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Review
. 2023 Aug 29;11(9):206.
doi: 10.3390/dj11090206.

Ectopic Permanent Molars: A Review

Samah Alfuriji  1   2 , Haifa Alamro  1   2 , Jomanah Kentab  3 , Lama Alosail  4 , Linah Alali  3 , Nada Altuwaijri  3 , Rahaf Alalwan  3
Affiliations
Review

Ectopic Permanent Molars: A Review

Samah Alfuriji et al. Dent J (Basel). .

Abstract

Ectopic permanent molar is a condition in which the permanent tooth deviates from its normal path of eruption. The etiology of this eruption anomaly is multifactorial, with both general and local factors. The principal results suggest that a valid indicator of irreversible consequences is the degree of impaction of the first permanent molar. Self-correction is most common between the ages of 7 and 8, after which help may be required. Accordingly, early management can assist in preventing subsequent potential challenges that could interfere with maintaining a balanced occlusion. Several variables, including the degree of mesial tilting, the level of root resorption, and the condition of the second primary molar, may be crucial in choosing the most effective method of treatment. Interproximal wedging and distal tipping are the two basic therapeutic strategies for ectopic permanent molars. Additionally, the use of fixed or removable appliances might also be required. Delaying treatment until a later stage is not recommended because early diagnosis and treatment are essential for optimal management. This review aims to provide a comprehensive overview of ectopic permanent molars, including their prevalence, etiologic factors, self-correction rates, clinical implications for adjacent teeth, and various treatment techniques, that emphasizes the importance of early detection and intervention in the successful management of ectopic permanent molars. In addition, it highlights the importance of future research into the contributing variables of irreversible ectopic molar outcomes.

Keywords: early treatment; ectopic; eruption; impacted; interceptive; molar; tipping; wedging.

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Conflict of interest statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Figures

Figure 1
Figure 1
Ectopic eruption of the maxillary right first permanent molar due to improper marginal adaptation of the stainless-steel crown placed on the second primary molar. (Courtesy of Dr. H. Alamro.)
Figure 2
Figure 2
An 8-year-old patient with ectopic mandibular first permanent molars. (A). Pre-treatment lateral and occlusal clinical pictures showing the ectopic eruption of right first permanent molar against the stainless-steel crown of the primary second molar (iatrogenic), and ectopic eruption of the left first permanent molar against the crown of primary second molar. (B). Pre-treatment panoramic radiograph confirming the clinical findings. (C). Post-treatment lateral and occlusal clinical pictures showing the correction on the path of eruption of lower permanent molars using an elastic separator placed between the second primary molars and the first permanent molars replaced every two weeks. (Courtesy of Dr. S. Alfuriji.)
Figure 3
Figure 3
Ectopic maxillary first permanent molar with Halterman appliance to tip the first molar distally in a 5-year-old girl. (A). Pre-treatment radiograph showing maxillary left ectopic permanent molar. (B). Bitewing radiograph during appliance treatment. (C). Clinical photograph of the Halterman appliance 6 weeks later. (D). Post-treatment radiograph showing satisfactory eruption of the permanent molar. (Courtesy of Dr. Abu-Hussein M, permission granted.)
Figure 4
Figure 4
A case of an 8-year-old patient with a bilateral ectopic eruption of the maxillary first permanent molars. (A). Occlusal photograph before the treatment. (B). The right side showed a moderate degree of impaction and was treated using an elastic separator for distal wedging of #16. The left side showed a severe degree of impaction and was treated using a Halterman appliance for distal tipping of #26. (C,D). Occlusal photographs after the treatment, and the overall treatment duration was 3 months. (E). Panoramic radiograph before the treatment shows complete resorption of the disco-buccal root of the maxillary second primary molars. (F). Panoramic radiograph after the treatment. (G). Illustration of the Halterman appliance. (Courtesy of Dr. H. Alamro.) (Illustrations by Dr. Linah Alali.).
Figure 5
Figure 5
Bilateral ectopic maxillary first permanent molars with cemented modified Croll’s appliance to tip the first molars distally. (A). Pre-treatment clinical photograph showing bilateral ectopic eruption of the maxillary molars. (B). Pre-treatment radiograph. (C). Modified Croll’s appliance after cementation. (D). Post-treatment radiograph showing normal eruption of maxillary permanent molars. (Courtesy of Dr. Ambriss B, permission granted.)
Figure 6
Figure 6
Ectopic maxillary left second permanent molar (#27) erupted against the first permanent molar (#26). (A). Pre-treatment radiograph showing the impaction of #27 against #26 causing a cervical root resorption on the distal surface of the first molar. (B). Occlusal photograph with partial eruption of #27. (C). Illustration of the appliance used to erupt #27, a fixed edgewise appliance with an open coil spring to tip and erupt #27 distally (illustrations by Dr. Linah Alali). (D). Progress radiograph with an erupted and aligned #27 with an obvious cervical root resorption on #26. (E). Occlusal photograph after alignment of #27. (Courtesy of Dr. S. Alfuriji.)
Figure 7
Figure 7
Ectopic mandibular left second permanent molar (#37) with impacted third molar (#38). (A,B). Occlusal photograph and panoramic radiograph before the treatment of the second molar (#37). (C). Occlusal photograph 11 days post-surgical uprighting of the second molar (#37) and extraction of third molar (#38). (D). Panoramic radiograph after the treatment. (Courtesy of Dr. S. Alfuriji.)
Figure 8
Figure 8
Design of the piston elastic. (A), The piston elastic is bonded on the occlusal surface of the ectopic molar, with its hook pointing distally; the elastic is placed as demonstrated. The angle between the straight part of the wire and the hook should be less than 90 to avoid the elastic slipping. (B). Device activation resulting in distal movement of the ectopic molar. (Courtesy of Dr. Kim IH, permission granted.)
Figure 9
Figure 9
Comparison between the regular rect-spring and the modified rect-spring in the passive (A,B) and the engaged states (C,D). (Courtesy of Dr. Song MS, permission granted).
Figure 10
Figure 10
Treatment decision flowchart for ectopic first permanent molars.
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