Dr Tsutomu Tanno
Orthodontic Implant Site Development Using Labial Root Torque: A Case Report
Abstract body:
Introduction: Replacing missing teeth with dental implants has become a viable solution for conventional fixed or removable prosthodontics. Dental implant therapy should be satisfied with not only function but also esthetic as stated in The Toronto Osseointegration Conference at 1982. Implant esthetic may be promised with optimal implant position and the volume of surrounding soft and hard tissue. Following tooth extraction, the alveolar ridge resorption that takes place can cause alterations in hard and soft tissue contours, particularly in the anterior maxilla. These biological change could have significantly adverse esthetic outcome in the anterior maxilla. Therefore, the key for the successful implant therapy in the anterior maxilla is to preserve or augment adequate hard and soft tissue volume. Many augmentation techniques were reported to achieve esthetic outcome. However most of techniques are invasive and technique sensitive. One of less invasive augmentation technique, the orthodontic extrusion by Salama H and Salama M in 1993 showed performing vertical orthodontic extrusion of the root with poor prognosis and followed by Implant placement. This method has an advantage of higher predictability to augment soft and hard tissue vertically with less invasive procedure. However, it is difficult to obtain enough tissue in horizontally to place implant by this technique alone especially when the extruded root has smaller diameter. In this situation, it is necessary to augment additional bone.
The following case report demonstrates the step by step Labial Root Torque (LRT) techniques to treat a single severe buccal ridge defect in the esthetic zone for following implant placement without any augmentation procedures.
Method: A 35-year-old man presented to private practice in Japan. The patient’s chief request was to fix occlusion and fractured tooth (tooth No. 11). The patient had no history of systemic disease, radiation or chemotherapy, smoking, or periodontal disease. Tooth #11 was fractured and diagnosed as hopeless. According to CBCT image, no buccal plate was present up to apex of the root. Treatment includes orthodontic therapy to improve occlusion especially cross-bite on tooth No. 10 and orthodontic implant site development by using labial root technique (OISD-LRT) on tooth No. 11.
i) Temporary crown was fabricated on tooth No. 11 then orthodontic therapy was performed with multi brackets and Ni-Ti 016 wire to improve crowding and cross-bite on tooth No. 10 and OISD-LRT on tooth No. 11.
ii) Bracket on the tooth No. 11 was bonded more apically position to extrude root and then the wire was placed above the bracket wing for the labial root torque.
iii) Bracket position of tooth No. 11 was changed to more apically and tooth was adjusted every 4 weeks until the position of the root will be perpendicular to the alveolar bone.
iv) OISD-LRT was completed when the attachment level was more coronal than the adjacent teeth. Total treatment time of OISD-LRT was 8 months. After the completion of the extrusion, the bracket was keeping at the same position for two months to allow mineralization of the alveolar bone and mature of the soft tissue.
v) Using periapical radiograph to evaluate the bone maturation after OISD-LRT and CBCT was taken for implant placement. Root was extracted without flap elevation.
vi) Implant placement was performed with computer guide as flapless procedure. The initial osteotomy preparation was completed with a 2.8 trephine bur with computer guide to harvest bone core biopsies approximately 2 x 10 mm in size for histological analysis. Implant placement with 4.3 mm by 10.0 mm was performed with computer guide.
vii) Three months after the implant placement, definitive restoration was fabricated then delivered. Total treatment time was 18 months.
Results:
According to CBCT, achievement of horizontally 7.92 mm and vertically 2.56 mm alveolar bone gain from peak of palatal bone without any augmentation procedures. Histomorphological analysis showed evidence of bone formation. The histomorphological measurements revealed the specimens to be occupied by 57.27% lamellar bone, 42.73 % marrow space. Periapical radiographic and CBCT shows no significant bone level change and clinically maintained healthy soft tissue around implant and satisfactory of esthetic two years after the final crown deliver.
Conclusion: Orthodontic implant site development by using “Labial Root Torque” can increase horizontal and vertical bone volume for placing implant without any additional augmentation procedures. Labial Root Torque was able to regenerate hard tissue without any surgical procedures hence it is beneficial for the patients.
I’d like to share with you our innovative site development,
“Orthodontic Implant-site Development, using Labial Root Torque
In order to achieve an esthetic and predictable Implant therapy,
sufficient volume of hard and soft tissue and optimal Implant positioning are critical.
Most of the anterior cases especially in Maxilla with implant therapy,
we need more bone, more soft tissue to achieve esthetic outcome.
Many different techniques and materials were published to manage hard and soft tissue for implant therapy.
However there are limitations and some techniques are too invasive procedure or technique sensitive.
According to A simplified socket classification by Dr. Elian,
depends on presence of buccal bone and / or buccal soft tissue , we have different treatment options for implant placement.
Case of type 1 socket, we have many option to achieve great outcome,
such as immediate placement, ridge preservation, socket shield technique, horizontal GBR and early placement.
Case of type 2 socket,
Ｗe still have treatment options
Socket Repair technique, Horizontal GBR ,
however we need to augment hard and soft tissue for implant placement.
Case of type 3 socket,
Treatment option will be major bone augmentation for site development first then implant placement.
Big problem of major bone or soft tissue augmentation is complications
such as exposure of membrane, infection and soft tissue capsulation.
Augmentation procedures are technique sensitive, need good knowledge and surgical skills.
and also we know how difficult to deal with failing GBR, this is nightmare.
Moreover, we have to think about patients, patients are suffering from many surgeries.
If we can achieve a good results without multiple surgery neither complications would be great for us and for patients!
Then I’d like to share with you modified orthodontic tissue augmentation, this procedure is less invasive and promising good outcome.
In the beginning, Orthodontic tissue augmentation, forced eruption was introduced by Dr. Salama et al in 1993.
This technique is great idea to gain hard and soft tissue.
However because of direction of the tooth movement which is vertical,
ridge width is not enough for placing implant due to knife edge shape of the ridge.
Then we propose Orthodontic Implant Site Development, Labial Root Torque,
to apply rotation torque with using orthodontic bracket
utilizing maximum PDL area for new bone formation
not only in vertical but also in horizontal.
So today I’d like to propose modified orthodontic forced eruption, Orthodontic Implant Site Development using Labial Root Torque for implant treatment in the esthetic zone
The patient was 35-year-old male, Asian
Upper left canine needs to be extracted due to root fracture. Cross bite on tooth #10 and less restorative space on tooth #11.
From PA, interproximal bone level is acceptable. However from the CBCT ,there is no buccal bone, usually need a major bone augmentation for placing implant.
Treatment plan include treatment of cross bite on tooth #10, making restorative space and site development for implant placement on tooth #11.
First, Orthodontic treatment is started.
Bracket on Tooth#11 was placed more apically and bring root more coronally. Initial wire is .016 Ni-Ti Round wire.
First leveling,
then putting labial root torque to the left upper canine.
And extrude root to be perpendicular to alveolar bone
and retain it for 2 months, then extract the root.
I pay special attention for esthetic by providing angled temporary crown
whatever the tilting of root maybe.
CBCT image shows enough bone gain Vertically and horizontally for placing implant without any augmentation procedures.
According CBCT image, adequate amount of bone for placing an implant.
Then computer guide was fabricated for the surgery and Implant was placed with flapless procedure.
We achieved not only esthetic outcome but also natural looking
because of no incision was made for any procedures.
No major bone change and maintained esthetic outcomes after 3 years of treatment.
Without any augmentation procedures, we achieved great results.
Achievement of bone gain in horizontally 7.92 mm, yellow arrow
and in vertically 2.56 mm, red arrow.
Alveolar bone gain without any augmentation procedures
and achievement of implant placement.
Overcorrection is essentisl elements for OISD
The histomorphological measurements revealed the specimens to be occupied by 57.27% lamellar bone.
OISD requires 8 months for extrusion and 2 months for retention,
which is not different than GBR.
Torque technique for implant site development in the esthetic zone.
This innovative site development can achieve great esthetic outcomes without any augmentation procedures and less traumatic procedures.
We have 10 cases with Labial Root Torque, included central incisor case, Lateral incisor case and multiple case.
however we need more time to observe, make sure no significant changing bone level and mid buccal soft tissue, So far no changing bone and soft tissue level in ３ years. If we will have opportunity to present next year, we will bring case series and I would like to discuss with you.
This procedure is not a magic!
This is science!
