Assessment of the Biomechanical Performance of 5 Plating Techniques in Fixation of Mandibular Subcondylar Fracture Using Finite Element Analysis.

PURPOSE: The aim of this study was to compare the performances of 5 plating techniques for fixation of unilateral mandibular subcondylar fracture. MATERIALS AND METHODS: Five titanium plating techniques for fixation of condylar fracture were analyzed using the finite element method. The modeled techniques were 1) 1 straight plate, 2) 2 parallel straight plates, 3) 2 angulated straight plates, 4) 1 trapezoidal plate, and 5) 1 square plate. Three-dimensional models were generated using patient-specific geometry for the mandible obtained from a computerized tomographic image of a healthy living man. Plates were designed and combined with the mandible and analyzed under a 500-N load. RESULTS: The single straight plate presented the most inferior performance; it presented maximum displacement and strain on cortical bone. The trapezoidal plate induced the least amount of strain on cortical bone and was best at resisting displacement. CONCLUSION: The trapezoidal plate is recommended for fixation of subcondylar fracture.

Assessment of the TMJ Dysfunction Using the Computerized Facebow Analysis of Selected Parameters.

THE PURPOSE OF THE PAPER: Qualitative and quantitative analysis of selected parameters of mandible movements, electronically registered in patients with temporomandibular joint dysfunction and healthy ones. MATERIAL: Function test of the mandible movements was conducted in 175 patients. Gender distribution was 143 women and 32 men, aged 9 to 84. METHODS: The studied population, after accurate clinical examination, was divided into age groups with the range of five years. All the patients had Zebris JMA computerized facebow examination done, according to the generally accepted principles and procedures. RESULTS: Mean values of mouth opening calculated to 45.6 mm in healthy group and 37.6 mm in TMJ dysfunction group. Mean length of condylar path amounted to 39 ± 7% of the maximum value of mouth opening in the group of healthy people, 44 ± 11% in the case of muscle-based disorders, and 35 ± 11% with joint-based. The mean value of the condylar path inclination oscillated in the range of 25° to 45°. CONCLUSIONS: The ratio of length of the condylar path to the size of mouth opening may be a significant value characterising the type and degree of intensification of the TMJ dysfunctions.

Axiographic and clinical assessment of temporomandibular joint function in patients with partial edentulism.

The aim of this study was to axiographically analyse the mobility of the condyles of the temporomandibular joints in patients with partial edentulism in lateral sections and try to specify whether the partial edentulism has an impact on the severity of temporomandibular disorders. 60 subjects with partial edentulism (different range groups) and 20 subjects in the control group (full dental arches) were examined. Every patient underwent a thorough clinical examination, including axiography conducted by means of Cadiax Compact II® system. The results show some correlation between the advancement of temporomandibular joint disorder, the range of partial edentulism and the abrasion of the residual teeth. In the study, a significant intensification of dysfunction symptoms and restricted condylar path was observed in patients with the largest partial edentulism and significant level of tooth wear of the residual teeth. A significantly higher percentage of asymptomatic subjects or those with minor dysfunction was also found among the patients with lowest-range partial edentulism in lateral sections.

Long-term outcome assessment of closed treatment of mandibular fractures.

Mandibular fractures are among the most common trauma injuries of the craniomaxillofacial region. This study evaluated the late results of mandibles fractures treated with arch bar. Forty-nine patients were examined clinically and by questionnaires for late results of arch bar treatment. Demographic data (age, sex, etc), trigeminal nerve sensation (Weber test), temporomandibular joint evaluation, masticatory muscle function, and occlusion were recorded. The data were analyzed by χ test using Sigma Stat 2.0 software. Fifty-one percent of the patients with angular fractures complained of sensory disturbances. Condylar and angular fractures demonstrated higher levels of pain. According to Pearson χ test, a statistically significant relation between angular fracture and tenderness of the internal pterygoid muscles (P = 0.047), angular fracture and cross-bite (P = 0.021), parasymphysial fracture and pain upon wind blowing (P = 0.026), and body fracture and mastication discomfort (P = 0.038) was found. In closed reduction therapy, fracture location of the mandible seems to be more likely correlated in producing particular long-term complications. Regular follow-ups for functional treatments and physiotherapy of chewing muscles and temporomandibular joint, along with removal of occlusal abnormalities, should be considered following arch bar reduction of mandibular fractures.

Tomographic assessment of temporomandibular joints in patients with malocclusion.

There is a paucity of information on the morphological assessment of the temporomandibular joint in relation to varying skeletal and dental relationships. The purpose of this study was to evaluate the morphologic relationship of the condyle and fossa in patients with different malocclusions and skeletal relationships. Pretreatment records of 232 orthodontic patients, 95 males and 137 females, of Caucasian descent and ranging in age from 9 years 4 months to 42 years 6 months, were examined. Records included dental casts, lateral cephalometric radiographs, hand-wrist radiographs, and corrected tomograms of right and left TM joints. Nonconcentricity and mild asymmetry of the condyle-fossa relationship were commonly observed. The left condyle was found to be more anteriorly positioned than the right, with the mean percentage of joint space being 6.93% on the left side and -1.24% on the right. Skeletal and dental Class III patients demonstrated significantly more anteriorly positioned condyles (P < 0.05). There were no significant differences in condylar position between Class I and Class II groups based on ANB or Angle's classification. Further, no significant difference in condylar position was observed between groups based on overbite or crossbite.

Valoración de la hipermovilidad articular y parafunciones en casos de disfunción temporomandibular / Valoration of articular hypermobility and parafunctions in temporomandibular disoder cases

Se presenta un estudio sobre desórdenes temporo Mandibular (DTM) en un grupo de pacientes básicamente infantiles y algunos adolescentes, con un rango de edad comprendido entre los 8 y los 20 años. El objetivo principal es averiguar el grado de incidencia de algunos factores en la aparición de estas alteraciones, los cuales por separados pueden resultar benignos para el paciente, pero que sumados podrían transformarse en patogénicos, como es el caso de la laxitud ligamentosa benigna y las parafunciones. Nuestros resultados en general han sido coincidentes con otros estudios y por lo tanto, concluimos que sería interesante la valoración permanente de estos aspectos en los cuadros disfuncionales

Assessment of condylar position following bilateral sagittal split ramus osteotomy with wire fixation or rigid fixation.

In this study, 53 patients who underwent a bilateral sagittal split ramus osteotomy to advance the mandible were examined radiographically to assess condylar position presurgically, postsurgically, and posttreatment. Subjects were separated into two groups, 29 patients who received wire fixation and 24 who received rigid internal fixation. Condylar position changes were measured on tracings of submentovertex and transcranial radiographs at the time periods mentioned. Differences in condylar position were evaluated in two defined time intervals--T1, presurgical to postsurgical, and T2, postsurgical to posttreatment. Right and left sides were evaluated independently. No correlation between amount of advancement and condylar position change was identified within or between the fixation groups at T1 and T2. No correlation between change in mandibular plane angle and change in condylar position was identified within or between the groups at T1 and T2. Statistically significant differences were identified between the fixation groups in the degree of condylar change measured on the tracings of both submentovertex and transcranial radiographs both right and left sides, at time T1. There was also a significant difference in the change in mandibular plane angle at T1 between the fixation groups. It appears from this study that use of rigid internal fixation following bilateral sagittal split ramus osteotomy results in a statistically significantly greater condylar displacement than does wire fixation. Further research is required to determine whether these changes in condylar position are clinically significant.