A Longitudinal Study of Continued Tooth Eruption During Adulthood

Edward F Harris,Yoav Shiloah

doi:10.26575/daj.v20i1.106

Abstract

Teeth retain their capacity to continue toerupt throughout life. What is less-well appreciated isthat occlusal migration—with corresponding alveolarproliferation—continues as a normal process duringadulthood. Historically, this continuous eruption hasbeen viewed as accommodative for the loss of crownheight due to serious occlusal abrasion. Nowadays,with only trivial wear, the result of continuous eruptionis to increase lower face height during adulthood. Thisstudy reports on changes in the mandibular first andsecond molars in 73 Americans whites (63 females)examined at 17 and again at about 31 years of age.A computer-assisted method was used to measurealveolar and dental changes using the inferior alveolarcanal as a fiducial benchmark. Each molar’s imagewas scaled to the mesiodistal molar crown dimensionmeasured from that subject’s dental cast. Major findingswere: Both lower molars erupted during adulthoodto statistically significant extents, more so in men.Alveolar bone proliferated apace with the coronal toothmigration, so the CEJ-to-crestal bone distance did notchange in these healthy, young, dentate adults. First andsecond molar roots increased in length, apparently bythe progressive deposition of cementum. Prior studieshave documented continuous eruption in peoples withsevere occlusal wear; this study shows that comparableincreases occur without any macroscopic loss of toothsubstance. These normative changes that—assumedlyoccur in both jaws—have discernible, cumulativeeffects on lower face height and facial proportions inadulthood.

Highlights

Teeth retain their capacity to continue to erupt throughout life
The argument was that teeth erupted more than bony remodeling could keep pace, thereby exposing more root coronal to the bone. These findings were readily criticized because inflammatory periodontitis—which has been prevalent (Carranza and Newman, 1996)—produces the same increase in cementoenamel junction (CEJ)-to-crestal bone distance over time
At T1 the root apices were about 5 mm above the inferior alveolar canal (IAC), and, as shown in Table 2, this distance increased to about 6 mm at T2

Summary

Introduction

Teeth retain their capacity to continue to erupt throughout life. What is less-well appreciated is that occlusal migration—with corresponding alveolar proliferation—continues as a normal process during adulthood. Prior studies have documented continuous eruption in peoples with severe occlusal wear; this study shows that comparable increases occur without any macroscopic loss of tooth substance These normative changes that—assumedly occur in both jaws—have discernible, cumulative effects on lower face height and facial proportions in adulthood. Less well studied is the second, slow and protracted, albeit cumulative phase of tooth eruption termed continuous eruption This consists of coronal movements of the permanent teeth that occur well after the active phase and that increases in crown height increase lower face height and change facial proportions with age (Iseri and Solow, 1996).

Methods

Results

Discussion

Conclusion