Panoramic radiographic predictors of mandibular third molar eruption

OBJECTIVE: To determine the frequency of mandibular third molar impaction in different vertical skeletal facial types. METHODOLOGY: Data was collected using pre-treatment records including orthodontic files, pre-treatment lateral cephalograms and OPGs of 90 orthodontic patients. Patients from both genders were included. The age group of selected patients was 18-30 years. Vertical skeletal malocclusion was measured using facial angle and mandibular plane angle on cephalogram to group the subjects into Mesiofacial, Brachyfacial and Dolichofacial patients. Third molar eruption status was assessed using OPG. RESULTS: Results showed that erupted third molars were mostly found in brachyfacial patients. Among 32 erupted mandibular third molars, 16 belong to brachyfacial, 11 belonged to mesiofacial and 5 belonged to dolichofacial group. Complete impaction of mandibular third molar was most common among dolichofacial patients. Among 29 completely impacted mandibular third molars, 14 belong to dolichofacial, 9 belonged to mesiofacial and 6 belonged to brachyfacial group. No significant difference was found for partially impacted third molars among the three groups of facial types. There was higher prevalence of mandibular third molar impaction in females as compared to males. CONCLUSION: Frequency of third molar impaction was found to be highest in dolichofacial patients and lowest in brachyfacial patients due to forward direction of mandibular growth contributing to greater resorption of the anterior border of ramus and the additional space required for third molar eruption.

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Radiographic assessment of lower third molar eruption in different anteroposterior skeletal patterns and age-related groups

The Angle Orthodontist ◽

10.2319/062714-463.1 ◽

2014 ◽

Vol 85 (4) ◽

pp. 577-584 ◽

Cited By ~ 2

Author(s):

Aleksandar Jakovljevic ◽

Emira Lazic ◽

Ivan Soldatovic ◽

Nenad Nedeljkovic ◽

Miroslav Andric

Keyword(s):

Logistic Regression ◽

Age Groups ◽

Third Molar ◽

Width Ratio ◽

Class Iii ◽

Second Molar ◽

Age Related ◽

Mandibular Third Molar ◽

Lateral Cephalograms ◽

Third Molar Eruption

ABSTRACT Objective: To analyze radiographic predictors for lower third molar eruption among subjects with different anteroposterior skeletal relations and of different age groups. Materials and Methods: In total, 300 lower third molars were recorded on diagnostic digital orthopantomograms (DPTs) and lateral cephalograms (LCs). The radiographs were grouped according to sagittal intermaxillary angle (ANB), subject age, and level of lower third molar eruption. The DPT was used to analyze retromolar space, mesiodistal crown width, space/width ratio, third and second molar angulation (α, γ), third molar inclination (β), and gonion angle. The LC was used to determine ANB, angles of maxillar and mandibular prognathism (SNA, SNB), mandibular plane angle (SN/MP), and mandibular lengths. A logistic regression model was created using the statistically significant predictors. Results: The logistic regression analysis revealed a statistically significant impact of β angle and distance between gonion and gnathion (Go-Gn) on the level of lower third molar eruption (P < .001 and P < .015, respectively). The retromolar space was significantly increased in the adult subgroup for all skeletal classes. The lower third molar impaction rate was significantly higher in the adult subgroup with the Class II (62.3%) compared with Class III subjects (31.7%; P < .013). Conclusion: The most favorable values of linear and angular predictors of mandibular third molar eruption were measured in Class III subjects. For valid estimation of mandibular third molar eruption, certain linear and angular measures (β angle, Go-Gn), as well as the size of the retromolar space, need to be considered.

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Orthodontic treatment with passive eruption and mesialization of semi-impacted mandibular third molar in an adult with multiple dental losses

Dental Press Journal of Orthodontics ◽

10.1590/2177-6709.24.6.036-047.oar ◽

2019 ◽

Vol 24 (6) ◽

pp. 36-47

Author(s):

Armando Yukio Saga ◽

Ariane Ximenes Graciano Parra ◽

Isteicy Cortêz Silva ◽

Cayana Dória ◽

Elisa Souza Camargo

Keyword(s):

Case Report ◽

Adult Patient ◽

Female Patient ◽

Dental Implant ◽

Orthodontic Treatment ◽

Third Molar ◽

Impacted Tooth ◽

Impacted Mandibular Third Molar ◽

Mandibular Third Molar ◽

Third Molar Eruption

ABSTRACT Objective: This article describes the orthodontic treatment performed on an adult patient with multiple dental losses. Case report: A female patient, 20 years and 4 months old, presented with the following conditions: absence of teeth #26, #35, #36 and #46; semi-impacted tooth #48; inclined molars adjacent to an edentulous space; canines and premolars in a Class II relationship; a convex profile; biprotrusion; and forced lip sealing. Results: Space in the region of tooth #26 was closed, as well the space of tooth #46; tooth #48 erupted and followed mesial movement passively; space of the region of tooth #35 was maintained for the placement of a dental implant; uprighting of tooth #37 was obtained. Aesthetic and functional goals of the treatment were achieved. Results remained stable 10 years after the end of the treatment. Conclusion: The modified helical loop could be effectively used in orthodontic mechanics to close edentulous spaces. Passive semi-impacted mandibular third molar eruption and mesialization can occur in adults when proper space is provided.

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

International Journal of Dental Health Concerns ◽

10.15713/ins.ijdhc.2 ◽

2015 ◽

Vol 1 ◽

pp. 2-7 ◽

Cited By ~ 1

Author(s):

Arth K. Patel ◽

Sonali V. Deshmukh ◽

C. R. Naik ◽

Sandeep Jethe ◽

Krunal A. Patel

Keyword(s):

Retrospective Study ◽

Orthodontic Treatment ◽

Third Molar ◽

Radiographic Assessment ◽

Premolar Extraction ◽

Mandibular Third Molar ◽

Group A ◽

Third Molar Eruption

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Longitudinal study of three views of mandibular third molar eruption in males

American Journal of Orthodontics ◽

10.1016/0002-9416(84)90303-8 ◽

1984 ◽

Vol 86 (2) ◽

pp. 119-129 ◽

Cited By ~ 23

Author(s):

Elisha R. Richardson ◽

Shyam K. Malhotra ◽

Kofi Semenya

Keyword(s):

Longitudinal Study ◽

Third Molar ◽

Mandibular Third Molar ◽

Third Molar Eruption

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Factors associated with mandibular third molar eruption and impaction

Journal of Clinical Pediatric Dentistry ◽

10.17796/jcpd.30.2.k359u03v100586h3 ◽

2006 ◽

Vol 30 (2) ◽

pp. 109-114 ◽

Cited By ~ 6

Author(s):

Hung-Huey Tsai

Keyword(s):

Third Molar ◽

Mandibular Ramus ◽

Second Molar ◽

Gonial Angle ◽

Mandibular Plane ◽

Mandibular Third Molar ◽

Distal Surface ◽

Discriminatory Analysis ◽

Mandibular Second Molar ◽

Third Molar Eruption

A retrospective study, using panoramic radiographs, was conducted on 152 Taiwanese (72 males and 80 females) to investigate mandibular third molar eruption and impaction. The following measurements were made: inclinations and mesiodistal crown widths of the mandibular molars, vertical and horizontal spaces between the distal surface of the second molar and the anterior surface of the ramus, lengths and widths of the mandibular ramus and body, the ramus inclination, the mandibular plane angle, and the mandibular gonial angle. Differences between non-impaction and impaction groups were studied, and the variables were analyzed with multivariate discriminatory analysis. Significant differences between the two groups were found; variables describing spaces between the anterior of the ramus and the distal of the mandibular second molar and tooth size appeared to be the primary contributors to the differences observed.

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