Bilaterally impacted mandibular supernumerary premolars associated with unusual clinical complications.

Supernumerary teeth are extra teeth in comparison to the normal dentition. Their prevalence varies between 0.1% and 3.8%. Supernumeraries are more common in permanent dentition and its incidence is higher in maxillary incisor region, followed by maxillary third molar and mandibular molar, premolar, canine, and lateral incisor. The prevalence of supernumerary premolars is between 0.075-0.26%, and they may occur in single or multiple numbers Bilateral occurrence is uncommon and large percentage of supernumerary premolars remains impacted, unerupted, and usually asymptomatic; radiograph plays an important role in diagnosis of these. The present paper reports a case of bilaterally impacted completely developed supernumerary premolars associated with common clinical complication in unusual manner along with taurodontism of the upper and lower molars.

Supernumerary teeth are defined as those teeth in addition to the normal series of deciduous or permanent dentition; they may occur anywhere in the mouth. The prevalence varies between 0.1% and 3.8%.[1] Males are affected twice and the incidence of supernumerary teeth is considerably high in maxillary incisor region, followed by maxillary third molar and mandibular molar, premolar, canine, and lateral incisor.[1]

Cases involving one or two supernumerary teeth most commonly involve the anterior maxilla, followed by the mandibular premolar region. When multiple supernumerary teeth are present (> 5), the most common site is mandibular premolar region.[2] It has been reported that prevalence of supernumerary premolars in permanent dentition is between 0.075% and 0.26%.[3] Supernumerary premolars account between 8% and 9.1% of all supernumerary teeth.[4] These are also the most common supernumerary teeth in the mandibular arch. The number of supernumerary premolars is usually one.[3] Single supernumeraries occur in 76-86%, double in 12-23%, and multiple in < 1% of all cases.[24]

Supernumerary teeth may appear as single tooth or multiple teeth, unilaterally or bilaterally, erupted or impacted, either in the maxilla or mandible or in both.[1] Supernumerary teeth are usually associated with Gardener's syndrome, Cleidocranial dysostosis, cleft lip, and palate. Non-syndromic multiple supernumeraries are rare and majority of these occur in mandible, especially mandibular anterior region.[56] Although mandibular supernumerary premolars are common, their bilateral occurrence and its association with clinical complication are uncommon.

Taurodontism is developmental disturbances of the tooth that lacks constriction at the level of cementoenamel junction and is characterized by vertically elongated pulp chambers, apical displacement of pulpal floor, and bifurcation or trifurcation of the roots.[7] Its prevalence is 2.5-11.3%.[7] It is more commonly seen in the second and third permanent molar; it is also seen in single tooth or in several teeth in the same quadrant and can be unilateral or bilateral.[7] Etiology remains unclear with possible causes such as retrograde character, primitive pattern, Mendelian recessive trait, atavism feature, and mutation resulting from odontoblastic deficiency during dentinogenesis of roots.[7]

This paper reports a case of concomitant occurrence of bilateral occurring mandibular supernumerary premolars-associated common clinical complication in unusual manner and taurodontism involving all molars.

Case Report

A 38-year-old male patient reported to the Department of Oral Medicine and Radiology with complaint of pus discharge from the right lower third of face of 2-3 months duration. Family, medical, and dental histories were non-contributory. Extra oral examination revealed a draining sinus surrounded by indurated granulation tissue on the right lower border of the mandible 4 cm away from the midline in the molar region [Figure 1].

Figure 1

Extra oral view showing the extra oral sinus and indurated granulation tissue

Intraoral examination revealed caries broken right mandibular molar along with pus discharge from the same [Figure 2]. An orthopantomograph view was taken that revealed presence of completely developed bilateral supernumerary premolars below the first molars. Right supernumerary premolar was placed near the lower border of mandible and was surrounded by intense pericoronal radiolucency of about 5-6 mm without sclerotic borders. The right first molar was caries broken and showed periapical radiolucency with both root apices, and track of radiolucency was running down from the apex of mesial root to involve the pericoronal radiolucency of the right supernumerary premolar. On the left side, supernumerary premolar was placed near the apex of the first molar with its follicle almost in close approximation with the root apices of the first molar. Taurodontism was observed with all the molars [Figure 3]. Considering the clinical and radiographic findings, a provisional diagnosis of supernumerary premolar associated secondarily infected dentigerous cyst with extra oral draining sinus on the right side and supernumerary premolar occurring in close vicinity of the left first molar on the left side and taurodontism of all molars was made.

Figure 2

Intra oral view showing the carious broken first molar

Figure 3

Panoramic view showing the bilateral supernumerary premolars and taurodontism with molars

The right supernumerary premolar associated with the cystic lining around its crown along with the extra oral chronic indurated tissue was surgically removed extra orally under local anesthesia. Extraction of the right carious broken first molar was performed. Sinus lining was completely removed [Figure 4]. The left supernumerary premolar was surgically removed intra orally under local anesthesia. Post operative healing was uneventful [Figures 5 and 6].

Figure 4

Showing the surgically removed supernumerary premolars

Figure 5

Postoperative intra oral view after six weeks

Figure 6

Postoperative extra oral view after six weeks

Discussion

Supernumerary teeth are classified according to the morphology as conical, tuberculate, supplemental, and odontoma, topographically as mesiodens, paramolar, distomolar, parapremolar, chronologically as pre deciduous, similar to permanent teeth and post permanent, or complementary and according to orientation as vertical, inverted, and transverse.[1] The term supplemental tooth refers to extra tooth resembling the tooth of normal series in dentition.[8] Supernumerary premolars are usually of normal form and 75% are impacted and generally unerupted.[9] In the present cases, both supernumerary premolars were unerupted and of supplemental type.

Cases of bilateral supplemental premolar teeth developing later than their counter parts have been reported in literature.[410] Supplemental premolars develop approximately 7-11 years after normal developmental.[4] The present case may also be a similar example. The etiology of supernumerary teeth is not completely understood. Various theories exist for different types of supernumerary.[10] The phylogenetic theory of atavism, dichotomy theory, heredity, hyperactivity of dental lamina, aberrations during embryologic formation, progress zone, and unified etiological explanation are various theories for the developmental of supernumerary teeth.[4511] The etiology appears to multifactorial being a combination of environment and genetic factors.[12] Supplemental premolars were formed from the extension of dental lamina in region. Accessory buds may possibly represent members of post permanent dentition.[4]

Effect of supernumerary teeth on the developing dentition may vary. There may be no effect with the supernumerary tooth or teeth discovered either as a chance radiographic finding or following their eruption.[2] Various complications associated with the presence of supernumerary tooth are failure of permanent teeth eruption, crowding, ectopic eruption displacement, root resorption, dilaceration, loss of vitality of adjacent teeth, dental caries, periodontal abscess, gingival inflammation, sub acute pericoronitis, incomplete space closure during orthodontic treatment, and pathological problems such as dentigerous cyst formation, ameloblastomas, odontomas, and fistulae. They may also interfere in alveolar bone grafting and implant placement.[1]

Because large percentage of supernumerary premolar remain impacted, unerupted, and are usually asymptomatic and because most cases are diagnosed by chance during inspection of radiograph prior to the commencement of orthodontic treatment.[12] Bodin, et al., reported only 2% of supernumerary premolar are likely to undergo pathological changes.[3] Dentigerous cyst and root resorption have been cited in literature as frequent complication associated with supernumerary premolar. Kasat, et al., reviewed bilateral multiple supernumerary premolars and none of them were associated with any pathology.[12] Kasat, et al.,[12] reported a case of supernumerary premolars associated with odontogenic keratocyst. Bhardwaj, et al.,[4] reported a case of bilateral supernumerary premolars present in close vicinity of permanent teeth. In the present case, left supernumerary premolar was present in close vicinity of molar that may cause its root resorption and, on the right side, periapical infection from first molar was moving down to infect the dentigerous cyst associated with supernumerary premolar and giving rise to extra oral draining sinus. The present clinical scenario is very unusual and has not been reported previously. Concomitantly taurodontism was noted in all molars. Although both taurodontism and occurrence of supernumerary premolars are different entity, such association has not been documented earlier.

In planning the treatment alternatives for impacted supernumerary premolars, the potential risk of leaving them in situ and hazards of surgical removal of these teeth especially around the lower premolar region, where the teeth are close proximity to inferior dental and mental nerves and blood vessels should be assessed judiciously.[3] The timing of surgical removal of supernumerary premolar is as much debated among clinicians as are treatment methods. Whenever these teeth are associated with any pathological formation or when hinder eruption of or give rise to malpositioning of permanent teeth, they should be removed as soon as possible.[313] If left in situ, periodic examination is recommended for their clinical behavior.[14] In the present cases, both the supernumerary premolar were surgically removed because right supernumerary premolar was associated with clinical complication and left supernumerary premolar might cause root resorption as it was in close approximation with the first molar roots. Extractions of supernumerary premolars should be performed carefully to prevent the damage to the adjacent permanent teeth. Clinician should also be alert during surgical removal of supernumerary premolars to avoid complications of damaging mental nerve and blood vessels. Recurrence of supernumerary premolars after being surgically removed has been reported in 8% of cases reviewed.[11] Periodic follow-up of such patients is extremely important.

Conclusion

Bilateral occurrence of mandibular supernumerary premolar is unusual. Impacted supernumerary premolars exhibiting the pathological changes seen in the present case should be removed at the earliest. Clinician should also be alert during surgical removal of supernumerary premolars to avoid complications of damaging mental nerve and blood vessels. Appropriate follow-up with panoramic radiographs are extremely important as the recurrence of supernumerary premolars after being surgically removed has also been reported.