JIDAM “An Official Journal of IDA - Madras Branch” ©2022. Available
online

ISSN No: 2582-0559

Volume No: 9, Issue No: 1

CASE REPORT

ALVEOLAR RIDGE SPLIT IN AN ATROPHIC POSTERIOR

MANDIBLE – A CASE REPORT

Dr. Divya Kumar, Dr. G.Sivaram*, Dr. T.S.S. Kumar* ,

Department of Periodontics , Sri Ramachandra Faculty of Dental Sciences, SRIHER, Chennai, Tamil Nadu, India

* Department of Periodontics, Ragas Dental College and Hospital, East Coast Road, Uthandi, Chennai, Tamil Nadu,

India.

DOI: 10.37841/jidam_2022_V9_I1_04

Address for Correspondence

Dr. Divya Kumar, MDS MFDSRCPS(Glasg) (Lecturer)

Department of Periodontics

Sri Ramachandra Faculty of Dental Sciences,

SRIHER, Chennai, Tamil Nadu, Chennai

Mail id: dr.divyakumar5889@gmail.com

Received : 16.12.2021

Accepted : 09.02.2022

First Published: 14.02.2022 Published : 30.03.2022

ABSTRACT

Atrophic  edentulous  ridges  often  pose  a  challenge  for
successful  rehabilitation  using  endosseous  dental
implants.  The  solution  to  this  is  bone  augmentation
procedures. This case report chronicles the management
of  an  atrophic  posterior  mandibular  ridge  by  a  ridge-
split  technique  along  with  simultaneous  implant
placement.    It  also  highlights  the  importance  of
maintaining  an  adequate  zone  of  keratinized  mucosa
around  the  implant  which  was  accomplished  by  means
of  an  apically  repositioned  flap  in  the  second  stage
surgery. A two year follow up reveals healthy implants
and  a  fully  functional  dentition.  Hence  the  ridge-split
procedure  can  provide  a  simpler  approach  to
augmentation

compared

traditional

complex

techniques that require an additional donor site which
raises the risk of morbidity. This approach also reduces
the total treatment time which is beneficial for both the
patient and the surgeon.

KEYWORDS:

Horizontal ridge resorption, ridge

augmentation,

ridge-split

technique,

endosseous

implants, keratinized mucosa

Volume No: 9, Issue No: 1

Divya et al: Alveolar Ridge Split in an Atrophic Posterior Mandible – A Case Report

INTRODUCTION

A  functional  dentition  is  indispensible  for  maintaining  the
overall health and quality of life. Edentulism is a debilitating
condition.    Complete  or  partial  edentulism  is  found  to  be
prevalent  in  majority  of  the  population  worldwide.  The
options  of  replacing  missing  teeth  range  from  removable
dentures  to  fixed  options  such  as  fixed  partial  dentures  and
dental  implants.  Dental  implants  have  emerged  as  a
successful treatment modality offering numerous advantages
such  as  superior  function,  better  esthetics,  enhanced
phonetics and mastication. They also most importantly aid in
maintenance  of  bone  levels.

Replacing missing teeth in

partly edentulous jaws with dental implants has been proven
be a very predictable and highly successful treatment
option

Following  tooth  loss  or  extraction,  alveolar  bone  undergoes
an  irreversible  and  progressive  process  called  resorption
resulting  in  an  unavoidable  loss  of  bone  width  and  height

The  alveolar  ridge  undergoes  accelerated  bone  loss  within
the  first  6  months  of  tooth  extraction  resulting  in
approximately  40%  loss  of  ridge  height  and  60%  loss  of
ridge width

. The

buccal plate of bone resorbs faster and to a

greater extent compared to the palatal or lingual plates
because of the loss of bundle bone

Atrophic  edentulous  jaws  often  pose  a  challenge  to  ideal
implant  placement  and  prosthetic  rehabilitation.  Inadequate
bone  width  and  height  in  the  ridge  is  a  common  limitation
for  successful  rehabilitation  with  implant  therapy.  This  is
overcome by using bone augmentation procedures that aid in
restoring the residual bone width and height to achieve ideal
three  dimensional  implant  placement  and  position.
Horizontal defects have been augmented using methods such
as  guided  bone  regeneration  (GBR),  Block  bone  grafting,
ridge splitting and distraction osteogenesis.

This case report describes a ridge split procedure with
simultaneous implant placement.

CASE REPORT

A  40‑year‑old  male  patient  reported  to  the  outpatient
department  with  a  chief  complaint  of  missing  teeth  in  the
right  lower  back  tooth  region  for  the  past  6  months.  A
complete  case  history  was  recorded.  The  patient  was
systemically healthy with a history of extraction of 46 and 47
due  to  caries.  On  intraoral  examination,  a  Siebert’s  class  I
alveolar  ridge  defect  was  noticed.  Pre-operative  oral
prophylaxis  was  performed  and  oral  hygiene  instructions
reinforced.  This  was  followed  by  blood  investigations
including  Complete  Blood  Count,  Bleeding  and  Clotting
time,  radiographic  investigations  including  conventional
orthopantomogram  (OPG)  and  periapical  radiographs.  Bone
sounding revealed a ridge width < 5 mm and the radiograph
showed  a  ridge  height  of  >10  mm  in  46  and  47  region.  An
informed consent form was provided and duly signed by the
patient prior to the procedure.

SURGICAL TECHNIQUE

A pre-procedural  mouth rinse with 0.2% Chlorhexidine was
given to the patient. After administration of local anesthesia
(2%  lidocaine  with  1:200,000  adrenaline),  a  mid  crestal
incision  was  given  and  a  full  thickness  mucoperiosteal  flap
elevated. A mid crestal osteotomy of the atrophied ridge was
done  using  a  round  tungsten  carbide  bur.  Osteotomes  were
used  in  a  progressive  manner  to  achieve  bone  expansion.
Sequential osteotomies were prepared and two implants were
placed  (Adin  Implants  :  4.2x11.5mm  in  46  region    and
4.2x10mm  in  47  region).  Primary  stability  was  achieved.
Cover-screws  were  placed.  The  interpositional  space
between  the  two  expanded  cortical  plates  was  filled  with
particulate allograft  – demineralized  bone  matrix  (DMBM ‑
Osseograft™) and membrane (Healiguide) was placed upon
the  crest  and  adapted  buccolingually.  The  flaps  were
approximated  and  primary  closure  obtained  using  3-0
Mersilk  sutures.  Postoperative  instructions  were  given,
antibiotics

and

analgesics

were

prescribed.

0.2%

chlorhexidine rinse was also prescribed in the post-operative
period. Suture removal was done after 14 days. (Fig 1A-2D)

SECOND STAGE SURGERY

In  order to  increase  the  width  of  keratinized  ginigiva  in  the
posterior  mandibular  region,  an  apically  repositioned  flap
was  combined  in  the  second-stage  surgery  to  expose  the
implants  after  a  period  of  6  months.  Standard  surgical
protocol was followed, healing collar / gingival formers were
placed  and  the  flaps  apically  positioned  and  sutured  around
the gingival formers.

The gingival former was removed after

a period of 15 days and tissue maturation of the gingival cuff
examined.    There  were  no  signs  of  inflammation  and  a
healthy  gingival  cuff  was  noted  on  removal  of  the  gingival
former. An abutment level impression was made. Following
the  impression,  a  definitive  restoration  –  a  screw  retained
prosthesis

(porcelain-fused-to-metal

crown

with

semiprecious alloy) was given. The patient was reviewed
after 6 ,12 and 24 months and radiographs were taken. (Fig
3A-7B)

Fig 1A: Preoperative Photo

Volume No: 9, Issue No: 1

Divya et al: Alveolar Ridge Split in an Atrophic Posterior Mandible – A Case Report

Fig 6 : Radiograph at 12 months post loading

Fig 7A : Post-loading at 24 months photograph

Fig 7B – Radiograph at 24 months Post - loading

radiograph

DISCUSSION

Atrophic  edentulous  ridges  often  present  with  insufficient
bone  for  endosseous  implant  placement.  Several  authors
have  reported  that

1.8 to 2.0 mm of buccal bone thickness

was critical in preventing buccal bone loss and the center of
a regular implant should

be placed 4 to 5 mm from the

buccal bony housing, depending on the diameter of the
implant placed

An implant must be surrounded by at least 1

of cortical bone on both sides. Replacing a molar or a

premolar with an implant of standard dimension is often

difficult to achieve in an alveolar ridge

narrower than 5 mm

Hence bone augmentation procedures are often  necessary to
ensure  optimal  implant  placement.  The  gold  standard  of
grafting  has  always  been  autogenous  bone  grafts.  The  main
limitation  in  harvesting  autogenous  grafts  is  that  intraoral
donor

sites invariably do not provide sufficient graft

volume

7,8

. Other disadvantages include donor site morbidity,

nerve  damage,  tooth  devitalization,  gingival  recession,
infection,  pain,  blood  loss,  drooping  of  chin,  membrane
exposure,  increased  duration  of  the  entire  treatment  and
patient discomfort

An ideal ridge width of 5-6mm is needed for placement of a
regular 4mm implant. Ridge-split / expansion can be ideally
accomplished  in  cases  where  the  residual  ridge  width  is  4-
5mm  facilitating  placement  of  a  regular  implant  with
primary  stability.  This  results  in  optimal  osseointegration
without  creating  another  donor  site  or  incurring  additional
expenses  in  the  form  of  commercial  bone  grafts

. In this

case, the patient presented with an initial ridge width < 5mm.
Residual ridge expansion by means of a ridge split procedure
was undertaken in anticipation of a 2-3mm increase in ridge
width.

Osteocondensation  is  more  commonly  used  in  the  maxilla
because  the  bone  density  is  usually  type  3  or  4  comprising
predominantly of trabecular /  cancellous  bone  in  contrast to
the thicker cortical bone of Type 1 or 2 seen in the mandible.
Cancellous  bone  in  the  maxilla  is  more  amenable  to
compression compared to the dense  cortical  bone present  in
the  mandible.  The  limitation  of  single  stage  ridge  split
procedures  in  the  mandible  using  osteotomes  is  the  higher
incidence  of  greenstick  fractures  due  the  presence  of  thick
cortical  bone.  However  in  this  case,  due  to  the  less  dense
nature  of  cortical  bone  present  on  drilling,  the  Summers
Osteotome technique

was opted for rather than using chisel

and  hammer,  rotating  and  oscillating  saws,  which  cause
trauma  to  the  soft  tissues  and  are  increasingly  stressful  for
the patient as well. More recently, Piezosurgery has emerged
as a viable tool for crest expansion. It works on the principle
of  piezoelectric  effect.    The  advantages  that  Piezosurgery
offers  include  selective  cutting  of  the  bone,  preservation  of
gingiva,  blood  vessels,  nerves,  and  sinus  membranes  from
injury  and  the  cavitation  effect  that  ensures  continuous
irrigation,  cleaner  surgical  field  and  lesser  heat  generation
which can prove detrimental to the bone cells.

Packing a horizontally expanded ridge with a bone substitute
results  in  reducing  resorption  in  the  bone  walls  around  the
implant. It has been postulated that despite the expansion of
the  ridge,  the  bone  walls  in  direct  contact  with  the  implant
probably  exert  minimal  pressure  on  the  implant  surface
which  in  turn  can  affect  bone  vascularization  leading  to
resorption  that  is  ischemic  in  origin.  This  can  be  overcome
by using synthetic bone substitutes. Post ridge expansion and
implant placement, a demineralized bone matrix (Osseograft)
was  used  to  fill  the  jumping  distance.  The  site  was  covered
with  a  membrane  (Healiguide)  and  primary  closure  was
obtained.

Volume No: 9, Issue No: 1

Divya et al: Alveolar Ridge Split in an Atrophic Posterior Mandible – A Case Report

The importance of having an adequate band of keratinized
mucosa around the implant cannot be undermined.

Several

studies have shown that

the presence of an adequate band of

keratinized  mucosa  is  of  greater  importance  around
restorations  and  prostheses  in  comparison  to  natural  teeth
regardless  of  oral  hygiene  status.  The  absence  of  adequate
keratinized mucosa (< 2mm)

especially in posterior implants,

was found to be associated with higher plaque accumulation
and gingival inflammation

and studies by Bouri et al have

shown  that  the  presence  of  an    increased  width  of
keratinized  mucosa  is  associated  with  lower  alveolar  bone
loss.  Hence  an  apically  repositioned  flap  was  combined
along  with  the  second  stage  surgery  to  expose  the  implants
for  insertion  of  the  gingival  formers.  This  resulted  in  an
increase  in  the  width  of  keratinized  tissue  around  the
implants  without  which  the  tissues  are  easily  susceptible  to
trauma and breakdown.

Some shortcomings in the present case report include only a
two-dimensional  radiographic  evaluation  and  interpretation
as opposed to more advanced three dimensional imaging that
provide  more  intricate  details.  Further  long  term  studies  of
several  cases  comparing  different  methods  of  ridge  –split
such as piezo surgery,  commercially  available  splitting kits,
chisel-mallet  and  osteotomes  are  required  to  gain  further
knowledge of the predictability of the procedure. Bone levels
surrounding  the  implant  at  different  time  spans  can  also  be
calculated to assess any hard tissue changes.

CONCLUSION

Every  surgical  procedure  presents  with  its  own  set  of
advantages  and  disadvantages.  It  would  be  prudent  for  the
clinician  to  choose  that  which  is  less  invasive  and  presents
with  reduced  risk.  Hence  horizontal  bone  augmentation
using ridge expansion /  split  is a  very predictable procedure
allowing  simultaneous  implant  placement  in  suitable  cases.
The morbidity associated with harvesting block grafts can be
avoided  when  only  minimal  expansion  is  needed  to  ensure
implant placement in an optimal restoration driven position.

FINANCIAL SUPPORT AND SPONSORSHIP:

Nil

CONFLICTS OF INTEREST:

There are no conflicts of interest.

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