Embedded root fragments in completely and partially

edentulous jaws

D.U. Kharat BDS, MDS,
T. Saini, BDS, MS, Dip. ABOMR
King Saud University Col­lege of Dentistry, P.O. Box 60169, Riyadh 11545, Saudi Arabia

Radiographic examination of the jaws is an essen­ tial part of the evaluation of prospective pros-thodontic patients. It helps in the detection of vari­ ous pathosis and abnormalities of the jaws. Radiog­ raphs assist the clinician in planning the treatment and in maintaining healthy and sound residual ridges. Retained rootfragments are often situated in the alveolus as a result of carious destruction of the crown, injury or incomplete extraction of teeth. The earliest available survey by Logan,1 probably first of the type, reported 10 retained roots in 35 edentulous jaws. Review of the literature over a 70-year period indicated the presence of root frag­ ments in 4.4 to 39.7 percent of the jaws of comp­ letely and partially edentulous patients.1-24 A digest of these studies is shown in Table 1.
The present investigation was undertaken to determine the frequency of occurrence of embed­ ded roots in the jaws of completely and partially edentulous patients admitted to the clinics of the King Saud University College of Dentistry in Riyadh, Saudi Arabia.

Orthopantomographs made prior to prosthetic treatment of 237 completely edentulous patients were included in this study. Of these, 136 radiog­ raphs were of Saudi patients and 101 of non-Saudi patients of various nationalities. All radiographs were examined in a darkened room using magnify­ ing glass and variable intensity view box. Root fragments above the bone level were excluded and only those embedded in the bone were included in the collected data. Vertical ramus, mental fora­ men, maxillary tuberosity, zygomatic process, and canine fossa were used as anatomical landmarks for recognizing the tooth to which the retained root belonged. The presence of any pathosis associated with the retained roots was carefully sought. In a second survey, 293 Saudi and non-Saudi partially edentulous patients were examined by using 20 intra oral radiographs for each patient. The col­ lected data of both groups of patients was analyzed to determine various distributions of embedded roots.

In 237 completely edentulous patients examined, 123 embedded root fragments were detected. The average prevalence of embedded root fragment per patient was 0.52. These root fragments were detected in 64 (27%) of the com­ pletely edentulous patients. Radiolucency indicat­ ing pathosis was not seen around any of these embedded roots. A thin radioiucent line indicating the periodontal space around all or part of the root fragment or part of it, was seen in 32 (26%) of the total 123 root fragments found. The presence of root canal was observed in 22 (17.9%) of the embedded roots.
The incidence of embedded roots in Saudi and non-Saudi completely edentulous patients was cal­ culated separately. In Saudi patients, the embed­ ded root fragments, varying from 1 to 3, were found in 42 (30.9%) of the total 136 Saudi patients. The total number of root fragments detected tn both arches was 81. Forty-three (53.2%) of these root fragments were found in the maxillary arch and 38 (46.9%) were found in the mandibular arch. Evaluation of location of these root fragments in the four quadrants of the mouth disclosed (59.3%) root fragments on the left side and 40.7% on the right side[Fig. 1]. The number of embedded root fragments per individual tooth in Saudi eden­ tulous patients is shown in Table 2. A compara­ tively higher prevalence of remaining roots of man­ dibular third molars, maxillary first molars, and maxillary first premolars was noticed.
Among the 101 non-Saudi completely edentul­ ous patients, 22 (21.8%) had one or more embed­ ded roots. The total number of root fragments found was 42; 26 (61.9%) in the maxilla and 16 (38.1 %) in the mandible. The left quadrants of both the jaws had more embedded roots 23, out of 42 (54.8%) than the right. Figure 1 shows the distribu­ tion of root fragments over the four quadrants. The distribution of root fragments per tooth is shown in Table 3. The distribution of retained root fragments in the molar areas was 27 roots (64.3%) relative to 15 roots (35.7%) in all other tooth areas.
Among the 293 partially edentulous patients, embedded root fragments were detected in 38 (13%) of the patients. A total of 39 root fragments were found. Thirty-six of the root fragments (92%) were in the areas of the maxillary and mandibular molars [Fig. 2J. Of the 39 roots, 23 (59%) were in the maxillary arch and 16 (41 %) were in the man­ dibular arch.

Since Logan's1 first report of retained roots in the edentulous jaws, several investigators have radiog- raphically examined jaws of fuily and partially edentulous patients for detection of retained root fragments. Studies which included both completely and partially edentulous patients have reported the prevalence of retained roots in 10 to 40 percent of the patients.2,4,6,8-10,12,17,20 Among these reports, Keith20 reported root fragments in 10.1 percent of the patients, all of whom he examined in his clinic, including the dentulous patients. Except for that of Smith,8 who reported retained roots in 15.7 percent of the patients, therest of the surveys indicated that one or more root fragments were present in 22 to 40 percent of the mixed populations of partially and completely edentulous patients. Retained roots were reported in 4 to 33 percent of the edentulous patients. Gas-ser18 reported the lowest prevalence of 4.4 percent of edentulous patients with retained roots. In that study, intra-oral source panoramic radiographs were used; inherent lack of details on these radiog­ raphs may account for the smaller number of retained roots detected. Other reports of retained roots in 10 to 20 percent of the edentulous patients are relatively recent.21,23,24 Such low prevalence  may be due to advances in radiography and exodontia.
The rest of the surveys reported retained roots in 16 to 33 percent of the completely edentulous patients. The number of edentulous patients with retained roots found in our study fall well within the prevalence range reported in previous studies.2,21 More of the Saudi edentulous patients had embed­ ded retained roots than the non-Saudis although the ratio of non-Saudi to Saudi edentulous patients with embedded roots was 2:3. Modern dental practices introduced in the Kingdom of Saudi Arabia are likely to cause future decreases in the number of edentulous patients with embedded roots.
Swenson7 reported retained root fragments in 31.2 percent of the edentuluos patients in a 1941 study. After 20 years, a similar study15 revealed retained roots in only 16 percent of the edentulous patients. Increased skill of dentists, morenumberof oral surgeons available and increased use of radiol­ ogy to assist in extraction are the likely reasons for fewer root fragments found in the latter survey.
Several studies reported a majority of retained roots (60 to 75%) in the edentulous maxillae.6-9, 13, 15, 17, 22, 24 No single reference was found show­ ing more roots in the mandible. Thin, slender, and more numerous roots of maxillary teeth are the reason for more root fragments in the maxillary arch.7 In this study, in non-Saudi edentulous patients, 62 percent root fragments were found in the maxillary arch. In Saudi edentulous patients, the maxillary arch showed 53 percent of the roots. The reason may be the larger number of mandibu­ lar third molar root fragments in Saudi patients.
Several studies7,15,19 reported more roots in the right side of the jaws than on the left. In this study, more root fragments were found in the left side for both Saudi and non-Saudi edentulous patients. Obscure vision, difficult access and unfavorable leverage are the difficulties faced in extracting teeth of the left side which may account for more root fragments being abandoned in the left side of the jaws.
Eusterman2 reported 10.1 percent roots with residual infection, Mourshed17 found bony disease in 5.9 percent retained roots. Swenson7 stated that 9.6 percent of the roots had an associated radiolu-cency with bone, whereas Smith8 indicated that the number was around 5.9 percent roots. This study revealed no inflammation around any of the embedded roots.

Orthopantomographs examination of 237 fully edentulous patients revealed the following infor­ mation.

In addition, a survey of 293 partially edentulous patients yielded the following conclusions: