Treatment of Horizontally Impacted Lower Cuspid with Two Roots Anatomical anomaly

Background: As the knowledge of the important of treatment the impacted canine since in many studies was considered as the key for ideal occlusion and to avoid the deleterious effect of lost, every effort must be done in order to retract and bring the impacted canine in to it is normal position. lower cuspid usually of a single rooted, but some time in about 15% of cases may have two canals in addition to that in a very rare cases approximately 1.7% associated with two roots. Our case showed these anomalies in addition to that the canine was horizontally impacted in the lower arch which is consider as challenge for many orthodontic since the angular of impaction was more than 25%. therefore, our case is a rare. Materials and Method: The treatment focus on the orthodontically extrusion and up righting of the impacted canine by using fix orthodontic appliance with the aid of traditional anchorage device (TDA). Result: this rare case was successfully managed with fix orthodontic treatment. Conclusion: Orthodontic extrusion of horizontally impacted incomplete transposition mandibular canine should be considered for similar cases.


INTRODUCTION
Delay in normal eruption time of teeth or obstruction to normal eruption path in a way that tooth eruption is partially or totally prevented is described as impacted tooth (1) . Any tooth in the dental Arch may be impacted, however, Mandibular third molars, maxillary third molars and maxillary canines have the highest incidence, three times higher rate in female patients (2,3) . Mandibular canine impaction less frequent (4,5) . A low prevalence of impacted lower canine has been reported by many studies with the percentage ranging between0.07% and 0.92% of a total number of teeth impaction (6)(7)(8) .The location of impacted lower canines are more likely to be on the labial aspect of the dental arch when compared to maxillary canines (9,10) .
Inadequate space, supernumerary teeth, premature loss or prolong retention of deciduous dentition, hereditary factors, tumours, cysts and trauma are the most reported causes of mandibular canine impaction (11,12) .
The effects of impacted teeth include ecchymosis of the soft tissues, infection, paresthesia and damage to adjacent structures (13,14) further, the presence of an impacted canine may cause resorption of the adjacent tooth, most likely a lateral incisor or the canine itself may undergo cystic changes (15,16) . several options proposed for treatment of impacted teeth to avoid it is deleterious effect includes the following no treatment ,autotransplantation of the canine, extraction of the impacted canine and movement of a first premolar in its position, extraction of the canine and posterior segmental osteotomy to move the buccal segment mesially to close the residual space, prosthetic replacement of the canine, Surgical exposure of the canine and orthodontic treatment to bring the tooth into the line of occlusion. This is obviously the most alternative treatments for impacted teeth (17) .
Normally, the mandibular canine is a single-rooted tooth with one root canal (18) . Variations in the internal and external morphology of the mandibular canine have also been documented in the literature.
Approximately 15% of the cases reported the presence of two canals in the lower canine. On very rare occasions, the presence of two different angulated roots was reported (19) . The anatomical variation of two roots with two separate root canals in lower canine is rare and literature search has revealed 5%, 1% and 1.2% cases with two roots and two root canals respectively (20) .    Table (1) showed the Pre-treatment (T1) lateral cephalometric analysis, the analysis confirmed a skeletal class I malocclusion.  Upper incisor -maxillary plane angle 115° 115°
The treatment objectives in the sequence were as follows: • Restore normal overbite and overjet.
• Alignment and leveling in the upper arch.
• Surgical exposure and bonding attachment on the impacted canine.
• Extrusion and uprighting the impacted and incomplete translocate mandibular left permanent canine.
• Preserving the periodontal health of the lower left permanent cane region following alignment.
• Achieve occlusal inter-cuspation with class I molar and canine relationship on both sides.

Treatment Plan:
In order to address the esthetic concern of the patient and upon her request, the decision was to bring the impacted canine into the normal position.
The major risks and benefits including surgical procedure and possibility of gum recession were discussed with the patient and an informed consent form was taken before the start of the treatment.

Progress of the treatment:
Upper and lower fixed orthodontic    All teeth in the oral cavity could be impacted, however, it has been reported that third molars, maxillary canines, maxillary and mandibular premolars, and maxillary central incisors are the teeth most frequently involved (21). The prevalence of impacted maxillary canines is 0.9-2.2%, but mandibular canine impaction occurs less frequently (22) .
Because of its location and anatomy, Maxillary and mandibular canines has been referred to as"Corner-stone" hence, every effort should be paid to avoid removal of impacted canine (23,24) .
Generally mandibular canine has one root canal, However, the presence of two roots and two separate canals has also been reported (20,25) . D'Amico et al (2003) concluded that the prevalence of these anatomic variations in mandibular canines is 1% . This anatomical anomaly could be the main causative factor for impaction (26) .
The canine is situated in a strategic position between the anterior and posterior segment of the dental arch and plays an important role in functional occlusion and aesthetics (27) also if not aligned can cause root resorption of adjacent teeth, a compromised occlusion and unpleasant appearance (28) .