Level Of Occlusal Plane Research Articles

Comparative study of changes in the airway dimensions following the treatment of Class II malocclusion patients with the twin-block and Seifi appliances.

Functional appliances are frequently used to stimulate mandibular growth in cases of Class II malocclusion with mandibular deficiency. Many studies have reported improved pharyngeal airway passage (PAP) dimensions following functional appliance therapy in children. The present study aimed to assess changes in the airway dimensions following the treatment of Class II malocclusion patients with the twin-block and Seifi appliances. Lateral cephalograms of 37 patients with Class II malocclusion and mandibular deficiency treated with the twin-block appliance (n = 20) or the Seifi appliance (n = 17) were assessed in this before-and-after study. The preoperative and postoperative lateral cephalograms were compared to determine changes in the airway dimensions at the level of the palatal plane (PP), the occlusal plane (OP) and the 2nd-4th cervical vertebrae (C2-C4) in the 2 groups. The results were analyzed with the t test and the one-way analysis of covariance (ANCOVA). After treatment, significant changes occurred in the point A-nasion-point B (ANB) and sellanasion-point B (SNB) skeletal cephalometric indices in the twin-block appliance group, and in ANB, SNB and incisor-mandibular plane angle (IMPA) in the Seifi appliance group. The airway dimensions at the level of PP, OP and the 3rd cervical vertebra (C3) significantly increased postoperatively as compared to the baseline in the twin-block appliance group (p < 0.05). The increases in the airway dimensions at the level of PP and C3 in the twin-block appliance group were significantly greater than in the Seifi appliance group (p < 0.05). The treatment of Class II Division I malocclusion with the twin-block appliance significantly increased the airway dimensions at the level of PP, OP and C3, whereas the Seifi appliance did not cause any significant changes in the airway dimensions.

An Evaluation of the Relation Between Variation in Arch Forms and Relative Parallelism of the Occlusal Plane to the Line Joining the Inferior Border of Ala of the Nose With Different Tragal Levels of the Ear in Dentulous Subjects: An In Vivo Study.

IntroductionThe purpose of this study was to evaluate which of the three positions on the tragus (superior, middle, and inferior), when connected to the inferior border of the ala of the nose, was the most parallel to the natural occlusal plane in dentate patients, to correlate the level of the naturally existing occlusal plane with the ala-tragal line when the tragus was divided into three portions (superior, middle, and inferior), and to determine which position in the tragus occlusal plane is the most parallel. The study also evaluated the correlation between the variation of arch forms and the relative parallelism of the occlusal plane to the ala-tragal line at different tragal levels.MethodsThis study included 1405 subjects between the ages of 18 and 35 years. A custom-made occlusal plane analyzer was used to check the relative parallelism between the existing occlusal plane and the ala-tragal line when the tragus was divided into the superior, middle, and inferior portions. The Fox plane of the occlusal plane analyzer was placed on the occlusal plane and the paralleling rod was adjusted till parallelism was obtained. The point on the tragus (superior, middle, or inferior) at which parallelism existed was recorded. The study also measured the inter-canine and intermolar distance to find the type of arch form and related it to the position (superior, middle, or inferior) at which the ala tragal line was parallel to the occlusal plane. The assessment was done on both the right and left sides of the subjects.ResultsOut of the 2810 tragi, the most common location at which parallelism was established was the inferior part of the tragus, which accounted for 47% of the total. Seventy-one percent (71%) of the subjects showed ovoid arch form. When the variation of arch forms was compared to the level of occlusal plane, 46.8% of the subjects with tapered arch form, 54.5% of subjects with square arch form, and 46.0% of subjects with ovoid arch form had the level of the occlusal plane at the inferior portion of the tragus.ConclusionThe result of the study indicated that in the majority of the tragi studied, 47% of the subjects had the occlusal plane parallel to a line joining the inferior border of the ala of the nose to the inferior part of the tragus. Irrespective of the arch form, the occlusal plane was found parallel to a line joining the inferior border of the ala of the nose and the inferior part of the tragus. Thus the tragal position did not show any correlation to the variation of arch forms.

Assessment of Mandibular Foramen Position for Inferior Alveolar Nerve Block in Children

Introduction: In children the administration of inferior alveolar nerve block at the target site varies and repeated injection may result in a negative behavior and also increase the risk of overdose. This study correlates the relative position of the mandibular foramen with occlusal plane as a clinical guide for inferior alveolar nerve block in children from 3-13 years.&#x0D; Methods: A cross-sectional study was conducted on 180 orthopantamographs of children from June 2021 to January 2022. The radiographs were digitally traced, analyzed to obtain linear and angular measurements of mandibular foramen to occlusal plane, anterior, posterior and lower border of mandible along with gonial angle. Paired t-test, unpaired t-test was used along with Karl Pearson’s test for correlation.&#x0D; Results: The results suggested that the needle for inferior alveolar nerve block should be placed below the occlusal plane in 3–4 year (L-1.38, R-1.36 mm approximately), above the level of occlusal plane in 5–7 years (L-2.59, R-2.77 mm), 7–9 years (L-3.71, R-3.86 mm), 9–12 years (L-3.5, R-4.14 mm), 11–12 years (L-3.97, R-4.35 mm), and 12–13 years (L-4.24, R-4.7 mm) old children respectively. The distance of the mandibular foramen from anterior border of mandible was greater than that from posterior border and the gonial angle values decreased with subsequent stages. However, there was statistically significant mean difference in mandibular foramen from anterior border of ramus as well as occlusal plane between right and left sides.&#x0D; Conclusions: There was vertical and horizontal alteration in the position of the bony landmarks within the jaws and it is necessary to modify the placement of needle during inferior alveolar nerve block with advancing age due to skeletal growth and also between right and left sides. The decrease in gonial angle indicated increased growth potential of the mandible with age.&#x0D;

Variability associated with mandibular ramus area thickness and depth in subjects with different growth patterns, gender, and growth status

The purpose of this study was to quantitatively evaluate the ramus bone parameters (ramus thickness and ramus depth) for miniscrew placement. An additional aim was to compare and contrast the ramus bone parameters in growing and nongrowing male and female subjects with hyperdivergent, normodivergent, hypodivergent facial types.Cone-beam computed tomography scans of 690 subjects were evaluated. They were classified in terms of growth status, gender, and facial type. Ramus thickness was measured as the distance from the outer (buccal) to the inner (lingual) aspects of the mandibular ramus. Ramus depth was measured as the distance from the anterior border of the ramus to the inferior alveolar nerve canal. The measurements for ramus thickness and ramus depth were performed at 3 different levels bilaterally: (1) occlusal plane (OP), (2) 5 mm above the occlusal plane (5OP), and (3) 10 mm above the occlusal plane (10OP).Males showed a significantly higher ramus thickness than females (P <0.05). Ramus thickness decreased significantly (P <0.05) as we moved superior from the level of OP to 5OP and 10OP in all 3 facial types in both females (growing and nongrowing) and males (growing and nongrowing). Growing females and growing males had significantly higher ramus thickness than nongrowing females and nongrowing males, respectively. Ramus depth increased as we moved higher from the OP to 10OP. Hyperdivergent facial type showed a significantly reduced ramus depth compared with hypodivergent and normodivergent facial type in growing and nongrowing males and females at all 3 locations, namely OP, 5OP, and 10OP (P <0.05).Because of adequate ramus depth and ramus thickness, 5OP was considered the optimal insertion site for the placement of miniscrews. Patients with a hyperdivergent facial type showed significantly reduced ramus depth than hypodivergent and normodivergent facial types. Ramus thickness in males was significantly higher than in females in all facial types.

Morphology of mandible - A two year digital radiographic study

Mandible is a unique single bone often recovered intact during mass disasters.To assess whether the specific morphological characteristics of mandible in males and females can be used as an aid for sex determination based on radiographs.A two-year retrospective study was conducted in 200 subjects [100 males and 100 females] using digital radiographs. Profile of chin and morphologic differences in the base of the mandible were assessed using digital lateral cephalogram. Mandibular ramus flexure was assessed from digital Orthopantomogram. The obtained data statistically analysed using SPSS software version 20. Descriptive statistics was analysed. Chi square test was done to determine the association between gender and different parameters. The level of significance set at p ≤ 0.05.There is a significant association between chin profile, base of mandible and mandibular ramus flexure with gender. Females have prominent chin compared to males. Males have undulating base of mandible while females have straight base of mandible. Mandibular ramus flexure in males seen at the level of occlusal plane while it is seen above the occlusal plane in females.There is a morphological difference in the mandible of the males and females.

Correlation of Mandibular Foramen to Occlusal Plane as a Clinical Guide for Inferior Alveolar Nerve Block in Children: A Digital Panoramic Radiographic Study.

Aim:The study aimed to correlate the position of mandibular foramen with occlusal plane as a clinical guide for inferior alveolar nerve block (IANB) injection in children from 3 to 13 years of age.Materials and Methods:The study was carried out on 180 children visiting our department and required orthopantomogram as a routine diagnostic aid. Mandibular casts were obtained and radiographs were digitally analyzed to obtain linear and angular measurements.Statistical Analysis:The measurements were correlated with the position of mandibular foramen with Karl Pearson's correlation test.Results:The results of the study suggest that the needle for IANB should be placed below the occlusal plane in 3–4-year-old children (1.26 mm approximately), almost at the level of occlusal plane in 5–7 years (0.33 mm), above the occlusal plane in 7–9 years (1.54 mm), 9–12 years (1.64 mm), 11–12 years (1.98 mm), and 12–13 years (2.9 mm), respectively. The distance of the mandibular foramen from anterior border of mandible was greater than that from posterior border. The gonial angle values decrease with increasing age.Conclusion:The bony landmarks within the jaws keep changing their relative positions along with the skeletal growth. It is therefore necessary to modify the placement of needle during local anesthesia techniques with advancing age.

Age-related changes in the location of the mandibular and mental foramen in children with Mongoloid skeletal pattern.

To observe age-related changes in the locations of mandibular foramen (MF) and mental foramen (mf) using dental panoramic tomographs (DPTs). Ethical approval was obtained for this retrospective study. Location of MF was related to the ramus and occlusal plane, while mf to (i) erupted primary molars (ii) unerupted premolar tooth germs (iii) vertical height at the body of the mandible. One hundred and sixty-five DPTs were obtained from children with Mongoloid skeletal pattern. The ethnic composition was 112 Malays and 53 Chinese children (Willems dental age = 5.2-16.0 years). At the horizontal plane, MF remained constant at middle mid-quadrant of the ramus (88 %) and vertical plane; 68 % located below and 40 % above the occlusal plane. At age 9 years and above, there was a significant tendency for MF to be located at the level of occlusal plane. The most common location of mf was related to (i) erupted primary molars, mesial root of second primary molar (38 %); (ii) unerupted premolars tooth germs, between the apices of first and second premolar (44 %); and (iii) proportional vertical height to the mandible, middle third (52 %). At age 11 years and above, a significant tendency of mf to be located at the middle third of the body of mandible was observed. With advancing age and growth, the position of MF remained constant at the ramus with tendency to move from below to at the level of occlusal plane, while mf moved distally and inferiorly.

Analysis of the mandibular foramen position and its implications to the inferior alveolar nerve block

The aim of this study was analyze the positioning of the mandibular foramen in men and women, relating it to the inferior alveolar nerve block. Were analyzed CBCT scans of the mandible of 25 women and 25 men, aged between 20 and 40 years, with toothed jaws, presence of the second molar erupted and in occlusion. To determine the position of the mandibular foramen, three measurements were taken in millimeters, Point A - distance from the foramen to the anterior border of the mandible; Point B - distance between the foramen to the base of the mandible and Point C - distance between the foramen and the mandibular notch. The mean measure point A was 11.8 mm and when compared the points A, B and C between the right and left sides, there was no significant difference, however men and women have significant differences were detected for point B and point C. Conclude that in men and women, can use needles with at least 21mm in length with the insertion in the level of occlusal plane for blocking the inferior alveolar nerve, enhancing the success of this procedure.

A determination of occlusal plane comparing different levels of the tragus to form ala-tragal line or Camper's line: A photographic study

PURPOSEThe purpose of this study was to determine accurately the part of the tragus to be used to form the Ala-Tragal line or Camper's line in orthognathic profile patients.MATERIALS AND METHODS150 dentate subjects with age of 18-40 years with orthognathic profile were sampled. Life-size lateral digital photographs of the face with fox plane were taken in natural head position. Different angles between Eye-Ear plane and occlusal plane (OT1-OP), Eye-Ear plane and ala-superior border of tragus (OT1-AT1), Eye-Ear plane and ala-middle border of tragus (OT1-AT2) and Eye-Ear plane and ala-inferior border of tragus (OT1-AT3) were calculated using computer software package, AutoCAD 2004. From the three angles formed by the Eye-ear plane (OT1 or FH plane) and the ala-tragal lines, the one closest to the angle formed between Eye-Ear plane (OT1) and occlusal plane (OP) was used to determine the occlusal plane of orientation. The obtained results were subjected to ANOVA F test, Tukey's Honestly significant difference test, followed by Karl Pearson coefficient of correlation test. P values of less than 0.05 were taken as statistically significant.RESULTSThe mean of base line angle i.e. OT1-OP angle (11.96 ± 4.36) was found to be close to OT1-AT2 angle (13.67 ± 1.93) and OT1-AT3 angle (10.31 ± 2.03), but OT1-OP angle was found to be more closer to OT1-AT3 angle. Comparison of mean angles showed that OT1-OP angle in both males (11.68) and females (12.51) is close to OT1-AT3 angle (males- 11.01, females- 11.95).CONCLUSIONThe line joining from ala to the lower border of the tragus was parallel to the occlusal plane in 53.3% of the subjects. There was no influence of the sex on the level of occlusal plane.

Prevalence of eruption status of third molars in Libyan students.

The aim of the present study is to determine the number of third molars per person, angulation, level, amount of space for eruption of third molar between ramus of mandible and second molar and the eruption status of third molar in a group of Libyan students, with different impaction patterns and agenesis of third molars. In this descriptive retrospective study, a total of 200 students (100 male and 100 female students of bachelor of dental surgery, Faculty of Dentistry, Garyounis University, Benghazi, Libya) were enrolled. Students who had complete complement of teeth within the age group 17-26 years were selected for this study, while those cases who had history of extraction of any of the teeth or who refused to give consent were excluded. Before starting the study, ethical concern from the ethical committee, IRB and informed consent from each student who underwent radiography were obtained. The results showed that 5% of third molars were congenitally missing. Approximately 93.5% of the subjects had all four third molars, 1% had two third molars and 0.5% had one third molars with 2.5% having agenesis of all third molars. Third molar agenesis showed predilection for maxilla with higher proportion in females (3%) than males (2.1%). Angular position was maximum with vertical position (5.83%), with least being horizontal impactions. Level of occlusal plane of third molar similar to that of adjacent tooth was seen in 44.74%, below the occlusal plane in 24.76%, totally impacted noted in 30%. The present study showed that 33% of the teeth were fully erupted and 66% were in various stages of eruption and 5% were congenitally missing in these students.

Eruption Status of Third Molars in South Indian City

Aim : The aim of the present study is to determine the number of third molars per person, angulation, level, amount of space for eruption of third molar between ramus of mandible and second molar status of root and also to study the difficulty index. Objective: To study the eruption status of third molar in South Indian population. Materials and methods: The study conducted at Department of Oral Medicine and Radiology. Maratha Mandals NG Halgekar College of Dental Sciences and Research Centre. Belgaum, Karnataka, India A total of 150 patients (54 females and 96 males) visiting outpatient department between the age group of 17 and 30 with a mean age of 23.5 years were selected- Before starting the study, ethical concern taken from the ethical committee and informed consent from each patent who underwent radiographic examination. Results: The results showed approximately 94.66% of the subjects had all four third molars, 8.6% had three third molars, 4.6% had two third molars and 2% had one third molars with 3.3% having agenesis of all third molars. Third molar agenesis showed predilection for upper jaw with higher proportion in females (5 5%) than males (2%). Angular position seen maximum with vertical position (66.16%) with least being horizontal impactions. Level of occlusal plane of third molar similar to that of adjacent tooth seen in 52.65%. Below the occlusal plane in 19.61 %, totally impacted teeth noted in 27.73%. More than 75% of the teeth had complete root formation. Among total number of teeth, 518 (91.51 %) teeth were easy to extract and remaining 33 (5.8%) were difficult to extract. Conclusion: Radiological and clinical findings have correlated to assess whether teeth were easy to extract or difficult. Because of the increasing incidence of unerupted third molars and the association of numerous complications with these retained teeth, assessment of germ position and prognosis of third molar eruption is necessary for better patient management.

The predictivity of mandibular third molar position as a risk indicator for pericoronitis

The aim of this study was to describe the characteristics of the mandibular third molar at highest risk for acute pericoronitis using clinical and radiographic analysis. A total of 102 volunteers, including 40 (39%) male and 62 (60%) female patients presenting with acute pericoronitis, participated in the study. The mean age of the participants was 23.4 years (range 17-30 years). The variables tested included the percentage of soft tissue coverage, availability of impinging maxillary dentition, and the angulation and eruption level of the mandibular third molar. While vertical impaction was the most frequent angulation (51%), horizontal impaction was quite rare (3%). Mesioangular impaction (25%) was slightly higher than distoangular impaction (21%). Difference between type of angulation was statistically significant for all groups (p < 0.05). The frequency of partial soft tissue coverage, particularly 75% coverage, was far more observed than the full soft tissue coverage (47%). The difference for the amount of soft tissue coverage was statistically significant (p < 0.05). In 57% of the cases, pericoronitis was associated with the third molars that erupted at the same level of the adjacent tooth occlusal plane. The difference among the three levels of eruption was significant (p < 0.000). Impinging maxillary dentition did not have a significant impact on development of pericoronitis (41%). Evidence of impinging maxillary dentition did not have a statistically significant impact on presence of pericoronitis (p = 0.075). Mandibular third molars at or near to the same level of the occlusal plane of the arch and exhibiting vertical inclination were considered at highest risk for developing pericoronitis. Such third molars can be given high priority for prophylactic care due to the possibility of severe consequences of acute pericoronitis.

The significance of neutral zone technique on complete denture retention

The aims of this study are to evaluate retention, differences between the level of occlusal plane, and patient's response to esthetic, speech, and masticatory efficiency, in patients using two sets of complete dentures [blind treatment] for one month, one was constructed in natural zone (neutral zone technique), and the other in conventional technique. Twenty-five completely edentulous patients, with age range (55-70) years were selected clinically with special criteria. Measurements of load required to dislodge (100) dentures were done using load apparatus. The levels of occlusal plane of (50) mandibular dentures were measured by using digital vernea. Results of mean square analysis of the neutral zone technique showed highly significant differences at (1%) level, the load required to dislodge mandibular denture done by the neutral zone technique was higher than that done by conventional technique (415.32gm). The differences between the level of occlusal plane done in both techniques ranged between (2.22mm and 2.47mm). The blind trail of treatment done showed (92-100%) acceptance with complete dentures done by neutral zone technique. This technique helps dentists, patients, and technicians to solve problems of sever resorption of alveolar bone, by increasing retention, stability, masticatory function, esthetic value, simplicity of construction, and time saving.