WO2023204772A1

WO2023204772A1 - Mini-screws anchored casted palatal plate for upper arch distalization

Info

Publication number: WO2023204772A1
Application number: PCT/SY2022/050001
Authority: WO
Inventors: Tuqa Rashad RAGHIS; Tareq Mosleh ALFRIH ALSULAIMAN; Mohamad YOUSSEF
Original assignee: Raghis Tuqa Rashad; Alfrih Alsulaiman Tareq Mosleh; Youssef Mohamad
Priority date: 2022-04-19
Filing date: 2022-07-01
Publication date: 2023-10-26

Abstract

A custom-made appliance designed for total distalization of the upper dental arch. It consists of a Vitallium bar with two posterior holes for mini-screws' insertion localized at the para-median area, and two extended lever arms with two posterior hooks. The palatal plate should be applied with a stainless steel anterior trans-palatal arch, which is inserted in the palatal tubes of the maxillary first molars' bands and provided with two anterior soldered hooks. Distalization of the upper arch can be accomplished by applying an elastic chain or closed coil spring from the anterior hooks of the trans-palatal arch to the posterior hooks of the palatal plate.

Description

Title of Invention: ini-screws anchored casted palatal plate for upper arch distalization

[1] Background Art

Class II malocclusion is considered as the most frequent problem presenting in the orthodontic practice, affecting about 20-30% of school children and occurring in 33% of all orthodontic patients (Youssef, 1996; Papadopoulos, 2014).

Treatment options for class II malocclusions are varied according to its etiology, it can be classified into extraction, non-extraction, functional and orthognathic surgery (Cope, 2005).

For non-growing patients, the decision from extraction or non-extraction is a subject of most debate; however, most patients desire non-extraction treatment, if possible (Vaden and Kiser, 1996; Janson et al., 2007).

During the past decade, non-extraction treatment has become increasingly popular for correction of Class II malocclusions; this treatment frequently accomplished by posterior movement of the maxillary teeth in order to achieve a Class I molar and canine relationship (Park, Lee and Kwon, 2005).

For a number of years, headgear was the standard approach to distalize molars or entire maxillary dentition; However, depending on patient's compliance and poor esthetics compromised its treatment effects (Greenspan, 1970; Egolf, BeGole and Upshaw, 1990; Haas, 2000).

Therefore, several non-compliance intraoral appliances have been effectively used for distaization; such as pendulum (Chiu, McNamara Jr and Franchi, 2005; Fuziy et al., 2006), distal jet (Carano, 1996; Chiu, McNamara Jr and Franchi, 2005), nickel-titanium open coil springs (Keles and Sayinsu, 2000) and several other appliances. However, some of drawbacks were encountered when using these appliances; including: the loss of anchorage characterized by mesial movement of premolars and protrusion of maxillary incisors (Gelgbr et al., 2004; da Costa Grec et al., 2013), the relapse in molars' distalizaion during retraction of premolars and incisors (Graber, Vanarsdall and Vig, 2005), In addition, a group distalization of the maxillary dentition was almost impossible in most patients.

To reduce these shortcomings, temporary anchorage devices (TADs) have been introduced and greatly expanded the boundaries of orthodontic tooth movement. Using TADs, individual teeth or the entire dental arch can be moved in three planes with minimal loss of anchorage, which make them a proper choice for use in distalizing the whole maxillary arch in the nonextraction treatment (Bae, 2002; Deguchi et aL, 2003)

Different types of TADs may be effectively used for total arch distalization of the maxillary dentition; such as mini-plates, inter-radicular mini-screws or palatal mini-screws with palatal plates. Mini-plates are applied in the infrazygomatic bone, but they need an additional surgery for placement and removal, and they are expensive (Miyawaki et al., 2003).

Mini-screws were used increasingly due to simple placement and removal without irreversible changes (Carano et al., 2005), immediate loading (Park, Kwon and Sung, 2004), low cost, short treatment time (Park and Kwon, 2004), minimal need for patient cooperation, and possibility of placing them in various anatomical sites due to their relatively small diameter (1.2 to 2 mm) (Park, Jeong and Kwon, 2006; Park, Yen and Jeoung, 2006).

Clinical studies have found that the maxillary posterior teeth could be distalized by 1.4 to 2.8 mm with approximately 3.5° to 4.8° of distal tipping using buccal mini-screws (Yamada et al., 2009; Oh, Park and Kwon, 2011; Bechtold et al., 2013). However, it may not be easy to place them buccally in narrow inter-radicular widths. Moreover, re-implantation of mini-screws might be necessary when a large amount of distalization is required (Chung et al., 2010; Hilgers, Nissen and Tracey, 2012).

Several studies have evaluated the quality and quantity of the palatal bone and confirmed that the paramedian palatal area is very suitable for mini-implanting without the need for any surgical procedures because of its thin keratinized soft tissue, sufficient high density bone (Graeco et al., 2008; Wehrbein, 2009), and the lack of interference with tooth movement during treatment (Jung et al., 2009). Kook et al reported the application of a flapless modified C-palatal plate (MCPP) appliance for total distalization of the maxillary dentition (Kook, Kim and Chung, 2010) during the non-extraction treatment of class II malocclusion in both adolescents and adults (Sa'aed et al., 2015). Studies about MCPPs have showed that it produced a significant distal movement of the maxillary first molar by about 3.5 to 4.6 mm (Lee et al., 2018; Shoaib et al., 2019). Moreover, in the comparison with headgear, MCPP showed a greater distalization of the maxillary first molars in adult patients with less distal tipping accompanied by intrusion (Park et al., 2017). That may be due to the non-depending on the patient compliance in the MCPP appliances. In addition, it showed a greater distalisation and less distal tipping of the posterior teeth when compared with that produced by using of inter-radicular mini-screws (Lee et al., 2018).

However, some of complications may be encountered when using MCPP appliance regarding its design; for example: the MCPP consists of a prefabricated nickel titanium bar that is adjusted manually by the orthodontist to fit on the patient's dental cast, which needs special considerations as inflammation of the palatal tissues may be resulted due to incomplete adaption, also in some cases the plate may be deformed during adjustment or force application due to its high flexibility.

In addition, the stability of MCPP depends on the insertion of three miniscrews in their holes at the paramedian area, tight adaptation between the holes and mini-screws should be achieved to reduce the potential for plate tipping. However, soft tissue impingement can result when force is applied (Kook et al., 2017). As well as the high expected cost of the plate and the three mini-screws.

Depending on the above-mentioned reasons, we introduced the mini-screws anchored casted palatal plate as a new customized skeletal anchored plate for total maxillary arch distalization during the treatment of class II malocclusion.

[2] Detailed description of the invention:

1) After evaluation of the maxillary retro-molar space, the maxillary third molars should be extracted. 2) Preadjusted brackets with 0.022 slots are bonded to the maxillary dental arch, and bands with lingual tubes should be cemented to the maxillary first and second molars.

3) The leveling and alignment phase of the orthodontic treatment is initiated using straight archwires, starting with 0.012 or 0.014 nickel-titanium and working up to 0.016 * 0.022 stainless steel wires.

4) The bands of the maxillary first molars are removed and the adhesion cement is cleaned, then the bands are set in their places on the maxillary first molars and an alginate impression for the upper arch including U6's bands should be taken.

5) After casting, the design and position of the casted palatal plate must be drawn on the patient's cast as the following:

The plate should be positioned on the posterior region of the palatal tissues between the maxillary second premolars and first molars with 4 mm of anterior-posterior dimension, and it must contain two holes (2 mm diameter) that are localized posteriorly at the paramedian area. The arms of the plate should be extended laterally to be ended with a sufficient distance from the palatal tubes of the Ulst molars' bands, also two 2 mm distally and posteriorly directed hooks should be added to the posterior edges of the extended arms [Fig. 1].

6) Then the cast is sent to the laboratory for manufacturing the casted palatal plate from vitallium according to the drawn design.

7) Before casting the plate, 1-2 mm of wax should be added as a negative relief to the working cast only under the extended arms; as the middle part of the plate must have a complete sealing on the paramedian area, while the arms should keep 1-2 mm of space away from the palatal tissues to permit cleaning procedures.

8) Anterior 1 mm stainless steel trans-palatal arch should be applied along with the casted palatal plate; it must be inserted in the palatal tubes of the Ulst molars' bands and has two U shaped loops working as a stop mesial to the bands, then it extends anteriorly 4 mm away from the palatal surfaces of the anterior teeth, and two mesially and posteriorly directed hooks must be soldered to its anterior part [Fig. 2].

9) After casting of the palatal plate, it must be sealed and sterilized by Autoclave before its application.

10) Placement procedures: a) Re-banding of the maxillary first molars. b) Applying the anterior trans-palatal arch. c) Swabbing the palatal tissues with a Povidone wetted cotton ball. d) Administrating of local anesthesia of the palatal tissues. e) Holding the sterilized casted palatal plate in its place on the posterior region of the palatal tissues between the second premolars and first molars. f) Stabilizing the plate by inserting two self-drilling mini-screws (1.6 mm diameter, 8 mm length) in their holes of the plate.

11) After the application of the casted palatal plate, the distalization of the maxillary dental arch can be initiated immediately by engaging an elastic chain from the anterior soldered hooks of the trans-palatal arch to the posterior hooks of the casted palatal plate applying about 200 g of force each side.

12) Giving the instructions to rinse twice a day with Chlorohexidine 0.12% mouthwashes.

13) Patient must visit periodically every three weeks in order to replace the elastic chains.

[3] Brief Description of Drawings

[Fig.l] The casted palatal plate consists of a customized vitallium bar provided with two posteriors holes at the paramedian area for mini-screws' insertion (1) and two extended lever arms with two posteriorly directed hooks for elastic application (2).

[Fig.2] The casted palatal plate is adapted on the posterior region of the palatal tissues between the second premolars and the first maxillary molars, and stabilized by inserting two mini-screws (1) (1.6 mm diameter, 8 mm length) in their holes of the palatal plate. The casted palatal plate must be applied along with a stainless steel anterior trans-palatal arch, that is inserted into the palatal tubes of the U6s' bands with two U-shaped loops (2) working as a stop mesial to U6s and two soldered anterior hooks (3). Distalization force can be applied by engaging an elastic chain from the anterior hooks of the trans-palatal arch to the posterior hooks of the casted palatal plate (4).

(Fig. 3-22] Clinical cases of upper arch distalization using the mini-screws anchored casted palatal plate.

[4] Reference Signs List:

1) Bae, S.-M. (2002) 'Clinical application of micro-implant anchorage', J Clin orthod, 36(5), pp. 298-302.

2) Bechtold, T. E. et al. (2013) 'Distalization pattern of the maxillary arch depending on the number of orthodontic miniscrews', The Angle Orthodontist, 83(2), pp. 266-273.

3) Carano, A. (1996) 'The distal jet for upper molar distalization', J Clin Orthod, 30, pp. 374-380.

4) Carano, A. et al. (2005) 'Clinical applications of the miniscrew anchorage system' , Journal of clinical orthodontics: JCO, 39(1), pp. 9-30.

5) Chiu, P. P., McNamara Jr, J. A. and Franchi, L. (2005) 'A comparison of two intraoral molar distalization appliances: distal jet versus pendulum', American Journal of Orthodontics and Dentofacial Orthopedics, 128(3), pp. 353-365.

6) Chung, K.-R. et al. (2010) 'Timely relocation of mini-implants for uninterrupted full-arch distalization', American journal of orthodontics and dentofacial orthopedics, 138(6), pp. 839-849.

7) Cope, J. B. (2005) 'Temporary anchorage devices in orthodontics: A paradigm shift', Seminars in Orthodontics, 11(1 SPEC. ISS.). doi: 10.1053/j.sodo.2004.11.002.

8) da Costa Grec, R. H. et al. (2013) 'Intraoral distalizer effects with conventional and skeletal anchorage: a meta-analysis', American Journal of Orthodontics and Dentofacial Orthopedics, 143(5), pp. 602-615.

9) Deguchi, T. et al. (2003) 'The use of small titanium screws for orthodontic anchorage' , Journal of dental research, 82(5), pp. 377-381.

10) Egolf, R. J., BeGole, E. A. and Upshaw, H. S. (1990) 'Factors associated with orthodontic patient compliance with intraoral elastic and headgear wear', American Journal of Orthodontics and Dentofacial Orthopedics, 97(4), pp. 336- 348.

11) Fuziy, A. et al. (2006) 'Sagittal, vertical, and transverse changes consequent to maxillary molar distalization with the pendulum appliance', American Journal of Orthodontics and Dentofacial Orthopedics, 130(4), pp. 502-510.

12) Gelgor, I. E. et al. (2004) 'Intraosseous screw-supported upper molar distalization', The Angle Orthodontist, 74(6), pp. 838-850.

13) Graber, T. M., Vanarsdall, R. and Vig, K. (2005) 'Current principles and techniques', Orthodontic Book, USA, pp. 607-611.

14) Graeco, A. et al. (2008) 'Quantitative cone-beam computed tomography evaluation of palatal bone thickness for orthodontic miniscrew placement', American Journal of Orthodontics and Dentofacial Orthopedics, 134(3), pp. 361-369.

15) Greenspan, R. A. (1970) 'Reference charts for controlled extraoral force application to maxillary molars', American journal of orthodontics, 58(5), pp. 486-491.

16) Haas, A. J. (2000) 'Headgear therapy: the most efficient way to distalize molars', in Seminars in Orthodontics. Elsevier, pp. 79-90.

17) Hilgers, J. J., Nissen, S. H. and Tracey, S. G. (2012) 'The PIT and the pendulum: pendulum-integrated TADs.', Journal of Clinical Orthodontics: JCO, 46(8), pp. 465-479.

18) Janson, G. et al. (2007) 'Class II treatment efficiency in maxillary premolar extraction and nonextraction protocols', American Journal of Orthodontics and Dentofacial Orthopedics, 132(4), pp. 490-498.

19) Jung, B. A. et al. (2009) 'Success rate of second-generation palatal implants: preliminary results of a prospective study', The Angle Orthodontist, 79(1), pp. 85-90.

20) Keles, A. and Sayinsu, K. (2000) 'A new approach in maxillary molar distalization: intraoral bodily molar distalizer', American Journal of Orthodontics and Dentofacial Orthopedics, 117(1), pp. 39-48.

21) Kook, Y.-A. et al. (2017) 'Application of palatal plate for nonextraction treatment in an adolescent boy with severe overjet', American Journal of Orthodontics and Dentofacial Orthopedics, 152(6), pp. 859-869.

22) Kook, Y.-A., Kim, S.-H. and Chung, K.-R. (2010) 'A modified palatal anchorage plate for simple and efficient distalization', Journal of Clinical Orthodontics (JCO), 44(12), p. 719.

23) Lee, S. K. et al. (2018) 'A comparison of treatment effects of total arch distalization using modified C-palatal plate vs buccal miniscrews', The Angle Orthodontist, 88(1), pp. 45-51.

24) Miyawaki, S. et al. (2003) 'Factors associated with the stability of titanium screws placed in the posterior region for orthodontic anchorage', American journal of orthodontics and dentofacial orthopedics, 124(4), pp. 373-378.

25) Oh, Y.-H., Park, H.-S. and Kwon, T.-G. (2011) 'Treatment effects of microimplant-aided sliding mechanics on distal retraction of posterior teeth', American Journal of Orthodontics and Dentofacial Orthopedics, 139(4), pp. 470-481.

26) Papadopoulos, M. A. (2014) Skeletal Anchorage in Orthodontic Treatment of Class II Malocclusion E-Book: Contemporary applications of orthodontic implants, miniscrew implants and mini plates. Elsevier Health Sciences.

27) Park, C. 0. et al. (2017) 'Comparison of treatment effects between the modified C-palatal plate and cervical pull headgear for total arch distalization in adults', The korean journal of orthodontics, 47(6), pp. 375-383.

28) Park, H.-S., Jeong, S.-H. and Kwon, O.-W. (2006) 'Factors affecting the clinical success of screw implants used as orthodontic anchorage', American Journal of Orthodontics and Dentofacial Orthopedics, 130(1), pp. 18-25.

29) Park, H.-S. and Kwon, T.-G. (2004) 'Sliding mechanics with microscrew implant anchorage', The Angle Orthodontist, 74(5), pp. 703-710.

30) Park, H.-S., Kwon, T.-G. and Sung, J.-H. (2004) 'Nonextraction treatment with microscrew implants', The Angle Orthodontist, 74(4), pp. 539-549.

31) Park, H.-S., Lee, S.-K. and Kwon, O.-W. (2005) 'Group distal movement of teeth using microscrew implant anchorage', The Angle Orthodontist, 75(4), pp. 602-609.

32) Park, H.-S., Yen, S. and Jeoung, S.-H. (2006) 'Histologic and biomechanical characteristics of orthodontic self-drilling and self-tapping microscrew implants', The korean journal of orthodontics, 36(4), pp. 295-307.

33) Sa'aed, N. L. et al. (2015) 'Skeletal and dental effects of molar distalization using a modified palatal anchorage plate in adolescents', The Angle Orthodontist, 85(4), pp. 657-664.

34) Shoaib, A. M. et al. (2019) 'Treatment stability after total maxillary arch distalization with modified C-palatal plates in adults', American Journal of Orthodontics and Dentofacial Orthopedics, 156(6), pp. 832-839.

35) Vaden, J. L. and Kiser, H. E. (1996) 'Straight talk about extraction and nonextraction: a differential diagnostic decision', American journal of orthodontics and dentofacial orthopedics, 109(4), pp. 445-452.

36) Wehrbein, H. (2009) 'Bone quality in the midpalate for temporary anchorage devices', Clinical Oral Implants Research, 20(1), pp. 45-49.

37) Yamada, K. et al. (2009) 'Distal movement of maxillary molars using miniscrew anchorage in the buccal interradicular region', The Angle Orthodontist, 79(1), pp. 78-84.

38) Youssef, M. (1996) 'The prevalence of dentofacial deformities in Syria', Damascus Univ J, 12, pp. 151-186.

Claims

1) The mini-screws anchored casted palatal plate is an appliance for distalizing the entire upper dental arch especially in the non-extraction treatment of class II malocclusion, where it consists of: a) A custom-made Vitallium palatal bar provided with two holes at its posterior edge on the paramedian area, and two laterally extended arms with two distal-posteriorly directed hooks. b) Two mini-screws for providing a skeletal anchorage of the plate that inserted in the holes of the plate at the paramedian area. c) An anterior stainless steel trans-palatal arch with two soldered mesial- posteriorly directed hooks. d) The distalizing force application methods (elastic chains or NiTi closed coil springs) that applied from the anterior hooks of the trans-palatal arch to the posterior hooks of the casted palatal plate.

2) The appliance in claim 1; where it can distalize the entire dental arch in one step by taking the advantage of the skeletal anchorage, provided by the palatal mini-screws, without any depending on patient's cooperation, which ensures an effective distalization of the upper teeth, also it reduces the overall treatment time and eliminates loss of anchorage observed with traditional distalization appliances.

3) The appliance in claim 1; where distalization can be accomplished with bodily movement of the upper teeth due to the palatal direction of the applied force, which is closer to the center of resistance.

4) The appliance in claim 1 is a custom-made, so it fits better with the anatomical features of the palate, which reduces inflammation of the soft tissues and accumulation of food debris.

5) The casted palatal plate is made from bio-acceptable Vitallium metal that can be manufactured in the laboratory easily and at a lower cost, also it can withstand high forces during distalization without tilting or impinging into the palatal tissues due to its high rigidity.

6) The appliance in claim 1, where the casted palatal plate has two (2 mm diameter) holes for mini-screws' insertion localized at its posterior edge, that has increased the effectiveness of the plate, as the anchorage reinforcement is in the direction of the distalization force.

7) The appliance in claim 1, where the casted palatal plate must have a tight sealing of its middle part on the paramedian area to prevent mini-screws' failure, while its arms must keep 2 mm of distance away from the palatal tissues to permit cleaning procedures.

8) Using two (instead of three) mini-screws for skeletal anchorage of the plate has reduced the cost of the appliance without compromising the stability of the plate, as the customized plate has already an adequate adaption on the palatal tissues, also applying the mini-screws at the paramedian area, which has adequate dense bone, provides an acceptable initial stability of the miniscrews.

9) The appliance in claim 1; where the placement of the plate at the posterior palatal region can provide a wide range of action without the limitation of root's damaging, also the application of mini-screws at the paramedian area, with avoiding the palatal suture, can permit to its use it for adolescent and adult patients.

10) The appliance in claim 1; which introduced for total upper arch distalization, and can be indicated in several cases; including: a. Non-extraction treatment of skeletal class I or mild skeletal class II accompanied with dental class II relationships. b. Extraction cases with severe upper lip protrusion and need to further distalization of the upper arch after closing of the extraction spaces. c. En-mass retraction in the extraction cases. d. Distalization of the maxillary arch in the pre-surgical orthodontic phase of class III orthognathic surgery to avoid extraction of upper premolars.