root resorption histological aspect of root resorption · before treatment four months after lipus...

1

Eiji Tanaka Professor and Chair, Department of Orthodontics

and Dentofacial Orthopedics

Institute of Health Biosciences

The University of Tokushima Graduate School

Graduated from Osaka University Faculty of Dentistry in

1988 and went on to complete his PhD in 1993.

Gained the special license as an orthodontist, the

orthodontic instructor license, and an accredited

specialist in temporomandibular disorders.

Took up his current post in 2008 and in May 2015 has

also been a Distinguished Adjunct Professor at King

Abdulaziz University, Jeddah, Saudi Arabia.

My research is centered around biomechanics of the

temporomandibular joint (TMJ), application of low-

intensity pulsed ultrasound in dental tissue

engineering, and development of nucleic acid

medicine for treatment of muscle atrophic diseases.

Bio introduction

AAO 117th Annual Session

San Diego Convention Center, San Diego, Calif

April 23, 2017

Introduction of accelerated orthodontic

tooth movement by a low-intensity pulsed

ultrasound exposure

Force

Compression

Compression Tension

Tension

Local responses of periodontal tissues to mechanical

loading during orthodontic tooth movements

A case of orthodontic treatment

using a lingual bracket system

Average duration for orthodontic treatment: about 2-3 years

Before treatment After treatment

The fact is that orthodontic tooth movement directly causes an irreversible

resorption of the root. Due to orthodontic tooth movement, the most severely

resorbed teeth are maxillary central and lateral incisors, followed by the

second premolars.

Root resorption Application of adequate mechanical stimulation to bone is essential for

maintaining bone mass and strength. Mechanical stimuli have been

reported to activate both osteoblasts and osteoclasts, resulting in the

promotion of bone remodeling. During orthodontic treatment, root

resorption sometimes occurs because odontoclast is similar to osteoclast.

Histological Aspect of Root Resorption

Moving

direction

Compressive

side Tensile

side

Root Alveolar bone New bone

2

Osteoblasts not only plays a central role in bone formation by synthesizing

multiple bone matrix proteins, but also regulate osteoclast maturation by

soluble factors and cognate interaction, resulting in bone resorption.

Osteoclast maturation requires stimulation by receptor activator of nuclear

factor κB ligand (RANKL) expressed on osteoblasts. Cementoblasts share

many properties with osetoblasts and recently, it has been reported that

cementoblasts also express RANKL and osteoprotegerin (OPG) and

probably influence cementoclastogenesis process.

RANKL

Cementoblast

Pro-resorptive and

calciotropic factors Pre-odontoclast

Cementum

RANKL/RANK/OPG Pathway

RANKL

RANK Odontoclast

RANK

OPG

Interventions on accelerating orthodontic

tooth movement

・Surgical procedure

Corticotomy: Making small perforations on the alveolar bones

Dentoalveolar distraction: Making monocortical perforations

on alveolar bones around canines

Periodontal distraction: Making vertical grooves on the mesial

side of the first premolar extraction sockets

・Non-surgical procedure

Low-level laser therapy

Electrical current

Pulsed electromagnetic field

Mechanical vibration

Low-intensity pulsed ultrasound

Efficacy of interventions on accelerating

orthodontic tooth movement:

A systematic review

Inclusion criteria for included studies:

Randomized or quasi-randomized controlled trials up to 2014

Long H et al., 2013 in Angle Orthod

Kalemaj Z et al., 2015 in Eur J Oral Implantol

Effects of interventions:

・ Corticotomy is safe and able to accelerate orthodontic tooth

movement.

・ Dentoalveolar or periodontal distraction is promising in

accelerating orthodontic tooth movement but lacks convincing

evidence.

・ Low-level laser therapy is safe but unable to accelerate

orthodontic tooth movement.

・ Electronic current and pulsed electromagnetic fields do not

allow for solid conclusions in accelerating orthodontic tooth

movement.

Today’s lecture objectives

1) to recognize the effectiveness of LIPUS on


2) to apply the LIPUS in clinical orthodontic

treatment.

Ultrasound • Ultrasound (US) is an acoustic radiation at frequencies above the limit of human hearing (30Hz – 20 kHz).

A fund of knowledge about the history of US development 1912 An excellent passenger ship, Titanic (UK), struck against an iceberg.

1919 France developed a Sonar (sound navigation ranging) with an

ultrasound oscillator in order to protect from Germany submarine

during the first World war.

Various uses of US For informative

・Sonar

・Non-invasive

diagnosis device

For mechanical

・US washer

・US metal welder

・US humidifier

・US beauty device (Esthetic aim)

Echo diagnosis device

Hepatitis

US Medical Uses It has previously been shown that US can accelerate many kinds

of bone healing, and stimulate nonunion and delayed union

(Dickson et al., 1994). In clinical practice of orthopedic surgery,

therapeutic US is widely used to decrease joint stiffness, reduced

pain and muscle spasms, improve muscle mobility, and

accelerate bone healing. Low-intensity pulsed US (LIPUS) is

commonly used as a promoter and

accelerator of bone fracture healing. Note:

On April 2002 immediately before FIFA

World Cup, Beckham was injured during a

Champions League match, breaking the

second metatarsal bone in his left foot.

Most people gave up his play in the World

Cup games. However, treatment remedy

with LIPUS and electrostimulation enabled

him to play soccer in the game because

these treatments accelerated a bone

healing in fracture site.

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US Dental Uses

・LIPUS accelerates bone formation at the osteodistraction site. El-Bialy et al., 2002 in Ann Biomed Eng

El-Bialy et al., 2008 in J Dent Res

・ LIPUS stimulation enhances the healing process of

orthodontically-induced root resorption in humans. El-Bialy et al., 2004 in Am J Orthod Dentofacial Orthop

・ LIPUS enhances human gingival fibroblasts differentiation

and neural differentiation of gingival stem cells. Mostafa et al., 2009 in Archs Oral Biol

Little is known about LIPUS effects on the acceleration of

tooth movement and the prevention from orthodontically-

induced root resorption.

Recently, a great concern has increasingly been given to US

therapy aimed for dental treatment.

1 Days 0 2

LIPUS exposure

Frequency 1 MHz

Intensity : 30 mW/cm2

Pulsed: 1:4 (2 ms on and 8 ms off)

Duration: 15 minutes per day

3 4 5 6

Suregry

7

Sacrifice

21

1st

molar

Implant

50 gｆ

Incisor

Right: LIPUS side

Left: Control side

BR Sonic Pro®

Force application on 1st molar

LIPUS exposure

In vivo experiment

Materials and Methods

12 week-old Wistar strain male rats (n = 8)

Inubushi T, Tanaka E, et al., 2013 in Bone

Control LIPUS

Micro-CT observations

3D image

2D-Sagittal

image

D

M


Control side

US side

Bone

Bone

Pulp

Pulp

Pulp

Pulp


Control LIPUS A plane

Cross-sectional

area of resorption

Level 3

Level 4

Length of

resorption

Level 5

Level 1

Level 2

Histometric findings

HE （×100） Distal root of upper first molar

Inubushi T, Tanaka E, et al., 2013 in Bone Control LIPUS

0.2

0.4

0.6

0.8

1.0

0

Length (mm)

**

0

500

1000

1500

2000

2500

3000 3500

4000 4500

Control LIPUS

(μm2) Cross-sectional area

**

** =p <0.01

Control LIPUS

Histometric findings

HE （×100）


4

LIPUS Control

Numbers of odontoclasts and osteoclasts

Bone

Tooth

TRAP staining

（×200）

Bone

Tooth

** p <0.01

* p <0.05

歯

骨

0

5

10

15

20

25

30

**

Odontoclasts

Control US

Num

ber

of

TR

AP

posi

tive

cell

s

ultrasound 0

2

4

6

8

10

12

14

16

18

*

Osteoclasts

Control US

Num

ber

of

TR

AP

posi

tive

cell

s

LIPUS Control

(mm)

0

0.1

0.2

0.3

0.4

0.5

0.6

Amount of tooth movement

Effect of LIPUS on lateral tooth movement

Arai C, Tanaka E, et al., under consideration

LIPUS exposure

Mesh

band

Glue

.010 in

SS wire

.019x.025 in

SS wire

Micro-CT images

Occlusal view Coronal view

After tooth movement

Before tooth movement


Intermolar

width


Images by the inspeXio SMX-225CT,

SHIMADZU Co.

Analyses of bone mineral density (BMD) and bone volume fraction (BV/TV)

R L

M1

M2

M3

M

B

D

P

M

B

D

P

Coronal section at the middle of the root

M1

M2

M3

Blue mark indicates Tissue Volume (TV).

Red mark indicates Bone Volume (BV).

Sagittal section

M1: 1st molar; M2: 2nd molar; M3: 3rd molar;

B: buccal; P: palatal; M: medial; D: distal

Micro-CT images



200μm

Calcein bone label Xylenol orange bone label

Fluorochrome labels of experimental tooth movement



Results

0

50

100

150

200

250

300

350

400

Body weight Intermolar width

Inetr

mola

r w

idth

(m

m)

Control

**

(gra

m)

BMC (mg) BV/TV (%)

LIPUS Control LIPUS

Control LIPUS Control LIPUS

** p < 0.01 vs Control



0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0

5

10

15

20

(mg)

** **

5

Untreated

control Control LIPUS

B: Alveolar bone

PDL: Periodontal ligament

Arrows indicate calcein line; Arrowheads

indicate xylenol orange line

Effect of low-intensity pulsed ultrasound (LIPUS) during

lateral tooth movement

Results


B B B

PDL

PDL

PDL

*

(μm)

Control LIPUS

* p < 0.05 by the Mann-Whitney U-test

This bone formation is the compensatory response to

lateral tooth movement, indicating that LIPUS

enhances bone remodeling during tooth movement

and can accelerate tooth movement.

Today’s lecture objectives

1) to recognize the effectiveness of LIPUS on


2) to apply the LIPUS in clinical orthodontic

treatment.

Clinical Trial

The use of LIPUS to a patient with short roots of maxillary incisors

Case : 16Y 9M Female

Traumatic history： n.p.

Chief Complaints : Anterior crowding

Oral photographs before treatement

Problem list

1. Minor crowding of bimaxillary anterior teeth

2. Slight deep bite

Panoramic radiograph at initial stage

Dental X-ray photographs

Time： 15 min per a day

Duration: 10 weeks

US properties:

Frequency 1.0 MHz

Pulse rate 20% (2 ms on and 8 ms off)

Intensity 150 mW/cm2

Exposure protocol

BR Sonic Pro® Probe

Gel for

exposure

10-week

treatment

Initial stage

Oral photographs before and after 10-week treatment

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Initial stage

10-week

treatment

Dental X-ray photographs

2 1 1 2 Aevo systemTM（1st intraoral LIPUS system）

Hand-held electronics

■Easy-to-use at-home

■Rechargeable

■Displays treatment status

Intra-oral appliance

■20 minutes/day

■Dual/Single arch treatment

■Intra-oral ultrasound gel

In-clinic software

■Activation

■Treatment zone (teeth) selectivity

■Displays usage compliance

Provided by prof. Tarek El-Bialy, University of Alberta

First Intraoral LIPUS Device

Provided by prof. Tarek El-Bialy

Subject demographics

Characteristic Per-Protocol Subjects

Gender

Male

Female

Age

Mean

Standard Deviation

Minimum

Maximum


Tooth movement measurement

・ dt0: the first extraction space measurement

・ dt1: the last extraction space measurement on either side

・ t: the number of weeks between dt0 and dt1

・ Tooth movement rate =

・ rexp: tooth movement rate on the LIPUS side

・ rcont: tooth movement rate on the control side

・ Percent change = x 100%

dt0 － dt1

t

rexp － rcont

|rcont|


1‐007 23 year-old female

2 months difference

88% faster tooth movement with LIPUS

Before treatment Two months after LIPUS exposure


7

1-013 13-year-old female

4 months difference

66.9% faster tooth movement with LIPUS

Before treatment Four months after LIPUS exposure


1-014 28-year-old female

4 months difference

265% faster tooth movement with LIPUS

Before treatment Four months after LIPUS exposure


Summary of the clinical trial

Preliminary study results:

-Aevo System provides a statistically significant (p=0.016)

increase in tooth movement rate, with an average

percentage increase of 29.0% in tooth movement rate

compared to the control.

-There was no increase in adverse events or pain reported

for Aevo System as compared to the control (p<0.001).

Inhibition of root resorption

Mechanoreceptor （cf. Integrin）

signaling

pathway

Activity of

transforming factor

Changes of gene

expressions

Inhibition of odontoclasts

expression by change of

RANKL/OPG ratio

Activation of cementum repairment

Cementoblasts

LIPUS exposure can inhibit root resorption on the

compression side without interference of tooth movement

and enhance bone remodeling during tooth movement,

resulting in the acceleration of tooth movement.

Summary

LIPUS may be a good as new technique for acceleration of orthodontic tooth movement, leading to the reduction of orthodontic treatment length and root resorption.

Thank you for your attention. AAO Donated Orthodontic Services (DOS) Program

All that is missing is You!

• Introduced in 2009, the DOS program provides access to care for children in need. Access to quality orthodontic care is missing in many children’s lives. The AAO DOS program mission is to serve indigent children without insurance coverage or that do not qualify for other assistance in their state of residence.

• The program has expanded and offers care to children nationwide in addition to the recognized state programs in Illinois, Indiana, Kansas, Michigan, New Jersey, North Carolina, Rhode Island, Tennessee, Texas and Virginia.

• In order to expand further, we need you to help us by volunteering to serve as a provider orthodontist or help identify orthodontists willing to lead efforts to establish a DOS chapter in your state.

• Stop by the DOS booth here in San Diego to learn more about the program or contact Ann Sebaugh at [email protected] with questions.

mailto:[email protected]

root resorption histological aspect of root resorption · before treatment four months after lipus...

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