CBCT

1. CBCT
Third Eye in
Dental Implants
By: Ghida Lawand
HassanAshkar

2. Pretreatment Clinical Evaluation
Clinical
Assessment
General
Health
Chief
Complain
Facial
Profile
Periodontal
Tissues
Soft
Tissues
Residual
Alveolar
Ridge

3. 1. Examine patient’s current and status medical history to assess
risk profile

5. 2. Periodontal/tissue biotype
Thin gingival tissue Thick gingival
tissue
- Highly scalloped, thin,
nonkeratinzied and flabby
mucosa  more susceptible
to gingival recession and
mechanical trauma  soft
tissue grafting indicated
- Thick, keratinized and non-mobile
mucosa  Less susceptible to gingival
recession following implant treatment
- Esthetics: thick mucosa is able to mask
the implants’ color and their
submucosal metallic components,
reducing the risk of a nonesthetic
result.

6. 3) Lip line
The lip line is associated with the amount of tooth and supporting tissues visible
when patient chews, speaks, or smiles.
High lip line: patient’s entire maxillary teeth and part of his/her alveolar process is
revealed
 presents highest esthetic risk in implant treatment
 provide a diagnostic set up or a temporary prosthesis for the patient to try on
before implant treatment to assess appearance regarding the lip line
 provisional prosthesis can also serve as a model for a surgical guide or stent to
aid placing implants
Low
Medium
High

7. 4) Occlusal status and functional exam
1.Parafunctional habits such as bruxism and
clenching must first be diagnosed and treated
before implant treatment to ensure occlusal
stability
2.Parafunctional habits cause excessive
loading on implants causing technical
complications such as screw or framework
fractures

8. 5) Evaluate edentulous ridge
1. Visually assess the contour, height and width of the edentuglous ridge
2. Fibrous overlying tissue can be deceiving
3. Palpate to detect any concavities or depressions
4. This step is essential to detemine if patient needs bone augmentation
5. Nevertheless, edentulous ridge must be radiographically examined
6. Observe crown to bone relationship (distance between the ideal position of the
clinical crowns and the underlying bone)
7. measure the distance between the dentulous ridge and the opposing dentition to
ensure there’s enough space for the restoration
8. length of endentulous area can be measured to determine the approximate
number of implants needed  only verified through radiographs
Labially, this ridge reveals a slight loss in
the center and the presence of healthy
keratinized gingiva
Occlusally, ridge appears wide enough
to accommodate implants  verified
through radiography

9. a. Characteristics of Ideal Imaging Techniques in Implants:
1. Ability to visualize the site of implant site in the mesiodistal,
faciolingual, and superoinferior dimensions
2. ability to determine axial orientation of implants
3. ability to allow reliable, accurate measurements
4. capacity to evaluate trabecular bone density and cortical
thickness
5. capacity to correlate the imaged site with the clinical site
6. reasonable access and cost to the patient
7. minimal radiation risk
Preoperative Radiographic Assessment

10. b. Preoperative radiographs should reveal: (15)
1. Position and size of relevant normal anatomic structures, including the:
a. Inferior alveolar canals
b. Mental foramina
c. Incisive or nasopalatine foramen and canal
d. Nasal floor
2. Shape and size of the antra, including the position of the antral floor and
its relation to adjacent teeth
3. Presence of any underlying disease that could compromise the outcome
of treatment e.g. osteoscleorosis
4. Presence of any buried teeth or retained roots
5. Quantity of alveolar crest/basal bone, allowing direct measuremtns of the
height, width and shape
6. Quality (density) of bone, noting:
a. Amount of cortical bone present
b. Density of the cancellous bone
c. the trabecular spaces size

11. CBCT Scans
The Standard of Care in
implants?

12. Advantages of CBCT in implant dentistry:
1. Evaluates all possible sites and anotmical structures:
2. No superimposition
3. Uniform magnification
4. Measurements accurate withing about 1 mm
5. Simulates implant pacement with implant planning software
6. CBCT dose of radiation exposure is less than that produced by CT scanning
7. Can limit radiation exposure according to Field of View chosen (FOV): small,
medium, or large
8. provides precise information about pathology
9. Less expensive than CT scanning
10. allows for the 3-D evaluation of an arch
Limitations of CBCT in implants:
1. Moderate cost and radiation risk as compared to other imaging techniques
2. Some metallic image artifacts
3. Special training for interpretation
4. Relative bone density measurements (HU) not calibrated

13. Pre-operative Diagnostic Planning
To decide the precise healing scope of a
prosthetic implant therapy to re-establish
chewing function, it’s imperative to assess
Bone availability and the existing anatomical
landmarks. This is easier when using 3D
diagnostics than using illustration with
traditional images

14. A) Bone Availability
The most frequently reported indication for the
use of CBCT in implant planning area are to
measure the alveolar ridge and map the bone
morphology of possible implant sites for
osseointegration of the implant.
1. Quantitative Evaluation of BoneAvailability
Bone compactness is an significant factor for implant placement to expect the ability to
stabilize the implant when minimal bone height is otherwise available.
Precise estimation of the alveolar bone height and width are mandatory:
1. For selecting the suitable implant size
2. Establish the degree of angulation of the edentulous alveolar ridge.

15. Bone Height: Bone Width:
Measured from the
crest of the alveolar
ridge to the opposing
border of the bone or
an anatomical
structure.
According to the bone
height, implant length
is determined
It is the bucco-lingual
width of the alveolar
bone. Implant diameter
is selected based on
this parameter.

17. Superior border of the
mandible

18. Height of the maxillary alveolar ridge
measured at a specific point at a specific
point prior to implant placement
Width of the maxillary alveolar
ridge measured at a specific point
prior to implant placement

19. After adequate height is available, the next most
significant criterion affecting long-term survival of
implants is the width of the available bone.
Axial cross-section on the
root level showing the
space aroundthe implant.

20. Note the little space
between the mesial
and distal surfaces of
the implant and the
adjacent teeth

21. 2. Qualitative Evaluation of BoneAvailability

22. Hounsfield scale
Referred to as HU, it is a scale used to measure the bone
density in the CBCT scans. It can measure accurately the
density of the selected point, whether it’s related to bone or
other tissues. HU gives a quantitative assessment of the bone
density where it’s measured by the ability of the tissue to
attenuate x-ray beam.
HU scale range from -1000 (air) to +3000 (enamel). While
bone quality refers to both thickness and density of the
cortical plates as well as trabecular portion of the bone. This
parameter affects to high limit the success of the treatment.

23. Example of Trabecular bone
density in the anterior region
of maxilla.
Example of Trabecular bone
density in the anterior region
of mandible.
Example of Cortical bone
density in the anterior region
of mandible.

25. Length of the Edentulous Area
Missing upper left
lateral incisor to
be restored with
implant. In 3D and
Axial Slice.

27. 3- Ridge Orientation and morphology:
it is the inclination of the alveolar edentulous ridge. Virtual implant can
be positioned in a cross sectional alveolar bone using special planning
software.
CBCT Shows the type of alveolar bone present
- Cross-sectional CBCT revealing three types of mandibular ridge
morphology:
- line A represents a the line of reference 2 millimeter coronal to
the inferior alveolar nerve canal

28. Choosing
the suitable
length and
diameter of
the implant.
Note the
angular
inclination
of the
implant

29. According to Tolstunov, a Diplomate of theAmerican Board of Oral Implantology/Implant
Dentistry the alveolar jaw can be divided into four regions or “functional implant zones”
with each region posessing "unique characteristics of anatomy, blood supply, pattern of
bone resorption, bone quality and quantity, need for bone grafting and other supplemental
surgical procedures, and a location related implant success rate.”
Anatomical factors assessed by CBCT imaging

30. Also known as the “traumatic zone”
consists of alveolar ridge of pre-maxilla and the teeth from right to left premolar
exhibits the greatest loss of bone after tooth loss/extraction  occurs in the facio-palatal
or horizontal direction and mainly on the facial side of the alveolar ridge
Any bone loss in this area is crucial due to its esthetic risk with dental implants  if
severe bone loss occurs, implants are harder to place in an esthetically favorable position.
1) Nasopalatine canal
Nasopalatine canal contains:
a. nasopalatine nerve
b. descending branch of the nasopalatine
artery
c. fibrous connective tissue
Functional Implant Zone 1
if an implant contacts neural tissue in this
canal, it could lead to failure of
osseointegration or sensory dysfunction.
Thus, when one or both central incisors have been
lost for a while, limited CBCT imaging is
indicated to determine the dimensions and
morphology of the nasopalatine canal before
dental implant surgery.
Nasopalatine canal on a
CBCT Coronal section

31. Cross-sectional views showing location
of naso-palatine canal

32. • the sinus zone
•located at the base of the maxillary sinuses
CBCT imaging is indicated to evaluate:
a. bone height between the floor of the maxillary sinus and alveolar bone must be
evaluated through CBCT before placing dental implants in this zone
b. When tooth is lost or extracted  pneumatization of Sinus into the area initially
occupied by the tooth  vertical augmentation via a sinus lift procedure
c. presence of sinus septa which could complicate the sinus lift procedure if encountered
interoperatively
Functional Implant Zone 2
CBCT sagittal section showing septa
in left maxillary sinus

33. d) Detecting superior alveolar artery
A. CBCT shows the posterior alveolar artery before creating a
lateral windown into the maxillary sinus.
B. The artery is seen during the sinus lift procedure located at
15 mm from the alveolar crest diagnosed with CBCT

34. “Inter-foraminal zone”
This zone is comprised of the area of the mandibular alveolar ridge between mental
foramen and right and left premolar
associated with a thin alveolar ridge
a) Sublingual undercuts
If the alveolar ridge is not properly evaluatedd preoperatively  perforation of lingual
cortex  severe bleeding with the formation of expanding sublingual hematomas
Perforated lingual
cortical plate
Severe hematoma on the anterior floor
of the mouth after implant placement in
the anterior mandible
Echymosis on the chin after
implant placement in the
anterior mandible
Functional Implant Zone 3

35. b) Position of mental foramen
Dental implants in the mandibular pre-molar region are dictated by the size and the
location of the mental foramen.
Its location can vary from the mandibular canine to the first molar.
Once a zone of safety is detected through CBCT, implants can be placed anterior
to, posterior to, or above the mental foramen.

36. d) Detection of Accessory Mental Foramens (AMF)
Detecting AMFs may decrase the risk of haemorrhage,
postoperative pain and paralysis in implant surgeries.

37. Functional Implant Zone 4
This zone is located behind the mental foramen on each side
and extends from the 2nd premolar to retromolar pad.
a. Mandibular canal through which the InferiorAlveolar
Nerve (IAN) passes
• Any damage to this nerve can result in persistent
dysesthesia as it supplies the sensory innervation of the
lower lip.
• Aminimum distance of 2 mm from is to be maintained
when placing implants in this zone.

39. Sinus Floor Elevation
Procedure: The procedure of sinus floor lifting is an inner augmentation of the maxillary sinus sheath, with /without grafts
Purpose: Proliferation of the upright bony measurement of the sinus cavity in the side maxilla. This shaped space customarily allows the
possibility of a dental implant to be inserted from the alveolar ridge to this chamber, to thereafter wait for osseo-integration from the
renewing implanted bone.
Indication: When an implant must be located in the posterior area of the maxilla
Pre-operative valuation of the maxillary sinus is vital for the achievement of this surgery. It is significant for the surgeon to be conscious
of the sizes of the facial maxillary sinus wall earlier in the begining .
Existing 2 D radiological methods do not deliver any treasured data in this field.
Pre-operative cone-beam computed tomography scan (CBCT) prior open sinus lift surgery has been recommended:
If the quantity of bone, among the crest of the ridge and the maxillary sinus bottom is insufficient, (<5 mm) then open sinus lift
process is specified. The CBCT technology permits us to quantify the quantity of bone in this zone:
Post-operative assessment of this procedure using CBCT is also necessary:
The height is more than 5 so a
Sinus lift is not recommended

40. Existing 2 D radiological methods do not deliver any treasured
data in this field.
Pre-operative cone-beam computed tomography scan (CBCT) prior open sinus lift surgery has
been recommended:
If the quantity of bone, among the crest of the ridge and the maxillary sinus bottom is
insufficient, (<5 mm) then open sinus lift process is specified. The CBCT technology permits us
to quantify the quantity of bone in this zone:
Post-operative assessment of this procedure using CBCT is also necessary:
The height is more than 5 so a Sinus
lift is not recommended

41. Features (other than the height and the width of the residual alveolar ridge) that should be
assessed in pre-operative CBCT scan for sinus floor lifting include:
Medial wall of the
sinus
Lateral wall of the
sinus
Sinus membrane:
Schneiderian
membrane
a) Wideness of the lateral maxillary sinus wall.
- If the lateral maxillary wall is dense open sinus lift procedure turn
into a more difficult one and more time consuming
- Plummeting the width of bone is essential to diminish problems.
- Extreme convexity of this wall forces the doctor to select exact
methods for this process

42. b) Occurrence of alveolar antral artery and its distance.
- A large diameter artery in the sinus lifting procedure can provoke profuse
bleeding concealing the vision in the surgical field. This blood vessel is
accountable for intraoperative bleeding which is the additional recurrent
problem of sinus lift procedure after membrane puncture. Alveolar antral blood
vessel with a diameter more than 0.5 mm can be observed on CBCT images
and profuse bleeding should be predictable if the artery has a diameter > 3 mm.
- If the entire blood vessel is surrounded by the bone, organization by thermal
cautery is all that is wanted but when this blood vessel is in near contact with
sinus membrane, use of thermal  membrane perforation.
Alveolar antral artery in in close proximity
to the Schneiderian membrane

43. c) Maxillary sinus floor width.
- It’s the length between the lateral maxillary sinus partition and the medial maxillary sinus partition
(lateral nasal cavity border) and the formed viewpoint.
- In actual thin and very extensive sinuses and sharp angulation between these two constructions,
the open sinus lift surgery becomes hard.
Cone-beam computed tomography (CBCT) scans representing three types of maxillary sinuses with
different widths:
Narrow sinus Average sinus Wide Sinus
a) Indiscretion of sinus floor.
Wrongdoings of the maxillary sinus bottom make the surgery more
problematic in contrast with the flat-surface bone .These irregularities can
be effortlessly noticed using CBCT.
a) Close relative of Schneiderian membrane with roots of nearby teeth
If Schneiderian membrane contacts the adjacent the roots of the teeth head-
to-head to the non-dentate area, the probability of casing puncture during
sinus lift process upsurges.

44. Postoperative assessment
The patient must be assessed every 6 months, starting from the first 4-6 months after
initial healing of the implants.
Clinical Signs of Implant Failure:
1) Implants lack sensory feedback of occlusal forces. Thus, occlusion must be
monitored, to detect
a. Screw loosening
b. Fracture of the prosthesis
c. Redness, swelling, discomfort
d. Denture ulcers
Postoperative ClinicalAssessment

45. 2) Examine for signs of peri-implant mucositis: inflammation of the soft
tissues surrounding the implant  reversible
3)Examine for signs of peri-implantitis: an inflammatory process affecting
the tissues around an osseointegrated implant in function:
1. Diagnostic feature: crestal bone loss
2. Mobility is its terminal stage
3. Infectious disease  causes of inflammation must be excluded such
as retained cement or cementitis
4) Presence of signs of pain, infection, neuropathies, paresthesia
5)Signs of inflammation such as sinusitis indicating involvement of maxillary
sinus

46. Postoperative Radiographic Assessment
Implants should be radiographically assessed on an annual or biannual basis. In the
implant’s first year of service, annual vertical bone loss be less than 0.2 mm is normal
Choice of radiographic technique:
1. For asymptomatic implants:
a. intraoral periapical
b. panoramic imaging in extensive cases
c. CBCT is not indicated for periodic review of asymptomatic implants
2. CBCT imaging
a. Implant mobility
b. altered sensation
c. implant retrievel
Radiographic signs of implant failure:
Peri-implant radiolouceny indicating bone loss: (2mm of loss is
acceptable in the first year, and 0.2mm each year after)
widening of the PDL space of adjacent natural teeth which indicates
poor stress distribution
Evidence of saucerization indicating loss of crestal bone  apical
migration of the alveolar bone or indistinct osseous margins.

47. Examination of Implant Failures and Complications
Using CBCT
a. Altered sensation:
Neurovascular disturbances following most often damage to several
canals is often easily detected by CBCT images allowing the
implantologist to indicate the reason of the patient’s constant pain or
numbness the implant should be removed from the nerve canal,
so that any additional compression of the nerve is eliminated
1. Disturbance to the mandibular canal :
Sagittal CBCT image Coronal CBCT image

48. 2. Damage to the nasopalatine canal
b) Infection or postoperative integration failure
Maxillary sinus infection following sinus floor elevation procedures with simultaneous dental
implant placement may be one of the problems that lead to postoperative complications. This
infection cannot be examined on normal panoramic x-rays.

49. c) Implant displacement (malpostion)
Displacement of the dental implant into the maxillary sinus. CBCT allows us to examine the
position of the displaced implant in different aspects allowing the implantologist to locate it for
removal. An intraoral approach consisting is needed where an elevation of a mucoperiosteal
flap and creation of a bony window pedicled to the Schneiderian membrane must be adopted in
reference to the CBCT images because perforation of the membrane is highly relevant in such a
procedure.

50. d)Perforations the implant tip may be shortened until soft tissue
coverage is attained.
1)Perforation of the lingual bone plate in the anterior mandible and
resulting severe hemorrhages and life-threatening airway
obstructions.
2)Perforation of the floor of the nose during implant bed preparation
and/or placement difficulty in breathing and infection