The envelope flap with a distal relieving incision to themandibular ramus is the most common approach forlower third molar surgery. This flap technique has oftenbeen described extensively in the relevant literature andis certainly favored by a majority of the oral surgerycenters.1-7 Usually, a primary wound closure isperformed, both to diminish the patient’s discomfortand to simplify postsurgical treatment.

There are no specific data available from the litera-ture, but when using the envelope flap, it must beremembered that wound dehiscences at the distofacialedge of the adjacent second molar are very frequent inthe first phase of wound healing.8 Such dehiscencesmay heal secondarily without any additional discom-fort or consequences. Nevertheless, they potentially

extend the time of postsurgical treatment. From thepatient’s point of view, they could cause a longerperiod of discomfort and continuous pain. Furthermore,they may favor the development of alveolar osteitis,and, in consequence, they could be the reason for a lossof attachment distal to the adjacent second molar (Fig1, A and B).

With the aim of avoiding potential periodontalcomplications to the adjacent second molar, severaldifferent flap techniques were developed, compared,and discussed.3-5,9-15 Nevertheless, all publishedstudies are restricted to long-term results of the peri-odontal tissue around the second and the first molar.None of the studies evaluates primary wound healingafter third molar surgery.

It was the aim of this prospective study to evaluatethe influence of flap design on the course of primarywound healing. We examined whether a modificationof a vestibular triangular flap, as first described bySzmyd,2 would reduce the incidence of dehiscences. Inaddition, the importance of flap design for woundhealing was compared with factors such as nicotinehabits, the patient’s age, the duration of surgery, andthe level of impaction.

Primary wound healing after lower third molar surgery: Evaluationof 2 different flap designsNorbert Jakse, MD, DDS,a Vedat Bankaoglu, DDS,a Gernot Wimmer, MD,b Antranik Eskici, MD,DDS,a and Christof Pertl, MD, DDS,a Graz, AustriaKARL-FRANZENS UNIVERSITY GRAZ

Objectives. Wound dehiscences after lower third molar surgery potentially extend the time of postsurgical treatment and maycause long-lasting pain. It was the aim of this prospective study to evaluate the primary wound healing of 2 different flapdesigns.Methods. Sixty completely covered lower third molars were removed. In 30 cases, the classic envelope flap with a sulcularincision from the first to the second molar and a distal relieving incision to the mandibular ramus was used, whereas the other30 third molars were extracted after preparation of a modified triangular flap first similarly described by Szmyd. Woundhealing was controlled on the first postoperative day, as well as 1 and 2 weeks after surgery.Results. The overall result was a total of 33% wound dehiscence. In the envelope-flap group, wound dehiscences developedin 57% of the cases. This represents a relative risk ratio of 5.67, with a 95% CI from 1.852 to 12.336. With the modified trian-gular-flap technique, only 10% of the wounds gaped during wound healing.Conclusion. This study confirms evidence that the flap design in lower third molar surgery considerably influences primarywound healing. The modified triangular flap is significantly less conducive to the development of wound dehiscence.(Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2002;93:7-12)

aThe Department for Oral Surgery and Radiology, Dental School,Karl-Franzens University Graz.bDepartment for Prosthetics and Periodontology, Dental School,Karl-Franzens University Graz.Received for publication Apr 12, 2001; returned for revision Jun 8,2001; accepted for publication Aug 13, 2001.Copyright © 2002 by Mosby, Inc.1079-2104/2002/$35.00 + 0 7/12/119519doi:10.1067/moe.2002.119519

7

ORAL AND MAXILLOFACIAL SURGERY Editor: Larry J. Peterson

ORAL SURGERY

ORAL MEDICINE

ORAL PATHOLOGY

Vol. 93 No. 1 January 2002

MATERIAL AND METHODS

A total of 60 completely covered lower third molarsfrom 60 patients were removed by 3 experienced oralsurgeons. Patients were between 15 and 60 years old,with the average age being 25 years. There were 32female and 28 male patients.

The medical history revealed no sickness or medica-tion that would influence the course of wound healingafter oral surgery. The number of smokers among those60 patients was 9, with 5 of them smoking occasionally(ie, up to 10 cigarettes a day), 3 patients smoking up to20 cigarettes a day, and 1 patient more than 20 a day.Among the relevant criteria for the study were a healthy

dental and periodontal state (CPITN 0-1). All patientswere referred for wisdom teeth removal. The referringdoctor gave the indication in each case, with all of thecases being prophylactic or concerning orthodontics.There was no case of local inflammation or pathology.

Before the procedure, all patients were informedabout the operation, the recommended postsurgicalbehavior, and possible complications. All patientsagreed to the operation, indicated by their signature (incase of minors, the parents gave the signed consent).

Out of 60 completely covered lower third molars, 38were totally osseously impacted. There were 33 leftlower wisdom teeth and 27 right lower wisdom teeth.

The surgery was carried out with the patients underlocal anesthesia. The anesthetic was Articaine in a 4%solution with additional epinephrine in a concentrationof 1:100 000 (Ultracaine-Dental forte; Höchst MarionRoussel, Frankfurt/Main, Germany).

In 30 cases, which were chosen at random, the enve-lope flap with a sulcular incision from the first to thesecond molar and a distal relieving incision to themandibular ramus were used (technique I), whereas theother 30 wisdom teeth were extracted after a modifiedtriangular flap design first described by Szmyd2 (tech-nique II).

Flap designsTechnique I: envelope flap with a sulcular incision

from the first to the second molar and a distalrelieving incision to the mandibular ramus. The inci-sion was done from the mandibular ramus to the disto-buccal crown edge of the second molar, cutting in onemove through all layers of the soft tissue to the bone.From there, a sulcular buccal incision was made to themiddle of the first molar (Fig 2). The mucoperiostealflap was elevated entirely down to the buccal surface ofthe mandible. Distal to the second molar a periostealelevator was used to prepare subperiosteally to thelingual area, to protect the lingual nerve.

Technique II—modified triangular flap. The firstpart of the incision was similar to technique I. The inci-sion was done from the mandibular ramus to the disto-buccal crown edge of the second molar, continued by aperpendicular incision line, obliquely into themandibular vestibulum, with a length of about 10 mm.In contrast to the incision line originally described bySzmyd,2 the modified incision extends over themucogingival borderline. The periodontium of thesecond molar was only touched at the distofacial edge(Fig 3). By preparing the buccal mucoperiosteum, atriangular flap was formed (vestibular triangular flap).The lingual preparation was the same as for technique I.

After mobilizing the mucoperiosteal flap and uncov-ering the surgical site, the proceedings were always the

8 Jakse et al ORAL SURGERY ORAL MEDICINE ORAL PATHOLOGYJanuary 2002

Fig 1. A, B, Illustration and clinical view of a dehiscence afterthird molar surgery using the envelope flap technique.

A

B

same, regardless of the flap design. The crown, whichwas partially or even completely osseously covered,was uncovered from occlusal down to the equator withrotating instruments of diminishing size. In case oftilted teeth, a fissure bur was used to separate the tooth.After extraction, potential rests of the dental folliclewere removed. The alveolus was filled with a gelatinsponge (Spongostan; Johnson & Johnson MedicalLimited, Gargrave, Skipton, United Kingdom). In allcases a primary wound closure was carried out withatraumatic sutures (Supramid 3-0; B. Braun SurgicalGmbH, Melsungen, Germany).

The envelope flap was closed with 2 or 3 single-buttonsutures distal to the second molar, paying special atten-tion to an exact repositioning in the area of the gingivalmargin. In addition, the flap was adapted with inter-dental sutures between the first and the second molar.

For the triangular flap, the same suturing technique wasused distally, whereas the perpendicular incision was onlyadapted with a single coronally placed suture. Again,exact reposition of the gingival margin in the area of thesecond molar was the aim. The loose adaption in theapical portion allows easy relief of a hematoma (Fig 4).

After the operation, all patients were treated antibiot-ically and antiphlogistically as follows: for 4 days withcephalosporin (Ospexin, 1000 mg 3 × 1; Biochemie,Vienna, Austria), and for 2 days with diclofenac(Voltaren, 50 mg 3 × 1; Novartis Pharma, Vienna,Austria).

All patients were seen on days 1, 7, and 14 aftersurgery. On the first postoperative day, all wounds wererelieved distally by slight spreading and compression

in case of envelope flaps, whereas triangular flaps wererelieved in the area of the vestibular incision. Visualcontrol and cautious exploration with a periodontalprobe were used to evaluate a possible dehiscence. Inthis study, every gaping along the entire incision linewas defined as a dehiscence. In this respect, particularattention was paid to the gingival margin at the distalrim of the second molar. This evaluation, as well as thepreoperative periodontal diagnosis, was performed byone periodontist who was not involved in the surgicalprocedure. Sutures were removed after 1 week.

Only patients with good oral hygiene and no signs ofplaque-induced inflammation before and after surgerywere included in the study.

The subsequent statistical evaluation was performedwith the relative risk ratio of cohort or prospectivestudies.16 It was composed of the factors that mayinfluence wound healing (ie, flap design, the patient’sage, duration of the surgery, level of retention, andnicotine habits). These aspects were defined in terms oftheir relationship with the occurrence of dehiscences.The relative risk of a disturbance in the healing process(ie, wound dehiscences) was determined for each of theaforementioned factors.

RESULTSOut of the 60 surgical sites, 20 dehiscences (33%)

were found. Although on the first day after surgery, allwounds were well closed without any sign of a begin-ning rupture, after 1 week, 20 cases showed gapingwound margins distobuccal to the second molar. Noadditional dehiscence developed between day 7 and

ORAL SURGERY ORAL MEDICINE ORAL PATHOLOGY Jakse et al 9Volume 93, Number 1

Fig 2. Illustration of the incision line used for the envelopeflap in lower third molar surgery—distal relieving incision tothe mandibular ramus and sulcular incision from the secondmolar to the first molar.

Fig 3. Illustration of the incision line used for the triangularflap in lower third molar surgery—with a distal relieving inci-sion to the mandibular ramus and a perpendicular anteriorincision into the mandibular vestibulum.

day 14 postsurgery. Neither the size nor the shape ofthe present dehiscences changed during this time.

The age of the patient did not influence the incidenceof dehiscences. In the group of patients up to the age of25 years (n = 41), a dehiscence occurred in 34% of thecases, whereas for those older than 25 years (n = 19),the percentage was 32%. The relative risk ratio for adehiscence was 0.93 (95% CI from 0.421 to 2.031) inthe group of older patients.

The duration of the surgery was between 10 and 50minutes. When the surgery lasted less than 25 minutes(n = 42), dehiscences occurred in 29% of the casesduring wound healing. When the duration of thesurgery exceeded 25 minutes (n = 18), there was adehiscence percentage of 44%. This represents a rela-tive risk ratio of 1.56 (95% confidence interval from0.769 to 3.145) for a dehiscence in the group with thelonger surgery duration compared with the ratio of thegroup with a surgery shorter than 25 minutes.

Among the 38 osseous impacted teeth, 10 cases(26%) of postoperative dehiscences were found. The22 molars that were only partially covered by bone in10 cases (46%) showed dehiscences. The relative riskratio of a rupture of the primary wound closure for thisgroup was 1.73 (95% CI from 0.856 to 3.485).

Without considering the extent of the individualnicotine habit, there was a 40% dehiscence rate foundin the group of smokers. The relative risk ratio for thesmoking patients to develop a dehiscence was 1.25(95% CI from 0.529 to 2.954).

Duration of surgery, level of impaction, and smokinghabit did influence the primary wound healing, butthese factors did not attain statistical significance.

In 17 (57%) of the 30 surgeries performed with theenvelope-flap technique, a dehiscence was found. The30 cases done with the triangular-flap technique, adehiscence developed in only 3 cases (10%). This

result represents a relative risk ratio of 5.67 (95%confidence interval from 1.852 to 12.336) for the enve-lope-flap design, which is of high statistical signifi-cance (Fig 5).

DISCUSSIONAn envelope flap with a sulcular incision from the

first to the second molar and a distal relieving incisionto the mandibular ramus is a widely used technique forlower third molar surgery.3-7 There are definite advan-tages of this flap design. The surgical site is generouslyuncovered, ensuring a good overview during surgery.The sulcular incision can be prolonged mesially anytime, in case cystic lesions should extend mesially or ifadditional endosurgery of the adjacent molars isrequested. As a consequence of the extensivelyprepared mucoperiosteal flap, the osseous defect canalways be safely covered after the removal of themolar. Moreover, a large flap with a broad base guar-antees good vascularity up to the wound margins.

In the literature, possible disadvantages of thismethod are discussed. Every preparation of a mucoper-iosteal flap leads to a growing activity of osteoclasts inthe area of the alveolar process, inducing loss of alve-olar bone.17 Every sulcular incision is an interventionto the periodontal ligament and may lead to periodontaldamage. Alternatively, paragingival13 and vestibulartongue-shaped11 flap designs, which aim at sparing theperiodontal ligament of the adjacent molar, have beendescribed. Especially in cases of thin keratinizedgingiva in the area of the second molar, the conven-tional flap design may lead to a total loss of theattached gingiva in this area after the operation. This,again, can cause pocket formation and loss of attach-ment in the area of the second molar.18

In addition, the frequent occurrence of dehiscencesdistofacial to the second molar seems to be anotherdisadvantage of the envelope-flap design.8 To ourknowledge, such primary wound healing disordershave not been studied—particularly in lower thirdmolar surgery.

These gapings are usually located at the distobuccalgingival rim of the adjacent second molar, where thedistal relieving incision leads into the sulcular incision.In this area, soft tissue tensions resulting from postop-erative hematoma and masticatory movements mayinduce a rupture of the wound margins during the firstfew postoperative days. This is particularly true for theenvelope flap because it is fixed anteriorly with inter-sulcular sutures. Such dehiscences can take placeinconspicuously and unnoticed by the patient and mayheal secondarily. Thus, secondary wound healing cancause wedge-shaped defects of the gingiva distal to thesecond molar, or it can favor a loss of attachment distal

10 Jakse et al ORAL SURGERY ORAL MEDICINE ORAL PATHOLOGYJanuary 2002

Fig 4. The triangular flap allows easy relief of the hematomaduring the first postoperative day.

to the second molar. This periodontal complicationafter lower third molar surgery has been studied byseveral authors.1,3-5

A dehiscence does make hygiene more difficult andrequires intense follow-up treatment (ie, frequent irri-gation and possible local medication). There is also achance for longer-lasting discomfort caused by hyper-sensitivity in the area of the distally exposed rootsurface of the second molar. Alveolar osteitis and softtissue abscess are more severe complications that arepossible.

The present study has clearly shown that the flapdesign considerably influences primary wound healingin lower third molar surgery. When the conventionalsulcular flap design is used, 56% of the patientsdevelop a disorder in primary wound healing, althougha primary wound closure was the aim. With the modi-fication of a flap design, primary wound healing can besignificantly improved. With this flap design, dehis-cences occurred in only 10% of our cases. We suggestthat this was because of a tension decrease in the areaof the distal wound closure compared with the situationof the envelope flap technique. The vestibular trian-gular flap can be easily moved to lingual, ensuring awound closure that is almost tension-free. The mesialvestibular relieving incision, which is only adaptedcoronally by a single suture, allows depletion of thepostoperative hematoma during masticatory move-ments. On the first postoperative day, a presenthematoma is easy to relieve by spreading and compres-sion. In this respect, we can see the advantage that therelease area has bone support.

This study has shown that the conventional sulcular flapdesign has a nearly 6-times-higher risk of rupture of theprimary wound closure than the modified triangular flap.

The patient’s age has been described as one of thefactors influencing primary wound healing. Woundhealing up to age 25 years was supposed to be moreuncomplicated.5 In our group of patients, primarywound healing was not influenced by age.

Molars with complete bone coverage do not causebone loss distal to the adjacent molar, nor do they exerta traumatic stimulus on the oral mucosa—in contrastwith impacted teeth, which lie directly underneath themucosa. In these cases, the covering mucosa oftendisplays chronic inflammation, with the impactedmolar having already caused loss of attachment of theadjacent molar at the time of its removal. This seems toexplain the higher rate of dehiscences in the group ofnot completely osseous impacted teeth.

It is obvious that longer-lasting and, thus, morecomplicated surgery causes wound healing disorders,but in our study the influence of the duration of thesurgery seemed to be less important than the flap design.

The group of smokers in this study is too small tohave statistical relevance. Nevertheless, it can be saidthat the percentage of wound healing disorders washigher in the smoking group, which corresponds toresults in the literature.19

In conclusion, it can be said that the flap designconsiderably influences primary wound healing afterlower third molar surgery. The modified triangular flapdesign, when compared with the conventional sulcularincision, definitely makes primary wound healingeasier. Factors such as the degree of impaction, theduration of the surgery, and nicotine habits clearly haveless influence on primary wound healing.

REFERENCES1. Ash MM, Costich ER, Hayward JR. A study of periodontal

hazards of third molars. Periodontol 1962;33:209-19.2. Szmyd L. Impacted teeth. Dent Clin North Am 1971;15:299-

318.3. Stephens RJ, App GR, Foreman DW. Periodontal evaluation of

two mucoperiosteal flaps used in removing impacted mandibularthird molars. J Oral Maxillofac Surg 1983;41:719-24.

4. Quee TA, Gosselin D, Millar EP, Stamm JW. Surgical removalof the fully impacted mandibular third molar. The influence offlap design and alveolar bone height on the periodontal status ofthe second molar. J Periodontol 1985;56:625-30.

5. Kugelberg CF, Ahlström U, Ericson S, Hugoson A, Kvint S.Periodontal healing after impacted lower third molar surgery inadolescents and adults. A prospective study. Int J OralMaxillofac Surg 1991;20:18-24.

6. Sands T, Pynn BR, Nenniger S. Third molar surgery: currentconcepts and controversies. Part 2. Oral Health 1993;83:19, 21-2, 27-30.

ORAL SURGERY ORAL MEDICINE ORAL PATHOLOGY Jakse et al 11Volume 93, Number 1

Fig 5. The relative risk ratio and 95% CI of dehiscences forfactors that might influence wound healing (ie, flap design,level of retention, duration of the surgery, nicotine habits, andpatient age). Compared with the triangular flap, the envelopeflap has a relative risk of a dehiscence during primary woundhealing of 5.67, with a 95% CI from 1.852 to 12.336. Thisresult is highly statistically significant, whereas the factorlevels of retention, duration, and smoking habits seemed toinfluence primary wound healing—but without statisticalsignificance.

7. Pajarola GF, Jaquiery C, Lambrecht JT, Sailer HF. DieEntfernung unterer retinierter Weisheitszähne (II) SchweizMonatsschr Zahnmed 1994;104:1521-30.

8. Klatil L. Komplikationen bei der Entfernung vonWeisheitszähnen [doctoral thesis]. KF-University Graz; 1998.

9. Thoma KH. The management of malposed inferior third molars.J Dent Res 1932;12:175-80.

10. Szmyd L, Hester WR. Crevicular depth of the second molar inimpacted third molar surgery. J Oral Surg Anesth Hosp DentServ 1963;21:185-8.

11. Berwick WA. Alternative method of flap reflection. Br Dent J1966;121:295-6.

12. Groves BJ, Moore JR. The periodontal implications of flapdesign in lower third molar extractions. Dent Pract Dent Rec1970;20:297-304.

13. Magnus WW, Castner DV, Hiatt WR. An alternative method offlap reflection of mandibular third molars. Mil Med1972;137:232-3.

14. Woolf RH, Malmquist JP, Wright WH. Third molar extractions:periodontal implications of two flap designs. Gen Dent1978;26:52-6.

15. Papassotiriou A. Parodontalbefunde nach Zahnfleischrandschnittzur Weisheitszahnentfernung. Zahnärztliche Praxis 1991;6:206-11.

16. Norusis MJ. SPSS for Windows: Base system user’s guide,Release 5.0. Chicago: SPSS Inc; 1992. p. 211.

17. Tavtigian R. The height of facial radicular alveolar crestfollowing apically positioned flap operations. J Periodontol1970;41:412-8.

18. Motamedi MH. A technique to manage gingival complicationsof third molar surgery. Oral Surg Oral Med Oral Pathol OralRadiol Endod 2000;90:140-3.

19. Silverstein P. Smoking and wound healing. Am J Med1992;93(1A):S22-S24.

Reprint requests:

Norbert Jakse, MD, DDSDepartment for Oral Surgery and RadiologyDental School, Karl-Franzens University GrazAuenbruggerplatz 12, 8036 Graz, Austrianorbert.jakse@uni-graz.at

12 Jakse et al ORAL SURGERY ORAL MEDICINE ORAL PATHOLOGYJanuary 2002

CALL FOR REVIEW ARTICLES

The January 1993 issue of Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology,and Endodontics contained an Editorial by the Journal’s Editor in Chief, Larry J. Peterson, thatcalled for a Review Article to appear in each issue.

These Review Articles should be designed to review the current status of matters that areimportant to the practitioner. These articles should contain current developments, changingtrends, as well as reaffirmation of current techniques and policies.

Please consider submitting your article to appear as a Review Article. Information forauthors appears in each issue of Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology,and Endodontics.

We look forward to hearing from you.