Extraction of third molars performed before complete root formation can mitigate mental nerve paresthesia risk

The study identified the completion of root formation of the mandibular third molar, and deformation of the mandibular canal as the key risk factors for mental nerve paresthesia, post-extraction. The findings highlight the importance of timing in third molar extractions.

Mental nerve paresthesia is a severe postoperative complication of mandibular third molar extraction. Paresthesia usually manifests as burning, tingling, prickling, itching, numbness, or any deviation from normal sensation No study seemed to have examined the relationship between the surface morphology of the mandibular third molar roots and the possibility of mental nerve paresthesia after tooth extraction.

To fill this knowledge gap, Hiroki Sakakura, Japanese Red Cross Aichi Medical Center Nagoya Daini Hospital, Nagoya-shi, Aichi, Japan, and colleagues aimed to examine the root morphology of the mandibular third molars according to age using dental cone beam computed tomography (CBCT). They also evaluated the possibility of mental nerve paresthesia following tooth extraction.

The study involved 1216 patients who underwent mandibular third molar extractions. The root morphology was studied of 1534 teeth in 791 patients who had CBCT performed before surgery. Factors evaluated were hypercementosis, age, periodontal ligament atrophy of the mandibular third molar roots, complete or incomplete formation of the mandibular third molar roots, and mandibular canal deformation.

The study revealed the following findings:

• Mandibular third molar root formation was completed between the ages of 19 and 30 years.
• Complete formation of the mandibular third molar roots and deformation of the mandibular canal were identified as risk factors for mental nerve paresthesia.

"These findings indicate that the risk of mental nerve paresthesia could be mitigated if the extraction of third molars is performed before complete root formation," the researchers concluded.

Reference:

Sakakura H, Hayashi Y, Sugimoto K, Matsubara A. Relationship between age-related changes in mandibular third molar roots and the possibility of mental nerve paresthesia after tooth extraction. Int J Oral Maxillofac Surg. 2024 Jan 9:S0901-5027(23)00948-7. doi: 10.1016/j.ijom.2023.12.008. Epub ahead of print. PMID: 38199951.