Increased occlusal vertical dimension in adult monkeys

Area of Science:

• Dental Science
• Orthodontics
• Maxillofacial Research

Background:

• Dental splints can alter vertical dimension.
• Understanding the effects on temporomandibular joints (TMJs) and tooth movement is crucial.

Purpose of the Study:

• To investigate the long-term effects of increased vertical dimension of occlusion using splints in rhesus monkeys.
• To assess the impact on TMJs, tooth intrusion/extrusion, and dimensional stability.

Main Methods:

• Five rhesus monkeys were fitted with splints to increase vertical dimension.
• Observations and measurements were taken over 3 to 36 months.

Main Results:

• No pathologic effects on TMJs were observed.
• Posterior teeth intruded, opposing teeth intruded, and incisors extruded.
• A gradual return towards the pretreatment vertical dimension was noted, with a tendency for rebound after growth completion.

Conclusions:

• Increased vertical dimension via splints is not pathologically detrimental to TMJs in this model.
• Significant tooth movement (intrusion and extrusion) occurs.
• The vertical dimension exhibits a tendency to revert to its original state, especially after growth cessation.