Measurement of the Lingual Position of the Lower Third Molar Roots Using Cone-Beam Computed Tomography

Topographic relationship between root apex of mesially and horizontally impacted mandibular third molar and lingual plate: cross-sectional analysis using CBCT

“…The distribution of spatial relationship between root apex of impacted third molar and lingual plate varied among diverse previous studies262729. Emes and his colleagues reported that only four root apexes of impacted third molars were identified on CBCT images which perforated beyond the lingual plate and directly contacted with lingual soft tissue (Type C) in 32 teeth (31 patients)26.…”

“…The anatomic morphology of the posterior mandible has increasingly attracted the attentions and interests in the dental clinic largely due to its importance and contributions to potential postsurgical complications following the third molar surgery and dental implant surgery24262730. A line of evidence has suggested that the thin and shape of lingual cortical plate as well as perforation or fenestration in lingual plate are associated with accidental displacement of third molars or root fragments, secondary infection of submandibular space and lingual nerve injury following surgical extraction of impacted third molars8102631.…”

“…A line of evidence has suggested that the thin and shape of lingual cortical plate as well as perforation or fenestration in lingual plate are associated with accidental displacement of third molars or root fragments, secondary infection of submandibular space and lingual nerve injury following surgical extraction of impacted third molars8102631. Therefore, comprehensive understanding and analyses of the anatomy in lingual plate of mandible and its spatial relationship with impacted third molars before surgery might be beneficial to prevent the complications and communicate with patients regarding the surgical risks, especially for those cases with high risks.…”

“…measured the distance between the root apex of third molars and lingual cortical plate with average 1.03 mm by CBCT. Their data indicated that root apex of impacted third molar can be very close to the lingual plate and sometimes even protruded into soft tissue of mouth floor in 25% cases26. Additionally, Tolstunov and his colleagues reported that fenestration in the lingual plate identified by CBCT scan was more commonly observed than originally expected at the third molar apex region and such fenestration of lingual bone was significantly associated with the angulation of the impacted third molar29.…”

“…Lingual plate morphology and bone thickness in mandible have been increasingly recognized as key factors to avoid unpleasant complications during implant placement and extraction of mandibular impacted molars132425262728. Previous studies have shown diverse types of the morphology of lingual plate (convergent, parallel, undercut) at the post-mandibular region on cross-sectional CBCT images24.…”