TITLE PAGE
Manuscript Type: Original Research
Title: Closed Flap Osseous Crown Lengthening Procedure
Running title: Closed Flap Osseous Crown Lengthening Procedure
Name(s) of the author(s), Affiliation(s) of author(s) (including current affiliation and
affiliation where the work was primarily carried out),
1. Dr Sana Farista
Consultant Periodontist and Laser Specialist
Laser Dentistry- Multispeciality Dental Laser lounge
G1 Sea Pebble, Perry cross road, Bandra (W)
Mumbai 400050
2. Dr Syed Sarwar Ahmed Qadri Nadeem
Associate Professor
Dept of Prosthodontics
Sri Balaji Dental College
Moinabad, Telangana 501504
3. Dr Aditi Chaudhary
Consultant Periodontist and Laser Specialist
Laser Dentistry- Multispeciality Dental Laser lounge
G1 Sea Pebble, Perry cross road, Bandra (W)
Mumbai 400050
4. Dr Shanin Farista
Consultant Endodontist and Laser Specialist
Laser Dentistry- Multispeciality Dental Laser lounge
G1 Sea Pebble, Perry cross road, Bandra (W)
Mumbai 400050
5. Dr Balaji Manohar
Professor and Head
Dept of Periodontology
Kalinga Institute of Dental Sciences
KIIT Deemed to be University
Campus 5
Patia
Bhubaneswar 751024
Name and postal address of corresponding author:
Dr Aditi Chaudhary
Consultant Periodontist and Laser Specialist
Address- Laser Dentistry- Multispeciality Dental Laser lounge
G1 Sea Pebble, Perry cross road
Bandra (W)
Mumbai 400050
Contact No- 9009005360
Email address- [email protected]
To,
The Editor
Sub: Submission of Manuscript for publication
Dear Sir,
We intend to publish an article entitled Closed Flap Osseous Crown Lengthening
Procedure in your esteemed journal as an Original Research Article.
On behalf of all the contributors I will act and guarantor and will correspond with the
journal from this point onward.
Financial Support- Nil
Conflicts of interest – There are no conflicts of interest
Permissions- Nil
We hereby transfer, assign, or otherwise convey all copyright ownership, including any
and all rights incidental thereto, exclusively to the journal, in the event that such work is
published by the journal.
Thanking you,
Yours’ sincerely,
Dr Sana Farista
Corresponding Contributor: Dr Aditi Chaudhary
COVERING LETTER
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CLOSED FLAP OSSEOUS CROWN LENGTHENING PROCEDURE
Abstract
Osseous crown-lengthening is often needed to enhance the appearance of a patient’s smile,
prevent the violation of biologic width, and/or provide sufficient tooth structure for the
placement of final restorations. The present technique for osseous crown lengthening
typically involves flap surgery, a procedure that frequently is associated with postoperative
complications that can interfere with the aesthetic outcome, such as infection, bleeding, and
change in tissue position during the healing process. The erbium laser enables the clinician to
offer the patient a minimally invasive alternative to osseous crown lengthening negating the
adverse effects associated with conventional treatment. Other advantages of using the laser
for osseous crown lengthening includes: hemostasis, improved visualization, fewer
postoperative complications and recession.
Key Words: Esthetics, Altered Active Eruption, Altered Passive Eruption, Crown
Lengthening, Surgical Stents, Erbium,Chromium:Yttrium-Scandium-Gallium-Garnet Laser,
Osseous Recontouring.
1. INTRODUCTION
Crown lengthening can be a solution to several problems with a patient’s smile which include
a high lip line, with a normal skeletal dimension between the upper lip and nose, revealing
excessive gingival display in the maxillary anterior region (a “gummy smile”). Another
indication being a high lip line or a normal lip elevation with excessive vertical dimension of
bone between the upper lip and nose. Crown lengthening can also correct a disproportionate
appearance of gingiva due to over-eruption of anterior teeth in cases of attrition in-order to
counteract occlusal wear.
Gummy smile can be a result of two different forms of eruption. First, there is altered active
eruption (AAE), which occurs when teeth prematurely achieves the opposite relationship to
the occlusal plane and the osseous crest is at, or very close to the cementoenamel junction,
(CEJ). The second type is altered passive eruption (APE), which is a developmental or
genetic condition and is characterized by coronal positioning of the gingival margin over the
enamel, thus resulting in short clinical crowns.[1] And hence, the correct understanding of
biological events related to AAE and APE must be considered while classifying a Gummy
Smile. The most accepted classification for APE was given by Coslet et al.[2]
To correct such conditions, the clinician must establish and maintain healthy, periodontal
tissue with specific dimensions. This can be achieved by maintaining biologic width around
the teeth undergoing crown lengthening as it exists around the patient’s other teeth. The
approximate biologic width in an individual is 2.04 mm and is the dimensional sum of 1.07
mm of connective tissue and 0.97 mm of epithelial attachment.[3]
The purpose of this study is to introduce a technique with erbium laser to perform closed flap
osseous crown lengthening with minimal tissue displacement.
2. PILOT STUDY
A comprehensive intraoral clinical examination was performed to assess the crown-to-
root ratios, probing depth, width of keratinized tissue, bone sounding.
Radiographic examination was performed to determine the bone level at or below the
CEJ.
Alginate impressions of maxillary arch were made for preparing surgical guide and
template.
Diagnostic digital photographs were taken in order to document the length and width
of the anterior teeth, midline, gingival symmetry, and the position of the free
gingivae in relation to the upper lip position upon smiling.[Figure 1]
On the basis of all diagnostic findings assessment was made whether to perform osseous
crown lengthening, and, if so, the technique that needs to be performed. The patient had a
Type I Subtype B class of gummy smile and a decision of performing osseous crown
lengthening guided by surgical stent using the erbium laser for teeth – 11,12,13,21 and 23
was made.
2.1. LABORATORY PROCEDURE
Step 1 - Marking of the Cast
Central incisor is the dominant component in the anterior dentition, with ideal height to width
ratio of 10:8.[4] Accordingly, the gingival zenith for lateral incisor and canine is adjusted. The
gingival margin for lateral incisor should be 1 mm coronal to that of central incisor and
canine should be at the same height as the central incisor.[5]
Stent Preparation Formula:-
The ideal crown to height measurement given by Galip Gurel[4] is 10:8. Using this, the crown
height of the respective central incisor can be figured out. As the width of the incisor can be
measured, the height can be calculated by the formula as given in the example below:
E.g. If the width of crown is 8.5, then the formula can be used to calculate the height of the
crown.
10: 8= X: 8.5
X = 10 x 8.5/8
X = 10.6
Thus, the calculated ideal height of central incisor in the present case was 9mm. The lateral
incisor height was kept 1mm less than that of central incisor, and for the canine it remained
same as the central incisor. [Figure 2(a), 2(b), 2(c)]
Step 2 – Preparation of Stent
Alginate impression of maxillary arch was made and a cast was obtained. The cast was
marked using a pencil according to the required contour. Surgical stent was prepared
extending from the markings done for crown lengthening to the palatal aspect of the teeth
involved which would then help stabilize the stent over the teeth for proper marking on the
gingival tissue. One tooth on either side of the area of interest was included in the stent
preparation. The stent margins were rounded and trimmed to avoid injury to the soft tissue.
Trial was done on the patient followed by final trimming and finishing of the stent. [Figure 3]
2.2. CLINICAL PROCEDURE
Step 1: Marking over Gingival Tissue using Lasers under the Guidance of Surgical
Stent
After the topical application of 20% Benzocaine [Figure 4], surgical stent was placed over the
maxillary anterior teeth and 2780 nm Er,Cr:YSGG laser (WaterlaseiPlus – BIOLASE) was
used for marking the contour over the gingiva [Figure 5] unlike conventional technique
wherein a periodontal probe is used to puncture the tissue for the reference. The purpose of
this step is to create reference line for soft tissue contouring. [Figure 6]
Step 2: Performing an External Bevel Gingivectomy
An erbium laser of power setting 2.5W and 50Hz frequency in the hard tissue mode with gold
handpiece, an external bevel gingivectomy was performed to level up the gingival tissue upto
the reference line.
After recontouring of the free gingival margin, a periodontal probe was inserted in the sulcus
to the level of bone around each tooth so as to check the bone level (bone sounding) [Figure
8].
Step 3: Intrasulcular Incisions with Laser
To access the bone for recontouring, intrasulcular incisions were placed using laser in order to
separate soft tissue from the root surface. Placing the tip parallel to the root, soft tissue was
ablated through the sulcular area to the bone crest to form a pouch. The papillae were left
intact. The tissue above the bone was released.
Step 4: Recontouring of the Bone
The bone was recontoured with a sweeping motion and the tip moving laterally from mesial
to distal following CEJ through the sulcus upto a depth of approximately 2 to 4 mm
(depending on the average biologic width). Each time after contouring the bone on each tooth
the uniformity of bone on all the sides was evaluated using a periodontal probe. [Figure 9]
The erbium laser was used at 3W power setting with 20-30Hz frequency with a gold
handpiece in hard tissue mode.
Step 5: Smoothening of the Bone
After the bone was resected it was smoothened by doing osteoplasty with lasers at very low
settings [Figure 10].
2.3. POSTOPERATIVE EVALUATION
Analgesic was prescribed to the patient for postoperative pain management. 0.2%
Chlorhexidine mouth rinse was prescribed twice a day for 15 days. The patient was recalled
for follow up after seven days to check for healing and the final position of the gingival
outline. [Figure 11]
3. DISCUSSION
One of the major advantage of osseous crown lengthening using erbium laser is that it results
in stable contours and tissue position, as compared to the conventional flap and osseous
crown lengthening surgeries. Using this technique (with laser) only a small intrasulcular
incision is made into the gingival tissue with minimum tissue reflection, and the papillae
remain attached. Thus the clinician need not require extensive incisions to displace the tissue.
A study by Deas et al.[6] concluded that there is significant tissue instability or “rebound” for
up to six months after conventional crown lengthening surgery. They also suggested that the
degree of rebound is related to the flap position relative to the bone crest at the time of suture
placement; and that greater rebound occurs when the flap margin is positioned closer to the
bone crest. The same finding was reported by Pontoriero and colleagues,[7] they stated that the
marginal tissue has a tendency to grow coronally after an apically positioned flap and osseous
resection surgery. These findings from the above studies support the assertion that side effects
associated with the flap reflection and suturing in conventional crown lengthening procedures
may lead to coronal proliferation, or possibly, recession. Keeping this in mind, the use of
erbium laser with minimal flap manipulation may significantly lower the risk of changes in
the gingival morphology following the procedure.
Averting flap reflection allows for a faster wound healing and eliminates the asymmetrical
tissue positioning due to tissue tension caused upon suturing. This irregularity in the tissue
position can lead to re-surgery at a later date .[8] Collateral tissue damage associated with
conventional techniques can be prevented with erbium laser, as it is end cutting. Use of rotary
burs/chisel for osseous crown lengthening is a more intrusive option than treating with the
erbium laser. When a bur comes in contact with bone tissue, heat is generated. Air and water
spray cannot keep the surgical site cool at the point of contact. Whereas the erbium laser
works in a non-contact mode along with a water spray for ablating the tissue, thereby
lowering the heat generation that could lead to thermal side effects. Another drawback of the
rotary bur is that they cut on the side of the bur as well as the end of the tip. Lateral cuts with
the bur cause a splintering effect of the bone that is adjacent to the surgical cut, while the cuts
made with erbium laser do not produce collateral damage, or a “melting” effect, on the bone
cells.[9] Also, precise soft tissue resection can be performed with the erbium laser. Tissue tags
can be easily trimmed, making the tissue smooth.
With regard to the patient satisfaction and erbium laser, patients can see the immediate
outcome after the crown lengthening procedure, whereas; conventional surgeries may take
months to achieve a stable result. Minimal sutures are used in this method, and patients are
more comfortable. Tooth preparation for provisional restorations can be carried out in one to
two weeks after the procedure. Little or no postoperative discomfort is experienced with this
procedure.
Limitations- The hard tissue laser machine is very expensive and so is it’s maintenance. The
clinician must be skilled and careful enough while performing the procedure as it is a
technique sensitive procedure.
4. CONCLUSION
From this study and description of closed flap osseous crown lengthening procedure using
lasers with minimal tissue placement, it can be concluded that the erbium laser is a suitable
alternative to conventional osseous crown lengthening procedures.
5. REFERENCES
1. Goldman HM, Cohen DW. Periodontal therapy. 4th ed. St. Louis: Mosby; 1968. p.
196-37.
2. Coslet JG, Vanarsdall R, Weisgold A. Diagnosis and classification of delayed passive
eruption of the dentogingival junction in the adult. Alpha Omegan 1977;70: 24–8.
3. Gargiulo AW, Wentz FM, Orban B. Dimension and relations of the dentogingival
junction in humans. J Periodontal 1961;32:261-67.
4. Murali KV, Shahabe SA, Patil SG, Nadeem A, Bhandi S. Esthetic Crown
Lengthening: Theoretical Concepts and Clinical Procedures. Int Journal of
Contemporary Dentistry 2012;3:33-7.
5. Gruel G. The science and art of porcelain laminate veneers. New Malden, Surrey,
United Kingdom: Quintessence 2000. p. 223-4.
6. Deas DE, Moritz AJ, Mc Donnell HT, Powell CA, Mealey BL .Osseous surgery for
crown lengthening: A 6-month clinical study. J Periodontol 2004;75:1288-94.
7. Pontoriero R, Carnevale G. Surgical crown lengthening: A 12-month clinical wound
healing study. J Periodontol 2001;72:841-48.
8. Lanning S, Waldrop T, Gunsolley J, Maynard J. Surgical crown lengthening:
Evaluation of the biological width. J Periodontol 2003;74:468-74.
9. Kimura Y, Yu DG, Fujita A, Yamashita A, Murakami Y, Matsumoto K. Effects of
erbium,chromium:YSGG laser irradiation on canine mandibular bone. J Periodontol
2001;72:1178-82.
6. LEGENDS
Figure 1- Preoperative View of Short Clinical Crowns
Figure 2(a)-Measurement of central incisor width
Figure 2(b)- Measurement of lateral incisor height
Figure 2(c)- Marking of gingival contour on the model after crown-height ratio calculation
Figure 3- Acrylic Stent Placed
Figure 4- Application of topical local anaesthetic
Figure 5- Reference Line marking using Laser Guided by Stent
Figure 6- Reference Created For Soft Tissue Recontouring
Figure 7- External Bevel Gingivectomy Performed With Laser
Figure 8- Bone Sounding After Soft Tissue Recontouring
Figure 9- Bone Sounding After Osseous Recontouring
Figure 10- Immediate Postoperative View
Figure 11- 7 days postoperative view