUSIONS: Compared with MMT and IID, tongue thickness and condylar translation measured by ultrasonography appear to be better indicators for predicting difficult laryngoscopy in parturients.The trial was registered at the Chinese Clinical Trial Registry (ChiCTR)(www.chictr.org), registration number ChiCTR-ICR-1800019991.

Dimension and morphology of the mandibular condyle in class I patients in cone beam computed tomography / Dimensión y morfología del cóndilo mandibular en pacientes de clase I en tomografía computarizada de haz cónico

To evaluate the anterior-posterior (A-P)/medial-lateral (M-L) dimension, and morphology of the mandibular condyle in patients aged 18 to 65 years with Class I skeletal pattern on Cone Beam CT scans. Materials and Methods: Seventy one scans were evaluated using RealScan 2.0 software. The dimension was determined by points A (most anterior in the sagittal plane), P (most posterior in the sagittal plane), M (most interior in the coronal plane), L (most exterior in the coronal plane). The morphology of the condyle was evaluated in two coronal and sagittal planes, being classified as: round, flat, convex or mixed. The size of the condyle was analyzed by descriptive statistics and the morphology by frequency distribution. For the bivariate analysis, the Student's t-test was applied. Results: Measurements were obtained for the A-P diameter of the right condyle (RC) (8.72mm ± 1.25mm) and the left condylar (LC) (8.50mm ± 1.50mm), the M-L diameter of the RC (19.24mm ± 2.03mm) and the LC (18.97mm ± 1.87mm). There were significant differences in the male M-L dimension of the LC compared to the female (p=0.002). The most prevalent morphology of RC (35.21) and IQ (23.94) in the coronal plane was round. Conclusion: The A-P dimension of the right and left condyle is similar in both genders; however, there are differences in the M-L dimension of the left male condyle. The most prevalent morphology of the right and left condyle was round in the sagittal plane with the exception of the coronal plane.

Evaluar la dimensión antero- posterior (A-P)/medio-lateral (M­L), y la morfología del cóndilo mandibular en pacientes de 18 a 65 años con patrón esquelético Clase I en tomografías computarizadas Cone Beam. Material y Métodos: 71 tomografías fueron evaluadas mediante el software RealScan 2.0. La dimensión fue determinada por los puntos A (más anterior en el plano sagital), P (más posterior en el plano sagital), M (más interno en el plano coronal), L (más externo en plano coronal). Se evaluó la morfología del cóndilo en dos planos coronal y sagital, clasificándose en: redonda, aplanada, convexa y mixta. La dimensión del cóndilo fue analizada por estadística descriptiva y la morfología mediante distribución de frecuencias. Para el análisis bivariado, se aplicó la prueba de t de Student. Resultado: Se obtuvieron las medidas del diámetro A-P del cóndilo derecho (CD) (8,72mm ± 1,25mm) y el izquierdo (CI) (8,50mm ± 1,50mm), el diámetro M-L del CD (19,24mm ± 2,03mm) y el CI (18,97mm ± 1,87mm). Hubo diferencias significativas en la dimensión M-L del CI del sexo masculino en comparación al femenino (p=0.002). La morfología más prevalente del CD (35,21) y CI (23,94) en plano coronal fue de tipo redonda. Conclusión: La dimensión A-P del cóndilo derecho e izquierdo es similar en ambos sexos; sin embargo, existen diferencias en la dimensión M-L del cóndilo izquierdo del sexo masculino. La morfología del cóndilo derecho e izquierdo más prevalente fue la redonda en plano sagital a excepción del plano coronal.

Effects of Twin Inclined Plane Device on Adaptation and Ultrastructure Variations in Condyle of Growing Rats.

OBJECTIVE: This study investigates the effects of using a twin inclined plane device (TIPD) on the remolding and ultrastructure variation of mandibular condyle in growing rats. MATERIALS AND METHODS: Forty-eight male Wistar rats (six weeks old, body weight of approximately 190-210 g) were divided into experimental group (wearing appliance, n = 32) and control group (no appliance, n = 16). Samples were collected on days 3, 14, 30, and 60. The immunohistochemical analysis for vascular endothelial growth factor (VEGF) and type II collagen was carried out. Tartrate-resistant acid phosphatase (TRAP) reaction was performed to evaluate the osteoclastic activity. Three-dimensional morphometric images were reconstructed for morphometric analysis by microcomputed tomography (micro-CT). The ultrastructure of the condylar surface was observed by scanning electron microscopy (SEM). RESULTS: The expression of VEGF significantly increased, while the expression of type II collagen decreased in the experimental group at days 30 and 60. Furthermore, the enhanced osteoclast activity was observed under the subchondral bone, which was highest at day 30, and decreased to the lowest at day 60 in the experimental group. In addition, adaptive subchondral bone remolding in the posterior part of the condyle was observed at day 60 in the experimental group, and the SEM revealed the ultrastructure variations after installation of the TIPD. However, these changes began to reverse after 30 days. CONCLUSION: Condylar tissue changes point to the osteoclastic activity in the posterior region of the condyle. These adaptive changes point to bone resorption in the posterior condyle. Type II collagen and VEGF contribute to the MCC remolding induced by the TIPD. The ultrastructural changes in the posterior condylar area in response to mechanical stresses are recoverable at the initial stage.

Three-dimensional micro CT derived morphology of the condylus mandibulae in older adults: implications for clinical dentistry / Micro tomografía computarizada tridimensional derivada de la morfología del cóndilo de la mandíbula en adultos mayores: implicaciones para la odontología clínica

Temporomandibular disorder (TMD) is a multi-etiologic disability, accompanied by a wide range of symptoms, requiring a variety of therapies, with TMJ reconstruction considered the most severe. TMJ surgery is associated with many morbidities and limitations, especially in the elderly. Previous studies have determined the shape and dimensions of the Condylus mandibulae in children and adults, but a range of measurements in the elderly population has yet to be created. This study aims to establish a range of measurements and the morphology of the Condylus mandibulae in an older population using micro CT. 14 cadaveric Condylus mandibulaes (8 male, 6 female; average age, 83±8.6) were scanned with microCT and measured using Amira 4.1.1 modeling software. The anteroposterior length (LAP), mediolateral width (WML) and height (H) of each Condylus mandibulae was measured from 5 equidistant slices in the coronal, sagittal and axial planes. Additionally, each Condylus mandibulae was measured at its greatest anteroposterior length, mediolateral width and height using digital callipers on the cadaveric specimen. This study is the first to accurately describe the morphology of the Condylus mandibulae in an elderly population. The length and width measurements of digital calliper (10.51 ± 0.87; 18.33 ± 2.35) and corresponding micro-CT (11.46 ± 1.60; 17.62 ± 2.05) both showed high consistency and reliability. Our findings lay the foundation for the creation of an off-the-shelf Condylus mandibulae prosthesis or anatomically shaped Condylus mandibulae scaffold for elderly patients.

El trastorno temporomandibular (TTM) es una discapacidad multi-etiológica, acompañada por una amplia gama de síntomas, que requieren una variedad de terapias, entre las cuales la reconstrucción de la articulación temporomandibular (ATM) es considerada una de las terapias más graves. La cirugía de la ATM se asocia con muchas morbilidades y limitaciones, especialmente en adultos mayores. Estudios previos han determinado la forma y las dimensiones del cóndilo de la mandíbula en niños y adultos, no obstante aún no se han identificado estas mediciones en una población de adultos mayores. Este estudio tiene como objetivo establecer un rango de mediciones y la morfología del cóndilo de la mandíbula en una población de adultos mayores mediante microtomografía computarizada (microCT). Se escanearon, con microCT, 14 mandíbulas cadavéricas (8 hombres, 6 mujeres; edad promedio: 83 ± 8,6 años), y se realizaron mediciones utilizando el software de modelado Amira 4.1.1. De cada cóndilo de la mandíbula se midió: longitud anteroposterior (LAP), ancho mediolateral (AML) y altura (A), a partir de 5 cortes equidistantes en los planos coronal, sagital y axial. Además, también se utilizaron calibradores digitales para realizar estas mismas mediciones. Este estudio es el primero en describir con precisión la morfología del cóndilo de la mandíbula en una población de adultos mayores. Las medidas de longitud y anchura del calibrador digital (10,51 ± 0,87; 18,33 ± 2,35) y el micro-CT correspondiente (11,46 ± 1,60; 17,62 ± 2,05) mostraron una alta consistencia y confiabilidad. Nuestros hallazgos sientan las bases para la creación de una prótesis de cóndilo de la mandíbula o un andamio condilar de forma anatómica para pacientes de edad avanzada.

Comparison of condylar morphology changes and position stability following unilateral and bilateral sagittal split mandibular ramus osteotomy in patients with mandibular prognathism.

BACKGROUND: Unilateral sagittal split ramus osteotomy (USSRO) is not widely used given the postoperative instability caused by the inevitable rotation of the mandibular segment during surgery. However, the influence of mandibular movement on the condylar morphology and position stability has not been completely explored. The aim of the study was to quantitatively evaluate the effect of USSRO on the condylar surface morphology changes and postoperative stability in patients with mandibular lateral prognathism and compare these findings with the classic bilateral sagittal split ramus osteotomy (BSSRO). PATIENTS/METHODS: This was a retrospective study involving 134 patients with mandibular lateral prognathism who received USSRO (n = 56) and BSSRO (n = 78) surgery. Here, cone beam computed tomography (CBCT) was performed before surgery (T0), immediately after surgery (T1), and 1 year postoperatively (T2). Differences of condylar sizes, condylar surface deviation, and mandibular positioning parameters (dental midline deviation, SNB, SN-MP) were calculated from T0 to T2. Comparisons were performed at the deviated side or nondeviated side of condyles between the USSRO and BSSRO groups. The relation between the dental midline deviation and condylar surface morphology changes from T0 to T2 were investigated. RESULTS: Condylar surface morphology changes at the deviated side of temporomandibular joint (TMJ) before and 1 year after the surgery were significantly different between the USSRO and BSSRO groups. The dental midline deviation was related to the changes of condylar volume, surface size and surface deviation at the deviated side of TMJ in patients following USSRO. No significant difference was noted between the USSRO and BSSRO groups for postoperative condylar surface morphology changes at the nondeviated side. In both groups, significant differences between T0 and T1 and no significant difference between T1 and T2 were noted for all of the mandibular positioning parameters. CONCLUSIONS: Both BSSRO and USSRO exhibit favorable postoperative stability in the correction of mandibular prognathism. After USSRO surgery, condylar surface changes occurred at the deviated side of the TMJ, and the dental midline deviation was closely related to the changes of condylar surface morphology. USSRO represents a stable alternative for minor asymmetric mandibular prognathism correction with the advantages of reduced operating time and surgical trauma.

Cone-Beam Computed Tomography Study of Mandibular Condylar Morphology.

OBJECTIVE: The purpose of this study was to evaluate the morphology of mandibular condyle using cone-beam computed tomography (CBCT) on coronal sections in a South-Eastern Anatolian population. METHODS: A total of 1820 joints in 910 subjects with age range of 18 to 86 years were examined retrospectively on CBCT images. The mandibular condylar morphology was examined in right and left sides on coronal sections and classified as convex, round, flat, and angled. In addition, condyle morphology was assessed according to age, gender, edentulism, Angle's classification. RESULTS: The study sample contained CBCT scans of 910 patients (50.3% female, 49.7% male) with a mean age of 42.31 ±â€Š15.74. Condylar morphologies were analyzed as convex in 40.5%, angled in 34.3%, flat in 15.5%, round in 9.6% of the cases. Condyle shape was found statistically related to group age, gender, edentulism (P <0.05). CONCLUSION: The findings suggest that mandibular condyle shape is associated with age, gender, and edentulism. CBCT may be considered as an appropriate imaging method for detection of condyle alterations of temporomandibular joints and it could provide early diagnosis of temporomandibular joint disorder.

Low intensity pulsed ultrasound increases mandibular height and Col-II and VEGF expression in arthritic mice.

OBJECTIVE: Rheumatoid arthritis (RA) is a chronic inflammatory disease involving persistent inflammation resulting in cartilage and bone damage. RA can affect the temporomandibular joint (TMJ), and damage to the TMJ condyle can lead to craniofacial developmental disturbances, causing micrognathia, malocclusion, retrognathia, and increased overjet. Current treatments of TMJ arthritis are unsatisfactory. This pilot study aimed to investigate the effect of low intensity pulsed ultrasound (LIPUS) on the mandible and TMJ condyles in an RA mouse model using micro-computed tomography (Micro-CT), histologic, and immunohistochemical analyses. METHODS: MRL-lpr/lpr mice received LIPUS application to their TMJs for 20 min/day for 2 and 4 weeks. Micro-CT analysis measured condylar length and width, posterior mandibular height (P.M.H), mandibular ramus length (M.R.L), effective mandibular length (Ef.M.L), angular process length (A.P.L), mandibular plane (M.P), mandibular axis (M.Ax), and lower incisor height (L.I.H). Condylar cartilage thickness was histologically measured, and type II collagen (Col-II), vascular endothelial growth factor (VEGF), nuclear factor kappa-B ligand (RANKL), and osteoprotegerin (OPG) expression was analyzed using immunohistochemistry. RESULTS: Comparing the LIPUS-treated group with the control, P.M.H, M.R.L, and M.P were significantly greater in the LIPUS-treated group. Immunostaining for Col-II and VEGF was stronger in the LIPUS-treated group after 4 weeks. OPG showed slightly more expression in the LIPUS group. CONCLUSIONS: LIPUS may enhance mandibular and TMJ condylar bone formation in this RA mouse model by preventing any growth disturbances involved in inflammation. Further studies are recommended to analyze the effect of LIPUS on TMJ of RA in other animal models.

Temporomandibular Joint Condyle-Disc Morphometric Sexual Dimorphisms Independent of Skull Scaling.

PURPOSE: Approximately 2 to 4% of the US population have been estimated to seek treatment for temporomandibular symptoms, predominately women. The study purpose was to determine whether sex-specific differences in temporomandibular morphometry result from scaling with sex differences in skull size and shape or intrinsic sex-specific differences. MATERIALS AND METHODS: A total of 22 (11 male [aged 74.5 ± 9.1 years]; 11 female [aged 73.6 ± 12.8 years]) human cadaveric heads with no history of temporomandibular disc derangement underwent cone beam computed tomography and high-resolution magnetic resonance imaging scanning to determine 3-dimensional cephalometric parameters and temporomandibular morphometric outcomes. Regression models between morphometric outcomes and cephalometric parameters were developed, and intrinsic sex-specific differences in temporomandibular morphometry normalized by cephalometric parameters were determined. Subject-specific finite element (FE) models of the extreme male and extreme female conditions were developed to predict variations in articular disc stress-strain under the same joint loading. RESULTS: In some cases, sex differences in temporomandibular morphometric parameters could be explained by linear scaling with skull size and shape; however, scaling alone could not fully account for some differences between sexes, indicating intrinsic sex-specific differences. The intrinsic sex-specific differences in temporomandibular morphometry included an increased condylar medial length and mediolateral disc lengths in men and a longer anteroposterior disc length in women. Considering the extreme male and female temporomandibular morphometry observed in the present study, subject-specific FE models resulted in sex differences, with the extreme male joint having a broadly distributed stress field and peak stress of 5.28 MPa. The extreme female joint had a concentrated stress field and peak stress of 7.37 MPa. CONCLUSIONS: Intrinsic sex-specific differences independent of scaling with donor skull size were identified in temporomandibular morphometry. Understanding intrinsic sex-specific morphometric differences is critical to determining the temporomandibular biomechanics given the effect of anatomy on joint contact mechanics and stress-strain distributions and requires further study as one potential factor for the increased predisposition of women to temporomandibular disc derangement.

Three-dimensional assessment of condylar position following orthognathic surgery using the centric relation bite and the ramal reference line: A retrospective clinical study.

Orthognathic surgery (OGS) is a relatively common procedure for solving functional and aesthetic problems in facial and jaw areas in patients with dentofacial deformities. The positioning of the mandibular condylar segment during OGS has an impact on the surgical outcome. This study aimed to investigate the changes in the condyle-fossa relationship three dimensionally after OGS using the centric relation (CR) bite and the ramal reference line (RRL).Thirty-two patients with skeletal malocclusion underwent OGS. Condylar repositioning was performed using the CR bite, as previously reported. A RRL was added to the existing method and used during the surgery. Cone-beam computed tomography scans were acquired at 4 time points. Sixty-four condyles were evaluated in the coronal, sagittal, and axial views. Two groups were created according to the amount of mandible setback (SB1 vs SB2), and another 2 groups were created according to the maxillary operation (1-jaw vs 2-jaw). Each was then compared at the 4 time points. Differences between the values before (T0) and a year after surgery (T3) were also investigated. The positions of the pogonion and the menton were examined at T2 and T3 for the simple evaluation of relapse.The change in the condylar position was significant over a time-course (P < .001) but not between T0 and T3 (P > .05). Neither the setback amount nor the maxillary operation affected the positional change (P > .05). There were no significant changes between T2 and T3 in the relapse evaluation.This condylar repositioning method using the CR bite and a RRL showed stable results after OGS. This method is noninvasive and cost-effective and can be easily performed even by an inexperienced surgeon because it reduces errors in repositioning the condyle during OGS.

Osteoarthritis of the temporomandibular joint and increase of the horizontal condylar angle: a longitudinal study.

OBJECTIVE: Our previous study of patients with unilateral temporomandibular joint (TMJ) osteoarthritis (OA) showed that the affected joints had greater horizontal condylar angle (HCA) compared with the contralateral unaffected joints. However, it was unclear whether the HCA changes preceded or were the result of OA changes. The aim of this longitudinal study was to investigate the relationship between HCA and OA progression. STUDY DESIGN: In total, 127 patients (with or without TMJ disorders) completed baseline and follow-up examinations (average time to follow-up 7.9 years). Generalized estimating equation models were used to account for correlation of observations within the same patients. RESULTS: (1) HCA was greater in OA-affected joints than in unaffected joints (P = .04). (2) Increased HCA at follow-up was associated with change in joint status from no OA to OA. (P = .001). (3) Baseline HCA value alone did not predict future OA diagnosis. (4) All OA changes in fossa/articular eminence morphology, and some combinations of condylar changes, were associated with a greater HCA. (5) OA diagnosis was associated with pain during maximum opening (P = .005) and pain history (P = .002). (6) Aging alone was not correlated with increased HCA. CONCLUSIONS: Clinical progression of OA preceded increases in HCA. HCA alone did not predict OA development.

Investigating possible correlation between condylar asymmetry and clinical dysfunction indices in patients with temporomandibular dysfunction using Cone-beam computed tomographic.

PURPOSE: Temporomandibular disorder (TMD) is a common problem in modern societies. Causes of TMD, as a consequence of condylar asymmetry index (CAI), are still a subject of controversy. The aim of the present study was to determine the possible correlations between the degree of condylar asymmetry and clinical dysfunction indices. MATERIALS AND METHODS: In this cross-sectional study, we used the Habets method to measure the CAI in 42 TMD patients. The participants' age and sex were matched in the control group. Patients were divided into mild, moderate and severe dysfunction groups based on Helkimo's clinical Di. The data were analyzed using Mann-Whitney U and Kruskal-Wallis tests. Also, the study attempted to assess the possibility of correlation between age and CAI. RESULTS: The CAI values of TMD patients were significantly higher than those of the control group (P = 0.001). However, CAI was not significantly different among TMD patients with different dysfunction index. There was no significant correlation between CAI and age (Spearman r = 0.655, P = 0.23). CONCLUSION: Based on the findings of the present study, patients with condylar asymmetry index are more susceptible to TMD. However, degree of the condylar asymmetry is not a criterion for TMD signs and symptoms.

Mandibular subcondylar fracture accessibility with transparotid approach by rhytidectomy and modified Risdon approach: An anatomical comparative study.

PURPOSE: The purpose of our anatomical study was to compare the accessibility of the area at the level of the neck of the condyle and the condylar head by two different approaches: the modified Risdon approach and a transparotid approach by rhytidectomy (TPAR). METHODS: An anatomical study was performed on 12 heads of cadavers preserved with a solution rich in glycerin and ethanol, but very low in formalin. A modified Risdon approach and a TPAR were each performed on a hemiface of the same head. The bone surface was rendered digitally accessible on an anatomical diagram using Image J software. The software was used to determine a concordance score between the area of accessibility and the area of interest necessary for osteosynthesis of a high subcondylar fracture. This score was presented as a numerical scale from 0 to 100. We measured the total number of pixels in our area of interest and assigned it a score of 100. We then compared the area of accessibility with the area of interest necessary for osteosynthesis of a high subcondylar fracture. RESULTS: Using the modified Risdon approach, an average score of 55.88 (SD = 18.96) was found, or 55.88% of the accessible area of interest. Using TPAR, we found a score of 91.05 (SD = 7.95) or 91.05% of the accessible area of interest. This difference in score between the two techniques was significantly different (p < 0.001), taking into account intra-hemiface and intra-individual correlation. CONCLUSION: TPAR seems to be more effective in treating high condylar process fractures of the mandible.

Índices de simetría condilar y mandibular a través de radiografías panorámicas digitales en una muestra de pacientes chilenos / Condylar and mandibular symmetry indexes through digital panoramic radiographs in a sample of Chileans patients

La simetría mandibular puede alterarse por diversos motivos. Variados estudios buscan definir parámetros de "normalidad" y para ello se han descrito técnicas que utilizan la radiografía panorámica (RPN). El objetivo de este estudio fue determinar índices de simetría mandibular/condilar en una muestra de pacientes chilenos. Se realizó un estudio descriptivo de corte trasversal en RPN digitales obtenidas de la Clínica Odontológica de la Universidad de La Frontera. Se aplicaron criterios de inclusión: pacientes mayores de 18 años, dentición permanente completa hasta el primer molar; y de exclusión: signos radiográficos de alteraciones óseas y/ o cirugía mandibular, cóndilos no visibles, ortodoncia. Se utilizó el software ImageJ para dibujar rectas y medir la altura de la rama y cóndilo mandibular del lado derecho e izquierdo de acuerdo a la técnica propuesta por Kjellberg et al. (1994). Con estas medidas se calculó el índice de simetría entre altura condilar y rama (S1); y entre altura condilar y mandibular (S2). 235 RPN digitales fueron analizadas (95 hombres; 140 mujeres) con edad promedio de 24,98±7,32 años. El promedio de S1 fue de 93,74 % (±3,85) en hombres y 93,41 % (±5,77) en mujeres, mientras que para S2 fue de 90,50 % (±6,51) en hombres y 90,27 % (±7,80) en mujeres, sin diferencias significativas para ninguno de ambos índices (p=0,347 y p=0,233, respectivamente). En cuanto a la edad, tampoco se encontraron diferencias significativas en el promedio de los índices S1 y S2 para cada rango etario (p=0,594 y p=0,669, respectivamente). Mediante este estudio se concluye que hay un alto porcentaje de pacientes con simetría mandibular/condilar en ambos sexos y en diferentes rangos etarios, esto sin considerar el estado de salud o presencia de alteraciones morfológicas y/o funcionales.

Mandibular symmetry may be modified by various conditions. A number of studies have attempted to define parameters of "normality" and several techniques have been described using digital orthopantomography (OPG). The aim of this study was to determine mandibular/condylar symmetry indexes in a sample of Chilean patients. A cross sectional descriptive study in digital OPG obtained from the Dental Clinic of Universidad de La Frontera was performed. Inclusion criteria applied were: Patients older than 18 years, complete permanent dentition up to the first molar. Exclusion criteria were also applied: Radiographic signs of bone disease and/or mandibular surgery, not visible condyles, orthodontics. ImageJ software was used to draw lines and measure the height of the ramus and mandibular condyle on the right and left side with the technique postulated by Kjellberg (1994). With these measurements, the symmetry index between condylar height and ramus (S1) and between condylar and mandibular height (S2) were calculated. The study analyzed 235 digital OPG (95 men, 140 women) with an average age of 24.98 ± 7.32 years. The S1 average was 93.74 % (± 3.85) for men and 93.41 % (± 5.77) for women, and for S2 it was 90.50 % (± 6.51) for men and 90.27 % (± 7.80) for women, without significant differences for either index (p=0.347 and p=0.233, respectively). No significant differences were found in reference to age, for indexes S1 and S2 (p=0.594 and p=0.669, respectively). Therefore, it is concluded that there is presence of condylar/mandibular symmetry in both sexes and in age ranges, when measuring digital OPGs without considering health status or presence of any morphological or functional alteration.

Study of condylar positional changes after sagittal split osteotomy for mandibular advancement: A prospective cohort study.

PURPOSE: To analyse the possible morphologic and positional changes of the mandibular condyles after orthognathic surgery. MATERIAL AND METHODS: A prospective cohort study was performed. Patients with mandibular retrognathism were surgically treated to advance the mandible. The study group included seventeen patients (34 condyles) treated with sagittal split osteotomies alone (4 patients) or in combination with maxillary osteotomies (13 patients). Only condyles located on the mandibular side that advance during surgery were studied, therefore only 25 condyles entered this prospective study. Beside it, a group of 6 patients undergoing maxillary surgery as only procedure, maxillary group, was also studied to determinate the influence of maxillary surgery on condylar displacement. Computed tomographies and lateral cephalometric radiographs were performed two weeks before surgery and one year after the surgical procedures. Different variables which analyse the position and morphology of the mandible were studied. The data obtained were analysed statistically by computing R2 values. RESULTS: In the maxillary group they were small displacements in magnitude and not significant. In the study group, 8 condyles showed morphological changes with alteration on reference points. In the remainder 17 condyles different displacements were noted after surgery. Several of these positional changes were predictable and did not affect postoperative mandibular stability. CONCLUSIONS: condylar displacements that occur after sagittal split osteotomies for mandibular advancement show significant correlation with the degree of mandibular advancement and can be defined by mathematical formulae. Maxillary osteotomies do not seem to influence condylar position when bimaxillary procedures take place.

Anatomical Examination of Mandibular Condyle Protrusion Into the Middle Cranial Fossa.

Trauma to the mandible can occasionally be a life-threatening event. Although extremely rare with only 56 reported patients in the English language, fracture of the floor of the middle cranial fossa with protrusion of the mandibular condyle into the middle cranial fossa was first reported in 1963 by Dingman. The authors review the anatomy of the temporomandibular joint in relation to the middle cranial fossa and demonstrate the possible complications due to condylar intrusion with anatomical dissection.