A rare case of impacted supernumerary premolar causing resorption of mandibular first molar.

The management of patients with pain in today's general practice has become a major concern and sometimes this pain is related to some rare causes. A male patient aged 26 years reported with pain in the lower left molar region (36) and then an intra-oral periapical radiograph (IOPA), and orthopantomograph was taken. IOPA revealed the presence of supernumerary premolar causing pressure and root resorption of 36. Also, there was missing 21 and proximal decay in 11. Eleven was treated endodontically, and then bridge was done in relation to 11, 21 and 22. Lower anterior crowding was also present. The treatment plan was to extract 36 followed by orthodontic extrusion of the supernumerary premolar and also the correction of lower anterior crowding. Hidden approach (lingual orthodontics) was used as the patient was insisting upon the braces not being seen outside during the course of the treatment. Later all ceramic bridge was done in relation to 11, 21 and 22. Orthodontic tooth extrusion techniques offer excellent treatment options for Partially Impacted tooth. It is a well-documented clinical method for extruding sound tooth material from within the alveolar socket by light forces. The use of lingual technique for forced eruption enhance acceptance of orthodontic treatment by adults. The treatment of a young adult patient illustrates the importance of treatment planning from one discipline to another, communication among team members and the benefits of working together in an interdisciplinary approach.

Resorption[1] of teeth can be defined as a chronic progressive damage or loss of tooth structure due to the action of some specialized cells called odontoclasts. There are two types of tooth resorption;

Physiological (roots of deciduous teeth)

Pathological

External

Internal.

Pathological resorption starting on the root surface or occasionally on the crown surface of the tooth is called as external resorption. The main cause of external root resorption are; periapical inflammation, reimplanted teeth, cysts, tumors, excessive mechanical or occlusal forces, impacted tooth and idiopathic resorption (burrowing resorption).[1]

Supernumery teeth[2] are the presence of any extra tooth in the dental arch in addition to the normal series of teeth. Supernumerary tooth develops from a third tooth bud arising from dental lamina near the permanent tooth bud or possibly from splitting of permanent bud itself.[2] It can occur in a location, but they often have a predilection for certain sites like its more common in maxilla (90%) when compared to mandible. Supernumerary teeth can be mesiodens, distomolars, paramolars, extra lateral incisors and in mandible the most common is the presence of extra premolars; though incisors and fourth molars are occasionally found. They may either be single or multiple in numbers and are either erupted or impacted.

When a supernumerary tooth is impacted, it can exert pressure on the root of the adjoining erupted tooth and cause resorption. Resorption most commonly begins on the crown or both crown and root of the tooth, destruction of all the enamel epithelium is not a prerequisite for the onset of resorption.[3] In some cases, limited amount of epithelium appears to be destroyed, allowing connective tissue to come in contact with the crown and thus initiating resorptive process.

Tooth traction (extrusion) was first coined by Heithersay in 1973.[4] Orthodontic extrusion is a conservative procedure that allows retention of a tooth without extraction. Orthodontic tooth movement can modify and improve the periodontal anatomy of the hard and soft tissue morphology as also periodontally damaged or fractured teeth.

Extrusion is a tooth movement that occurs in the direction of the normal eruptive process; forced orthodontic extrusion is a movement of vertical translation (in a coronal direction) obtained through the application of light continuous force.[56]

First molar extraction is usually avoided. But on certain unavoidable conditions like when it is grossly decayed or when there is crown and/or root shows resorption the first molars are extracted. The problems associated with the extraction of first molar and replacing it with a premolar are;

Loss of arch length,

Loss of molar relationship

Contact points are varied.

In this report, we document an interdisciplinary approach for the treatment of impacted premolar causing resorption of left mandibular first molar in a patient.

The treatment of a young adult patient is reported to illustrate the importance of sequencing treatment from one discipline to another, communication among the team members and the benefits of working together in an interdisciplinary approach. The objectives of treatment were to get a good arch form, an esthetic smile displaying incisors without crowding, to get the supernumerary premolar into occlusion for a functional purpose and a harmonious profile.

Case Report

Pretreatment evaluation

A 26-year-old male patient presented with a complaint of pain in the lower left molar region (36). The patient also revealed that the pain was persisting for the past 2–3 months. On intra-oral clinical examination 36 was slightly mobile and painful. An intra-oral periapical radiograph was taken, which revealed the presence of a supernumerary premolar causing pressure resorption of 36; orthopantomograph was taken, which revealed that 11 was endodontically treated, and 21 was missing [Figure 1]. Fixed partial denture (FPD) was given in relation to 11, 21, 22 [Figure 2].

Figure 1

Orthopantomogram showing supernumerary premolar

Figure 2

Pre treatment photo

There were presence of supernumerary premolars in 2nd, 3rd and 4th quadrants [Figure 1] and the patient's chief complaint was in relation to 3rd quadrant where the supernumerary premolar was causing pressure resorption of 36 where the distal root was already resorbed, which was causing pain. Though the option of extraction of other supernumerary teeth was offered, the patient declined and insisted upon treatment for 36 region only.

Treatment plan

The treatment plan included oral prophylaxis with oral hygiene instructions followed by extraction of resorbed 36 under local anesthesia [Figure 3]. Lingual self-ligating braces were bonded, and the supernumerary premolar was to be brought into occlusal level of 36 for a functional purpose. Replacement of FPD in relation to 11, 21 and 22 with all ceramic bridge for esthetics.

Figure 3

Intra-oral periapical radiograph showing impacted supernumerary premolar

The patient was very co-operative and presented no contra-indications for orthodontic treatment. The patient preferred the braces to be put lingually and not labially on esthetic grounds. All the pretreatment records and impressions were taken. Lingual self-ligating braces (Forestadent-2D) * were positioned on the lower cast [Figure 4] and a transfer tray was fabricated from glue gun**.

Figure 4

Indirect bonding

*Self-ligating Brackets from Forestadent 2D.

**Bosch PKP Ise Glue Gun, Robert Bosch Gmg H

P.O. Box. 106050

Stuttgart, Germany.

After complete oral prophylaxis, etching with 37% orthophosphoric acid was done, primer was applied, and the brackets were bonded onto the lower teeth [Figure 5]. The most compelling potential advantage attributed to self-ligating brackets are reduction in the overall treatment[78] and less associated to subjective discomfort.[9] The wire sequence of 0.012” Ni-Ti lingual arch wire for the initial alignment was given and in between 32 and 41 an open coil spring was given to bring 31 in alignment and arch form [Figure 6].

Figure 5

Lingual appliance in situ

Figure 6

Open coil spring placed in between 41 and 32 for space opening

The supernumerary premolar was surgically exposed, and a composite button was placed [Figures 7 and 8]. Once the lower anterior decrowding and the premolar were brought into occlusion 0.016” titanium molybdenum alloy wire was given for mild correction and for finishing purpose. Once the result was achieved [Figures 9 and 10] the arch wire was removed, and the lingual brackets were debonded. Lingual fixed retainers were bonded from canine to canine.

Figure 7

Surgical exposure of supernumerary premolar and bonding

Figure 8

Premolar in eruption

Figure 9

Post operative treatment orthopantomogram

Figure 10

Post operative treatment photo

The bridge on 11.21 and 22 was removed. Tooth preparation was modified on 11 and 22. Cervically the finish line was 1 mm short of the free gingival margin. A 5 mm horizontal groove was given on the lingual surface to assist in confirming a positive seal of the final restoration.

A polyvinyl siloxane impression was taken and sent to the lab along with the photographs, opposing model and a bite registration. Upon delivery of the final restoration from the laboratory, the resin framework fit, and all ceramic crowns were evaluated on the stone die for proper margin fit and path of seating. To prepare the restoration for bonding the tissue surface of the restoration were treated with a silane ceramic primer for 60 s and air dried. The tooth preparations were acid etched with 37% orthophosphoric acid gel for 30 s, rinsed and blotted dry. Multiple coats of bonding agent were applied to each prepared tooth. The resin bridge was cemented with dual cure adhesive resin. Excess cement was removed and then light cured. Permanent all ceramic crowns [Figure 11] were cemented to the teeth, to achieve proper esthetics.[1011]

Figure 11

Post operative occlusal photo

Treatment results

After treatment class-I canine relationship with coincident midlines, correct tooth positions, and proper alignment were obtained, which helped in improving patents facial balance.

The method of tooth extrusion was first described by Heithersay,[4] uses the simple physiologic process of normal tooth eruption and applies it clinically to extrude the partially impacted supernumerary premolar. Tooth extrusion has been achieved by different methods including labial fixed appliance, modified arch wires, mini-implants, and recently lingual bracket systems.

Many adult patients now prefer the use of lingual brackets to labial appliance for esthetic reasons. In this case the patient himself showed interest for the treatment only after the option of lingual appliance was given.

In this case report, a multidisciplinary approach of resorbed mandibular first molar with extrusion of supernumerary premolar was done using lingual orthodontics (Hidden Braces) has been put into light.

Conclusion

As patient's knowledge about esthetics and function increases, the dentists are challenged to provide services that will encompass the well-being of the whole patient. The creation of esthetic smile with proper phonetics, balance and function, may involve multiple procedures and disciplines. Correct diagnosis of the problem is the key to successful treatment. A successful team involves constant discussion, communication and education in order to arrive at a common vision. Understanding patients by discussing their desires, concerns and values also enable the team to establish customized treatment planning.