The assesment of relationship between the angulation of impacted mandibular third molar teeth and the thickness of lingual bone: A prospective clinical study.

D Menziletoglu,B Kubilay-Isik,A Esen,M Tassoker

doi:10.4317/medoral.22596

D Menziletoglu, B Kubilay-Isik + Show 2 more

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https://doi.org/10.4317/medoral.22596

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Abstract

BackgroundOur purpose was to investigate the relationship between the angulation of mandibular third molars and the thickness of the lingual bone, which can affect the risk of lingual nerve damage during lower third molars surgical extraction.Material and MethodsThis study consisted of 104 patients (42 males and 62 females), aged between 18-42 years (24.67 ± 6.11 years). Cone Beam Computed Tomography (CBCT) images were taken for preoperative assessment. The teeth were divided into four groups according to their positions: mesioangular, distoangular, vertical and horizontal. Lingual bone thickness around impacted teeth were measured at three points: cementoenamel junction (CEJ) of the mandibular second molar, mid-root of the impacted third molar, and apex of the impacted third molar root. Two predisposing factors of lingual nerve damage were recorded: lingual bone perforated by the impacted tooth and lingual bone thinner than 1 mm. Additionally, buccolingual angulations of the teeth in each group were measured. Impacted mandibular third molars were removed in usual way. One week after surgery, the patients were evaluated regarding lingual nerve paresthesia.ResultsNone of the 104 patients experienced paresthesia, including the ones who had teeth with close proximity with lingual nerve. The mean thickness of bone was 1.21±0.63 mm at CEJ of the second molar; 1.25±1.02 mm at the mid-root; and 1.06±1.31 mm at the apex. Horizontally impacted teeth had thinner lingual bone at mid-root level (p=0.016). Buccolingual angulated teeth were more often associated with perforated lingual bone (p=0.002). Buccolingual and mesial/distal angulation had negative correlation with lingual bone thickness (p<0.05).ConclusionsAs the buccolingual and mesiodistal angulations increase, lingual bone thickness decreases. Horizontally impacted teeth seemed to compromise the integrity of the lingual bone more than impacted teeth in other positions. During the surgery, thin or perforated lingual bone may result in displacement of the impacted tooth lingually. Key words:Lingual bone, impacted third molar, cone beam computed tomography, angulation, paresthesia.

Highlights

During extraction of impacted mandibular third molars, lingual nerve may be damaged
Impacted teeth seemed to compromise the integrity of the lingual bone more than impacted teeth in other positions
Thin or perforated lingual bone may result in displacement of the impacted tooth lingually

Summary

Introduction

During extraction of impacted mandibular third molars, lingual nerve may be damaged. The incidence for this complication has been reported between 0.5% and 2.6% (1). Age of the patient (2), surgeon’s experience (3), trauma to the soft tissue during inferior alveolar nerve block anesthesia (4), impaction pattern of the tooth, retraction of the lingual flap, overall difficulty of the surgery (2,5), amount of the bone removal (6), suturing (7), exposing the lingual nerve during the operation (5) can affect the situation. Most of these nerve damages heal spontaneously. Our purpose was to investigate the relationship between the angulation of mandibular third molars and the thickness of the lingual bone, which can affect the risk of lingual nerve damage during lower third molars surgical extraction. Buccolingual and mesial/distal angulation had negative correlation with lingual bone thickness (p

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