Journal of Interdisciplinary Dentistry

: 2021  |  Volume : 11  |  Issue : 2  |  Page : 78--83

Management of an ectopically erupted permanent mandibular first molar: A review and case report

Saima Sultan1, Chaitra Ravishankar Telgi1, Seema Chaudhary1, Naveen Manuja1, Ashish Amit Sinha2,  
1 Department of Pedodontics and Preventive Dentistry, Kothiwal Dental College and Research Centre, Moradabad, Uttar Pradesh, India
2 Department of Pediatric Dentistry, Kothiwal Dental College and Research Centre, Moradabad, Uttar Pradesh, India

Correspondence Address:
Dr. Saima Sultan
Department of Pedodontics and Preventive Dentistry, Kothiwal Dental College and Research Centre, Moradabad - 244 001, Uttar Pradesh


Ectopic eruption is the disturbance in the eruptive path of a tooth in an abnormal position. The purpose of this manuscript is to provide a brief review regarding the prevalence, etiology, classification, and management of ectopically erupting mandibular molar. This manuscript further presents a case report for uprighting the mesially drifted permanent mandibular first molar due to premature loss of primary second molar using Halterman appliance to allow the eruption of permanent second premolar.

How to cite this article:
Sultan S, Telgi CR, Chaudhary S, Manuja N, Sinha AA. Management of an ectopically erupted permanent mandibular first molar: A review and case report.J Interdiscip Dentistry 2021;11:78-83

How to cite this URL:
Sultan S, Telgi CR, Chaudhary S, Manuja N, Sinha AA. Management of an ectopically erupted permanent mandibular first molar: A review and case report. J Interdiscip Dentistry [serial online] 2021 [cited 2021 Dec 4 ];11:78-83
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 Clinical Relevance to Interdisciplinary Dentistry

Early intervention of ectopically erupting permanent molars is very crucial to avoid complex orthodontic treatment later on. This clinical report demonstrates an appliance which is simple to use, more effective and reliable for uprighting the mesially drifted permanent mandibular first molar.


During the initial stages of mixed dentition, the permanent first molars are guided in the stable and functional occlusion using the distal aspect of deciduous second molars as an eruption guide.[1]

However, if the deciduous second molar is lost prematurely, and there is no space maintenance provided, a significant loss of space in the dental arch occurs and the permanent first molar often tips mesially with some rotation, a condition called as ectopic eruption.[2]

Ectopic eruption of the permanent mandibular first molar is defined as a disturbance in the eruptive path of a tooth in an abnormal position, first described by Chapman in 1923.[3]

Early diagnosis of ectopic eruption, which is an integral part of interceptive orthodontics, can be made in children aged between 5 and 7 years on a periapical or bitewing radiograph. Failure to do so, the consequences expected include loss of arch length, the presence of the unerupted second bicuspid, and malposition of the permanent first molar.[4]

The chief goal in correcting ectopic eruption is therefore to regain the lost space, using various corrective procedures, until eruption of the ectopic tooth occurs, and maintaining a normal arch circumference.

 Literature Review


Ectopic eruption of the permanent first molars occurs in 3%–4% of children.[5] It can occur in the maxilla or mandible. The permanent maxillary first molar, however, is the most commonly affected tooth – with a prevalence of 2%–6% of the general population followed by mandibular lateral incisor and maxillary canine.[6],[7] Rarely does this occur in the mandible.

A higher prevalence of 25%–30% has been reported in cleft palate patients.[8],[9] Siblings of affected children experience this incidence five times greater than the general population.[10] In few previous studies, this anomaly was observed more frequently in boys than in girls.[6],[11] However, a recent study on Spanish subpopuation of 505 children showed that ectopic eruption of the permanent maxillary first molar affects males and females equally and bilateral occurrence (67.6%) was more common than unilateral occurrence (32.4%) with a prevalence of 6.7%.[12]


Various hypotheses have been put forward in the literature regarding the cause of ectopic eruption. Chapman described four possible causes for ectopic eruption of the first permanent maxillary molars: (1) early eruption of permanent first molars, (2) lack of forward movement of all deciduous teeth, (3) forward movement of first permanent molars in excess of the downward movement, and (4) small arches.[3]

Sweet in 1939 related its cause to evolutionary changes that leads to reduction in the number of permanent teeth in human dentition.[13]

Meara and Williams mentioned the major factor to be deficient intercanine and anteroposterior growth of the jaws.[14]

Pulver suggested the etiology of ectopic eruption of the maxillary first molar to be a combination of a larger primary and permanent molars, abnormal angulation of the eruption of the permanent first molar, small maxilla, and delayed calcification of the affected permanent molar.[15]

Chintakanon and Boonpinon found no association between the presence of high interproximal carious lesion and the prevalence of ectopic eruption.[16]

Inadequate placement of a stainless steel crown on the second primary molar was described as one of the iatrogenic causes of ectopic eruption of the first permanent molar, which is self-corrected once the crown is replaced and properly adapted.[17]

Yaseen et al. have summarized its etiology as being a disturbance of the differential growth pattern of the individual.[18]

Artmann et al. correlated ectopic eruption to the morphological ectodermal deviations in dentitions.[19]


Young classified ectopic eruption of the permanent first molar into two forms: (1) reversible or jump and (2) irreversible or hold. In the reversible form, after the distal root surface of the second primary molar resorbs, the permanent molar becomes free and erupts into a normal position and hence is self-corrected. This pattern occurs in approximately 66% of ectopically erupting permanent first molars. In the irreversible form, permanent molar becomes blocked by second primary molar and remains in a “locked” position until treatment or premature exfoliation of the primary molar occurs.[20]


The problem of space loss in mixed dentition must be solved by regain and then maintenance. The moment of starting the treatment by molar distalization plays an important part, being known that molars get displaced more easily in late mixed dentition, before the eruption of second molars.[21]

After the early diagnosis, a 3–6-month observation period is indicated because the molar may spontaneously self-correct and erupt into a normal occlusion. If the molar is prevented from erupting at the end of the observation period, therapeutic intervention is necessary.[22]

Several methods of treating ectopically erupting permanent first molars have been suggested: (1) interproximal wedging: after the occlusal surface of the first permanent molar becomes exposed in the oral cavity and (2) distal tipping.[18]

The approach to treatment depends on the eruption status of the first permanent molar. Interproximal wedging is used in cases of minimal-to-intermediate impaction of the first permanent molar on the distal aspect of the second primary molar. When the impaction is severe, distal tipping techniques with or without the second primary molar extraction have been indicated.

Many types of removal and fixed molar distalization appliances have occurred, and there is currently no well-documented evident on the efficiency of each molar distalization method.

(Examples include the elastomeric separator, brass wire, prefabricated clip separator, lip bumper, Humphrey appliance, Halterman appliance, distal jet, Jones jig, or extraction of the primary molar.)[23],[24]

Kupietzky utilized the brass wire technique for the correction of ectopic eruption of permanent molars. He has suggested to use such method for minimum to moderate cases of molar impaction.[25]

Thakur et al. illustrated a simple distal tipping technique for the correction of ectopic eruption of the molar that eliminated the need for any laboratory work and the need for the activation of the appliance using nickel titanium archwire.[26]

Kim and Park suggested the use of triangular wedging spring consisting of three helical loops in a triangular shape with 0.018-inch Australian wire.[27]

Auycha and Walker reported a case of bilateral ectopically erupted mandibular first permanent molars, which was corrected by hemisection of both mandibular second primary molars, thereby providing a clear pathway for eruption.[28]

A literature search revealed no case reports that demonstrate early mixed dentition space regaining in the mandibular arch, in which anchorage is taken from partially erupted first premolar.

The purpose of this case report is to demonstrate the management of a rare case of an ectopically erupted permanent mandibular left first molar that was preventing the eruption of second premolar in mixed dentition.

 Case Report

A 10-year-old patient came to the department of pedodontic and preventive dentistry with the chief complaint of space in the lower left back region of the jaw. Patient's father gave a history of extraction of the lower left region of the jaw around 1 year before and was worried about nonemergence of the new one. Clinical examination showed a mixed dentition with Class II molar relationship and the presence of space at primary second molar region [Figure 1].{Figure 1}

It was important to determine the development and eruption status of premolars. Intraoral periapical radiograph revealed that the permanent first molar had tilted mesially due to the early loss of primary second lower molar and was impinging on the distal surface of second premolar preventing its emergence. Primary first molar was also at exfoliating stage [Figure 2]. Mixed dentition analysis showed adequate space for both the premolars to erupt.{Figure 2}

Our primary goal was to free the second premolar by uprighting the permanent first molar and bring them in normal occlusion. Hence, treatment was started with lingual holding space maintainer with a loop and preformed bands were placed on the lower first molars. This appliance was placed till eruption of first premolar took place [Figure 3].{Figure 3}

Next part of treatment started after 4 months of eruption of first premolar. It included placement of Halterman appliance as described by Halterman in 1982.[29]

Most ectopic eruption correction methods rely on the second primary molar for anchorage purposes. However, since that was not possible in this case, first premolar was used for anchorage which was at Nollas 8th stage of root development [Figure 4].{Figure 4}

First premolar was slightly rotated, and the amount of tooth structure available for band preparation was not adequate. Hence, for adequate anchorage, superior part of band material was adapted on mesial and distal pits. Premolar was banded with a soldered wire extending distally to the permanent first molar with a distal hook. A bonded button was attached to the occlusal surface of the permanent first molar [Figure 5].{Figure 5}

The occlusal button was placed as far mesially as possible to prevent occlusal interference and to allow greater length of elastic chain to assist in distalization of the first permanent molar. Chain elastic was used from the bonded button to the distal extension of the appliance and was replaced at 2–3-week intervals. The distal extension must be accurately adapted to avoid tissue impingement.

During the follow-up, radiographs were taken and the tension on the elastic was increased by adjusting the chain elastic with the distal hook. Distalization of the first permanent molar took a period of 9 months. When the follow-up radiographs revealed eruption of second premolar taking place, Halterman appliance was removed and was replaced by reverse band and loop [Figure 6], till the eruption bulge in the gingiva at the second premolar region was seen [Figure 7], which took another 3 months. [Figure 8] and [Figure 9] show complete distalization of permanent first molar along with eruption of the second premolar, radiographically and clinically. One-year follow-up showed root lengthening of the second premolar as well as interdental bone formation at premolar and molar region [Figure 10] and [Figure 11]. The final molar relation was Class I, which was Class II at the beginning of the procedure.{Figure 6}{Figure 7}{Figure 8}{Figure 9}{Figure 10}{Figure 11}


Clinically, the mandibular premolars erupt after the mandibular first molar and mandibular canine;[30] thus, if the room for eruption of premolars is insufficient, one of the premolars usually the second premolar remains unerupted and chances of getting impacted are more.

Mandibular second premolars rank third, after third permanent molars and maxillary permanent canines, in the frequency of impaction.[31]

Irreversible ectopic eruption of the mandibular permanent molar, which has a low prevalence rate, when overlooked, may lead to loss of the primary second molar, mesial tipping and rotation of the permanent molar, space deficiency for the second premolar, and unfavorable occlusion.[32]

The situation usually requires active treatment. A space loss of 6–8 mm can be prevented by diagnosing this eruption disorder and intercepting it before the primary second molar has been lost.[33]

The treatment objective is to move the ectopically erupting molar distally from the tooth it is resorbing, or preventing the eruption, to regain space and correction of mesial tipping of the permanent molar to allow normal eruption.[4]

This case reports shows satisfactory results of the ectopic eruption of the mandibular first permanent molar in a young patient who was treated with Halterman appliance. This case was challenging for us as primary first molar was at exfoliating stage and anchorage had to be taken from partially erupted premolar. The total time taken for first permanent molar to distalize and second premolar to erupt was 1 year. This relatively long treatment time reflects the severity of the impaction, as shown in [Figure 2]. Early aggressive intervention to correct an impacted mandibular molar was successful in achieving the overall treatment goals of completing the patient's treatment without extraction. Kennedy demonstrated the management of an ectopically erupting permanent mandibular left first molar using Halterman Appliance using anchorage from resorbed primary second molar.[22]

There are various advantages of Halterman appliance, such as it is easy to fabricate, not bulky as compared to various other fixed appliances, can be fabricated for maxilla as well as mandible, and adjustments can be made directly in the child's mouth with a How pliers or Bird-beak Pliers. If required, it can be removed easily and re-cemented after the adjustments are made. Only disadvantage related to this appliance is frequent changing of elastics and patient cooperation.

From this case report, it was confirmed that correction with Halterman appliance is highly effective in distalizing the ectopic permanent molar, as well as allowing the premolar to erupt in normal occlusion.


It is essential for professionals to be familiar with the diagnostic factors, clinical consequences, and therapeutic options for ectopic eruption of permanent molars. Ectopic eruption sometimes is self-correcting, and some practitioners suggest observation before therapy. However, earlier, the treatment is started, and the more acceptable results could be achieved. Halterman appliance is an effective interceptive treatment option for the correction of ectopically erupting first permanent mandibular molar in children, during mixed dentition period with limited disadvantages.

More research including large sample size is required to evaluate the effectiveness of Halterman appliance comparing with other techniques.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the legal guardian has given his consent for images and other clinical information to be reported in the journal. The guardian understands that names and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


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