technetium-tc-99m-medronate and Malocclusion

Bone scintigraphy (BS) has been the mainstay in evaluating patients with mandibular condylar hyperplasia (CH). Both planar BS and single photon emission computed tomography (SPECT) have been used to determine cessation of condylar hyperactivity before corrective surgery. The present study aimed to examine the utility of the relatively new single photon emission computed tomography/computed tomography (SPECT/CT) technique for evaluation of CH.. Sixty-one mandibular Tc-99m methylene diphosphonate bone SPECT/CT studies were reviewed. Images were analyzed without and with fusion with anatomical CT. Condylar uptake were quantified and differences in uptake between the right and left condyles were determined by both maximum uptake and average uptake in the region of interes (ROI). Differences exceeding 10 percentage points indicated condylar hyperactivity.. SPECT and SPECT/CT showed positivity in 34 and 31 examinations, respectively. Agreement between the two modalities was high, but was not perfect. SPECT was found to be more reproducible than SPECT/CT. Quantification using maximum ROI counts was more reproducible than using average ROI counts.. No evidence was found to indicate superiority of SPECT/CT over simple SPECT for evaluation of condylar\ hyperactivity in CH, as demonstrated by the lower intra-modality reproducibility and a trend towards lower sensitivity for detection of hyperactive condyles. Utilization of SPECT alone would further benefit in terms of reduction of patient radiation exposure which is a concern, especially in younger patients such as those with CH. When using quantification, maximum ROI counts should be used over average ROI counts.

Topics: Adolescent; Adult; Female; Humans; Hyperplasia; Male; Malocclusion; Mandibular Condyle; Reproducibility of Results; Retrospective Studies; Technetium Tc 99m Medronate; Tomography, Emission-Computed, Single-Photon; Tooth Abnormalities; Young Adult

Mandibular asymmetry is commonly caused by disproportionate mandibular growth due to unilateral condylar hyperactivity. The current standard for mandibular condyle bone scintigraphy uses single photon emission computed tomography (SPECT) imaging after intravenous administration of technetium-99m-labeled diphosphates. To our knowledge, the use of hybrid SPECT integrated with multidetector computed tomography (SPECT/CT) imaging in the scintigraphic quantitative functional assessment of mandibular condyle growth has not yet been described.. A 22-year-old male with mandibular asymmetry due to suspected unilateral condylar hyperactivity underwent SPECT/CT imaging of the skull and facial bones after intravenous administration of technetium-99m methylene diphosphonate. Using CT to guide anatomical contouring, precise regions of interest were drawn over the mandibular condyles and clivus in adjacent SPECT/CT transaxial slices to calculate the mean radiotracer count ratios. For comparison of quantitative results, conventional SPECT images were obtained from the SPECT/CT data and processed according to conventional methods. Planar images were also obtained for visual assessment of mandibular condyle activity. All three methods, SPECT/CT, conventional SPECT, and planar imaging, found unilateral condylar hyperactivity of the left mandibular condyle. The condyles and clivus were easily and confidently identified on SPECT/CT images.. We speculate that SPECT/CT imaging will improve the diagnostic accuracy of unilateral condylar hyperactivity. More studies are necessary to further define its role, obtain baseline reference values, and establish analysis protocols.

Topics: Cranial Fossa, Posterior; Facial Asymmetry; Humans; Image Interpretation, Computer-Assisted; Male; Malocclusion; Mandibular Condyle; Multimodal Imaging; Positron-Emission Tomography; Sensitivity and Specificity; Software; Technetium Tc 99m Medronate; Tomography, X-Ray Computed; Young Adult

Treatments to correct skeletal deformities in patients with hemimandibular hyperplasia differ, particularly about the age at which the operation is done and the operation itself. To some extent, the differences can be attributed to the unknown biological basis of disease. The aim of the present study was to evaluate clinically the outcome of a rationale for the operation based on condylectomy on the affected side. Histological, radiological, and nuclear methods were used to get a more detailed insight into the reason for the operation. Six patients with hemimandibular hyperplasia were treated by a combined orthodontic-maxillofacial protocol. All patients had the affected joint removed. The histological morphology of each condylar specimen was compared with the bone scintigraphy to try and find a correlation between the methods. The clinical evaluation showed morphological and functional rehabilitation of all six patients. During the 2-year follow-up, all patients had stable symmetrical mandibles with no disturbance of temporomandibular function. Remodelling of the joint and the destruction of the cartilaginous layer was accompanied by much bone scintigraphic activity. We conclude that condylectomy can correct hemimandibular hyperplasia, even in patients with active condylar growth, by removing the underlying disease.

Topics: Adult; Cartilage, Articular; Cephalometry; Facial Asymmetry; Female; Humans; Hyperplasia; Jaw Abnormalities; Male; Malocclusion; Mandible; Mandibular Condyle; Oral Surgical Procedures; Orthodontics, Corrective; Osteotomy, Le Fort; Radionuclide Imaging; Radiopharmaceuticals; Technetium Tc 99m Medronate; Treatment Outcome

To evaluate the skeletal effects of nonsurgical rapid maxillary expansion (RME) on craniofacial structures with bone scintigraphy in young adult female subjects.. The material of the present study consists of scintigraphic records taken from 17 early adult females treated with RME. All patients had a bilateral posterior crossbite, transverse maxillary deficiency, deep palatal vault, and dental crowding at the beginning of the treatment. The age range of the patients was 16.1 to 18.8 years, and the mean age was 17.3 +/- 0.86 years. Bone scintigraphy records were obtained before RME (T1), during the splitting of the midpalatal suture (T2), and after the end of active widening period (T3). Repeated measure analysis of variance was used to assess the differences between the periods. In addition, Bonferroni multiple comparison tests were applied to the measurements at which F values were found to be statistically significant.. According to the statistical analysis, significant activity changes were found in all regions studied and in all slices. The metabolic activity in all regions showed significant increases up to the separation of the midpalatal suture (T1-T2), whereas the metabolic activity exhibited a remarkable decrease (T2-T3) after the opening of the midpalatal suture.. Scintigraphic records revealed an increase in the regions of interest scores during RME in all regions and all slices. Therefore, it can be speculated that RME has had not only dental effects but also skeletal effects on young adult patients.

Topics: Adolescent; Cranial Sutures; Facial Bones; Female; Follow-Up Studies; Frontal Bone; Humans; Image Processing, Computer-Assisted; Malocclusion; Maxilla; Nasal Septum; Occipital Bone; Palatal Expansion Technique; Palate, Hard; Radiopharmaceuticals; Skull; Sphenoid Bone; Technetium Tc 99m Medronate; Tomography, Emission-Computed, Single-Photon; Zygoma

The purpose of this study was to evaluate bone activity at the midpalatal suture that had been biomechanically stimulated by rapid maxillary expansion (RME). A rigid acrylic-bonded expansion device with a maxiskeleton screw was used for RME in three patients who were in three different growth periods. The screw was activated twice a day by 1/4 turns. After sufficient expansion, the screw was fixed with acrylic resin, and the same appliance was used as a removable retention plate for three months. Single photone emission computed tomography (SPECT) bone scintigraphy records were obtained before (T1) and at the end of RME (T2) and three months after the retention period (T3). According to the scintigraphic records, the increase in bone activity was highest in the anterior and medial sections on both the left and right sides of the maxilla in all cases. After three months of retention, the bone activity returned to its original level. Therefore, it may be stated that the retention period of three months was sufficient for bone reorganization.

Topics: Adolescent; Cephalometry; Child; Cranial Sutures; Female; Follow-Up Studies; Humans; Male; Malocclusion; Maxilla; Models, Dental; Orthodontic Appliances; Orthodontic Retainers; Palatal Expansion Technique; Palate; Radiopharmaceuticals; Technetium Tc 99m Medronate; Tomography, Emission-Computed, Single-Photon

Isotope bone scans have been used for a number of years to assess growth activity in the mandibular condyle in patients who present with facial asymmetry. The aim is to distinguish normal bone growth within the condyle from increased activity that may be the cause of the asymmetry. Previous studies have, however, relied only on planar images. SPECT (single photon emission computed tomography) has been used with quantitative assessments of one mandibular condyle to clivus or lumbar spine, but we have compared one condyle with the other, which is more sensitive and accurate in detecting abnormal activity. A relative percentage uptake of 55% or more in the affected mandibular condyle is considered to be abnormal, and this has been validated by comparison with an age-matched control group. We have used SPECT as an aid to diagnosis and treatment in 18 patients with asymmetrical growth and have constructed a therapeutic algorithm to aid the treatment of these patients.

Topics: Adolescent; Adult; Case-Control Studies; Child; Cranial Fossa, Posterior; Facial Asymmetry; Female; Follow-Up Studies; Humans; Hyperplasia; Lumbar Vertebrae; Male; Malocclusion; Mandibular Condyle; Osteotomy; Radiopharmaceuticals; Reproducibility of Results; Technetium Tc 99m Medronate; Tomography, Emission-Computed, Single-Photon