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PREVENTING PERIODONTAL POCKET FORMATION AFTER REMOVAL OF AN IMPACTED MANDIBULAR THIRD MOLAR
CLINICAL
DIRECTIONS
PREVENTING PERIODONTAL POCKET FORMATION AFTER REMOVAL OF AN IMPACTED MANDIBULAR THIRD MOLAR MOHAMMAD HOSEIN KALANTAR MOTAMEDI, D.D.S., O.M.F.S.
M
any complications are associated with the surgical removal of impacted third molars. One of the most overlooked is the formation of a deep periodontal pocket distal to the second mandibular molar after the removal of an impacted mandibular third molar. It can result from improper bone removal in the area distal to the second mandibular molar during surgery, among other factors. To eliminate the periodontal pocket or to regenerate bone in the defect, further surgical interventions such as distal wedge excision, apical repositioning of soft tissues, guided-tissue regeneration techniques, autografts or allografts, and amputation of the distal root of the second molar may be required. Ultimately, extracting the second molar may be the only way to treat a deep distal periodontal pocket that extends to approximately the apex of the molar. Although much has been written about treatment, little
1482
has been said about prevention.1-3 In this article, I present a simple and effective technique to help prevent this complication. THE TECHNIQUE
The standard procedures used to remove bone-impacted mandibular third molars are reflecting a full-thickness
Extracting the second molar may be the only way to treat a deep distal periodontal pocket that extends to approximately the apex of the molar. mucoperiosteal flap, removing the bone overlying the impaction superiorly, removing the buccal cortical bone, sectioning the tooth, and removing the tooth segments and the dental follicle.2 Peterson2 recommends that when removing a horizon-
tally impacted third molar, “bone overlying the tooth (i.e., bone on the distal and buccal aspects of the tooth) should be removed with a bur.” However, when the crown of an impacted third molar is in direct contact with the distal root of the second molar and is not separated from it by a bony septum, removing the bone that superiorly overlies the impaction may result in the formation of a very deep periodontal defect behind the second molar. The depth of this defect will equal the mesiodistal length of the crown, as well as the angulation and depth of the impaction. Thus, the subsequent postsurgical pocket also can be expected to have similar parameters. The result is a three-walled bone defect in which bone formation is unpredictable, as epithelium may migrate down into the defect and prevent bone formation. To remove a fully boneimpacted mandibular third molar (Figure 1) while preserving the bone superiorly overlying the impaction, I first make a sulcular incision from the interdental papilla mesial to the second molar that extends distally to the anterior border of the ramus. After reflecting a full-thickness mucoperiosteal envelope flap, I start to remove the bone 2 to 3 millimeters below the bony crest in the buccal cortex using a surgical
JADA, Vol. 130, October 1999 Copyright ©1998-2001 American Dental Association. All rights reserved.
CLINICAL DIRECTIONS handpiece and a round surgical bur. Then I remove an oval window of buccal bone overlying the lateral part of the crown and root of the impacted third molar. I am careful not to make the anterior part of the buccal window too close to the distal root of the second molar. After I expose the crown and cervical portion of the impacted tooth and the upper one-third of its roots, I section the tooth vertically at the cementoenamel junction by using either a round or fissure bur to create enough space for the sectioned crown to be moved. (To prevent damage to the lingual cortex or the inferior alveolar nerve, I do not section the tooth completely. Instead, I place a straight elevator in the vertical groove and separate the crown from its roots. Then I section the crown horizontally as necessary and deliver it buccally in two or more pieces.) I then section the roots at the bifurcation and remove the distal and mesial roots. The roots can be removed in one piece if they are fused, or they can be removed before the crown when space permits. After I remove the dental follicle, I suture the flap using resorbable or nonresorbable sutures, with the flap covering the oval window and the flap edges resting on solid bone.
Figure 1. Periapical radiograph of a typical fully bone-impacted mandibular third molar with a crown-to-root relationship, intact crestal bone and no distal periodontal pocket.
DISCUSSION
When this technique is used, crestal bone is preserved distal to the second molar, and the buccal bone defect lies several millimeters behind the distal root of the second molar. In effect, instead of a three-walled vertical defect, a lateral defect—a buccal window—is created through which the tooth is removed. This enhances bone
Figure 2. Periapical radiograph demonstrating bone healing without postoperative pocket formation or increased probing depth after the impaction was removed using the buccal window technique.
formation in the extraction socket area. After the flap is sutured in place, the defect is not accessible from either the superior or the distobuccal aspect (Figure 2). This prevents
pocket formation distal to the second molar even if a fibrous scar develops or if epithelium should migrate laterally into the defect. It also prevents the wound from splitting open and
JADA, Vol. 130, October 1999 Copyright ©1998-2001 American Dental Association. All rights reserved.
1483
CLINICAL DIRECTIONS food debris from lodging in the remaining socket. Therefore, the potential for postoperative inflammation or infection is decreased, and damage to lingual structures is avoided as the flap is not extended or reflected lingually. This technique also can be used for deep vertical impactions, if the overlying crestal bone is intact. In such cases, a vertically oriented buccal window of bone is removed instead of a horizontally oriented buccal window. Impacted mandibular third molars vary in their orientation relative to the second molar. Horizontally impacted third molars that have a crown-to-crown or crown-to-cervix relationship normally are associated with variable amounts of crestal bone resorption distal to the second molar, which means that the technique I described cannot be used. When the impacted tooth has a crown-to-root relationship with the second molar, however,
the dentist should determine whether there is an associated crestal bone loss behind the second molar. This depends on the caudal depth of the impaction. If at least 1 mm of intact
When this technique is used, crestal bone is preserved distal to the second molar, and the buccal bone defect lies several millimeters behind the distal root of the second molar. crestal bone overlies the impaction, the technique can be used. The buccally oriented impacted third molars are easier to access than lingually oriented ones, although using this technique is possible in both situations. In most crown-to-root– oriented third molar impactions, distoproximal bone behind the
distal root of the second molar is nonexistent. Thus, removing the impaction through the crest inevitably will expose the distal root of the second molar. I believe this technique prevents postsurgical pocket formation distal to the second molar by preventing root exposure. In my experience, postoperative inflammation, edema and pain also appear to be reduced compared with use of the standard technique, although this aspect remains to be documented. ■ Dr. Motamedi is an assistant professor of oral and maxillofacial surgery and an attending surgeon, Clinic of Oral and Maxillofacial Surgery, Baqiyatallah University Medical Center, The Azad University of Medical Sciences, Tehran, IR Iran. Address reprint requests to Dr. Motamedi at Africa Expressway, Golestan St., Giti Blvd. No. 11, Tehran, 19667 IR Iran. 1. Kugelberg CF. Third molar surgery. Curr Opin Dent 1992;2:9-16. 2. Peterson LJ. Principles of management of impacted teeth. In: Peterson LJ, Ellis E III, Hupp JR, Tucker MR, eds. Contemporary oral and maxillofacial surgery. St. Louis: Mosby; 1998:224. 3. Alling RD, Alling CC. Mandibular third molars. In: Alling CC, Helfrick JF, Alling RD, eds. Impacted teeth. Philadelphia: Saunders; 1993:183-6.
Do you have a tip to share? Do you have a time- or work-saving clinical technique to share with your colleagues? Submit it to JADA’s Clinical Directions department. A Clinical Directions item should be a maximum of two double-spaced typed pages and should include no more than one figure or illustration. Submit items to Clinical Directions, JADA, 211 E. Chicago Ave., Chicago, Ill. 60611.
1484
JADA, Vol. 130, October 1999 Copyright ©1998-2001 American Dental Association. All rights reserved.
DIRECTIONS
PREVENTING PERIODONTAL POCKET FORMATION AFTER REMOVAL OF AN IMPACTED MANDIBULAR THIRD MOLAR MOHAMMAD HOSEIN KALANTAR MOTAMEDI, D.D.S., O.M.F.S.
M
any complications are associated with the surgical removal of impacted third molars. One of the most overlooked is the formation of a deep periodontal pocket distal to the second mandibular molar after the removal of an impacted mandibular third molar. It can result from improper bone removal in the area distal to the second mandibular molar during surgery, among other factors. To eliminate the periodontal pocket or to regenerate bone in the defect, further surgical interventions such as distal wedge excision, apical repositioning of soft tissues, guided-tissue regeneration techniques, autografts or allografts, and amputation of the distal root of the second molar may be required. Ultimately, extracting the second molar may be the only way to treat a deep distal periodontal pocket that extends to approximately the apex of the molar. Although much has been written about treatment, little
1482
has been said about prevention.1-3 In this article, I present a simple and effective technique to help prevent this complication. THE TECHNIQUE
The standard procedures used to remove bone-impacted mandibular third molars are reflecting a full-thickness
Extracting the second molar may be the only way to treat a deep distal periodontal pocket that extends to approximately the apex of the molar. mucoperiosteal flap, removing the bone overlying the impaction superiorly, removing the buccal cortical bone, sectioning the tooth, and removing the tooth segments and the dental follicle.2 Peterson2 recommends that when removing a horizon-
tally impacted third molar, “bone overlying the tooth (i.e., bone on the distal and buccal aspects of the tooth) should be removed with a bur.” However, when the crown of an impacted third molar is in direct contact with the distal root of the second molar and is not separated from it by a bony septum, removing the bone that superiorly overlies the impaction may result in the formation of a very deep periodontal defect behind the second molar. The depth of this defect will equal the mesiodistal length of the crown, as well as the angulation and depth of the impaction. Thus, the subsequent postsurgical pocket also can be expected to have similar parameters. The result is a three-walled bone defect in which bone formation is unpredictable, as epithelium may migrate down into the defect and prevent bone formation. To remove a fully boneimpacted mandibular third molar (Figure 1) while preserving the bone superiorly overlying the impaction, I first make a sulcular incision from the interdental papilla mesial to the second molar that extends distally to the anterior border of the ramus. After reflecting a full-thickness mucoperiosteal envelope flap, I start to remove the bone 2 to 3 millimeters below the bony crest in the buccal cortex using a surgical
JADA, Vol. 130, October 1999 Copyright ©1998-2001 American Dental Association. All rights reserved.
CLINICAL DIRECTIONS handpiece and a round surgical bur. Then I remove an oval window of buccal bone overlying the lateral part of the crown and root of the impacted third molar. I am careful not to make the anterior part of the buccal window too close to the distal root of the second molar. After I expose the crown and cervical portion of the impacted tooth and the upper one-third of its roots, I section the tooth vertically at the cementoenamel junction by using either a round or fissure bur to create enough space for the sectioned crown to be moved. (To prevent damage to the lingual cortex or the inferior alveolar nerve, I do not section the tooth completely. Instead, I place a straight elevator in the vertical groove and separate the crown from its roots. Then I section the crown horizontally as necessary and deliver it buccally in two or more pieces.) I then section the roots at the bifurcation and remove the distal and mesial roots. The roots can be removed in one piece if they are fused, or they can be removed before the crown when space permits. After I remove the dental follicle, I suture the flap using resorbable or nonresorbable sutures, with the flap covering the oval window and the flap edges resting on solid bone.
Figure 1. Periapical radiograph of a typical fully bone-impacted mandibular third molar with a crown-to-root relationship, intact crestal bone and no distal periodontal pocket.
DISCUSSION
When this technique is used, crestal bone is preserved distal to the second molar, and the buccal bone defect lies several millimeters behind the distal root of the second molar. In effect, instead of a three-walled vertical defect, a lateral defect—a buccal window—is created through which the tooth is removed. This enhances bone
Figure 2. Periapical radiograph demonstrating bone healing without postoperative pocket formation or increased probing depth after the impaction was removed using the buccal window technique.
formation in the extraction socket area. After the flap is sutured in place, the defect is not accessible from either the superior or the distobuccal aspect (Figure 2). This prevents
pocket formation distal to the second molar even if a fibrous scar develops or if epithelium should migrate laterally into the defect. It also prevents the wound from splitting open and
JADA, Vol. 130, October 1999 Copyright ©1998-2001 American Dental Association. All rights reserved.
1483
CLINICAL DIRECTIONS food debris from lodging in the remaining socket. Therefore, the potential for postoperative inflammation or infection is decreased, and damage to lingual structures is avoided as the flap is not extended or reflected lingually. This technique also can be used for deep vertical impactions, if the overlying crestal bone is intact. In such cases, a vertically oriented buccal window of bone is removed instead of a horizontally oriented buccal window. Impacted mandibular third molars vary in their orientation relative to the second molar. Horizontally impacted third molars that have a crown-to-crown or crown-to-cervix relationship normally are associated with variable amounts of crestal bone resorption distal to the second molar, which means that the technique I described cannot be used. When the impacted tooth has a crown-to-root relationship with the second molar, however,
the dentist should determine whether there is an associated crestal bone loss behind the second molar. This depends on the caudal depth of the impaction. If at least 1 mm of intact
When this technique is used, crestal bone is preserved distal to the second molar, and the buccal bone defect lies several millimeters behind the distal root of the second molar. crestal bone overlies the impaction, the technique can be used. The buccally oriented impacted third molars are easier to access than lingually oriented ones, although using this technique is possible in both situations. In most crown-to-root– oriented third molar impactions, distoproximal bone behind the
distal root of the second molar is nonexistent. Thus, removing the impaction through the crest inevitably will expose the distal root of the second molar. I believe this technique prevents postsurgical pocket formation distal to the second molar by preventing root exposure. In my experience, postoperative inflammation, edema and pain also appear to be reduced compared with use of the standard technique, although this aspect remains to be documented. ■ Dr. Motamedi is an assistant professor of oral and maxillofacial surgery and an attending surgeon, Clinic of Oral and Maxillofacial Surgery, Baqiyatallah University Medical Center, The Azad University of Medical Sciences, Tehran, IR Iran. Address reprint requests to Dr. Motamedi at Africa Expressway, Golestan St., Giti Blvd. No. 11, Tehran, 19667 IR Iran. 1. Kugelberg CF. Third molar surgery. Curr Opin Dent 1992;2:9-16. 2. Peterson LJ. Principles of management of impacted teeth. In: Peterson LJ, Ellis E III, Hupp JR, Tucker MR, eds. Contemporary oral and maxillofacial surgery. St. Louis: Mosby; 1998:224. 3. Alling RD, Alling CC. Mandibular third molars. In: Alling CC, Helfrick JF, Alling RD, eds. Impacted teeth. Philadelphia: Saunders; 1993:183-6.
Do you have a tip to share? Do you have a time- or work-saving clinical technique to share with your colleagues? Submit it to JADA’s Clinical Directions department. A Clinical Directions item should be a maximum of two double-spaced typed pages and should include no more than one figure or illustration. Submit items to Clinical Directions, JADA, 211 E. Chicago Ave., Chicago, Ill. 60611.
1484
JADA, Vol. 130, October 1999 Copyright ©1998-2001 American Dental Association. All rights reserved.