| Abstract|| |
Aim: The study aimed to answer for the question whether a tooth in line of fracture predispose to complications such as infection and thereby warranting removal of the plates.
Materials and Methods: Surgically rehabilitated patients for unilateral angle of mandible fractures at author's center from 2000 to 2013 were considered in this study. During the study period, about 116 cases fulfilled the inclusion and exclusion criteria, and hence included in this study. All patients were treated by open, rigid fixation.
Results: During the fracture reduction and immobilization, 52.6% (n = 61) cases, the third molar was extracted and in 47.4% (n = 55) cases, the tooth was preserved. Only two cases of infection that required the plate removal occurred by 3 months and another one case within the next 6 months. When the tooth in question was removed, infection did not occur. In all, 52.72% (n = 29) of the 55 cases preserved were needs to be extracted for various reasons. The most common being periodontal causes followed by periapical pathology. Statistically the relationship between demographic data and outcome measures were analyzed using Chi-square test bivariate statistics. A P < 0.05 was taken as significant.
Conclusion: The present study fails to identify any concrete factors that would predict the failure of the retained third molar that were involved in the line of mandibular fractures. The proof presented here, especially with low complication rates indicate that all impacted third molar along the line of fracture be removed and unless necessary, the partially erupted teeth would also be extracted. In such a situation, the rate of infection and survival of the third molar would have been entirely different.
Keywords: Angle fracture, line of fracture, mandibular fracture, third molar
|How to cite this article:|
Balaji P, Balaji S M. Fate of third molar in line of mandibular angle fracture - Retrospective study. Indian J Dent Res 2015;26:262-6
The most common site of infection in posttreatment phase of mandibular fractures occurs along with the angle of the mandible. The reasons attributed to the phenomenon are: Junction of dentate and edentate region of jaw, poor access to oral hygiene aids, nonself-cleansing area, method of treatment, time-lapse and most importantly, the tooth in line of fractures., The debate of preserving or removing the third molar in the line of fractures and has been discussed widely in maxillofacial surgical literature., There have never been a consensus treatment or an algorithm proposed for the same. The decision still is taken on a case by case basis and is dependent on several factors including surgeon's experience and preference. The study aimed to answer for the question whether a tooth in line of fracture predispose to complications such as infection and thereby warranting removal of the plates.
|How to cite this URL:|
Balaji P, Balaji S M. Fate of third molar in line of mandibular angle fracture - Retrospective study. Indian J Dent Res [serial online] 2015 [cited 2019 Jan 21];26:262-6. Available from: http://www.ijdr.in/text.asp?2015/26/3/262/162875
| Materials and Methods|| |
Surgically rehabilitated patients for mandibular fractures at author's center from 2000 to 2013 were considered for this study. All consecutive patients fulfilling the inclusion and exclusion criteria were enrolled for this study. Only cases (20–50 years) with unilateral angle fracture of mandible, with fracture line involving third molar, treated with intraoral, open, rigid fixation were included for the study. Patient who had compromized pretreatment oral hygiene, those who had any factor – local or systemic contributing to poor oral hygiene or that impede oral hygiene measures were excluded from this study. In similar, patients requiring maxilla-mandibular fixation were excluded from this study. Patients having < 6 months of follow-up (±2 weeks) were excluded from this study.
From such identified and collected cases from archives, the following details were collected – age, gender, and side of angle fracture, whether the teeth were removed/preserved, and postoperative infection requiring removal of tooth and bone plates, if necessary. The definitions included in the study were those internationally recommended and as per previous publication. Data were collected at baseline, third and sixth month postoperative periods.
The third molar was removed when the teeth were fractured, established pericoronal/periodontal infection, dental caries, tooth mobility, exposure or involvement of the apical half or more of the root, and third molar does not compromize the reduction of bone fragments. In case of impacted teeth, if the position was unfavorable, it was removed during the treatment itself. For the purpose of this study, postoperative infection was defined as that has a purulent discharge requiring surgical intervention including removal of plates.
More than 70% of the cases had concomitant fractures. It was ensured that all such fractures were treated with rigid fixation – with plates and screws. After fracture reduction, standard analgesics and antibiotic coverage were given.
Such data collected were entered and analyzed. Descriptive statistics for the predictor and outcome measures are presented. The relationship between demographic data and outcome measures was analyzed using Chi-square test bivariate statistics. A P < 0.05 was taken as significant.
| Results|| |
During the study period, about 1200 cases of mandibular fractures were treated. Of these, only 116 cases fulfilled the inclusion and exclusion criteria and hence included for this study.
The mean age of the study population was 30.7 ± 7.3 years (range 21–45 years). Of these, 58.6% (n = 68) are males and 52.6% (n = 61) had the angle fracture in the right side. Of all the cases, 35.3% (n = 41) cases had reported with complete impaction while 25.9% (n = 30) were completely erupted. The rest of them had partially erupted tooth. Of the impacted (fully/partially) teeth, 44% (n = 51) were mesioangularly impacted while 21.6% (n = 25) were distoangularly impacted. The rest were vertically (n = 6) and horizontally (n = 4) impacted. The mean delay of presentation from time of fracture was 3.12 ± 0.97 days with a range of 1–5 days.
Of all the teeth, the third molar in the line of fracture, from the axial view, in 51.7% (n = 60) of the cases was positioned along with the confines of the external oblique ridge, while in 43.1% (n = 50) of cases, the tooth was positioned buccally. The rest of the cases were positioned lingually. The third molar tooth axis was parallel to jaw in 93 cases (80.2%) and in rest the tooth axis was oriented obliquely [Table 1].
During the fracture reduction and immobilization, 52.6% (n = 61) cases, the third molar was extracted [Figure 1] and in 47.4% (n = 55) cases, the tooth was preserved [Figure 2]. Only two cases of infection that required the plate removal occurred by 3 months and another one case within the next 6 months. When the tooth in question was removed, infection did not occur.
|Figure 1: (a) Mandibular angle and left parasymphysis fracture. Note the third molar in line of fracture, (b) tooth in line of fracture is removed during open reduction and internal fixation of mandibular angle and parasymphysis fracture|
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|Figure 2: (a) Mandibular angle fracture. Note the third molar in line of fracture, (b) tooth in line of fracture is preserved during open reduction and internal fixation of mandibular angle fracture|
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In addition, third molars were extracted for various reasons, including tooth mobility, periapical pathology formation, and periodontal compromize. In the following 3 months, another 21 cases underwent extraction. In all, 52.72% (n = 29) of the 55 cases preserved were needs to be extracted for various reasons. The most common being periodontal causes followed by periapical pathology.
On comparing the predictor factors for the preservation of third molar during the treatment, it was observed that gender (P = 0.001), eruption status (P = 0.001), degree of impaction (P = 0.000), and axial position of the third molar (P = 0.000) were statistically significant [Table 2]. On studying the relation between tooth status at the end of the 3rd month and 6th month follow-up, it was observed that the same parameters were statistically related, albeit with lower significance [Table 3] and [Table 4].
|Table 2: Comparison of third molar factors based on preservation of third molars|
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When the 61 cases of third molars that were extracted during the fracture reduction were removed and rest cases used for analysis, it was observed that by the end of the 6-month period, in all 29 cases were extracted. When the predictor factors were compared [Table 5], it was observed that gender, eruption status, impaction and axial positions were significantly related. More males had their third molar preserved, left third molar had been preserved more than the right one. Similarly more fully erupted third molar (73.1%) were preserved that partially erupted (26.9%). Similarly, nonimpacted third molar were more commonly preserved followed by mesioangularly erupted ones. The statistical significance between these parameters was different [Table 5].
|Table 5: Comparison of third molar factors based on survival of third molars along line of fracture at the end of 6 months|
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| Discussion|| |
The aim of this retrospective work is to identify the fate of the third molar along the line of fracture in mandible over a period of 6 months. The accessory goal is to identify the risk of infection and removal of plates at a 6 months follow-up period after fracture reduction.
This has been a question of debate and the risk has been varyingly assessed in literature. A recent systematic review considered prognosis of 1542 third molars along mandibular angle fractures. In this 1542 cases, in 788 (51.1%) cases the tooth was removed. Of these 788 cases, during the follow-up infection occurred in 84 cases (10.66%). Of the 754 third molar retained 84 (11.14%) cases had infection. This difference had no statistical significance. This study showed that removal of the third molar along the line of fracture did not confer any exemption from infection. However, to the best of our knowledge, this study or any similar studies did not demonstrate the fate of such retained third molar at a 6 months follow-up. Most of the study had a 6 week follow-up which was directly related to the immediate surgical follow-up. However, the present study revealed the infection rate of 3 in 116 instances making a 2.6% of all treated cases to have infection. This low prevalence could be attributed to removal of all impacted teeth involved in the line of fractures as advised by recommending bodies.
In the present study, during fracture reduction, of the 116 cases enrolled for the study, 61 cases had their third molar extracted and another 8 extractions in the 3 months followed. Further 21 molars were needed to be extracted in the 3–6th month follow-up. The cause for removal included development of severe periodontal problem including mobility and periapical lesions. As these could impede the healing, the teeth were extracted. In total, at the end of the study, only 22.4% of the teeth remained. During the healing period, of the 55 teeth that were left behind with the strong notion that they would not impede healing, three cases of infection that required surgical intervention were observed. Additionally of the 55 cases, only 26 (47.27%) cases survived at the end of 6 months.
These results have to be interpreted with caution for the following reasons: It is a single center experience, the patient sample is not uniform, oral hygiene measures generally in Indian population is reported to be poor, accessory treatment protocols, besides factors such as socioeconomic status of the patient, nutritional status, oral hygiene, tobacco usage, and other factors could impede treatment outcome. When a uniform protocol is designed, the extent of the influence of factors could be arrived at.
From [Table 5] one could deduce that in the present sample, males have better preservation than females. This bias could be due to higher number of males having fractures and gender disparity in treatment seeking behavior in this part of the world.
In the preantibiotic times, it had been a norm to remove the entire tooth in lines of fracture. This was carried under the school of thought that such tooth would be an area of weakness through which microbes would trespass to cause infections. Extractions were performed prophylactically to avoid infections. With the introduction of antibiotics and antimicrobials, the efforts were directed to save the tooth while the drugs took care of the microbes. However, the inherent defects of a tooth in the line of fractures could not be under estimated. As per reviews in the subject, Muller as early as in 1964, had recommended that multi-rooted tooth in the line of fracture be always removed.
Later, James et al., proposed that tooth with extreme mobility, those with the fracture of root, apical pathology and those not necessary for stability of fracture be removed. In their sample, they removed only 39% of the teeth. In the present study, we nearly used similar, but more stringent criteria, specifically those for impacted teeth, extracted 52.6% of the teeth during the fracture reduction.
Kahnberg and Ridell found that 59% of teeth left along the line of fracture obtained satisfactory healing. This was later supported by works of Macan et al. However, in these studies all mandibular teeth were studies while the present study focused on third molars. Other teeth have relatively better access and survival rate with root canal therapy while the third molar would lack the same. Also, this study proves that fully impacted third molar teeth when removed does not cause any further infection, while the partially impacted teeth are left behind, proceeds to infection and subsequent loss of teeth. The cause for this unique phenomenon is interesting. On one hand, the partially erupted teeth (or impacted teeth) when left behind harbors inaccessible (for self-cleansing) areas which could act as a point of entry for micro-organisms. On the other hand, if extracted, the defect along the superior margin of the mandible during course of healing could serve as an inherent area of weakness as well as portal of entry for microbes. Unless, it is proposed, that even the partially impacted third molar, along the line of fracture, if not required for stabilizing the fracture, may be removed during fracture reduction itself.
In the present study, though the difference in survival of third molar was not statistically significant between right and left side, the left side had a relatively better chance. This was probably due to the fact, that the operating surgeon being right handed, had more comfortable and easier access for the left side rather than the right side. The 73.1% of fully erupted teeth were preserved at the end of the 6-month period while 72.4% of partially impacted teeth were extracted. Similarly third molar that were obliquely placed had a better survival. The partially impacted teeth, by virtue of its position would harbor more debris and pathogens contributing to poor periodontal health while the obliquely placed tooth gives cross anchorage which probably helped to survive better. Though there is no evidence to support to this dimension of thinking our previous hypothesis in this direction is in agreement to the present finding too.
| Conclusion|| |
The present study fails to identify any concrete factors that would predict the failure of the retained third molars that were involved in the line of mandibular fracture. The evidence presented here, especially with low complication rates indicate that all impacted third molar along with the line of fracture to be removed and unless necessary, the partially erupted teeth would also be extracted. In such a situation, the rate of infection and survival of the third molar would have been entirely different. Still the appropriate criteria modification is necessary for estimating and preserving the third molar along with the line of fractures. Until such an algorithm is developed, the outcome of retaining the third molar along with the line of fracture may continue to puzzle surgeons.
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Conflicts of interest
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Balaji Dental and Craniofacial Hospital, Teynampet, Chennai, Tamil Nadu
Source of Support: Nil, Conflict of Interest: None
[Figure 1], [Figure 2]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]