Third Molar Angulation Research Articles

Prevalence of Impacted Wisdom Teeth in Middle Black Sea Population

Objective: The aim of this cross-sectional randomized study was to investigate the prevalence and angulation of third molar impaction in patients between 19‒26 years old who were living in the Middle Black Sea region of Turkey. Patients and Methods: Total 1006 patients between 19 and 26 years of age who were referred to the Ordu University Faculty of Dentistry Department of Oral Maxillofacial Surgery between 2010 and 2015 were included in the study. Of these 1,006 patients, 410 were male and 596 were female. The prevalence and positions of the impacted third molar teeth from the 4th quadrant on the panoramic radiographs were documented according to the classifications of Pell and Gregory as well as that of Winter. In the Pell and Gregory classification, the teeth in class C were evaluated as impacted teeth. Results: There was a total of 1,518 impacted molars. Of the included patients, 48.3% had impacted third molars. The most common angulation of impacted third molars was the vertical position in both mandible (28.4%) and maxilla (28.8%). The prevalence of impacted mandibular third molars (57.3%) was significantly higher than that of the impacted maxillary third molars (42.7%) (P<0.05). The prevalence and angulation of impacted third molars between genders was not significant (P>0.05). Conclusion: The pattern of third molar impaction in the Middle Black Sea region was characterized by a high prevalence of level C impaction with a vertical position that was greater in the mandibles and had no sex predilection.

Short-Term Evaluation of Gustatory Changes After Surgical Removal of Mandibular Third Molar—A Prospective Randomized Control Trial

The present study was carried out to prospectively determine the incidence and severity of suprathreshold taste changes after surgical removal of mandibular third molars. Sixty patients who required removal of impacted third molars were included in the study. Based on the Winter criteria of angulation of impacted mandibular third molars, 15 patients each with mesioangular, distoangular, horizontal, and vertical impacted third molars were selected. The chemo-gustometry chart in pentagon scheme was used to represent the results of gustometry and to establish a correlation between the difficulty index of impacted third molar removal and the incidence of gustatory changes. All patients underwent spatial taste testing preoperatively and 1week postoperatively. The highest incidence of taste changes was noted in category 3 (difficulty score, 7 to 8) and mostly for distoangular and vertically impacted teeth. In their extensive patient analysis of 4 different taste sensations, the authors found that suprathreshold taste changes do occur after surgical removal of an impacted mandibular third molar, with a high difficulty index score indicating the highest prevalence for altered taste sensations for distoangular and vertical impactions.

The effect of headgear on upper third molars: a retrospective longitudinal study.

To investigate the effects of orthodontic non-extraction treatment with or without headgear on the position of and the space available for upper third molars in growing children with class II malocclusions. The sample consisted of pre- and post-treatment panoramic radiographs and lateral cephalograms of 294 class II orthodontic patients; 160 were treated with headgear and 134 were treated without headgear. The space available for the upper third molar was measured on the lateral cephalogram as the distance from pterygoid vertical (PTV) to the distal surface of the upper first molar crown (PTV-M1). Angulation, vertical position and tooth development stage of the upper third molars were evaluated on panoramic radiographs. All measurements were evaluated statistically. In both groups PTV-M1 increased, but the increase in PTV-M1 was significantly higher for patients treated without headgear. A linear model for repeated measures revealed that this difference was still significant after correction for age, gender and molar occlusion. Further, there is no evidence that the change in angulation, vertical position and development stage of the upper third molars during orthodontic treatment is influenced by headgear therapy. This study indicates that the use of headgear in growing patients significantly affects the space available for upper third molars. However, orthodontic treatment with headgear does not influence the angulation, vertical position and development stage of upper third molars. It is therefore important to always take into account third molars during treatment planning.

Evaluation and prediction of impacted mandibular third molars by panoramic radiography: A retrospective study

Aim: The aim of this study was to evaluate the factors associated with impaction of mandibular third molars and to find a method for predicting eruption of the third molars using panoramic radiographs. Materials and Methods: Ninety pretreatment panoramic radiographs of patients with a full complement of teeth were selected. The mandibular third molars were divided into two groups depending on their eruption status: Group 1: erupted and Group 2: impacted molars. Various angular and linear measurements were made on the panoramic radiographs. Results: Shapiro–Wilk test showed that the data were not normally distributed. Mann–Whitney U-test showed that mean rank of angulation between third molar and second molar (M3M2), gonial angle (GoA), and mesiodistal width of third molar (MDW3M) of impacted group was significantly higher than the erupted group. Spearman's correlation coefficient showed positive correlation between angulation of third molar with mandibular plane (M3MP) and retromolar space (RS) with eruption of mandibular third molar. M3M2, GoA, and MDW3M were found to have negative correlation with eruption of mandibular third molar. Conclusions: Increased RS and M3MP were strongly associated with eruption of the mandibular third molar. An increase in the M3M2 and MDW3M predisposed impaction of third molar. GoA was smaller and mandibular length was larger in the erupted group although both had a weak correlation.

Effect of orthodontic treatment involving first premolar extractions on mandibular third molar angulation and retromolar space

BackgroundThird molars present more problems than other teeth because they are the last teeth to erupt, and so it is important to assess their development when designing an orthodontic treatment plan. The aim of this study was to compare the angulation of the mandibular third molar and retromolar space before and after orthodontic treatment in cases involving first premolar extraction.Material and Methods76 patients, 59 women (77.63%) and 17 men (22.36%), were recruited from the Orthodontics Clinic at Benemérita Universidad Autónoma de Puebla (Mexico). Panoramic radiographs were analyzed before and after orthodontic treatment that included first premolar extractions, measuring retromolar space (RS) and the angles formed by the intersection of the axes of the third and second molar (α) and the intersection of the axis of the mandibular plane and third molar (β).ResultsThe data obtained underwent statistical analysis. The angle α and β showed statistically significant differences on the left side in women. In men, only the right side α angle showed significant differences. Retromolar space increased significantly on both sides for both sexes.ConclusionsThird molar angulation presents different behaviors between men and women, with greater verticalization in women. Key words:Third molar, retromolar space, orthodontics.

The effect of modified surgical flap design for removal of lower third molars on lingual nerve injury.

The objective of this study was to evaluate a modified flap design for removal of lower third molars with avoidance of lingual flap elevation and its effect on postsurgical lingual nerve sensory impairment. The patients included in this prospective study were those referred for removal of symptomatic lower third molars at two Oral and Maxillofacial Surgery clinics. Different patterns of impaction were included regarding the angulation and depth of the lower third molar. Patients were reviewed 1day after surgery, then after 1week. Each patient was examined at each recall visit for any sensory alterations of the lingual nerve. The data collected was correlated to several variables including the age, gender, side of operation, state of eruption, angulation, depth of impaction, and tooth division. A number of 53 patients (23 males and 30 females), at ages ranging from 16 to 43years, underwent surgical removal of 66 fully or partially impacted lower third molars under local anesthesia using a modified flap design. The modified flap design provided adequate exposure for removal of the lower third molar for all patterns of impactions included, regarding the state of eruption, angulation, and depth of the tooth. This study showed that the investigated flap design can be safely used to remove lower third molars for different patterns of impaction without jeopardizing the lingual tissues thus providing optimum protection for the lingual nerve since it provided adequate exposure to remove the tooth without the reflection of a lingual flap.

Identifying the risk factors causing iatrogenic mandibular fractures associated with exodontia: a systemic meta-analysis of 200 cases from 1953 to 2015.

Iatrogenic fracture of mandible (IFM) associated with exodontia though rare, they do occur with an incidence ranging from 0.0034 to 0.0075%. Most of the data is in the form of case reports or a small case series. This is an attempt to amass the data available in literature since the last 62years. The purpose of this meta-analysis is to identify the etiologies and risk factors leading to IFM associated with exodontia and also the measures to minimize the complication. Articles published between 1953 and 2015 were searched in Medline database. Data was collected and analyzed based on age, gender, extracted tooth, status of dentition, pathological bone lesion adjacent to the tooth, type of impaction, angulation of the impacted third molar, site of fracture, side of fracture, time of fracture, and treatment of fracture. A review identified 200 documented cases of IFM associated with the removal of teeth. The reasons for its occurrence found to be multifactorial with a higher incidence in the fifth decade of life with male prevalence. Risk factors more commonly identified were removal of the third molar, fully dentate patient, associated pathology, impacted tooth, angle region, left quadrant, and time interval of 3weeks postoperatively. IFM related to the removal of teeth is a rare complication. Identifying and addressing the risk factors will enable the surgeon to avoid the complication of IFM associated with exodontia.

Epidemiological Status of Third Molars in an Iranian Population

Background: Impaction of third molars is a common phenomenon. The incidence of impacted third molars varies in different populations. Objectives: The aim of this study is to assess radiographic status (root development degree, angulation, and eruption level) of the third molar in Iranian population via panoramic radiographs. Patients and Methods: 647 patients, ranging in age from 17 - 25, were selected from three regions of Iran. Based on their panoramic radiographs, their root development degree, angulation, and eruption levels were analyzed. Results: The angulation of upper third molars were vertical (44.6%), distoangular (44.1%), mesioangular (10.7%), and horizontal (0.6%). For lower third molars, the angulation was mesioangular (44.5%), vertical (33.8%), distoangular (12.2%), and horizontal (9.5%). The eruption levels of maxillary third molars were C > A> B, and for mandibular third molars they were A > B> C. The order of root development prevalence of the maxillary and mandibular third molars was complete > 2/3 > 1/3. Conclusions: The most common status of impaction of the third molars in the maxilla was vertical angulation, level C of eruption, and complete root formation. In the mandible it was mesioangular, level A of eruption, and complete root formation. Since the study sample consists of patients from the north, middle, and south of Iran, the sample can represent the whole population of Iran.

Is the angulation of mandibular third molars associated with the thickness of lingual bone?

To find out whether the angulation of mandibular third molars is associated with the thickness of the bone at the site of impaction, and if so, which particular angulation affects the protective mechanism of the nerve, we retrospectively studied the thickness of lingual bone at the sites of impaction of 200 mandibular third molars in 149 patients using coronal, sagittal, and axial slices of cone-beam computed tomograms (CT). We measured the bone at the cementoenamel junction of the mandibular second molar, at the mid-root of the third molar, and at the apex of the root. Bone less than 1mm thick was defined as “thinning”. We correlated these measurements with the angulation of the tooth based on the position of the second molar and the occlusal plane in 3 dimensions: vertical, mesiobuccal, and buccolingual. The primary outcome was the thickness of the bone around the third molar. A total of 102 teeth were on the left (51%), and 125 were angulated with an occlusal plane of <85° (63%). The mean (SD) thickness of bone at the cementoenamel junction of the second molar was 1.40 (0.87) mm, at mid-root 1.07 (1.03) mm, and at the apex 1.07 (1.30) mm. When the horizontal and mesioangular angulations of teeth were <85°, the thickness of bone at the mid-root differed significantly from that when the vertical and distoangular angulations were 85° or more (p<0.001). Correlations between the thickness of the bone and the buccolingual angulations were significantly associated with perforation of the bone at mid-root and apex (p<0.003). The bone around horizontal and mesioangular impactions was 3.6 times more likely to be “thin” than that at mid-root of vertical and distoangular third molars. A buccolingual angulation was also associated with perforation of the lingual cortex (p<0.003). As the bone was thinner at the mid-root of horizontally and mesioangularly impacted teeth, it seemed to compromise the integrity of the lingual plate, which is the natural protective barrier of the lingual nerve. These findings could be of prognostic value.

A multi-centre retrospective study of mandibular fractures: do occlusal support and the mandibular third molar affect mandibular angle and condylar fractures?

This retrospective study was performed to investigate the influence of occlusal support and the presence, state, and position of mandibular third molars on the incidence of mandibular angle and condylar fractures. The following variables were investigated: age, sex, cause of fracture, presence and state (impaction, angulation, and the number of roots) of the mandibular third molars, site of the mandibular fracture, presence of occlusal support, duration of intermaxillary fixation, and postoperative complications. Various risk factors for mandibular angle and condylar fractures were investigated by univariate analysis. The risk of mandibular angle fracture was significantly higher in patients with occlusal support and mandibular third molars. The risk of condylar fracture was significantly higher in patients without occlusal support or mandibular third molars. The position and angulation of the mandibular third molars were not significant risk factors in mandibular angle and condylar fractures. This study demonstrated the influence of occlusal support and the presence of mandibular third molars on the incidence of mandibular angle and condylar fractures. The presence of occlusal support may be a more important factor affecting mandibular angle or condylar fractures than the position of the mandibular third molars.

Which route of antibiotic administration should be used for third molar surgery? A split-mouth study to compare intramuscular and oral intake.

To compare the effectiveness of two different routes of antibiotic administration in preventing septic complications in patients undergoing third molar extraction. Twenty-four healthy patients requiring bilateral surgical removal of impacted mandibular third molars were successfully enrolled for this study. Depth of impaction, angulation, and relationship of the lower third molars with the mandibular branch had to be overlapping on both sides. A split-mouth design was chosen, so each patient underwent both the first and second surgeries, having for each extraction a different antibiotic route of administration. The second extraction was carried out 1 month later. To compare the effects of the two routes of antibiotic administration, inflammatory parameters, such as edema, trismus, pain, fever, dysphagia and lymphadenopathy were evaluated 2 and 7 days after surgery. Side effects of each therapy were evaluated 48 h after surgery. Oral and intramuscular antibiotic therapies overlap in preventing post-operative complications in dental surgery (p>0.05), even if the oral intake, seems to promote the onset of significant gastrointestinal disorders (p=0.003). This study could help dentists in their ordinary practice to choose the right route of antibiotic administration in the third molar surgery. At the same effectiveness, the higher cost and the minor compliance of the patient seem not to justify a routine antibiotic intramuscular therapy, reserving it for patients with gastrointestinal disorders.

Segmental cross-sectional assessment of the left impacted mandibular third molar using cone beam computed tomography

Clinicians in general practice routinely diagnose impacted mandibular third molars. After clinical assessment of the impacted mandibular third molar, a detailed three-dimensional radiographic assessment is of utmost importance in arriving at a diagnosis and explaining to the patient, the treatment plan and the surgical risks involved in third molar surgery. For decades, orthopantomogram (OPG) has been used to diagnose the type of third molar impaction and in few cases dentists have used intra-oral peri-apical radiographs to assess the angulation and depth of the third molar. Cone beam computed tomography has always been indicated when the root of the third molar is close to the nerve. This cross-sectional study provides an assessment of the angulation of impacted mandibular third molar on the left side using cone beam computed tomographic tomography.

Prevalence of mandibular third molar impaction pattern in a private dental clinic of Sultanpur Lodhi

Background: Mandibular third molar is the most commonly impacted tooth, and its removal is a frequently performed dentoalveolar procedure. It is important to know the prevalence rate in a particular community.Objective: This article aims at evaluation of angulation, ramus relationship and depth of impacted mandibular third molars among patients visiting a private dental clinic in Sultanpur Lodhi.Methodology: 150 patients presenting with 228 cases of lower third molar impaction were included within this study. IOPAR and where necessary, OPG was used for radiographic assessment. Age, sex and tooth number were recorded in each patient on a specially designed performa. Angulation was determined using winter’s method whereas assessment of ramus relationship and depth was done using Pell and Gregory's method.Results and Conclusion: The age of patients ranged from 21-43 years with mean age of 26.6 years. Males showed preponderance to mandibular M3 impaction (54%) in our study, and right side was found more frequently involved (53%). Radiographic assessment revealed that mesioangular impaction (45.2%) was the most prevalent angular pattern followed by vertical, distoangular and horizontal types, and Class 2 Position A (29.4%) most common and Class 1 Position C the least common type of impaction depth and ramus relationship.

Evaluation of localisation of mandibular foramen in patients with mandibular third molar teeth using cone-beam computed tomography.

It is important to know the correct anatomical location of the mandibular foramen to obtain successful anaesthesia of inferior alveolar nerve and to prevent injury to the mandibular vessels and nerve, during a variety of oral and maxillofacial surgical procedures. The aim of this study is to evaluate localisation of the mandibular foramen in patients with the third molars using cone-beam computed tomography (CBCT). Cone-beam computed tomography was used to determine the location of the mandibular foramen in 67 patients (totally 99 sides) with unilateral or bilateral impacted mandibular third molars. The distance from the posterior border of the mandibular ramus to mandibular foramen did not differ significantly among the other angulations. But the difference between vertical and horizontal angulation of the impacted mandibular third molars according to 'fd' values (the shortest distance between mandibular foramen and the posterior border of mandibular ramus) was found to be statistically significant (p < 0.05). The present study provides new information to the literature concerning relationship between the location of the mandibular foramen and the mandibular third molars.

A study to evaluate the changes in 3rd molar angulation with extraction of four premolars in class II malocclusion therapy

Aim: The objectives of the study are to evaluate the changes in third molar angulation during orthodontic treatment with extraction of premolars in Class II malocclusions, and to evaluate the relationship between the angulation of third molars and positional changes of incisors and molars. Materials and Methods: This study was conducted on lateral cephalograms and dental panoramic tomograms of 30 patients (mean age 13.48 years) with skeletodental Class II malocclusion treated with four first premolar extractions. Twenty-four cases were treated with edgewise, and six were treated with Begg technique. The changes in the eruption pattern of the third molars were observed at the beginning of the treatment (T1) and at the end of the treatment (T2). The changes in the anteroposterior position of the incisors and molars, original molar space, and mesiodistal third molar angulation were tested by paired t-test. Results: The positional changes of the upper/lower incisors and first molars and original molar space were found similar in edgewise and Begg technique. Original molar space was increased in both jaws during orthodontic treatment. Long axis angle of the upper right third molar due to occlusal plane was increased nonsignificantly. Lower right third molars uprighted significantly. A positive correlation was found between the inclination of the lower right third molars and position of lower incisors and first molars. Conclusion: Treatment with extraction of premolars result in a greater space in the third molar region as a result of the mesial movement of the molars during space closure.

Radiographic Assessment for Predicting the Mandibular Third Molar Eruption after Orthodontic Treatment in First Premolar Extraction Group and Non-Extraction Group: A-retrospective Study

Introduction: The third molars are the most congenitally missing teeth. If present, they might follow ectopic eruption path and become impacted. Because it is the last tooth erupt in the arch, and usually there is no space in the arch. Effects of orthodontic treatment may also affect the position of third molar after treatment and may changes the eruption pattern of third molar. Materials and Methods: 30 patient’s pre-treatment and post-treatment lateral cephalogram and orthopantomogram (OPG) were taken out of which 15 patients were treated with first pre-molar extraction, and 15 patients were treated with non-extraction approach. Cephalomatric and OPG tracing were done at T1 (pre-treatment) and T2 (post-treatment). Distance from Xi-point to distal surface of second molar, distance from anterior border of ramus to the distal surface of second molar, angulation of third molar in relation with second molar and mesio-distal width of third molar were checked. Descriptive analysis was perform for both the groups and paired t-test and un-paired t-test were performed for first pre-molar extraction and nonextraction group with two different methods such as panoramic radio graph (OPG) and lateral cephalograms at significant level P < 0.05. Results: In extraction group, there were more possibility of the eruption, more mesial movement and more angulation changes noted compare to non-extraction group. Conclusion: Panoramic radiographs were more accurate when compared to lateral cephalogram while checking minor changes.

The Influence of Mandibular Third Molar Position on Distal Caries in Mandibular Second Molar

Introduction: Distal caries of mandibular second molars has been documented to be associated almost exclusively with impacted third molars. The level of involvement of second molars in distal caries is influenced by the angulation of the occlusal surface of mandibular third molars and third molars depth. In spite of the importance of these factors on the occurrence of distal caries, their influence on prophylactic extraction decision of asymptomatic impacted molars for Iraqi population did not get enough attention. Aim: of the study: To determine the influence of mandibular third molar impaction, as identified by panoramic radiograph, on distal caries incidence in second molar in Iraqi population. Materials and Methods: Panoramic radiographs of impacted mandibular third molars prior to surgical extraction were retrieved from the database of Al-Karamah Secondary Dental Care Centre in the period 2004-2013. Demographic data were collected for all cases. Each panoramic radiograph was examined for the presence of distal caries of mandibular second molar and for the level of depth and degree of angulation of adjacent impacted mandibular third molar. Results: One hundred forty-eight panoramic radiographs of 214 pre-surgically extracted impacted mandibular third molars were reviewed. Eighty-four (56.8%) of the cases were for males and sixty-four (43.2%) were for females. ChiSquare Test showed significant relationship between age group, impaction angulation, impaction depth and incidence of mandibular second molar distal caries. It also showed highly significant relationship between angulation and depth of impaction. Conclusion: Horizontally impacted mandibular third molars close to the level of occlusion increases the chance of distal caries incidence in adjacent mandibular second molars. Close monitoring for such cases would be a suitable option. Further prospective studies should be conducted to study the influence of other factors on distal caries incidence.

Relationship between mandibular angle fracture and state of eruption of mandibular third molar: A digital radiographic study

Objectives: The purpose of this study was to assess the relationship between mandibular angle fracture and the status of eruption of the mandibular third molars. Materials and Methods: The sample consisted of 50 mandibular angle fracture cases with or without the presence of mandibular third molars, inclusive of both genders in the age group 18 years and above. The mandibular angle fractures were assessed by taking an orthopantomograph for each case following strict radiation protection protocol after an informed consent was obtained. The captured image was assessed and traced for the presence of mandibular angle fracture, angulation, and status of mandibular third molar by using Windows Trophy DICOM and Master View 3.0 software. Pell and Gregory's and Winter's classifications were followed. Results: We observed the following: Increased incidence of angle fractures in the presence of mandibular third molar, male predominance, the mean average age being 29 years, and the most common cause of angle fractures was road traffic accident; the fractures were observed more on the left side. In the total sample, mandibular third molar was present in 90% of the cases with angle fracture; of this, 73% of the teeth were impacted. Increased incidence of mandibular angle fracture was observed in position A, class II, and mesioangular impaction of third molar, which were statistically significant. Conclusion: The presence of mandibular third molar was in strong association with mandibular angle fracture and there was an increased incidence of position A, class II, and mesioangular impaction, when compared with other positions. This study concludes that there is a direct relationship between the presence and status of impacted third molars with increased risk of mandibular angle fracture.

Difficulty index in extraction of impacted mandibular third molars and their post-operative complications

Background: Although the removal of impacted mandibular third molars is a common minor oral surgical procedure, the extraction of these teeth can present with certain post–operative complications. Koerner KR proposed a Difficulty Index Scale for removal of these teeth on the basis of local anatomy and radiographs, which were helpful in predicting the difficulty that would be encountered intra-operatively, as well as the post-operative complications. Objective: To study the different post-operative complications in the removal of impacted mandibular third molars calculating their difficulty index value. Method: A total of 119 patients, 79 females and 40 males who underwent extraction of their impacted third molars were selected over a one year period. Data were collected prospectively, according to the angulation, depth and position of the impacted mandibular third molars and their difficulty index calculated. This was further correlated with the postoperative complications encountered. Results: Mesio-angular impaction (43.7%), with level A (66.4%) and Class I (70.6%) impaction were the major type of impaction seen. The difficulty index showed that majority were in the moderately difficult category (51.2%), with swelling and trismus seen to increase as the difficulty index value increased. Females were affected more than males, with swelling (Odds ratio 2.206) and trismus (Odds ratio 2.570) seen to be significantly more. Conclusion: Surgical removal of impacted mandibular third molars causes post-operative complications and special care is required in their removal, especially in females. The Difficulty Index, as described by Koerner KR can be used as a tool for predicting the frequency of the post-operative complications, especially swelling and trismus. DOI: http://dx.doi.org/10.3126/jkmc.v3i1.10918 Journal of Kathmandu Medical College Vol. 3, No. 1, Issue 7, Jan.-Mar., 2014, Page: 14-20

Pre-operative assessment of relationship between inferior dental nerve canal and mandibular impacted third molar in Saudi population.

To study the correlation between the position of the inferior dental (ID) nerve canal and the angulation of impacted mandibular third molars using dental cone beam computed tomography (CBCT). The study considered 100 impactions in 85 patients (60 males, 25 females), for whom an initial panoramic radiographic assessment had revealed that the ID canal and the lower 3rd molar were in close proximity. A CBCT scan of each patient was carried out to assess how the ID nerve canal position influenced the class and position of impaction, angulation of impaction, and bone contact. Class I position B impactions were found in the majority of cases, where the position of the ID canal was approximate to the lingual plate and inferior to the 3rd molar (85.7%). The results were statistically significant (p=0.001). 96% of the ID canals showed bone contact. Of these, 77.1% of ID canals exhibited lingual bone contact, inferior to impaction. The results were statistically significant (p=0.001). Horizontally angulated impactions were most common in the mandible, and significantly associated with lingual and inferior positioning of the ID canal (76.2%). Our sample population most commonly exhibited horizontally angulated class I position B impactions of the mandible. The position of the ID canal significantly influenced the type of impaction and bone contact.