-No movement on the tooth once orthodontic forces have been initiated. -This occurs more often in palatal impactions
Causes: 1. Not enough bone was removed around the crown of the impacted tooth. 2. Inappropriate orthodontic mechanics. Often a tooth will resist lateral tooth movement because of its angulation. 3. Ankylosis. If a tooth is found to be ankylosed during the surgery, forces should be placed on the tooth immediately. In some cases the tooth will not move and will need to be extracted. 4. Improper bonding. The orthodontic bracket is bonded to bone rather than the impacted canine.
*Seldom as a treatment option, as it may severely compromise a patient's functional occlusion. *The extraction can be unavoidable in some cases such as if the impacted canine is malformed, ankylosed, unable to move after a period of orthodontic activation, severely dilacerated root, internal or external root resorption, or pathologic changes.
Such as endocrine deficiencies, febrile diseases, and irradiation
(1) tooth size/arch length discrepancies. (2) prolonged retention or early loss of the primary canine. (3)abnormal position of the tooth bud. (4) the prescience of an alveolar cleft. (5) ankylosis. (6) cystic or neoplastic formation. (7) dilacerations of the root. (8) iatrogenic origin. (9) idiopathic condition with no apparent cause. (10)Missing or peg lateral incisors.
palpate the canine bulge above the primary canine
Notice the clinical signs of canine impaction, retention of the primary canine beyond 14 to 15 years of age, absence of a normal labial canine bulge, asymmetry in the canine bulge, presence of a palatal bulge, delayed eruption, distal tipping, or migration of the lateral incisor
Buccal object rule, A- two radiographs are taken at different horizontal angulations. B- apply the SLOB rule which stands for same lingual opposite buccal C- If the object (impacted tooth) moves in the same direction as the movement of the x-ray beam, the tooth is located on the lingual D- if the impacted tooth moves opposite of the x-ray beam, the tooth is located on the buccal
Facially impaction, only 17% of facially impacted maxillary canines have sufficient space for eruption into dental arch, more likely to have a favorable vertical angulation, have the potential to erupt without surgical intervention
Palatally impaction, 85% of palatally impacted maxillary canines have sufficient space for eruption into the dental arch, more inclined to be in a horizontal angulation, seldom erupt without surgical intervention, This may be because of an increased thickness of the cortical bone on the palate and the thick palatal tissue
Presurgical orthodontic treatment, adequate space must be created to facilitate movement of the impacted canine into dental arch by bracketing the entire maxillary arch, Bracketing the entire arch will provide adequate anchorage for extrusion of the impacted canine, Or use a microim-plant or mini-implant as anchorage to move the impacted canine
Surgical treatment, Buccally/facially impacted, Open approached, Adequate keratinized gingiva, Gingivectomy, The canine cusp tip must be located coronal to the cementoenamel junction of the adjacent lateral incisor, exposure of the impacted canine by gingivectomy to uncover 1/2 to 2/3 of the crown to ensure stable bracketing. Dressing can be placed over the exposed enamel to prevent gingival overgrowth, Figure, Simplest and least traumatic technique, -It can be used in only a few instances, -Attached gingiva is lost, -Damage to the attachment apparatus is possible. -Tissue may regrow over the surgical area if the gingivectomy is too conservative, Inadequate keratinized gingiva, Apically positioned flap, Incisions are made on the crest of the edentulous ridge with the intent to preserve as much KG as possible, then incisions are extended vertically into the vestibule, raising a split thickness flap. About 2/3 of the crown should be exposed and the dental follicle must be removed. The bracket can be bonded at the time of surgery,The pedicle flap is then apically positioned and sutured to the periosteum so that 2 to 3 mm of the crown is covered, Figure, -Most commonly used technique for facial impactions. -Keratinized gingiva is preserved, leading to fewer post operative problems, -Accessory frena can be created and cause orthodontic relapse. -There is a greater risk of recession and uneven gingival margins. -Considerable labial bone may need to be removed, and impactions near the nasal spine cannot be left uncovered, Closed approached, It used when the maxillary impacted canine is located more apically in the vestibule, a flap is raised using a crestal incision, and enough bone is removed around the tooth so a bracket or eyelet can be placed at the time of surgery on the impacted canine. The bracket/eyelet is then attached to the archwire with a wire or chain that passes under the flap and through the incision, before flap closure, the tooth should be gently luxated with a small straight elevator to ensure that it is not ankylosed. The flap is then sutured back into its original position and orthodontic force is activated in 1 week, Figure, A closed flap usually produces the best gingival esthetics and increased ease of tooth movement, -More discomfort is noted with this technique. -If debonding of the bracket occurs, a second surgery is required. -Mucogingival problems can be created by improper orthodontic mechanics and cause the tooth to erupt through the mucosa, Lingually/palatally impacted, Often the primary canine is still present with palatally impacted permanent canines. Although controversial, it has been suggested that extraction of the primary canine be delayed because of the following possible benefits: -It holds space for the permanent canine, -It maintains the width of the alveolar ridge, -It avoids the need for an additional procedure since the primary canine can be removed during the uncovering procedure., Closed flap technique, Full-thickness flap is raised from premolar to the midline, then tooth follicle is removed, and the tooth is gently luxated, isolated, bracketed, and then the flap returned to its original position, the flap is completely closed (no window is made) and the chain is placed through the incision line, Figure, Trap door open technique, full-thickness flap is raised, as in the closed technique, then tooth with the bracket/eyelet is palpated through the flap to locate the bracket/eyelet. The area is then fenestrated with a blade or round bur to create a window (the “trap door”) to expose the bracket through the flap. The flap is then sutured and a wire or gold chain is attached from the bracket/eyelet to the arch outside of the flap. After 1 to 2 weeks, orthodontic force is initiated, Figure
Canine exposure/ movement by orthodontic force