title: Vertical dimension increases in the adult rhesus monkey: a pilot study.
abstract: Tooth impaction, increased muscle activity, and histologic changes in the bone of the temporomandibular joint have been reported following attempts to increase the vertical dimension of occlusion. The purpose of this research was to study the effects of increases in the vertical dimension of occlusion on bone density at five levels of the mandible in the adult rhesus monkey, and to assess dentoalveolar changes by lateral cephalometric radiographs and mounted diagnostic casts. Mandibular cobalt chromium splints measuring 3 mm in height at the first molar, providing even occlusal contact to the maxillary anterior and posterior teeth, were cemented in place on two monkeys. Five similar monkeys without splints were used as controls. Computed tomograms were completed to evaluate bone density bilaterally at five levels of the mandible after 3 months of splint wear. Pretreatment and posttreatment lateral cephalometric radiographs and mounted diagnostic casts were completed to assess tooth impaction. Periodontal ligament (PDL) thickening and mobility of molars and premolars were evaluated before splint placement and after splint removal. There was no statistically significant difference in the bone density levels of the animals with splints compared with the controls. Minimal dentoalveolar changes were observed.
authors.affiliation: University of California, School of Dentistry, San Francisco.
authors.forename: D A
authors.initials: DA
authors.lastname: Curtis
authors.forename: S
authors.initials: S
authors.lastname: Kapila
authors.forename: T
authors.initials: T
authors.lastname: Curtis
authors.forename: A
authors.initials: A
authors.lastname: Miller
mesh_terms: D000818:Animals; D015519:Bone Density; D002508:Cephalometry; D007574:Jaw Relation Record; D008253:Macaca mulatta; D008334:Mandible / Q000473:pathology*; D008335:Mandibular Condyle / Q000473:pathology; D010513:Periodontal Ligament / Q000473:pathology; D010865:Pilot Projects; D013165:Splints; D013704:Temporomandibular Joint / Q000473:pathology*; D014057:Tomography, X-Ray Computed; D014072:Tooth Abrasion / Q000209:etiology; D014076:Tooth Diseases / Q000209:etiology*; D014086:Tooth Mobility / Q000209:etiology; D014716:Vertical Dimension; D015050:Zygoma / Q000473:pathology