The Minimally Invasive Closed Osteotomy

INTRODUCTION
In recent years, dental procedures have been simplified, and many are becoming less invasive; we have come to the point where “less means more.”
This technique, the minimally invasive closed osteotomy, which the author has worked with for more than 10 years to master, is a new minimally invasive crown-lengthening procedure that is predictable and easy to use. This article will present one case report in which the successful use of this technique will be described in detail.
Indications for this technique can involve the following: gingival margin line-up, crown lengthening, gummy smile, subgingivally fractured teeth, endodontically treated teeth that exhibit a minimal ferrule effect, subgingival caries, altered passive eruption, and gingival hyperplasia.
Contraindications for this technique include: minimal keratinized tissue band width,¹ osteotomy more than 3 mm, triangular teeth, a very scalloped gingival architecture, and thin tissue.

Before Image. Preoperative full-face photo.	After Image. Full-face photo of the completed case.	Two Years Later. Full-face photo of the completed case, 2 years later.

In order to know if we are able to apply this technique, one should first measure the:

• Amount of keratinized tissue
• Distance between the gingival margin and the osseous crest
• Width-to-length ratio of the upper centrals.

In the process of presenting a patient example, we will look at each of these measurements, observing the photos that demonstrate the key steps of the technique.

CASE REPORT
Diagnosis and Treatment Planning
A 20-year-old female patient presented with severe parafunction, a gummy smile, and an incorrect width-to-length ratio for the upper central incisors. All of these made her look like an infant (the author refers to this as “facial-odonthoinfantilism”), which is unpleasant to the eye (Before Image and Figure 1).

Figure 1. The patient presented with a history of severe parafunction, a gummy smile, and an incorrect width-to-length ratio for the upper central incisors.	Figure 2. The amount of keratinized tissue was measured.
Figure 3. Once anesthetized, distance between the gingival margin and the osseous crest was measured using a Williams 10 mm probe (Hu-Friedy).	Figure 4. Length-to-width ratio was measured: length was found to be 7 mm.
Figure 5. Width was measured at 8 mm; for a 70% to 80% length-to-width ratio we would need a length of 10 mm.	Figure 6. Using the tip of a probe, the tissue is marked at 2.5 mm above the gingival margin.
Figure 7. From the tissue mark (see Figure 6), the probe was placed horizontally facing the canine.	Figure 8. The probe was then pushed to depress the tissue, leaving a horizontal mark.
Figure 9. With the same instrument, a dot (zenith) was then made 1 mm toward the incisal edge from the horizontal line.	Figure 10. The Radiolase II (Ellman International) radiosurgical unit.

Amount of keratinized tissue: The very first thing we have to check on is the amount of keratinized tissue. This should be of appropriate size so that, after the procedure is completed, we have a minimum of 3 mm in all the areas of the natural teeth and a minimum of 5 mm, should restorations be placed in the patient’s mouth (Figure 2).¹
Distance between the gingival margin and the osseous crest: The second measurement we must know is the distance between the gingival margin and the osseous crest (biologic width). This should measure about 3.0 mm in more than 80% of healthy adult patients.^2,3 (This measurement should be observed throughout the procedure.)
The most precise way to check on this distance is to first apply anesthesia, and then to sound to the osseous crest in all the teeth to be worked on. A Williams 10 mm probe (Hu-Friedy) was used to take this measurement (Figure 3). (It is strongly recommended that the clinician check this measurement at the moment of surgery to eliminate the need to anesthetize the patient twice.) In this case we found a 3 mm distance (normal osseous crest). This means that for every millimeter of tissue we planned to remove, we would have to remove the same amount of bone.
Width-to-length ratio of the upper centrals: This measurement is very important and is the key to this technique. Through this measurement, the whole procedure is defined, and the final aesthetic outcome will be incorrect if the precise values are not observed and executed.
According to Chiche and Pinault,⁴ the width of an upper central should be between 70% and 80% of the length; if a tooth measures 10 mm in length, the width should not be less than 7 mm, or more than 8 mm. In this case, the width was almost 8 mm (Figure 4), which meant that we should have had a minimum length of 10 mm. However, note that we had a length of only have 7 mm in this case (Figure 5).
To achieve an acceptable width-to-length ratio, we would have to make the clinical crowns of both central incisors 3 mm longer. Owing to the gingival smile and the severe parafunction, we planned to lengthen it in both the gingival and incisal directions. To be able to do this, we must check on the amount of keratinized tissue remaining, since the biggest enlargement in this case will be done in a gingival direction at the expense of the tissue. The keratizined tissue measured 7 mm, providing enough to cut out the 2.5 mm that was to be removed. This still left 4.5 mm of keratinized tissue; this left the patient with 2.5 mm more than the 2 mm minimum width needed to maintain good periodontal health.^5,6
With the tip of a probe, we placed a mark in the tissue at 2.5 mm above the gingival margin (Figure 6); from this, we placed the probe horizontally facing the canine (Figure 7). Then we proceeded to push on the probe onto the tissue, leaving a horizontal mark (Figure 8). Then, with the same instrument, a dot (zenith) was made 1 mm toward the incisal edge from the horizontal line (Figure 9). (We must remember that, generally, the gingival zenith of the laterals is one mm shorter than the zenith of centrals and canines.)
Once the marks were correctly completed, the Radiolase II unit (Ellman International) (Figure 10) was put into use. The author recommends and uses the Ellman (patented) technology because it is the only radiosurgical equipment available to dentists that produces a 4.0 MHz output; this controls bleeding beautifully while preventing the thermal damage.^7-9 This minimizes untoward healing results usually associated with traditional low-frequency electrosurgical equipment. It has been the author’s experience that this technology is faster, easier to use, and more cost-effective than most dental lasers currently available.

Surgical Procedure
With the electrode n° (108 B), a new radiotomy of the gingival margins was begun (Figure 11), following the traces up to the canine, lining up the canine with the central, and leaving the laterals one mm shorter (Figure 12). Once the procedure was done on the left side, the same was done on the right side, thus finishing the planned gingiradiotomy (Figure 13). Important clinical tip: The cutting limit is the cement enamel line. The clinician must not cut beyond that limit.

Figure 11. With the electrode nº (108 B), the new radiotomy of the gingival margins was begun.	Figure 12. The radiotomy was created by following the traces up to the canine, lining up the canine with the central, and leaving the laterals 1 mm shorter.
Figure 13. The completed gingiradiotomy.	Figure 14. The next step was to determine what distance from the gingival margin the osseous crest was now located. Bone was sounded again on each tooth.
Figure 15. An exploring instrument was inserted between the tissue and the bone to detach the gingival tissue.	Figure 16. A “kangaroo’s pouch” was created until the osseous crest was seen.
Figure 17. An end-cutting diamond bur (10839-010 [Brasseler USA]) was used at a 45° angle. This bur de­sign, along with the pouch created, provided tissue protection and helped to ensure ample water irrigation.	Figure 18a. With continuous movement and using maximum irrigation to prevent any heat buildup, we start to cut he bone out little by little (a closed osteotomy) carefully following the bony contours.
Figure 18b. The bone-to-gingival margin distance was checked frequently until 3 mm was achieved for all teeth.	Figure 19. The clinical crown length, planned to be 9.5 mm upon completion, was checked and verified.

Figure 20. Retracted view (taken 10 days postoperatively) with composite resin restorations placed.

The next step was to determine what distance from the gingival margin the osseous crest was now located. To know this, we sounded to bone again on each tooth (Figure 14).⁴
In this case, the osseous crest was now found at only 0.5 mm from the new gingival margin (high osseous crest); we had to cut out 2.5 mm of bone to go back to the normal distance of 3 mm from which we had started off. In order to do this, we first introduced a little exploring instrument between the tissue and the bone to detach the gingival tissue (without lifting a flap) (Figure 15), forming a kind of tissue pouch until we were able to see the osseous crest (Figure 16). Through this so-called “kangaroo’s pouch” we introduced a tissue protective end-cutting bur (10839-010 [Brasseler USA]) at an approximate angle of 45°. This bur design, along with the creation of the tissue pouch, kept the inner part of the tissue from being traumatized. The pouch also helped to ensure that ample water irrigated the bone during the cut (Figure 17).
With continuous movements (moving the bur frequently to avoid heating up the osseous crest), we followed and felt the contour of the bone. Then, with maximum irrigation, we started to cut the bone little by little (a closed osteotomy), checking the distance with the gingival margin constantly until we reached 3 mm in all teeth (Figures 18a and 18b).⁴
The procedure was finished when a distance of 3 mm that restored the biological width was achieved.^10,11
The last thing checked was to see if the length of the clinical crown corresponded to the one that we had planned (9.5 mm) (Figure 19).
Once the procedure was completed, several layers of mirra ink (Mirra Ink [Ellman International]) were placed on the gingival tissue. Following this, the patient was asked to rinse her mouth using chlorexidine gluconate (such as Peridex [OMNI Preventative Care, a 3M ESPE company]) twice a day for one week. The procedure is so minimally traumatic that there is usually no need to prescribe any other medicines (painkillers/antibiotics).
Any needed restorative work can be initiated immediately after the procedure is completed. If desired, one can also wait for a few days until the tissue heals.
In a photo taken 10 days postoperatively (Figure 20) (also after the placement of composite resin restorations), we can observe the excellent tissue response. If a flap procedure had been utilized in this case, healing would have taken several months before we would have seen the same results (After Image).

CLOSING COMMENTS
The advantages of this minimally invasive closed osteotomy technique are numerous. It is a minimally invasive (less traumatic) technique that is a much faster procedure than other traditional methods, requiring no flap or sutures. In addition, postoperative pain is extremely rare and there is no significant inflammation in the shorter healing phase, thus there is usually no need for painkillers and/or antibiotics. Finally, any restorative work (if necessary) can be initiated at the same appointment. Of course, as with any procedure, there are some areas of concern that the clinician should keep in mind before attempting this procedure for the first time: one is limited to a maximum of 3 mm; this procedure should not be performed on thin tissue types; it is somewhat difficult to visualize the osseous crest during the procedure at times; practice and sensitivity are required to cut the bone; and training is required to use the radiosurgical unit properly.
The preoperative and postoperative photos demonstrate that, with a carefully planned and executed technique, the procedures employed resulted in a significant correction of the facial odonthoinfantilism problem (After Image).
After 2 years we can see the changes she has made on herself due to the improvement of her self-esteem after this procedure was made (Two Years Later Image).

References

1. Maynard JG Jr, Wilson RD. Physiologic dimensions of the periodontium significant to the restorative dentist. J Periodontol. 1979;50:170-174.
2. Kois JC. The restorative-periodontal interface: biological parameters. Periodontol 2000. 1996;11:29-38.
3. Kois JC. Altering gingival levels: the restorative connection, part I: biologic variables. J Esthet Dent. 1994;6:3-7.
4. Chiche GJ, Pinault A. Esthetics of Anterior Fixed Prosthodontics. Chicago, IL: Quintessence Publishing; 1994:61-63.
5. Goldberg PV, Higginbottom FL, Wilson TG. Periodontal considerations in restorative and implant therapy. Periodontol 2000. 2001;25:100-109.
6. Padbury A Jr, Eber R, Wang HL. Interactions between the gingiva and the margin of restorations. J Clin Periodontol. 2003;30:379-385.
7. Goldstein AA. Radiosurgery in dentistry. [In French] Chir Dent Fr. 1978; 48(35):39-43. (Article continued in Chir Dent Fr. 1978;48(36):77-81.)
8. Sherman JA. Radiosurgery: the answer to quality dentistry and increased production. Dent Econ. 1994;84:78-79.
9. Maness WL, Roeber FW, Clark RE, et al. Histologic evaluation of electrosurgery with varying frequency and waveform. J Prosthet Dent. 1978;40:304-308.
10. Gargiulo AW, Wentz FM, Orban B. Dimensions and relations of the dentogingival junction in humans. J Periodontol. 1961;32:261-267.
11. Ingber JS, Rose LF, Coslet JG. The “biologic width”—a concept in periodontics and restorative dentistry. Alpha Omegan. 1977;70:62-65.

Dr. Escalante graduated from the University of Guadalajara in 1976, and in 1980 graduated with a specialty in prosthodontics and occlusion from Ciero postgraduate school in Mexico City. He was a professor of fixed prosthodontics and occlusion at the Specialization and Investigation Center of Oral Rehabilitation in Mexico City, and later was the general coordinator. He is a professor and speaker for the Mexican Dental Association, and is a recognized member of the Chicago Dental Society and has assisted the Midwinter Dental Meeting every year since 1991. Dr. Escalante is an active member of the International College of Dentists and the Facta Group of Occlusion. He is the founder and president of the Occlusion Group of the State of Guerrero and a member of the Scientific Commission of the Mexican Dental Association. He is the recipient of awards such as the National Award of Research in 1980 with the Facta Group of Occlusion, the National Award of Research in 1989 with the Group of Occlusion of the State of Guerrero, and the first recipient of the National Merit Award in Dentistry in 1996. He maintains an aesthetic dentistry practice in Acapulco where he also does all his own dental laboratory work. He can be reached at scalarod@yahoo.com.mx.

Disclosure: Dr. Escalante reports no disclosures.