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ORIGINAL ARTICLE
Year : 2023 | Volume
: 14
| Issue : 1 | Page : 46-50
Prevalence and pattern of third molars impaction: A retrospective radiographic study
Ramizu Bin Shaari1, Mohamad Arif Awang Nawi1, Ameera Kamal Khaleel2, Ali Sultan AlRifai2
1 School of Dental Sciences, Health Campus, Universiti Sains Malaysia, Kubang Kerian, 16150 Kota Bharu, Kelantan, Malaysia
2 Department of Dentistry, Al-Amal University College for Specialized Medical Sciences, Karbala, Iraq
Correspondence Address:
Prof. Ali Sultan AlRifai
College of Dentistry, University of Ahl al-Bayt, Karbala
Iraq
Source of Support: None, Conflict of Interest: None
CheckDOI: 10.4103/japtr.japtr_489_22
Third molar impaction is considered a prevalent issue. The research aimed to study the pervasiveness and pattern of impaction in Karbala/Iraqi population. Orthopantomograms were studied regarding its angulation, impaction depth, and correlation with ramus. The outcomes manifested that the prevalence of 3rd impacted molars was 34.71%, with the proportion of male to female as 0.83:1. Impacted mandibular 3rd molars were significantly encountered. The prevalence of vertical angulation, mesioangular, horizontal, and inverted were significantly associated with the impacted mandibular 3rd molars (P < 0.05). However, the prevalence of distoangular and bucco/lingual was significantly associated (P < 0.05) with the upper impacted 3rd molars. Level C of impaction was significantly (P < 0.05) the most typical level in the maxilla impacted the 3rd molar, and level A and level B of impaction were significantly (P < 0.05) the most prevalent level correlated with the mandibular 3rd molar impaction. Class II was significantly (P < 0.05) the frequently occurring condition subsequent to Classes III and I. In conclusion, the impaction of 3rd molars was significantly predominant in females and lower jaw. The vertical angulation, level C of impaction associated with maxillary 3rd molars and levels A and B of impaction related with mandibular 3rd molars, and Class II are the most encountered conditions.
Keywords: Impaction, panoramic radiography, wisdom teeth
Impaction is a common pathological dental problem in which the teeth partially or completely fail to erupt into the correct placement in the dental arch.[1] The 3rd molars are the prevalent impacted tooth and makeup 98% of all types of impacted teeth with a prevalence range from 18.97% to 30.80%.[2] The causes of impaction may be insufficient skeletal growth, mucosal thickness over the growing tooth, macrodontia, lack of space, deciduous teeth retention or systemic condition as Down's syndrome.
The associated complications with impaction may be crowding, caries, pericoronitis, resorption of an adjacent tooth root, facial pain, temporomandibular joint dysfunction, and dentigerous cyst which is the most common problem or tumors.[3] Serious complications sometimes occur like cystic wall transformation into squamous cell carcinoma. This life-threatening condition if treated from the beginning may be able to avoid complications.[4]
Digital panoramic radiography can introduce the panoramic view of all the maxillofacial regions. It was used widely in the diagnosis of impacted of 3rd molars variations. The type of impaction assessment can facilitate the treatment plan and the proper method of surgical intervention.[5]
The 3rd molars in humans have the highest impaction rate than other types of teeth and the incidence of this impaction was differing across different ethnic groups and populations.[6] Based on the digital panoramic radiograph, there was no radiographical data dealing with the prevalence and pattern of impacted 3rd molar teeth in Karbala/Iraqi population, so the purpose of the current research was to ascertain the prevalence and the pattern of impaction of third molars.
Materials and MethodologyStudy design
This transverse analysis was executed on high-quality digital orthopantomogram (OPGs) of 2150 patients referred to a maxillofacial radiology private clinic in Karbala City/Iraq, between a time period 2017–2022. Patient data were obtained from their medical records. All OPGs had been taken using an extra-oral digital Kodak 9000 imaging system with an exposure time of 12.5s, a voltage of 73 kV, and a current of 12 mA. The exclusion criteria were patients with the subsequent conditions: The age ≤20 years or above 40 years, craniofacial anomalies, had orthodontic treatment, erupted third molars or third molars associated with incomplete root formation, OPG with incomplete records, poor quality OPG, radiographs with missing first, second, and third molars. If the third molars did not have functional occlusion and their roots were fully formed, they were considered impacted. This investigation was authorized by the Ahl al-Bayt University Ethics Committee.
Study parameters
The parameters which were evaluated in the present research were:
Angulation of impacted 3rd molar tooth was classified depending on Winter's categorization [Figure 1][6]The depth of the impacted 3rd molar tooth was classified depending on the Pell and Gregory categorization [Figure 2][7]The relation of impacted 3rd molar with ramus was classified depending on the Pell and Gregory classification [Figure 3].[7]
Figure 1: Winter's categorization depends on the relation of the impacted third molar tooth to the long axis of 2nd molar tooth. (a) Vertical. (b) Mesioangular. (c) Horizontal. (d) Distoangular. (e) Bucco/lingual. (f) The inverted
Figure 2: Pell and gregory categorization relates the occlusal plane level or the greatest portion of the impacted 3rd tooth is either (a1 and a2) at the level or above the occlusal plane of the 2nd molar (Position A), or (b1 and b2) between the cervical margin of the 2nd molar and occlusal plane (Position B), or (c1 and c2) below the cervical margin of the 2nd molar (Position C)
Figure 3: Pell and Gregory classification shows the relation of the position of the tooth to the ascending ramus and 2nd molar: (a) Class I: Margin in the middle of the distal surface of the 2nd molar and the ramus is more than the mesiodistal size of the crown of the 3rd molar. (b) Class II: The margin linking the distal surface of the 2nd molar and ramus is slighter than the mesiodistal size of the crown of the 3rd molar. (c) Class III: Most or all of the 3rd molar crown is located inside the ramusStatistical analysis
By employing using Statistical Package for the Social Sciences (SPSS), all data were scrutinized. Patient's age, gender, impacted third molars number, degree of impaction, angulation and its relation with the ramus were exhibited by the rate of occurrence and proportion. A Chi-square test was utilized to ascertain the potential interrelation of the third molars and the different studied variables. P < 0.05 was considered statistically significant. Twenty per cent of the designated radiograms were also reviewed by an experienced clinician in oral radiology to assess the inter-observer variations. The level of agreement between observers was tested using Kappa statistics. Randomly repeating 20% of the radiographs, the intra-examiner variability was removed.[8]
ResultsThe number of digital panoramic radiographs studied was 2150. Within the inclusion criteria, only 677 OPGs were selected, 359 (53.03%) were for males, and 318 (46.97%) were for females [Table 1]. Regarding the inter observers' assay, the Kappa statistics revealed a good (k = 0.80) to an excellent agreement (k > 0.80) between the reference data set of the first and the second observer.
Table 1: The total number of patients (orthopantomograms) within the inclusion criteria with or without the presence of impacted 3rd molars in accordance with the age-groups and genderThe total number of digital panoramic radiographs that appeared with impacted 3rd molars was 235 with 34.71% prevalence, 112 (47.66%) radiographs for males and 123 (52.34%) radiographs for females, with a proportion between the genders of 0.83:1. A significant relation was perceived between the genders (P = 0.00312) regarding the number of radiographs with impacted 3rd molar teeth, and as the age progresses, the number of patients with impacted 3rd molar teeth was significantly reduced (P = 0.00001), as shown in [Table 2].
Table 2: Prevalence of impacted 3rd molars accordance with the age and genderThe result also showed that 121 OPG (51.49%) were seen with one impacted 3rd molar tooth, 39 OPG (16.60%) were seen with two impacted 3rd molar teeth, 26 OPG (11.06%) were seen with three impacted 3rd molar teeth, and 49 OPG (20.85%) were seen with four impacted 3rd molar with a total of 473 impacted tooth [Table 3]. [Figure 4] shows OPGs with different numbers of impacted 3rd molars/patient.
Figure 4: OPGs shows impaction of one (a), two (b), three (c), and four (d) third molarsThe mandibular 3th molars (285 tooth, 60.25%) were most commonly encountered, followed by the maxillary 3rd molars (188 tooth, 39.75%), with a significant difference (P = 0.0095). Statistical analysis also showed that the prevalence of vertical angulation, mesioangular, horizontal, and inverted were significantly higher in the mandibular impacted 3rd molars than the uppers. However, the prevalence of distoangular and bucco/lingual was significantly higher in upper impacted wisdom teeth than that of lower one, as shown in [Table 4].
Table 4: Rate of distribution and percentage of impacted 3rd molar as per angulation[Table 5] demonstrates the dispersal of 3rd molars as per the level of impaction. Level C of impaction was significantly (P < 0.05) prevalent in the maxillar impacted 3rd molar (135, 28.54%), followed by level B (44, 9.31%), then level A (9, 1.90%). Level A (109, 23.04%) and level B (127, 26.85%) of impaction were significantly (P < 0.05) the most occurring level corresponded with the mandibular impacted 3rd molar, accompanied by level C (49, 10.36%). Among 285 impacted mandibular 3rd molars, Class II was significantly (P < 0.05) the most common condition (184, 64.56%), followed by Class III (75, 26.32%), then Class I (26, 9.12%), and Class II exhibited substantial proportion of prevalence in the age group 21–30, as shown in [Table 6].
Table 5: Frequency distribution and proportion of impacted 3rd molar as per the level of impaction
Table 6: Frequency distribution and proportion of impacted mandibular 3rd molar as per its relation to ramus and age groups Discussion In the current investigation, the impacted 3rd molars showed 34.71% prevalence, and a substantial differentiation was perceived among the genders (P = 0.00312). Hashemipour et al.[9] research revealed that the extent of impacted 3rd molars in Iran was estimated at 44.3%, Yıldırım and Büyükgöze-Dindar[10] research found 23% incidence, but Hattab et al.[11] study found it was 33%. Studies by Hazza'a et al.[12] and Gupta et al.[13] found male predominance, but Hashemipour et al.[9] and Hattab et al.[11] studies showed female predominance. In Saudi Arabia, Alfadil and Almajed[14] found no gender predilection.
The present study showed that as age progresses, the number of patients with impacted 3rd molar teeth was significantly reduced. This result comes in concurrence with that of Hashemipour et al.[9] and El-Khateeb et al.[15] studies, they also observed that beyond 50% of the patients with 3rd molar impaction were in their thirties. The result also showed that 51.49% of OPGs examined were seen with one impacted 3rd molar tooth, and the mandibular 3rd molars were significant and most commonly encountered. Statistical analysis also showed that the prevalence of vertical angulation, mesioangular, horizontal, and inverted was significantly higher in the mandibular impacted 3rd molars than the uppers. However, the prevalence of distoangular and bucco/lingual was significantly higher in upper impacted wisdom teeth than that of the lower ones.
El-Khateeb et al.[15] research found that 5.8% of the patients in Saudi with impacted 3rd molars had 3 or more impacted teeth, 13.1% had 2 impacted teeth, and 15.6% had 1 impacted tooth, and the mandibular 3rd molars were found the most widespread. Idris et al.[16] study found that the distribution was: 1 impaction in (41.6%); 2 impactions in (30.9%); 3 impactions in (14.4%); and 4 impactions in (13.1%) patients. Another study found that the impaction of 3rd molars was more commonly associated with the mandibular jaw (58.5%) than the maxilla (41.5%).
The current investigation demonstrated that the level C of impaction was most frequent in the maxillary impacted 3rd molar, and levels A and B were significantly the most recurrent associated impaction with the mandibular impacted 3rd molar, and among 285 impacted mandibular 3rd molars, Class II was significantly the most common condition. In Al-Madinah study, they also found that level C of impaction was mostly observed in the maxillary impacted 3rd molar, followed by level A, B, and levels A and B were the most common followed by level C in mandibular impacted 3rd molar.[16] Turkia, Yilmaz et al.[17] found that level B impaction was the most observed in the maxilla and level C was most common in the mandible.
El-Khateeb et al.[15] found 77.6% of all the cases studied were of Class II, Class I, and then III, and Class II exhibited a considerable portion of eventuality (89.2%) in the age group 20–30 years, accompanied by Class I (76%) for the same age group. In Iran, Eshghpour et al.[18] also perceived that Class II was most common subsequent by classes I and III. All the differences between the present study and other investigations might owe to the ethnic and genetic divergences.
ConclusionsIn summary, the prevalence of impacted 3rd molars was 34.71%, with a proportion between the genders of 0.83:1, and as the age progresses, the number of patients with impacted 3rd molar teeth was significantly reduced, and most of the OPGs were seen associated with 1 impacted tooth. The impacted mandibular 3rd molars were seen significantly the most commonly encountered (P < 0.05), and the prevalence of vertical angulation, mesioangular, horizontal, and inverted was significantly higher in the impacted mandibular 3rd molars. However, the prevalence of distoangular and bucco/lingual was significantly higher in the upper impacted 3rd molar teeth. C level impaction was most frequent in the maxillary impacted 3rd molar, and Level A and B impaction was the most prevalent level associated with the mandibular impacted 3rd molar. Class II was significantly (P < 0.05) the most recurrent condition related with the impacted mandibular 3rd molar, followed by Class III and I.
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Self-funding.
Conflicts of interest
There are no conflicts of interest.
References
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