Asymptomatic impacted teeth in edentulous jaws undergoing preprosthetic surgery. A long-term evaluation

Prevalence of cysts and tumors around the retained and unerupted third molars in the Indian population

AIM

Tooth impaction is a frequent phenomena and surgical removal of these teeth are the commonest of the dental surgical procedures. The debate over the removal of asymptomatic impacted third molars still continues. The aim of this retrospective study was to determine the incidence of development of cysts and tumors around the retained and unerupted third molars in the Indian population.

MATERIAL AND METHODS

5486 impacted third molars of 4133 patients were studied through the panoramic radiographs for the presence of associated cysts and tumors. The ages of the patients ranged from 17 to 67 years, with a mean of 33.7 years. The results were evaluated using the Pearson chi-square test. P-values less than 0.05 were considered to be statistically significant.

RESULTS

There were 134 cysts (2.24%) and 63 tumors (1.16%) found that were associated with impacted third molars, of which 3 were malignant (0.05%). 143 patients had symptoms such as swelling or pain due to cystic or neoplastic lesions. The remainder 54 patients had no symptoms suggestive of pathology. The most common cyst was dentigerous cyst and the most common tumor was ameloblastoma.

CONCLUSION

The results indicate that cysts and tumors do develop in a relatively small but still considerable minority of patients. The fact that a considerable number of patients had no signs or symptoms indicating pathology is certainly worth considering. Consultation should be sought from dental specialists if there are symptoms in the third molar region.

Clinical outcome of third molars in adults followed during 18 years

PURPOSE

The aim of the present study was to follow the clinical changes in third molar status during an 18-year period in patients aged 20 to 38 years.

PATIENTS AND METHODS

The series consisted of 118 subjects (37 men and 81 women). In the beginning of the study, the mean age was 20.2 years (SD, +/-0.6 year), and at the end, it was 38.6 years (SD, +/-0.6 year). Panoramic radiographs were taken at baseline and at age 38. All of the subjects were clinically examined at baseline and at the end of the study. A portion of the subjects (n = 69) were also examined at age 32.

RESULTS

Most of the initially unerupted third molars were removed during the follow-up period (73%, maxilla and mandible together). More than half of the initially partially erupted third molars were removed during the follow-up period (64%, maxilla and mandible together). The percentage of erupted third molars found in the mouth at age 38 increased significantly depending on the initial status. Of the initially unerupted, partially erupted, or erupted third molars, 10%, 33%, and 50%, respectively, were erupted at age 38 (maxilla and mandible together). Changes in the status of third molars continued from age 32 to age 38, although to a lesser extent (8%). The 3 third molars with advanced eruption were all maxillary teeth in men.

CONCLUSION

Third molars undergo continuous clinical change on a reduced scale at least up to the age of 38 years.

Radiographic follow-up of impacted third molars from age 20 to 32 years

Nineteen patients (13 male, six female) with 34 impacted third molars, 21 in the mandible and 13 in the maxilla were radiographically followed from age 20 to 32. All were examined clinically and panoramic radiographs were taken at baseline and at the end of the study. Radiographic analysis included resorption of teeth, enlargement of the follicle, development of the root, change in inclination of the third molar, state of impaction, relative depth of the third molar in bone and relation to the ramus of the mandible and to the second molar tooth. In the mandible, the mean change in inclination was 19 degrees and the percentage of teeth with changed angulation was 76%. In the maxilla, only 23% of the teeth changed their inclination. The state of impaction (soft tissue, partially in bone, completely in bone) had changed for 44% of the teeth. According to the questionnaire, no pain or symptoms in the region of the third molars were reported by 74% of the students during the 12-year period. It is concluded that considerable radiographic changes, without notable symptoms, may occur involving inclination of the tooth and state of impaction in impacted third molars after the usual age of eruption.

Incidence of inflammation in completely impacted lower third molars

The influence of ageing and the contact of the adjacent tooth on purulent inflammation associated with the completely impacted lower third molar was assessed in 26 patients with clinical symptoms of infection out of 800 patients who had roentgenographically-confirmed completely impacted lower third molars. These 26 patients were 23 years of age or older. The 9 with pain alone ranged from 25 to 44 years of age, whereas the 17 patients with inflammation ranged from 29 to 67 years of age, and non-contact to adjacent tooth was associated with purulent inflammation in older patients, indicating completely impacted lower third molars may cause pain only until 45 years of age; but purulent inflammation occurs even in the group of non-contact to adjacent tooth after 45 years of age. The authors recommend that a completely impacted lower third molar should be removed if the risk factors of advanced age and contact with the adjacent tooth are present.

Completely impacted teeth in dentate and edentulous jaws

Panoramic radiographs from 1026 patients were examined for the presence of completely impacted teeth. The prevalence of completely impacted teeth in the edentulous jaw was lower than that in the dentate jaw in both the upper and lower jaws. The prevalence of completely impacted third molars in the edentulous jaw was also lower than that in the dentate jaw. However, there was no difference in the prevalence of completely impacted canine teeth and completely impacted anterior maxillary supernumerary teeth (mesiodens) in the edentulous jaw. These findings may indicate that completely impacted canine teeth and impacted anterior maxillary supernumerary teeth (mesiodens) are not influenced by the loss of erupted teeth.

Influence of adjacent teeth on impacted third molars in the upper and lower jaws

Panoramic radiographs of 1834 patients older than 21 years were evaluated for the prevalence of impacted teeth at different ages. The frequency of impacted teeth by age was constant, that is, the presence of completely impacted teeth could not be related to age. The interrelationship between the angulation of impacted teeth and the existence of adjacent teeth was studied in individuals older than 61 years. The angulation of most of the completely impacted teeth in the upper-third molar region was horizontal when adjacent teeth were not present, whereas impacted teeth in the upper-third molar region showed vertical angulation when adjacent teeth were present, suggesting that vertically impacted teeth may become exposed by bone resorption or infection and should be removed. The angulation of impacted lower third molars was horizontal irrespective of the presence of adjacent teeth. It appears that the interrelationship between the angulation of completely impacted teeth and the presence of adjacent teeth is different between the upper and lower third molar regions. The angulation of completely impacted teeth and the presence of adjacent teeth should be included in those criteria which determine whether or not completely impacted teeth should be removed.

Supernumerary impactions of the mandibular cuspids and bicuspids. Case report

A case involving the presence of supernumerary cuspids and bicuspids is described. The condition was probably an inherited one because of the family history and the bilateral incidence. The supernumerary teeth erupted because of alveolar resorption in which inflammatory factors probably played a role. Radiographic follow-up of the site of supernumerary impacted teeth and alveolar resorption should be undertaken.

A long-term, follow-up, radiographic evaluation of asymptomatic impacted third molars in orthodontically treated patients

Long-term follow-up orthopantomographs of 251 adult orthodontically treated former patients showed 113 clinically asymptomatic impacted third molars in 58 patients. Radiographic assessment revealed contact of impacted third molars with the second molars, resorption of maxillary and mandibular second molars, as well as pathologically widened pericoronal spaces of the maxillary and mandibular third molars. The comparison of the sagittal third molar position in 52 impacted teeth revealed a sagittal change in all third molars from post-treatment to follow-up: maxillary and mandibular third molars had rotated to a more upright position and showed an increase in mesio- or distoangulation or a change of axial inclination. The lack of predicting factors such as age, period of impaction, extent of space deficiency, developmental stage, level of eruption, and bone conditions leads the authors to recommend that former orthodontic patients be recalled at regular intervals for assessment of changes in the condition and position of erupting or impacted third molars.

Cysts associated with long-standing impacted third molars

Three patients are described in whom large cysts developed around third molars that had purposely been left in place. The cases presented emphasize the need for an adequate prospective study to evaluate the long-term morbidity of asymptomatic third molars that are left in place.