Dilaceration is defined as a deviation or bend in the linear relationship of a crown of a tooth with its roots (Figs. 18-21, 27, 28) with the exact criteria ranging from a 90 degree or greater deviation along the axis of the tooth2,3 to a deviation of 20 degrees or more in the apical part of the root.4 Tooth dilaceration might present itself in various ways including non-eruption of the affected tooth, prolonged retention of the primary predecessor tooth, impacted tooth that refuses to move by conventional orthodontics, or it can be asymptomatic.5-8 Most authorities agree on two possible causes of dilaceration. The most accepted is mechanical trauma to the primary predecessor that results in dilaceration of the developing succedaneous permanent root. The calcified portion of the permanent tooth germ is displaced in such a way, the remainder of the permanent tooth germ forms at an angle to it.14-16 Idiopathic developmental disturbance is another possible cause in cases that have no clear evidence of traumatic injury.15-17 Recognition and diagnosis are essential for any tooth requiring orthodontic movement,10 as dilacerations could make the procedure quite complicated or even impossible.11 Radiographic examination is required for the diagnosis of root dilaceration, and if the curvature is mesial or distal, it can be seen in a panoramic or a periapical X-ray. However, if the curvature is labial/buccal or palatal/lingual, the image may be different, and have the appearance of a dark rounded opaque area, surrounded by radiolucency. This may be the apex of the tooth, surrounded by the periodontal ligament, creating the image of a “bull’s eye” or target (Figs. 18- 21). In some maxillary cases, the geometry might preclude recognition of the dilaceration.11,12 Due to the above variations, conventional X-rays such as panoramic, or periapical images, may require several angulations or be supplemented by a computed tomography scan (Figs. 27-32), which can help to determine the exact position and angulation of the dilaceration.13 The current report will illustrate how the authors arrived at the diagnosis and treatment of a maxillary central incisor with severe root dilaceration, combining behavior management, orthodontic, surgical and radiographical techniques.
Medical and Dental History
VG, a pediatric male, was initially referred to our office due to behavioral and multiple dental issues that required comprehensive pediatric management. A possible impaction of #8 was noted, and treatment to stimulate its own eruption was instituted, with removal of tooth#E. VG’s immediate dental needs were addressed over the next year and #8 continued to be monitored. His behavior and oral hygiene needed to improve before comprehensive orthodontic procedures could be instituted. At 7 years, 9 months of age, the patient’s cooperation, oral health and hygiene were under control. His medical history was unremarkable for allergies or medical problems but dental concerns included anterior cross bite of #7, 9, 10, anterior maxillary constriction, premature loss of primary molars, and mesial displacement of tooth #7. Dental conditions at the time of initial orthodontic consult were unremarkable for dental decay and gingivitis. There were no temporo-mandibular joint problems, but obvious skeletal and dental situations were in need of orthodontic correction.
Clinical Analysis
The oral exam revealed a Class I dental malocclusion with anterior crossbite and edge to edge molar relation- ships. The right maxillary incisor #7 was mesially displaced, and in crossbite. Mandibular incisors were moderately aligned but already had a protrusive inclination. First mandibular primary molars had been replaced by space maintainers. His open bite and anterior crossbite were both 1 mm. The midline was centered for #9 and the frontal image showed possible lack of midface development (Fig. 1).
TMJ Examination
The TMJ examination was within normal parameters and there was no history of headaches, joint dysfunction, pain, or clenching and grinding. Clinical examination revealed no popping, clicking or crepitus. Joint screening was within normal limits, with a vertical opening of 42 mm, a left deviation of 8mm, and right deviation of 8 mm.
Radiographic Analysis
Initial periapical and panoramic X-rays showed tooth #8 in an impacted, possibly horizontal position and angulation (Figs. 2, 8, 9), but the cephalometric image clearly showed its’ incisal edge pointing towards the anterior nasal spine (Fig. 3). The panoramic image revealed a mixed dentition stage, space maintainers for teeth L and S, and presence of all permanent teeth, except the wisdom teeth (Fig. 2). The cephalometric radiograph (Fig. 3) was traced using Gerety analysis (Fig. 4) which revealed a Class II skeletal classification based on the 7 ANB and a Class I dento-alveolar skeletal classification of 1 Wits. The mandibular plane angle indicated a neutral vertical growth potential. The Y-Axis and SL measurement indicated a clockwise growth tendency (Fig. 4). The prognosis for continued facial growth was critical as VG had full growth potential left. Upper and lower lips extended beyond the soft tissue lip and profile line. The analysis indicated a Class II skeletal, Class I dental classification, where the ANB was affected and indicated a Class II due to the potential vertical long facial growth, and anterior open bite.
Diagnosis
- Class II skeletal
- Class I dental
- Anterior open bite and crossbite.
- Maxillary constriction, especially in the pre-maxilla area
- Transverse mid-face deficiency
- Severe impaction and ectopic position of #8
Treatment Objectives for Phase I and II
- Improve facial and dental esthetics
- Attempt to bring #8 into the arch and into occlusion
- Align and level teeth in their arches
- Eliminate anterior open bite, and crossbite
- Create space for eruption of permanent teeth
- Re-establish matching anterior midlines
- Retain positive results over time
Treatment Plan Phase I:
- Develop the maxillary arch in a transverse manner using a palatal expander.
- Use arch wire sequence (AWS) on all available teeth to help develop maxillary arch.
- Correct anterior and posterior dimensions in maxilla to eliminate the crossbite and stimulate eruption of #8.
- If no eruption seen on #8 after expansion, expose it surgically, bond attachment and gently traction into position.
- Align anterior teeth and retain through the transition from mixed to permanent dentition.
- Treat with Phase II orthodontics as needed.
Treatment Plan Phase II (if needed)
- Incorporate permanent teeth as they erupt into arch increasing potential anchorage
- Use AWS on mandibular teeth to align and level the arch
- Bring # 8 into position
- Achieve positive overbite and overjet relationships
- Maintain positive result by long-term retention using bonded maxillary and mandibular fixed lingual and palatal retainers
- Long-term retention and recall visits protocol
Estimated Treatment Time
- Phase I: 8-12 months
- Phase II: Unknown at time of initial work-up
After reviewing our clinical cases with marked dilacerations diagnosed with 3D imaging, and reviewing the literature, we have concluded that it is nearly impossible to place an estimated treatment time in future cases as the variables are not predictable.
Case Summary and Analysis
VG, a pediatric male was initially seen in our office by one of our doctors on staff (EAE) as a referral due to the patients age, as well as multiple dental issues that required comprehensive pediatric treatment. Of special interest, in addition to the other problems, was the complete absence of #8 (right maxillary central incisor) on the pediatric periapical maxillary X-ray (Fig. 7). A second film, angled slightly higher (Fig. 8), revealed that #8 was indeed present but set higher in what appeared to be a more horizontal position. VG’s mother was questioned about possible trauma to the area, which she seemed to remember. This could have been the precursor to the aberrant position of #8 as the literature suggests. The prevalence of traumatic injuries to the primary dentition ranges from 11%-30%.17 While VG’s dental needs were being addressed during the following year #8 continued to be monitored. His behavior and oral hygiene (OH), needed to improve before comprehensive orthodontic procedures could be instituted to address #8’s problem. At 7 years, 9 months of age, VG’s cooperation, oral health and hygiene were considered to be under control and orthodontics was initiated to correct the anterior crossbite and impaction of #8. Orthodontic records were taken, including a clinical assessment of TMJ health and movements (Figs. 1- 6), and a treatment plan was elaborated.
Approximately 2 years after initial diagnosis, orthodontic treatment was started by placing brackets on first permanent maxillary molars (#3, 14) and brackets on maxillary incisors #7, 9, 10, starting with a .014 NiTi archwire for initial alignment and leveling. One month later the archwire was changed to a .018 NiTi and an open coil spring was inserted between # 7 and #9 to begin the expansion of the space required for #8, and distalization of #7. For the next six months, expansion with archwires continued until teeth #7, 9 and 10 were aligned to place in their desired position and sufficient space for #8 had been created (Fig. 12).
Oral hygiene continued to be an issue however and patient and parent were continuously counseled tenuously on this, in addition to more frequent brushing with Peridex® mouth rinse, attempting to control the negative effects on teeth and gingival tissue caused by dental plaque. Once space for #8 had been created, sedative and surgical procedures were explained to VG’s mother, consent forms obtained, patient was sedated with oral medication. The surgery consisted of raising a full flap, uncovering the lingual part of the incisor, bonding a gold pad and chain attachment, followed by suturing of the flap, leaving the traction chain under light tension to the existing archwire (.016 X .022 SS), with an elastic thread (Fig. 14). VG exhibited excellent healing and traction continued gently for the next three months. At this time, he was now almost 9 years old, ad his remaining primary teeth removed.
New records were taken to be able to obtain pre-approval for Phase II from VG’s Medicaid coverage plan, to allow us to continue providing his care (Figs. 13-17). Treatment continued, as his behavior was greatly improved due to his previous pediatric management. Starting Phase II, his maxillary base wire was a .018 SS, and his “overlay pulling” wire was a .014 NiTi while his initial mandibular wire was a .014 NiTi (Figs. 11, 13). Of note, one month after starting phase II, mother was warned that if OH was not improved, all appliances would have to be removed. Promises were made by VG and his mother to the effect that the OH would be greatly improved. The maxillary overlay wire was changed to a .016 X .022 CNA® inverted intrusion archwire by Ortho Organizers.® By using this pre-fabricated archwire upside down, molars would be the single anchorage, receiving an intrusion momentum, and # 8 would receive an extrusive force that would not affect the remaining incisors (Fig. 22).
After 8 ½ months of traction, a new surgical intervention was performed using a diode laser. Labial aspect of tooth #8 was exposed, moving the attachment from the lingual surface to the buccal surface of the tooth, and bonding of an attachment to the buccal of the crown. This allowed orthodontic forces to better direct the crown of the tooth. After three months, this attachment was changed for a bracket. While these maxillary movements were happening, the lower arch was in a .016 X .022 NiTi, which was changed for a .018 NiTi as the canines and bicuspids were incorporated into the arch sequence. VG continued to have periodic recall visits for hygiene and dental decay control. Several teeth developed decay and were treated, as soon as they were diagnosed. At each hygiene recall visit, fluoride therapy was administered in the form of fluoride varnish application and the importance of home control of OH was re-emphasized.
As soon as the maxillary canines erupted into position, they were incorporated into the archwire sequence (Figs. 23, 24). The maxillary expansion probably prevented the maxillary canines from impacting, thus aggravating the orthodontic situation. After 26 months of orthodontics, a .016 X .022 NiTi archwire was used to start correcting the torque of tooth #8. Eight months of treatment consisted of refining tooth position in both arches including closing diastemas and torqueing #8. During this period the treating team and the patient noticed that the buccal portion of the root section of #8 seemed to have a buccal torus. Palpation revealed a marked protrusion similar to a torus and VG complained of bumping himself more frequently with it (Fig. 24). A plan to lift a buccal flap and eliminate the buccal torus was discussed and approved by parents.
Before scheduling the procedure, a new cephalometric image was taken (Fig. 25), as the conventional periapical film did not reveal the true anatomy of this short root (Fig. 20). This new image orientation, using a different approach revealed the true cause of the bump. The root had a severe curvature with the apical portion coming out the buccal plate. At this time, the authors realized that this was a totally different scenario in the orthodontic therapy. The findings and treatment options originated with this discovery were explained to the parents and patient. The first option in dealing with the “bump” was to perform the best root canal possible due to the root dilaceration followed by osteotomy and partial root amputation, using a full flap exposure.19 The risk of endodontic failure, poor root anchorage and/or premature loss of the tooth were the disadvantages of this approach. The second alternative was to continue the orthodontic therapy adjusting as best as possible, the torque of the crown, accepting a slightly more protrusive upper lip, and only opting for a root canal, if the tooth lost its vitality. Doctor, patient and parents opted for plan B. Four months later, the office acquired an Orthophos XG-3D® hybrid panoramic CBCT machine by Sirona®, allowing us to scan the patient. The panoramic image extracted from the scan showed a shorter root on #8, with an image of “bulls eye” or target where the apex should be. Many teeth had a mesio-distal or disto- mesial root dilaceration of a minor type. The wisdom teeth are now evident, including #17 affecting the position of #18 in an 11 ½ year old patient (Fig. 26). Images #26 and 27 are cross-sectional cuts (buccal-lingual) of teeth #8 and #9. Observe how the root of #8 protrudes through the buccal cortical bone. While the root of #9 (Fig. 27) is the expected image involving root and cortical bone anatomy of an anterior tooth. Figs. 29 and 30 represents right and left images in a 3D image of the complex anatomy of the maxillary arches. Not only is the dilaceration easily seen, but all teeth, including those unerupted can be easily visualized and their path of eruption or impaction easily predicted. Figs. 31 and 32 represent a close-up view of the crown and root anatomy of the maxillary incisor area. This allowed the authors to visualize root location and to program treatment modifications due to these anatomical variations.
Four more months were used in an attempt to create the best anatomical position of the anterior teeth. By this time, even though the second molars had not fully erupted the treatment team decided it was best to finalize treatment, due to OH issues, and continuous presence of new carious lesions. Patient was debonded during two visits, allowing posterior teeth to articulate without the influence of active wires, followed by retention based on clear removable retainers. Our patient’s total active treatment time was 45 months from initial phase I records to retainer delivery at the end of phase II. His cephalometric image and tracing before the finish of therapy revealed a Class II skeletal relationship based on the ANB measurement of 6 (decrease of 1 degree), where both SNA and SNB decreased. Witts parameters increased to 2. The new maxillary incisor position improved his clinical appearance and helped to create a new overbite and acceptable overjet. The mandibular incisors proclination compensated for a smaller chin by increasing their angulation, even with no use of Class II inter-maxillary elastics (Fig. 25). Correction of the anterior open bite and crossbite was based on maxillary arch development and intrusion of the maxillary molars with the use of the inverted .022 CNA® inverted intrusion archwire.
Extrusion of the impacted #8 tooth was based on maxillary arch expansion, correct creation of space for #8, and positioning of the other maxillary incisors, the correct anchorage for a steady and continuous traction, correct oral surgery and the fact that the dilacerated root did not get blocked by another root. A final panoramic image was taken together with final pictures 60 days after placing patient in retainers. Of interest are the four wisdom teeth that are planned for removal in the near future, to prevent periodontal issues on the distal aspect of the second molars. There is an image of a BB pellet, caused by an accident per patient narrative (Fig. 33). The esthetic and function result are highly acceptable, especially considering the protrusion caused by the root of #8, and the difficulty in the final manipulation of this tooth, due to its abnormal anatomy. At the time of these final records, his dental classification was Class I, with very adequate overjet and overbite. No final cephalometric image was taken as its use could not be justified after taking a previous cephalometric image and only torqueing teeth after that image. His face was balanced, with improved facial and dental esthetics. He was pleased with the results and the initial objectives were met (Figs. 33, 34).
The authors now believe that a 3D scan is quite useful and highly recommended in situations where tooth impaction or an anatomical presence that cannot be read or understood in a conventional X-ray, as exemplified in the present report they have discovered multiple pathologies and dental malformations, with each new scan taken in the course of treatment. The value of teamwork in the successful management of this complex and demanding case cannot be overestimated.
We appreciate the invaluable help of Dr. Harris Keene with the final editing of our manuscripts. With his help, these case reports, come to life.
Editor’s Note: Article references are available upon request or for download in the digital version at www.orthodontics.com.
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