Somatosensory changes in Chinese patients after coronectomy vs. total extraction of mandibular third molar: a prospective study

Abstract

Objectives This study aimed to quantitatively compare the somatosensory function changes of inferior alveolar nerve (IAN) after mandibular third molar extraction with a surgery protocol of coronectomy, as opposed to the conventional method. Materials and methods Patients with a lower third molar directly contacting IAN were recruited and assigned either to a test group (coronectomy group) or a control group (conventional extraction). A standardized quantitative sensory testing (QST) battery was performed for four times: one week before surgery and the second, seventh, and 28th days after surgery. Z-scores and the loss/gain coding system were applied for each participant. Results A total of 140 molars (test group: n = 91, control group: n = 49) were enrolled. The sensitivity of the mechanical detection threshold (MDT) and pressure pain threshold (PPT) significantly increased after surgery more than before surgery in both groups (P ≤ 0.001). After the surgery, the sensitivities of the cold detection threshold (CDT), cold pain threshold (CPT), and heat pain threshold (HPT) were significantly higher in the test group than in the control group (P ≤ 0.027). The risk of IANI was significantly larger (P = 0.041) in the test group than in the control group. Conclusions QST was a sensitive way to detect somatosensory abnormalities even with no subjective complaint caused by surgery. Coronectomy had less influence on IAN function than conventional total extraction. Clinical relevance The somatosensory function changes after mandibular third molar extraction were quantitatively studied, and coronectomy was proved a reliable alternation to reduce IAN injury rate.

Evaluation of the Outcomes of Coronectomy Procedure versus Surgical Extraction of Lower Third Molars Which Have a High Risk for Inferior Alveolar Nerve Injury: A Systematic Review

“…Accordingly, 44 full-text articles were assessed for eligibility, and 37 were excluded (Figure 1). Only 7 studies fulfilled the inclusion criteria for the quality synthesis: 3 RCTs [16][17][18] and 4 CCTs [5,15,19,20] (Table 2).…”

“…All studies considered a control group. Six studies monitored both sexes [5,[16][17][18][19][20]. e secondary outcomes including numbers and percentages of patients, teeth, incidence of pain, infection, alveolar osteitis, failure, and other variables are available in Table 3.…”

Computer-aided three-dimensional assessment of periodontal healing distal to the mandibular second molar after coronectomy of the mandibular third molar: a prospective study

“…First, a control group (total extraction of the M3M) was not included. The reason was because coronectomy is widely accepted as an effective alternative to prevent IAN injury [2]. Also, our ethics committee suggested that random grouping might not suitable in our study.…”

“…This is a single arm and single-blinded study. It is also part of an ongoing study on the long-term changes in the M3M after coronectomy [2]. Ethical approval of the study protocol was granted by the Biomedical Ethics Committee of Peking University Hospital of Stomatology (PKUSSIRB-201736080) in Beijing, China.…”

“…"Coronectomy" is an alternative to total extraction of the mandibular third molar (M3M) to protect the inferior alveolar nerve (IAN) [1,2]. Coronectomy is applied mainly to a deeply impacted M3M vulnerable to a distal intra-bony defect (DBD) of the mandibular second molar (M2M) after M3M surgery [3].…”