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- aditi671992@gmail.com

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

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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