Tract-Specific Diffusion Tensor Imaging in Cervical Spondylotic Myelopathy Before and After Decompressive Spinal Surgery: Preliminary Results.

PURPOSE: Diffusion tensor imaging (DTI) metrics of the cervical spinal cord in patients with cervical spondylotic myelopathy (CSM) were compared to those measured in healthy volunteers, using tract-specific region of interests (ROIs) across all cervical intervertebral disc levels. METHODS: Magnetic resonance (MR) imaging of the cervical spinal cord was performed in four patients with CSM and in five healthy volunteers on a 3-T MR scanner. Region-specific fractional anisotropy (FA) and mean diffusivity (MD) were calculated on axial imaging with ROI placement in the anterior, lateral, and posterior regions of the spinal cord. FA and MD were also calculated on sagittal acquisitions. Nonparametric statistical tests were used to compare controls and patients before and after surgery. RESULTS: FA values were significantly lower (p = 0.050) and MD values were significantly higher (p = 0.014) in CSM patients measured at level of maximal compression before surgery than in healthy controls in lateral and posterior ROIs, respectively. In posterior ROIs, MD values were significantly higher in patients before surgery compared to controls at all levels except C7-T1. CONCLUSION: Patients with CSM may demonstrate region-specific changes in DTI metrics when compared to healthy controls. Changes in DTI metrics may also occur at levels remote from site of compression.

Combined orthodontic-orthognathic surgical treatment of a Class II, Division I malocclusion.

This case report shows the need to extract four first premolars in addition to orthognathic surgery, even though the initial treatment plan involved a nonextraction strategy. The extractions were necessary to reduce maxillary dental protrusion and proclination and also to recover from the mandibular incisor proclination that occurred as a consequence of leveling the mandibular arch.

An assessment of treatment outcome in American Board of Orthodontics cases.

In a retrospective study, 90 American Board of Orthodontic (ABO) cases were evaluated for treatment outcome. Changes in occlusion, cephalometric skeletal and dental variables, soft tissue variables, and root resorption were evaluated. The occlusions of completed ABO cases were compared with 147 naturally occurring good-to-excellent occlusions from the Andrews Foundation for Education and Research, using the Ideal Tooth Relationship Index (ITRI). Cephalometric variables were evaluated in relation to an "acceptable range" based on established standards. Photographs were evaluated for lip posture at rest and at closure, and the incidence and the severity of root resorption of maxillary and mandibular teeth excluding second molars were evaluated from panoramic radiographs. After treatment, occlusions of ABO cases scored significantly higher overall and for all ITRI segments except the anterior interarch segment when compared with Andrew's sample. In all the ABO cases, ideal overjet and overbite were attained. Cephalometrically, the mandibular plane and the Y-axis angle showed no significant change as a result of treatment. However, skeletal dysplasia (ANB) and skeletal convexity (Na-A-Po) showed improvement. Dentally, the maxillary incisor position and inclination, the interincisal angle, and the lower incisor position ended within the acceptable range, whereas the lower incisors were proclined. Soft tissue variables also improved, lip balance and harmony, closure at rest, and closure without strain all improved. The nasolabial angle showed little change. Most of the root resorption was minor in nature and involved the maxillary and mandibular central and lateral incisors. In conclusion, the ABO cases were well treated and showed marked improvement in occlusion, cephalometric, and soft tissue changes, although experiencing minor iatrogenic effects.

Temporomandibular joint sounds related to orthodontic therapy.

A cross-sectional survey for temporomandibular joint (TMJ) sounds was conducted on 347 orthodontic patients before, during, and after treatment. Those patients who reported joint sounds, or in whom sounds were noted on clinical examination, were subjected to an audiovisual evaluation which was recorded on videotape to identify more precisely the character of the sounds during jaw opening and closing. TMJ sounds were quite common before, during, and after orthodontic treatment. There was a significant association among three variables: joint sounds, age, and treatment. It is not clear, however, whether joint sounds increased due to orthodontic treatment, age, or both. No significant associations were found between TMJ sounds and functional occlusal factors. Significantly more sounds were noted by the examiners than were reported by the patients. Medium or high amplitude sounds were evident in 32.6% of the 135 subjects who underwent the audiovisual examination.

Alexia without agraphia, hemianopia, or color-naming defect: a disconnection syndrome.

A patient with alexia without agraphia, hemianopia, or color-naming defect was found at operation to have a meningioma arising from the tentorium cerebelli that compressed the inferior aspect of the left temporal-occipital junction. It is presumed to have involved only the left ventral visual association cortex and its inferior outflow tracts to the angular gyrus. The input from the right occipital area also was disconnected from the visual language verbal association area by involvement of the ventral outflow of the splenium of the corpus callosum. Preservation of color naming and matching suggests that these functions are dependent on the integrity of more dorsal occipital association systems.

Postradiation motor neuron syndrome.

We report an unusual case of selective lower motor neuron syndrome (MNS) complicating whole neuraxis radiation therapy. Only three well-documented similar cases have been found in a thorough review of the literature. The syndrome has a stereotyped time course and is self-limited. We discuss here possible pathogenetic mechanisms and their relationship to motor neuron disease.