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A clinical investigation into the incidence of dry socket
British Journal of Oral and Maxillofacial Surgery (1984) 22, 115-122 0 1984 The British Association of Oral and Maxillofacial Surgeons
A CLINICAL
INVESTIGATION P. A. HEASMAN,
INTO THE INCIDENCE
B.D.s.’
and D. J. JACOBS, B.D.s.,
OF DRY SOCKET B~.s~.~
‘Department of Oral Biology, University of Newcastle upon Tyrze 2Department of Restorative Dentistry, Newcastle upon Tyne Dental Hospital
Summary. A clinical investigation was undertaken to find the incidence of dry socket as a post-operative complication of dental extraction on an out-patient basis. Two thousand three hundred and sixty three extractions were carried out under local anaesthesia by clinical staff and students over a four month period. The results are presented and their significance discussed, the incidence of dry socket being found to be dependent upon the site of the tooth extracted, the relative difficulty of the extraction and upon the integrity and size of the blood clot in the extractidn socket.
Introduction Dry socket is a post-extraction complication characterised by the onset of a severe pain usually 48 to 72 hours after the extraction of a tooth. Clinical examination will reveal a necrotic blood clot in the extraction wound which, on removal, will disclose alveolar bone with a ‘dry’ appearance, a finding which prompted Crawford (1896) to suggest the term dry socket to describe this condition. In this paper we present an analysis and assessment of the incidence of dry socket according, as far as possible, to local and operative factors in patients requiring intra-alveolar extractions (Howe, 1974) under local anaesthesia. Patients whose medical history revealed a condition which may have predisposed to a dry socket (Harang, 1948; Ringsdorf & Cheraskin, 1975) were not included in the survey. For the same reason (Schow, 1974; Lilly et al., 1974) female patients who admitted to taking oral contraceptives, or who were pregnant, were omitted from the survey. The factors with which we were primarily concerned in this project were the patient’s age and sex, the number of teeth extracted during the operation, the site of the extracted tooth and the reason for its removal, the relative difficulty of the extraction and the level of the blood clot in the socket as observed when haemostasis had been achieved. Methods Extractions were undertaken by members of staff and students in the Oral Surgery Department of the Dental Hospital of Newcastle upon Tyne. Extraction forceps were used unless a tooth fractured during the surgical procedure, when the use of elevators may have been indicated. Prilocaine with felypressin was the local anaesthetic agent of choice, although plain prilocaine and lignocaine 2 per cent with adrenaline (1:80,000) were available if required. The age and sex of the patient, the number and site of teeth to be extracted, the reason for the extraction and the time taken to complete each operation (the latter parameter taken subsequently to reflect the degree of trauma. inflicted upon the alveolar bone during the removal of the tooth-Table I) were re’corded. (Received 13 May 1982; accepted 9 November
115
1982)
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Table I Time taken to extract tooth
Difficulty of extraction
Less than 1 minute Between 1 and 5 minutes More than 5 minutes
‘Easy’ ‘Moderate’ ‘Difficult’
After each extraction an assessment of the vertical level of the blood clot in the extraction socket was made by one of the authors. This observation was detailed to one of three categories:(1) socket less than one third full; (2) socket between one third and two thirds full; (3) socket more than two thirds full. Patients were then told to return to the hospital should they experience discomfort from the site of the extraction during the following few days.
any
All patients diagnosed as having a dry socket had returned to the Departfour days of the extraction and were examined by one of the authors. Diagnosis was based upon the history obtained and a clinical examination.
Diagnosis. ment
within
Results
In the survey a total of 2,363 extractions of permanent teeth from 1,486 patients over a period of four months was analysed. As a result of these extractions 69 dry sockets were diagnosed from 60 patients. Single extractions from 1,020 patients resulted in 34 dry sockets representing an incidence of 3.3 per cent, whereas multiple extractions made from 466 patients accounted for 1,343 teeth and gave rise eventually to 35 dry sockets, an incidence of 2.6 per cent (Table II). Chi-squared analysis indicates that the difference between these results was not significant (~‘0.1) and, therefore, the remaining variables were analysed over a combination of single and multiple extraction data. Sex. 1,421 extractions were made from male patients and 942 from female patients. In males 39 dry sockets were found showing an incidence of 2.7 per cent whereas 30 were diagnosed in the female group, an incidence of 3.2 per cent. The difference between these findings was not significant (~‘0.5) (Table III).
Table II
Overall incidence of dry socket Extractions
Patients
Number of teeth extracted
Number of dry sockets
Incidence of dry socket %
Single Multiple Combined
1020 466 1486
1020 1343 2363
34 35 69
3.3 2.4 2.9
x2=1.019, ld.f., p=O.31
DRY
SOCKET
117
INCIDENCE
Table III
Incidence of dry socket according to sex of patient
Males Females x*=0.37,
ld.f.,
Extractions
Number of dry sockets
Incidence of dry socket %
1421 942
39 30
2.7 3.2
p=O.55
Age. Patients were divided into lo-year
age groups and the number of cases of dry socket in each age group recorded and analysed (Table IV). The highest overall incidence of patients with dry socket was seen in the 21 to 30 age group (5.5 per cent) as was the highest incidence of males with dry socket (6.0 pe:r cent). In females however the highest incidence of patients with dry socket was found in the 61 to 70 age range, although the small cell size for this group suggests that this information is unreliable.
The incidence of dry socket according to the site of the extracted tooth may be seen in Table V, and in order to increase the cell size for a satisfactory statistical analysis, teeth were grouped according to anatomical distribution as illustrated in Table VI. It may then be observed that the incidence of dry socket is dependent upon the site of the tooth extracted (p
Site of extraction.
All teeth were categorised according to the reason necessitating their extraction (Table VII). Because a definite diagnosis is not always possible, and because one tooth may be classified into two categories, for example, a tooth
Reasons for extraction.
Table IV
Incidence of dry socket according to patient’s age Patients Age range 1 l-20 21-30 31-40 41-50 51-60 61-70 71-80 81-90 Totals
Patients with dry sockets
Incidence of patients with dry socket %
Male
Female
Male
Female
Male
Female
Combined
113 268 156 121 103 51 14 -
148 206 135 89 45 28 7 2 660
1 16 6 6 3 2
7 10 2 4 1 2
0.9 6.0 3.8 5.0 2.9 3.9
4.7 4.8 1.5 4.5 2.2 7.1
3.1 5.5 2.7 4.8 2.7 5.1
-
-
-
-
-
34
26
4.1
3.9
4.0
826
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Table V Incidence
JOURNAL
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ORAL
of dry socket according
Maxilla Incidence of dry socket Number of dry sockets Number of extractions
%
%
MAXILLOFACIAL
to the site of extraction
79
95
1
2
3
86 1 1.2
81 1 1.2
75 2 2.7
Tooth Mandible Number of extractions Number of dry sockets Incidence of dry socket
&
2.6 2 78
SURGERY
of each tooth
1.3 0.8 2.3 2.0 2 1 5 4 148 122 214 204 4
5
6
115 148 223 1 9 25 0.9 6.1 11.2
7
0.5 1 181 8
227 124 9 4 4.0 3.2
0.9 1 110
1.3 16 1231
Roots
Total
53 1132 1 53 1.9 4.7
Chi-squared analysis on totals only x2=22.24, ld.f., p
Table VI Incidence
of dry socket according
Anatomical
group
Incisors and canines Lower premolars Upper premolars Lower molars Upper molars Retained roots x*=38.508,
5d.f.,
to the anatomical
grouping
of teeth
Number of extractions
Number of dry sockets
Incidence of dry socket %
494 263 270 574 599 163
6 10 3 38 10 2
1.2 3.8 1.1 6.6 1.7 1.2
p
Table VII Incidence of dry socket according
to the reason
for the extraction
Reason for tooth extraction
Number of extractions
Number of dry sockets
Incidence of dry socket %
Caries Periodontal Orthodontic Pericoronitis Trauma*
1578 520 50 9 43
54 11 1 1 -
3.4 2.1 2.0 11.1 -
163
2
1.2
Retained *Maxillary
disease therapy
roots third molars
causing
trauma
to opposing
operculum
extracted for pulpitis could well have lost a substantial amount of alveolar support due to periodontal disease, statistical analysis is invalid and only basic trends can be observed. The highest incidence of dry socket appeared in the extractions group because of caries; within this group 83 teeth were diagnosed from intra-oral radiographs to have an associated periapical abscess, and from this subgroup ten dry sockets developed representing an incidence of 12.0 per cent.
DRY
SOCKET
119
INCIDENCE
Table VIII
Incidence of dry socket according to the degree of difficulty of extraction Degree of difficulty
Time taken to extract tooth (minutes)
Number of extractions
Number of dry sockets
Incidence of dry socket %
Easy Moderate Difficult
Less than 1 Between 1& 5 More than 5
1082 1007 274
27 24 18
2.5 2.4 6.6‘
x2=13.35,
2d.f., p=O.O013
The incidence of dry socket following ‘easy’ and ‘moderately difficult’ extractions was almost identical (2.5 per cent and 2.4 per cent respectively) yet the incidence of dry socket following ‘very difficult’ extractions was significantly greater (6.6 per cent) than in either of the two previous groups. The occurrence of dry socket appears to be dependent upon the time taken to extract the tooth and probably therefore upon the trauma inflicted on the socket walls (O.Ol>p>O.OOl).
Difficulty of extraction.
socket. (Table IX). The ma,jority of extraction sockets (1,982) were seen to fill with blood to a level greater than two thirds the vertical height of the socket, and of these sockets 54 developed post-operative complications diagnosed as dry socket, representing an incidence of 2.7 per cent. In 304 cases where the level of the blood clot was judged to be between one third and two thirds the vertical height of the socket eight dry sockets developed (2.6 per cent) and of the remaining 77 extraction sockets (blood clot less than one third of the vertical height of the socket) seven dry sockets developed showing an occurrence of 9.1 per cent. It may, therefore, be concluded that the occurrence of dry socket is dependent upon the level of the blood clot in the extraction wound after achieving post-operative haemostasis (0.01>p>0.001).
Size of the blood clot in the extraction
Note. Because of uncontrolled
variation in the data due to, for example, the difference in operator experience, results have not been regarded as significant unless pCO.01 (or the one per cent level).
Table IX
Incidence of dry socket according to the size of the blood clot in the extraction socket Level of clot in socket as a fraction of the vertical height of the socket walls Less than one third Between one third and two thirds Greater than two thirds x*=9.54,
ld.f.,
p=O.O085
Number of extractions
Number of dry sockets
Incidence of dry socket %
77
7
9.1
304 1982
8 54
2.6 2.7
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Discussion The overall incidence of dry socket in this survey was 2.9 per cent of 2,363 intra-alveolar extractions, a result in close agreement with those of previous studies (Table X). There was no significance in the difference between the incidence of dry socket following single and multiple extractions, a finding in disagreement with that of Krogh (1937) and of MacGregor (1968), who concluded that the more adjacent teeth removed at one operation the less chance of dry socket developing. Our result led us to analyse further variables over the combined data for single and multiple extractions. An interesting finding of this investigation was that males and females appear equally susceptible to dry socket, a conclusion also reached by Krogh (1937) and Lehner (1958). MacGregor (1968) found the incidence of dry socket to be sexspecific, females being more susceptible than males, a finding which may have resulted from the more widespread use of oral contraceptives during this later study. The results from this project would be expected to compare with the results of Krogh and of Lehner (whose surveys were conducted before the widespread use of oral contraception) as an attempt was made to disregard all females taking oral contraceptives. In males the highest incidence of patients with dry socket (6.0 per cent) was found in the 21 to 30 age group, whereas in females it was in the 61 to 70 age range (7.1 per cent), although because of the small numbers of patients in the older groups (particularly females) these results cannot be regarded as reliable, and statistical analysis is invalid. Lehner (1958) has suggested that the incidence of dry socket in patients in the 18-25 age range can be expected to be high as this is the normal eruption period for third molars. Dry socket was found, in accordance with the results of previous workers, to be dependent upon the site of the tooth extracted. The occurrence of dry socket in the mandible (4.7 per cent) was significantly higher than that in the maxilla (1.3 per cent), and after combining the groups in Table V to achieve adequate cell size in Table VI it can be seen that there is a descending order of occurrence of dry socket in lower molars, lower premolars, upper molars, incisors and canines and upper premolars. Previous investigators (Krogh, 1951; Archer, 1966) have indicated that there is an increased likelihood of post-operative complication following the extraction of teeth associated with periapical infection. In our present investigation ten dry sockets developed from 83 extraction sockets (12.0 per cent) when the teeth were seen from intra-oral radiographs to have periapical rarefaction of bone creditable to an associated infection. Little emphasis can be placed on this result, however, since not all Table X Results of previous investigations into the incidence of dry socket Numberof Study
extractions
Incidence of dry socket %
Lehner (1958) Hansen (1960) MacGregor (1968)
2040 1079 10199
3.1 3.1 3.2
DRY
SOCKET
INCIDENCE
121
the teeth extracted in this survey were radiographed beforehand, and undoubtably some teeth must have been extracted which had periapical pathology that went undetected. Nine partially erupted mandibular third molars were extracted in the presence of a mild pericoronitis and a single dry socket resulted from these operations (an incidence of 11.1 per cent), whereas the remaining 11.5 mandibular third molar extractions (non-surgical) gave rise to three dry sockets (2.6 per cent). Unfortunately no significance can be attached to these results due to the small number of extractions in the ‘periocoronitis’ group. We were able to show conclusively from our results that the occurrence of dry socket is dependent upon the difficulty experienced in extracting the tooth. Operations classified as being ‘very difficult’ had a dry socket incidence of 6.6 per cent which is significantly higher than that following ‘moderately difficult’ and ‘easy’ extractions. These findings are in accordance with the consistent observation made by previous workers (Wald, 1932; Machat, 1934; Krogh, 1937; Alling & Kerr, 1957; Lehner, 1958; Archer, 1966; MacGregor, 1968) that trauma is undoubtably an important factor in the production of dry socket. The development of dry socket in accordance with the extent of the blood clot present in the extraction wound has been analysed by Hindle and Gibbs (1977). They showed that when no protection was afforded to extraction wounds, dry socket developed in 12 out of 273 single extraction sockets (4.4 per cent) which were completely filled with blood whereas 20 dry sockets developed from 243 wounds (8.2 per cent) which were only partially filled with blood. It must be acknowledged that a consistent critical subjective assessment of the blood clot level is difficult to achieve. Results however do indicate (Table IX) that the incidence of dry socket was significantly higher when there was minimal immediate post-operative haemorrhage resulting in an unsatisfactory blood clot in the wound. It has been suggested (Hut, 1963) that the main cause of complicated wound healing after the extraction of a tooth is not, as previously indicated, the degree of trauma inflicted upon the socket walls during the extraction, but the disturbance of the blood clot in the socket after the extraction. Winter (1931) cited that constant and excessive rinsing will destroy and wash away the blood clot leading to infection of the clot by saliva. It may, therefore, be envisaged that a small, poorly organised blood clot, the integrity of which may be affected by foreign bodies or saliva leading to secondary infection by commensal microorganisms (Brown et al., 1970; MacGregor & Hart, 1970) will afford little protection to the socket walls and. will soon succumb to the proven high fibrinolytic activity (Birn, 1970; 1972) of the alveolar bone and, therefore, predispose to dry socket. When the blood supply to the socket, post-operative bleeding and blood clot organisation are adequate, then there will be ample opportunity for the early proliferation of the fibroblastic tissue necessary to stabilise the wound healing (Huebsch, 1958). Conclusions (1)
Occurrence of dry socket is not dependent upon the number of teeth extracted at one operation. (2) Males and females are equally susceptible to dry socket when females who are pregnant or are taking oral contraceptives are discounted. (3) The incidence of dry socket is significantly higher as a post-extraction complication in mandibular molars than any other teeth.
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(4) The incidence of dry socket is found to be dependent upon the duration of physical irritation afforded to the alveolar bone. (5) The incidence of dry socket is greater in wounds which display poor immediate post-operative filling with blood clot. Acknowledgements This study was undertaken while the authors were on the Junior Hospital staff in the Oral Surgery department of the Newcastle upon Tyne Dental Hospital and grateful thanks are due to Dr G. S. Blair and Mr J. Murgatroyd for their assistance and encouragement with this survey. References Alling, C. C. & Kerr, D. A. (1957). Trauma as a factor causing delayed repair of dental extraction sites. Journal of Oral Surgery, 15, 3. Archer, W. H. (1966). Manual of Oral Surgery, 4th Edn., pp. 699. Saunders, Philadelphia and London. Birn, H. (1970). Bacteria and fibrinolytic activity in ‘dry socket’. Acta Odontologica Scandinavica, 28, 773. Birn, H. (1972). Fibrinolytic activity of alveolar bone in ‘dry socket’.Acta Odontologica Scandinavica, 30, 23. Brown, L. R., Merrill, S. S. & Allen, R. E. (1970). Microbiologic study of intraoral wounds. Journal of Oral Surgery, 28, 89. Crawford, J. Y. (1896). Dry sockets. Dental Cosmos, 38, 929. Hansen, E. H. (1960). Alveolitis sicca dolorosa (dry socket): frequency of occurrence and treatment with trypsin. Journal of Oral Surgery, 18, 409. Harang, H. L. (1948). The prevention of dry socket in the extraction of teeth. Oral Surgery, Oral Medicine and Oral Pathology, 1, 601. Hindle, M. 0. & Gibbs, A. (1977). The incidence of dry socket following the use of an occlusive dressing. Journal of Dentistry, 5, 288. Howe, G. L. (1974). The extraction of teeth, 2nd Edn. (rev.), pp. 21-39. Wright, Bristol. Huebsch, R. F. (1958). Clinical and histological study of alveolar osteitis. Journalof OralSurgery, 16,473. Hut, M. (1963). Complications in post-extraction healing. International Dental Journal, 13, 440. Krogh, H. W. (1937). Incidence of dry socket. Journal of the American Dental Association, 88, 802. Krogh, H. W. (1951). Extraction of teeth in the presence of acute infections. Journal of Oral Surgery, 9, 136. Lehner, T. (1958). Analysis of one hundred cases of dry socket. Dental Practitioner, 8, 9. Lilly, G. E., Osborne, D. B., Rael, E. M., Samuels, H. S. & Jones, J. C. (1974). Alveolar osteitis associated with mandibular third molar extractions. Journal of the American Dental Association, 88, 802. MacGregor, A. J. (1968). Aetiology of dry socket: A clinical investigation. British Journal of Oral Surgery, 6, 49. MacGregor, A. J. & Hart, P. (1970). Bacteria of the extraction wound. Journal of Oral Surgery, 28, 885. Machat, B. B. (1934). The facility of surgery in the general practice of dentistry, (exodontia). Dental Cosmos, 76, 342. Ringsdorf, W. M. & Cheraskin, E. (1975). Dry socket and dysglycaemia. Journal of Dental Research, 54, 184. Schow, S. R. (1974). Evaluation of post-operative localised osteitis in mandibular third molar surgery. Oral Surgery, 38, 352. Wald, A. (1932). Post-operative complications in exodontia. Dental Cosmos, 74, 72. Winter, L. (1931). Local anaesthesia and exodontia. Dental Cosmos, 73, 545.
A CLINICAL
INVESTIGATION P. A. HEASMAN,
INTO THE INCIDENCE
B.D.s.’
and D. J. JACOBS, B.D.s.,
OF DRY SOCKET B~.s~.~
‘Department of Oral Biology, University of Newcastle upon Tyrze 2Department of Restorative Dentistry, Newcastle upon Tyne Dental Hospital
Summary. A clinical investigation was undertaken to find the incidence of dry socket as a post-operative complication of dental extraction on an out-patient basis. Two thousand three hundred and sixty three extractions were carried out under local anaesthesia by clinical staff and students over a four month period. The results are presented and their significance discussed, the incidence of dry socket being found to be dependent upon the site of the tooth extracted, the relative difficulty of the extraction and upon the integrity and size of the blood clot in the extractidn socket.
Introduction Dry socket is a post-extraction complication characterised by the onset of a severe pain usually 48 to 72 hours after the extraction of a tooth. Clinical examination will reveal a necrotic blood clot in the extraction wound which, on removal, will disclose alveolar bone with a ‘dry’ appearance, a finding which prompted Crawford (1896) to suggest the term dry socket to describe this condition. In this paper we present an analysis and assessment of the incidence of dry socket according, as far as possible, to local and operative factors in patients requiring intra-alveolar extractions (Howe, 1974) under local anaesthesia. Patients whose medical history revealed a condition which may have predisposed to a dry socket (Harang, 1948; Ringsdorf & Cheraskin, 1975) were not included in the survey. For the same reason (Schow, 1974; Lilly et al., 1974) female patients who admitted to taking oral contraceptives, or who were pregnant, were omitted from the survey. The factors with which we were primarily concerned in this project were the patient’s age and sex, the number of teeth extracted during the operation, the site of the extracted tooth and the reason for its removal, the relative difficulty of the extraction and the level of the blood clot in the socket as observed when haemostasis had been achieved. Methods Extractions were undertaken by members of staff and students in the Oral Surgery Department of the Dental Hospital of Newcastle upon Tyne. Extraction forceps were used unless a tooth fractured during the surgical procedure, when the use of elevators may have been indicated. Prilocaine with felypressin was the local anaesthetic agent of choice, although plain prilocaine and lignocaine 2 per cent with adrenaline (1:80,000) were available if required. The age and sex of the patient, the number and site of teeth to be extracted, the reason for the extraction and the time taken to complete each operation (the latter parameter taken subsequently to reflect the degree of trauma. inflicted upon the alveolar bone during the removal of the tooth-Table I) were re’corded. (Received 13 May 1982; accepted 9 November
115
1982)
116
BRITISH
JOURNAL
OF
ORAL
&
MAXILLOFACIAL
SURGERY
Table I Time taken to extract tooth
Difficulty of extraction
Less than 1 minute Between 1 and 5 minutes More than 5 minutes
‘Easy’ ‘Moderate’ ‘Difficult’
After each extraction an assessment of the vertical level of the blood clot in the extraction socket was made by one of the authors. This observation was detailed to one of three categories:(1) socket less than one third full; (2) socket between one third and two thirds full; (3) socket more than two thirds full. Patients were then told to return to the hospital should they experience discomfort from the site of the extraction during the following few days.
any
All patients diagnosed as having a dry socket had returned to the Departfour days of the extraction and were examined by one of the authors. Diagnosis was based upon the history obtained and a clinical examination.
Diagnosis. ment
within
Results
In the survey a total of 2,363 extractions of permanent teeth from 1,486 patients over a period of four months was analysed. As a result of these extractions 69 dry sockets were diagnosed from 60 patients. Single extractions from 1,020 patients resulted in 34 dry sockets representing an incidence of 3.3 per cent, whereas multiple extractions made from 466 patients accounted for 1,343 teeth and gave rise eventually to 35 dry sockets, an incidence of 2.6 per cent (Table II). Chi-squared analysis indicates that the difference between these results was not significant (~‘0.1) and, therefore, the remaining variables were analysed over a combination of single and multiple extraction data. Sex. 1,421 extractions were made from male patients and 942 from female patients. In males 39 dry sockets were found showing an incidence of 2.7 per cent whereas 30 were diagnosed in the female group, an incidence of 3.2 per cent. The difference between these findings was not significant (~‘0.5) (Table III).
Table II
Overall incidence of dry socket Extractions
Patients
Number of teeth extracted
Number of dry sockets
Incidence of dry socket %
Single Multiple Combined
1020 466 1486
1020 1343 2363
34 35 69
3.3 2.4 2.9
x2=1.019, ld.f., p=O.31
DRY
SOCKET
117
INCIDENCE
Table III
Incidence of dry socket according to sex of patient
Males Females x*=0.37,
ld.f.,
Extractions
Number of dry sockets
Incidence of dry socket %
1421 942
39 30
2.7 3.2
p=O.55
Age. Patients were divided into lo-year
age groups and the number of cases of dry socket in each age group recorded and analysed (Table IV). The highest overall incidence of patients with dry socket was seen in the 21 to 30 age group (5.5 per cent) as was the highest incidence of males with dry socket (6.0 pe:r cent). In females however the highest incidence of patients with dry socket was found in the 61 to 70 age range, although the small cell size for this group suggests that this information is unreliable.
The incidence of dry socket according to the site of the extracted tooth may be seen in Table V, and in order to increase the cell size for a satisfactory statistical analysis, teeth were grouped according to anatomical distribution as illustrated in Table VI. It may then be observed that the incidence of dry socket is dependent upon the site of the tooth extracted (p
Site of extraction.
All teeth were categorised according to the reason necessitating their extraction (Table VII). Because a definite diagnosis is not always possible, and because one tooth may be classified into two categories, for example, a tooth
Reasons for extraction.
Table IV
Incidence of dry socket according to patient’s age Patients Age range 1 l-20 21-30 31-40 41-50 51-60 61-70 71-80 81-90 Totals
Patients with dry sockets
Incidence of patients with dry socket %
Male
Female
Male
Female
Male
Female
Combined
113 268 156 121 103 51 14 -
148 206 135 89 45 28 7 2 660
1 16 6 6 3 2
7 10 2 4 1 2
0.9 6.0 3.8 5.0 2.9 3.9
4.7 4.8 1.5 4.5 2.2 7.1
3.1 5.5 2.7 4.8 2.7 5.1
-
-
-
-
-
34
26
4.1
3.9
4.0
826
118
BRITISH
Table V Incidence
JOURNAL
OF
ORAL
of dry socket according
Maxilla Incidence of dry socket Number of dry sockets Number of extractions
%
%
MAXILLOFACIAL
to the site of extraction
79
95
1
2
3
86 1 1.2
81 1 1.2
75 2 2.7
Tooth Mandible Number of extractions Number of dry sockets Incidence of dry socket
&
2.6 2 78
SURGERY
of each tooth
1.3 0.8 2.3 2.0 2 1 5 4 148 122 214 204 4
5
6
115 148 223 1 9 25 0.9 6.1 11.2
7
0.5 1 181 8
227 124 9 4 4.0 3.2
0.9 1 110
1.3 16 1231
Roots
Total
53 1132 1 53 1.9 4.7
Chi-squared analysis on totals only x2=22.24, ld.f., p
Table VI Incidence
of dry socket according
Anatomical
group
Incisors and canines Lower premolars Upper premolars Lower molars Upper molars Retained roots x*=38.508,
5d.f.,
to the anatomical
grouping
of teeth
Number of extractions
Number of dry sockets
Incidence of dry socket %
494 263 270 574 599 163
6 10 3 38 10 2
1.2 3.8 1.1 6.6 1.7 1.2
p
Table VII Incidence of dry socket according
to the reason
for the extraction
Reason for tooth extraction
Number of extractions
Number of dry sockets
Incidence of dry socket %
Caries Periodontal Orthodontic Pericoronitis Trauma*
1578 520 50 9 43
54 11 1 1 -
3.4 2.1 2.0 11.1 -
163
2
1.2
Retained *Maxillary
disease therapy
roots third molars
causing
trauma
to opposing
operculum
extracted for pulpitis could well have lost a substantial amount of alveolar support due to periodontal disease, statistical analysis is invalid and only basic trends can be observed. The highest incidence of dry socket appeared in the extractions group because of caries; within this group 83 teeth were diagnosed from intra-oral radiographs to have an associated periapical abscess, and from this subgroup ten dry sockets developed representing an incidence of 12.0 per cent.
DRY
SOCKET
119
INCIDENCE
Table VIII
Incidence of dry socket according to the degree of difficulty of extraction Degree of difficulty
Time taken to extract tooth (minutes)
Number of extractions
Number of dry sockets
Incidence of dry socket %
Easy Moderate Difficult
Less than 1 Between 1& 5 More than 5
1082 1007 274
27 24 18
2.5 2.4 6.6‘
x2=13.35,
2d.f., p=O.O013
The incidence of dry socket following ‘easy’ and ‘moderately difficult’ extractions was almost identical (2.5 per cent and 2.4 per cent respectively) yet the incidence of dry socket following ‘very difficult’ extractions was significantly greater (6.6 per cent) than in either of the two previous groups. The occurrence of dry socket appears to be dependent upon the time taken to extract the tooth and probably therefore upon the trauma inflicted on the socket walls (O.Ol>p>O.OOl).
Difficulty of extraction.
socket. (Table IX). The ma,jority of extraction sockets (1,982) were seen to fill with blood to a level greater than two thirds the vertical height of the socket, and of these sockets 54 developed post-operative complications diagnosed as dry socket, representing an incidence of 2.7 per cent. In 304 cases where the level of the blood clot was judged to be between one third and two thirds the vertical height of the socket eight dry sockets developed (2.6 per cent) and of the remaining 77 extraction sockets (blood clot less than one third of the vertical height of the socket) seven dry sockets developed showing an occurrence of 9.1 per cent. It may, therefore, be concluded that the occurrence of dry socket is dependent upon the level of the blood clot in the extraction wound after achieving post-operative haemostasis (0.01>p>0.001).
Size of the blood clot in the extraction
Note. Because of uncontrolled
variation in the data due to, for example, the difference in operator experience, results have not been regarded as significant unless pCO.01 (or the one per cent level).
Table IX
Incidence of dry socket according to the size of the blood clot in the extraction socket Level of clot in socket as a fraction of the vertical height of the socket walls Less than one third Between one third and two thirds Greater than two thirds x*=9.54,
ld.f.,
p=O.O085
Number of extractions
Number of dry sockets
Incidence of dry socket %
77
7
9.1
304 1982
8 54
2.6 2.7
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Discussion The overall incidence of dry socket in this survey was 2.9 per cent of 2,363 intra-alveolar extractions, a result in close agreement with those of previous studies (Table X). There was no significance in the difference between the incidence of dry socket following single and multiple extractions, a finding in disagreement with that of Krogh (1937) and of MacGregor (1968), who concluded that the more adjacent teeth removed at one operation the less chance of dry socket developing. Our result led us to analyse further variables over the combined data for single and multiple extractions. An interesting finding of this investigation was that males and females appear equally susceptible to dry socket, a conclusion also reached by Krogh (1937) and Lehner (1958). MacGregor (1968) found the incidence of dry socket to be sexspecific, females being more susceptible than males, a finding which may have resulted from the more widespread use of oral contraceptives during this later study. The results from this project would be expected to compare with the results of Krogh and of Lehner (whose surveys were conducted before the widespread use of oral contraception) as an attempt was made to disregard all females taking oral contraceptives. In males the highest incidence of patients with dry socket (6.0 per cent) was found in the 21 to 30 age group, whereas in females it was in the 61 to 70 age range (7.1 per cent), although because of the small numbers of patients in the older groups (particularly females) these results cannot be regarded as reliable, and statistical analysis is invalid. Lehner (1958) has suggested that the incidence of dry socket in patients in the 18-25 age range can be expected to be high as this is the normal eruption period for third molars. Dry socket was found, in accordance with the results of previous workers, to be dependent upon the site of the tooth extracted. The occurrence of dry socket in the mandible (4.7 per cent) was significantly higher than that in the maxilla (1.3 per cent), and after combining the groups in Table V to achieve adequate cell size in Table VI it can be seen that there is a descending order of occurrence of dry socket in lower molars, lower premolars, upper molars, incisors and canines and upper premolars. Previous investigators (Krogh, 1951; Archer, 1966) have indicated that there is an increased likelihood of post-operative complication following the extraction of teeth associated with periapical infection. In our present investigation ten dry sockets developed from 83 extraction sockets (12.0 per cent) when the teeth were seen from intra-oral radiographs to have periapical rarefaction of bone creditable to an associated infection. Little emphasis can be placed on this result, however, since not all Table X Results of previous investigations into the incidence of dry socket Numberof Study
extractions
Incidence of dry socket %
Lehner (1958) Hansen (1960) MacGregor (1968)
2040 1079 10199
3.1 3.1 3.2
DRY
SOCKET
INCIDENCE
121
the teeth extracted in this survey were radiographed beforehand, and undoubtably some teeth must have been extracted which had periapical pathology that went undetected. Nine partially erupted mandibular third molars were extracted in the presence of a mild pericoronitis and a single dry socket resulted from these operations (an incidence of 11.1 per cent), whereas the remaining 11.5 mandibular third molar extractions (non-surgical) gave rise to three dry sockets (2.6 per cent). Unfortunately no significance can be attached to these results due to the small number of extractions in the ‘periocoronitis’ group. We were able to show conclusively from our results that the occurrence of dry socket is dependent upon the difficulty experienced in extracting the tooth. Operations classified as being ‘very difficult’ had a dry socket incidence of 6.6 per cent which is significantly higher than that following ‘moderately difficult’ and ‘easy’ extractions. These findings are in accordance with the consistent observation made by previous workers (Wald, 1932; Machat, 1934; Krogh, 1937; Alling & Kerr, 1957; Lehner, 1958; Archer, 1966; MacGregor, 1968) that trauma is undoubtably an important factor in the production of dry socket. The development of dry socket in accordance with the extent of the blood clot present in the extraction wound has been analysed by Hindle and Gibbs (1977). They showed that when no protection was afforded to extraction wounds, dry socket developed in 12 out of 273 single extraction sockets (4.4 per cent) which were completely filled with blood whereas 20 dry sockets developed from 243 wounds (8.2 per cent) which were only partially filled with blood. It must be acknowledged that a consistent critical subjective assessment of the blood clot level is difficult to achieve. Results however do indicate (Table IX) that the incidence of dry socket was significantly higher when there was minimal immediate post-operative haemorrhage resulting in an unsatisfactory blood clot in the wound. It has been suggested (Hut, 1963) that the main cause of complicated wound healing after the extraction of a tooth is not, as previously indicated, the degree of trauma inflicted upon the socket walls during the extraction, but the disturbance of the blood clot in the socket after the extraction. Winter (1931) cited that constant and excessive rinsing will destroy and wash away the blood clot leading to infection of the clot by saliva. It may, therefore, be envisaged that a small, poorly organised blood clot, the integrity of which may be affected by foreign bodies or saliva leading to secondary infection by commensal microorganisms (Brown et al., 1970; MacGregor & Hart, 1970) will afford little protection to the socket walls and. will soon succumb to the proven high fibrinolytic activity (Birn, 1970; 1972) of the alveolar bone and, therefore, predispose to dry socket. When the blood supply to the socket, post-operative bleeding and blood clot organisation are adequate, then there will be ample opportunity for the early proliferation of the fibroblastic tissue necessary to stabilise the wound healing (Huebsch, 1958). Conclusions (1)
Occurrence of dry socket is not dependent upon the number of teeth extracted at one operation. (2) Males and females are equally susceptible to dry socket when females who are pregnant or are taking oral contraceptives are discounted. (3) The incidence of dry socket is significantly higher as a post-extraction complication in mandibular molars than any other teeth.
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(4) The incidence of dry socket is found to be dependent upon the duration of physical irritation afforded to the alveolar bone. (5) The incidence of dry socket is greater in wounds which display poor immediate post-operative filling with blood clot. Acknowledgements This study was undertaken while the authors were on the Junior Hospital staff in the Oral Surgery department of the Newcastle upon Tyne Dental Hospital and grateful thanks are due to Dr G. S. Blair and Mr J. Murgatroyd for their assistance and encouragement with this survey. References Alling, C. C. & Kerr, D. A. (1957). Trauma as a factor causing delayed repair of dental extraction sites. Journal of Oral Surgery, 15, 3. Archer, W. H. (1966). Manual of Oral Surgery, 4th Edn., pp. 699. Saunders, Philadelphia and London. Birn, H. (1970). Bacteria and fibrinolytic activity in ‘dry socket’. Acta Odontologica Scandinavica, 28, 773. Birn, H. (1972). Fibrinolytic activity of alveolar bone in ‘dry socket’.Acta Odontologica Scandinavica, 30, 23. Brown, L. R., Merrill, S. S. & Allen, R. E. (1970). Microbiologic study of intraoral wounds. Journal of Oral Surgery, 28, 89. Crawford, J. Y. (1896). Dry sockets. Dental Cosmos, 38, 929. Hansen, E. H. (1960). Alveolitis sicca dolorosa (dry socket): frequency of occurrence and treatment with trypsin. Journal of Oral Surgery, 18, 409. Harang, H. L. (1948). The prevention of dry socket in the extraction of teeth. Oral Surgery, Oral Medicine and Oral Pathology, 1, 601. Hindle, M. 0. & Gibbs, A. (1977). The incidence of dry socket following the use of an occlusive dressing. Journal of Dentistry, 5, 288. Howe, G. L. (1974). The extraction of teeth, 2nd Edn. (rev.), pp. 21-39. Wright, Bristol. Huebsch, R. F. (1958). Clinical and histological study of alveolar osteitis. Journalof OralSurgery, 16,473. Hut, M. (1963). Complications in post-extraction healing. International Dental Journal, 13, 440. Krogh, H. W. (1937). Incidence of dry socket. Journal of the American Dental Association, 88, 802. Krogh, H. W. (1951). Extraction of teeth in the presence of acute infections. Journal of Oral Surgery, 9, 136. Lehner, T. (1958). Analysis of one hundred cases of dry socket. Dental Practitioner, 8, 9. Lilly, G. E., Osborne, D. B., Rael, E. M., Samuels, H. S. & Jones, J. C. (1974). Alveolar osteitis associated with mandibular third molar extractions. Journal of the American Dental Association, 88, 802. MacGregor, A. J. (1968). Aetiology of dry socket: A clinical investigation. British Journal of Oral Surgery, 6, 49. MacGregor, A. J. & Hart, P. (1970). Bacteria of the extraction wound. Journal of Oral Surgery, 28, 885. Machat, B. B. (1934). The facility of surgery in the general practice of dentistry, (exodontia). Dental Cosmos, 76, 342. Ringsdorf, W. M. & Cheraskin, E. (1975). Dry socket and dysglycaemia. Journal of Dental Research, 54, 184. Schow, S. R. (1974). Evaluation of post-operative localised osteitis in mandibular third molar surgery. Oral Surgery, 38, 352. Wald, A. (1932). Post-operative complications in exodontia. Dental Cosmos, 74, 72. Winter, L. (1931). Local anaesthesia and exodontia. Dental Cosmos, 73, 545.