RESUMEN
The rotation of the maxillary molars is considered important in the orthodontic treatment of malocclusions. In this study, a computer analysis program was developed to examine the rotations of maxillary molars, mandibular molars, and maxillary first premolars in casts of permanent dentitions with acceptable occlusions. Ninety-three sets of untreated 'acceptable occlusion' models from the collection of the Foundation for Orthodontic Research (FOR) were scanned on a flat bed scanner. The images were analysed using custom software. Measurements were made by relating maxillary first permanent molars to the midline, archform, opposite canine, and mandibular first permanent molars. The mandibular first molars and maxillary first premolars were also analysed and their rotations measured. The mean rotations of the maxillary first molars, measured as the angle between a line joining the tips of the buccal cusps and a line tangent to the appropriate archwire form (from Ricketts' Pentamorphic Arches) at the first molars, were 0.59 and -0.72 degree (positive values represent mesio-lingual rotations) for the right and left, respectively. For the mandibular molars, these means were 6.34 and 8.40 degrees, respectively. The mean differences in rotation between buccal cusp tips of maxillary and mandibular first molars in occlusion were 5.75 and 9.12 degrees for the right and left, respectively, with the mandibular being more mesio-lingually rotated. The differences between left and right were significant for all measurements. The present study brings into question the suitability of our present "straight wire" prescriptions in producing similar occlusions. It also suggests that scanning models for computer analysis may be a practical and precise way to measure similar rotations in untreated normal and treated occlusions.
Asunto(s)
Diente Premolar , Oclusión Dental , Diente Molar , Ortodoncia Correctiva/métodos , Análisis de Varianza , Diagnóstico por Computador/métodos , Diagnóstico por Computador/estadística & datos numéricos , Humanos , Maloclusión/diagnóstico , Maloclusión/terapia , Mandíbula , Maxilar , Modelos Dentales , Ortodoncia Correctiva/estadística & datos numéricos , Valores de Referencia , Rotación , Programas Informáticos , Estadísticas no ParamétricasRESUMEN
This report describes an etiology for a compression syndrome involving the lateral antebrachial cutaneous nerve (LACN) that is unique to high level quadriplegia. Two cases are presented that involve this syndrome in C5-C6 quadriplegia. Electrodiagnostic techniques and normal values have previously been established for the LACN, but not involving high-level spinal cord injured patients. A series of asymptomatic high-level quadriplegics at various times since their spinal cord injury was studied for appropriate comparison with the symptomatic cases and previously reported normal values. In the cases described, electrodiagnostic evidence of compression was documented and a diagnostic block was performed by injecting a local anesthetic at Olson's point. Once the diagnosis was established, injection with a long-acting local anesthetic and corticosteroid was therapeutic.
Asunto(s)
Brazo/inervación , Vértebras Cervicales/lesiones , Síndromes de Compresión Nerviosa/etiología , Cuadriplejía/complicaciones , Piel/inervación , Humanos , Masculino , Persona de Mediana Edad , Síndromes de Compresión Nerviosa/fisiopatología , Conducción Nerviosa , Sensación , Heridas y Lesiones/complicacionesRESUMEN
Space-regaining therapy is an important treatment modality in the management of developing occlusions. Success is dependent on recognition of relationships and forces not seen when attention is focused only on the dental segment containing the lost space. This article has discussed other considerations for determining when to treat, as well as offering suggestions concerning types of appliances useful in treatment. A case was used to demonstrate the diagnostic procedure and appliance design.