Optimal Periodontal Heaiing
As noted earlier, one of the most important indications for .removal of impacted third _ars is to preserve the, f:~nodontal healtl •. A great deal of attennon has been given to the two primary parameters of periodontal
FIG.9-10 Impaction in atrophic mandible, which may result in jaw
fracture during extraction.
health after third molar surgery; that is, bone height on
the distal aspect of the second molar and attachment
1L\’e1 on the distal aspect of the second molar.
Recent studies have provided information on which to
bast.’ the likelihood of optimum periodontal tissue healing.
II.IS The two most important factors have been
shown to be the extent of the preoperative infrabony
defect on the distal aspect of the second molar and the
patient’s age at the time of surgery. If a large amount of
distal bone is missing because of the ‘presence of. the
impacted tooth and the associated follicle, it is less likely
that the infrabony pocket can be decreased. Likewise, if
the patient ,is older, then the Iikelihood of optimum bony
healing is decreased. Patients whose third molars are
removed before age 2S are more Ilkely t~ have better bone
FIG. 9-11 Small dentigerous cyst arising around impacted tooth.
FIG. 9-12 Large dentigerous cyst that extends jrorn coronoid
process to mental foramen. Cyst has displacecfimpacted t,hird molar
to inferior border of mandible.
healing than those whose impacted teeth are removed after age 25,14 In the younger patient, not only is the ini-. tial periodontal healing better but the long-term continued regeneration of the periodontium is clearly better. H As mentioned previously, unerupted .teeth may continue to erupt untilage 25. Because the terminal portion of the eruption process occurs relatively slowly, the chances of developing ‘pericoronitis increase, as do the amount of contact between the third molar and second molar. Both of these factors decrease the possibility for ‘ optimum periodontal healing. However, it should be noted that the completely bony impacted third molar in a patient older than age 30 should probably be left in place unless some specific pathology develops. Removal of such asymptomatic completely impacted-third molarsin older patients will clearly result in pocket depths and alveolar bone loss, which will be greater than if the tooth were left in place