Non-syndromic multiple impacted teeth: two case reports

Multiple impacted permanent teeth is a rare finding and often associated with systemic diseases or some rare syndromes. This article reports two Iranian cases with multiple impacted teeth without systemic disease or syndromes. The first patient, a 17-year-old male, had 18 unerupted teeth and 9 unerupted supernumerary teeth. The second patient, a 16-year-old female, had 14 unerupted teeth. In these cases, an interdisciplinary approach between orthodontist, oral surgeon and prosthodontist is required to achieve optimum facial aesthetics and functional occlusion.


INTRODUCTION
In normal dental development, permanent teeth will erupt to their functional occlusion and replace their successor teeth. Teeth that cease to erupt before emergence are known as impacted teeth. Impaction is one of the most common dental problems seen among the eruption disorders 1 . Common reasons in the etiology of impacted teeth include lack of space due to crowding or early loss of deciduous teeth, prolonged retention of deciduous teeth, abnormal position of tooth bud, excessive fibrous tissue, ankylosis and cystic formation [2][3][4][5] . Impaction of an individual tooth is a common condition and maxillary canine exhibits the highest incidence of impaction and occurs in 1% to 3% of the population 6-8 . However, multiple impacted teeth is a rare finding and often associated with systemic diseases or some rare syndromes such as Cleidocranial dysplasia, Gardener's syndrome, Zimmerman-laband syndrome and Noonan's syndrome 3,[9][10][11][12][13][14][15] . Impaction of multiple permanent teeth with no obvious etiology is a rare condition and few cases have been reported in the literature 5,[16][17][18][19][20][21] . In this study, we are presenting 2 cases with multiple impacted teeth in non-syndromic patients.

Case 1
A 17-year-old male referred to our clinic with a chief complaint of multiple missing teeth. During the physical examination, the patient was of normal build and didn't reveal any sign of syndromes, mental retardation or skeletal abnormalities. On intraoral examination, he had retained deciduous teeth in both jaws with no eruption of permanent teeth. The patient was advised radiographic investigation in the form of panoramic. The panoramic radiograph of the patient revealed multiple impacted permanent teeth in the maxilla and mandible, retained deciduous teeth and multiple supernumerary teeth in the maxilla and mandible (Figure 1, Table 1). Nine supernumerary teeth were observed in the panoramic radiograph, two in the maxilla and seven in the mandible. It was planned to extract retained deciduous teeth, surgical removal of supernumerary teeth, surgical exposure of permanent impacted teeth and assisting eruption of impacted teeth by orthodontic traction. If the patient doesn't respond to the orthodontic traction, surgical removal of impacted teeth and prosthodontic treatment is required.

Case 2
A 16-year-old female referred to our clinic with a chief complaint of multiple missing teeth. During physical examination the patient was of normal build and didn't show any sign of syndromes, mental retardation or skeletal abnormalities. Intraoral examination revealed that the patient's maxilla and mandible was partially edentulous. The patient was advised radiographic investigation in the form of panoramic and lateral cephalometric. Analysis of the lateral cephalometric radiograph revealed a skeletal class 1 malocclusion and anterior open bite. The panoramic radiograph of the patient demonstrated multiple impacted teeth in the maxilla and mandible (Figure 2, Table 2) It was planned to assist the eruption of impacted teeth by surgical exposure and orthodontic traction. If the patient doesn't respond to the orthodontic traction,     surgical removal of impacted teeth and prosthodontic treatment is required.

DISCUSSION
Multiple impacted teeth are a rare condition and usually present in some syndromes. Impacted teeth are those prevented from eruption by some physical barrier in their path of eruption. Common reasons in the etiology of impacted teeth include lack of space due to crowding or early loss of deciduous teeth, prolonged retention of deciduous teeth, abnormal position of tooth bud, excessive fibrous tissue, ankylosis and cystic formation [2][3][4][5] . Impaction of maxillary canine and third molar is a common finding, however in present cases there were impaction of maxillary central and lateral incisors along with canines and third molars. In this circumstance, systemic disorder or some rare syndromes such as cleidocranial dysplasia, Gardener's syndrome, Zimmerman-laband syndrome and Noonan's syndrome should be detected [9][10][11][12][13][14][15][16] . In our cases, no features of any disorder or syndrome were diagnosed and syndromes were ruled out. Further investigation and medical history of patient didn't show any sign of metabolic disorders like vitamin D deficiency. The supernumerary teeth can lead to multiple complications such as delayed teeth eruption, failure of teeth to erupt, pathological changes and root resorption 21 .
In case 1, it seems that over retained deciduous teeth along with multiple supernumerary teeth might have resulted in multiple impactions of permanent teeth. According to root development of the adjacent teeth, it was decided to extract retained deciduous teeth and surgical removal of supernumerary teeth, and then monitor the impacted teeth until the spontaneous eruption occurs. If eruption doesn't occur, surgical exposure of permanent impacted teeth and assisting eruption of impacted teeth by orthodontic traction should be needed. In case 2, it seems that impaction of teeth is probably caused by lack of space in the dental arch and rotation of tooth buds which some of the most common causes are contributing to impaction. In these cases, an interdisciplinary approach between orthodontist, oral surgeon and prosthodontist is required to achieve optimum facial aesthetics and functional occlusion. If ankylosis has occurred and the patient doesn't respond to the orthodontic traction, surgical removal of impacted teeth and prosthodontics treatment is required.

CONCLUSIONS
The simultaneous occurrence of multiple supernumerary and impaction of permanent teeth can occur in both sexes with healthy systemic condition without syndromic symptoms. Occasionally, the presence of a large number of over retained primary teeth may indicate a more complex condition in the pathway of permanent teeth, such as supernumerary teeth that have blocked the eruption way, under which early radiographic examination is necessary.

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