| Abstract|| |
The sequelae of chronic edentulous space is the supraeruption of the opposing teeth which hinders prosthodontic replacement. Molar intrusion of overerupted teeth can be done using miniscrew implants which serves as a promising technique, especially in adult patients. This case report highlights pre-prosthodontic therapy by pure molar intrusion using Temporary Anchorage Device (TAD) in an adult patient seeking prosthesis to enhance chewing efficiency.
Keywords: Adult orthodontics, miniscrew implants, molar intrusion, pre-prosthodontic therapy
|How to cite this article:|
Adeni MK, Parameswaran R, Vijayalakshmi D, Unni SR. Management of supraerupted maxillary molars in an adult patient using orthodontic miniscrew implants: A pre-prosthodontic therapy. Indian J Dent Res 2020;31:318-22
|How to cite this URL:|
Adeni MK, Parameswaran R, Vijayalakshmi D, Unni SR. Management of supraerupted maxillary molars in an adult patient using orthodontic miniscrew implants: A pre-prosthodontic therapy. Indian J Dent Res [serial online] 2020 [cited 2020 May 30];31:318-22. Available from: http://www.ijdr.in/text.asp?2020/31/2/318/284582
| Introduction|| |
The demographics of the orthodontic patients has changed with more number of adult patients seeking orthodontic treatment either to improve esthetics or function. Invariably most adult patients present with missing teeth, which are either extracted due to extensive caries or periodontitis. Supraerupted tooth with missing antagonist is an often encountered clinical scenario which impedes prosthodontic rehabilitation. It has always been considered challenging for orthodontists to attain pure intrusion, which can be achieved only when the anchorage system allows forces to be directed through the tooth's center of resistance. This article describes the use of temporary anchorage device for efficient intrusion of overerupted upper molars in an adult patient seeking prosthetic replacement of missing teeth.
Diagnosis and etiology
A 32-year-old female patient reported to the Department of Prosthodontics seeking for replacement of missing lower left and right molars. The patient was then referred to the Department of Orthodontics and Dentofacial Orthopaedics for the management of supraerupted upper molars, which hampered prosthetic replacement.
Extraoral examination revealed a normodivergent facial pattern, acute nasolabial angle, and high clinical Frankfort Mandibular plane Angle (FMA).
The upper and lower dental midline coincided with facial midline. There was extrusion of 16 and 26 into the edentulous space. The maxillary and mandibular arch forms were ovoid with spacing seen in anterior region with mild recession of 41. Patient exhibited Class I canine relationship bilaterally with over bite and overjet of 1 mm [Figure 1].
Pretreatment orthopantomogram (OPG) indicated that patient was in her permanent dentition stage with missing 36, 37, 46, and 47. It was also confirmed that 16 and 26 were below the maxillary occlusal plane.
Cephalometric evaluation revealed class I skeletal base with orthognathic maxilla and orthognathic mandible with a relatively short cranial base length and high mandibular plane angle. Upper incisors and lower incisors were proclined along with an increase in upper posterior dentoalveolar height [Table 1].
Based on the investigations, the patient was diagnosed as class I skeletal malocclusion with class I canine relationship on both sides on a high mandibular plane angle with extruded 16 and 26, proclined upper and lower incisors, and missing 36, 37, 46, and 47.
- To improve facial profile
- To intrude 16 and 26 to regain space for prosthetic replacement of 36, 37, 46, and 47
- To achieve ideal over bite
- To achieve functional molar relationship
- To maintain class I canine relationship
- To align the upper and lower teeth
- To achieve ideal overjet.
- To enhance masticatory efficiency.
The ideal treatment plan comprises a holistic orthodontic approach which would address both function and esthetics. This involves intrusion of supraerupted 16, 26 via orthodontic miniscrews and extraction of 15 and 25 and enmasse retraction of lower arch. Extraction of the upper second premolars is essential as intrusion of molars requires space and also addresses the proclination in upper anterior teeth to achieve good lip seal.
- The compromised treatment options that were discussed are as follows:
- Tooth reduction with endodontic intervention and crown placement, but this would compromise tooth vitality
- A less invasive and simplistic approach is using a lower removable acrylic plate with posterior bite blocks for molar intrusion. The mode of action of bite plane is to load the molar sequentially to deliver intrusive forces on biting. However, effects are transitory as it would deliver intermittent force and relies on patient compliance. This plan was not considered as the patient wanted faster results and bite plane wear will not be comfortable both esthetically and functionally
- True intrusion of 16, 26 using miniscrews without any fixed appliance therapy.
After analyzing the cost-risk benefit of the different options, the patient chose full-fledged orthodontic approach.
Based on the clinical and radiological observation, the treatment involved extraction of 15 and 25, followed by intrusion of 16 and 26 and en masse retraction of lower arch via temporary anchorage devices (TADs).
Orthodontic therapy was initiated with banding of second molar using a transpalatal arch with mesial hook. Two miniscrew implants were placed on the buccal side, mesial, and distal to the first maxillary molar, which served as the anchor unit for molar intrusion. To achieve an unhindered molar intrusion a separator was placed to create space between the first and second molar. Elastic chain was tied from the mini implants to the bondable Begg bracket bonded on the molar and simultaneously another elastic chain was tied between the hook and a bonded lingual attachment on the first molar to prevent the roots of the molars tipping lingually [Figure 2]. The elastomeric chains were changed every 4 weeks for 5 months to bring about 2.5 mm of intrusion until the occlusal clearance was sufficient to rebuild the posterior occlusion by a prosthesis. The intruded molars were retained using ligature wires. Subsequently, upper and lower teeth were strapped up using 0.022 × 0.028” pre-adjusted edgewise prescription. Alignment and leveling was done sequentially with 0.016 NiTi, 16 × 22 NiTi, and 19 × 25 NiTi archwires. The anterior teeth were retracted against the same microimplant anchorage with friction mechanics on 19 × 25 rectangular stainless steel archwires. In addition, two mini-implants were placed distal to the lower second premolar to facilitate en-masse retraction of lower arch. The entire treatment was completed in 18 months [Figure 3]. In the retention phase, an upper Essix and lower lingual bonded retainers were delivered. Prosthetic rehabilitation involved replacement of missing 36, 37 and 46, 47. Due to financial reasons, the patient opted for removable partial dentures [Figure 4].
|Figure 2: Orthodontic miniscrew implants placed for intrusion and retraction|
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|Figure 4: Orthodontic retention and post-prosthodontic treatment intraoral photographs|
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| Results|| |
At the end of the treatment, the patient had a pleasing smile and stable functional molar occlusion with class I canine relationship and normal overbite and overjet [Figure 3] and [Figure 4].
Superimposition of the pre and postorthodontic cephalometric tracing illustrates the amount of molar intrusion and associated dental and soft tissue changes [Figure 5] and [Table 1].
| Discussion|| |
Adult patients who have supraerupted molars due to the loss of antagonists is a common clinical finding, most often requiring a pre-prosthodontic therapy in the form of molar intrusion to provide adequate clearance for prosthetic rehabilitation. Management with fixed orthodontic appliances can be vexing because of the reciprocal extrusion of the adjacent teeth, which would be more pronounced than the actual intrusion itself. Moreover, molar intrusion is difficult in adults. Various conservative alternatives include use of magnetic bite blocks, corticotomy, removable plates, tooth reduction with intentional root canal therapy, and most aggressive being extraction of a vital tooth.,,, With the scope of orthodontics expanding, the use of TADs helps to overcome anchorage limitations and perform exceptionally well in difficult tooth movements with minimal patient compliance. Moreover, the implantation technique is relatively simple and provides greater control on the direction and amount of force. For unhampered molar intrusion, a separator needs to be placed between the first molar and second molar to counteract the door-wedge effect. It is suggested that in harmony with buccal intrusive forces, reinforcing lingual forces in the form of soldered transpalatal arch or palatal mini-implants can avoid undesirable tipping.
Retention after molar intrusion becomes critical due to inevitable relapse. Several authors have reported that the tendency of relapse using TADs for molar intrusion ranges between 20% and 30%.,,, Thus, overcorrection is advised as a means of overcoming relapse.
In the present case, a transpalatal arch (TPA) on the upper first molars was not considered for molar intrusion as it would require an inferior placement away from the palate to produce sufficient intrusive force on the molars. Further, the patient's palatal contour was not high arched to allow inferior placement of the modified palatal arch. Further, the upper molars were extruded by 2.5 mm creating lack of space for any prosthetic replacement of the lower posterior teeth. Because the attempt to level the molars vertically to create space for the prosthesis was the primary aim, an active intrusive force could be acquired only by implants or a modified contraption from the already levelled upper second molar. Palatal implant was also an alternate option. However, the site of implant placement could be a problem owing to the presence of greater palatine artery. Thus, a modified TPA was considered on the upper second molars.
The lingual tipping of the second molars were counteracted by cementing a transpalatal arch with hooks tied to the lingual attachment on the first molar. Literature states that in multirooted teeth excessive intrusion is not possible if the teeth are in a normal vertical relation to the arch as they are influenced by the presence of maxillary sinus and the height of the alveolar process in the molar region. In the present situation, the extruded molars were intruded back to the original vertical level of the upper arch, hence 2.5 mm of intrusion provided 6 mm of interarch clearance for the prosthetic rehabilitation, which has been confirmed by the pre and post-cephalometric data.
Studies have shown that the treatment duration of various orthodontic appliances warrants special consideration regarding their cytotoxicity. Though the effects become evident after 6 months of wear, these biological changes are reversible once the appliance is removed., The soldered palatal arch was kept in place for only 3–4 months until the active intrusion was achieved. The intruded molars were retained with passive ligature wires tied to miniscrews and later on with a stiffer archwire until the prosthesis was placed.
Orthodontic treatment per se may be conducive to development of gingival recessions, especially when there is pre-existing dehiscence, thin gingival biotype, inclination of lower incisors, or mechanical trauma., It has been reported that at the end of orthodontic treatment of adult patients, lower incisors demonstrated more propensity for gingival recession. This was in concordance with the present case where 41 had pre-existing gingival recession which worsened by the end of orthodontic therapy.
| Conclusion|| |
This article highlights the significance of adult orthodontic treatment not merely in the sphere of esthetics but also in functional rehabilitation. It mainly involves the synergistic orchestration among dental specialties to help improvise the patient's quality of life.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Hwang HS, Lee KH. Intrusion of overerupted molars by corticotomy and magnets. Am J Orthod Dentofacial Orthop 2001;120:209-16.
Hakami Z. Molar intrusion techniques in orthodontics: A review. J Int Oral Health 2016;8:302-6. [Full text]
Bonetti GA, Giunta D. Molar intrusion with removable appliance. J Clin Orthod 1996;30:434-7.
Kravitz ND, Kusnoto B, Tsay PT, Hohlt WF. Intrusion of overerupted upper first molar using two orthodontic miniscrews. Angle Orthod 2007;77.915-22.
Park Y-C, Lee S-Y, Kim D-H, Jee S-H. Intrusion of posterior teeth using mini-screw implants. Am J Orthod Dentofacial Orthop 2003;123:690-4.
Melsen B, Fiorelli G. Upper molar intrusion. J Clin Orthod 1996;30:91-6.
Marzouk ES, Kassem HE. Evaluation of long-term stability of skeletal anterior open bite correction in adults treated with maxillary posterior segment intrusion using zygomatic miniplates. Am J Orthod Dentofac Orthop 2016;150:7888.
Baek MS, Choi YJ, Yu HS, Lee KJ, Kwak J, Park YC. Long-term stability of anterior open-bite treatment by intrusion of maxillary posterior teeth. Am J Orthod Dentofacial Orthop 2010;138:396.e1-9.
Krishnaswamy NR. Vertical control with TADs- procedures and protocols, seminars in orthodontics. Semin Orthod 2018;24:108-22.
Sugawara J, Baik UB, Umemori M, Takahashi I, Nagasaka H, Kawamura H, et al
. Treatment and post-treatment dentoalveolar changes following intrusion of mandibular molars with application of a skeletal anchorage system (SAS) for open bite correction. Int J Adult Orthodon Orthognath Surg 2002;17:243-53.
Hafez HS, Selim EM, Kamel Eid FH, Tawfik WA, Al-Ashkar EA, Mostafa YA. Cytotoxicity, genotoxicity, and metal release in patients with fixed orthodontic appliances: A longitudinal in-vivo
study. Am J Orthod Dentofacial Orthop 2011;140:298-308.
Martín-Cameán A, Jos A, Cameán AM, Solano E, Iglesias-Linares A. Genotoxic and cytotoxic effects and gene expression changes induced by fixed orthodontic appliances in oral mucosa cells of patients: A systematic review. Toxicol Mech Methods 2015;25:440-7.
Allais D, Melsen B. Does labial movement of lower incisors influence the level of the gingival margin? A case–control study of adult orthodontic patients. Eur J Orthod 2003;25:343-52.
Renkema AM, Fudalej PS, Renkema A, Bronkhorst E, Katsaros C. Gingival recessions and the change of inclination of mandibular incisors during orthodontic treatment. Eur J Orthod 2013;35:249-55.
Dr. Moina K Adeni
Department of Orthodontics and Dentofacial Orthopedics, Meenakshi Ammal Dental College and Hospital, Alapakkam Main Road, Maduravoyal, Chennai - 600 095, Tamil Nadu
Source of Support: None, Conflict of Interest: None
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]