Conserved odontogenic potential in embryonic dental tissues

Classic tissue recombination studies have demonstrated that, in the early developing mouse tooth germ, the odontogenic potential, known as the tooth-inductive capability, resides initially in the dental epithelium and then shifts to the dental mesenchyme. However, it remains unknown if human embryonic dental tissues also acquire such odontogenic potential. Here we present evidence that human embryonic dental tissues indeed possess similar tooth-inductive capability. We found that human dental epithelium from the cap stage but not the bell stage was able to induce tooth formation when confronted with human embryonic lip mesenchyme. In contrast, human dental mesenchyme from the bell stage but not the cap stage could induce mouse embryonic second-arch epithelium as well as human keratinocyte stem cells, to become enamel-secreting ameloblasts. We showed that neither post-natal human dental pulp stem cells (DPSCs) nor stem cells from human exfoliated deciduous teeth (SHED) possess odontogenic potential or are odontogenic-competent. Our results demonstrate a conservation of odontogenic potential in mouse and human dental tissues during early tooth development, and will have an implication in the future generation of stem-cell-based bioengineered human replacement teeth.

Factors influencing inferior alveolar nerve injury after extraction of mandibular third molar

BACKGROUND

This study sought toexplore the manifestations of clinical symptoms and identify the risk factors linked to inferior alveolar nerve injury (IANI) in the context of mandibular third molar extraction.

MATERIAL AND METHODS

In this study, 172 patients admitted to our hospital for mandibular third molar extraction from June 2021 to December 2022 were selected for the study, and the clinical data of the participants were retrospectively analyzed, and the risk factors of IANI associated with mandibular third molar extraction were analyzed by uni/multi-factor logisitic regression.

RESULTS

Noticeable distinctions were noted between the groups with and without injuries in relation to age, time of surgery, number of broken roots, angle of blockage, CEJ (cementoenamel junction) distance, curved roots of the molar, clarity of the upper and lower walls of the nerve canal, and Pell & Gregory classification. Logistic regression analysis showed that age, time of surgery, number of broken roots, angle of blockage (40°-70°), CEJ distance (10-12 mm, >12 mm), and curved roots of the molar were independent risk factors for IANI. Multi-factor logistic regression analysis further confirmed that age, number of broken roots, angle of blockage (40°-70°), CEJ distance (10-12 mm, >12 mm), and curved roots of the molar were associated with IANI.

CONCLUSIONS

Alveolar nerve injury manifests as hyperalgesia or absence of sensation, numbness and abnormal pain in the lower lip. Factors influencing IANI associated with mandibular third molar extraction were age, number of broken roots, angle of blockage (40°-70°), CEJ distance (10-12 mm, >12 mm), and curved roots of the molar.

Sources of information on surgical options for patients undergoing antireflux surgery: a single-center questionnaire-based survey

BACKGROUND

To explore the sources of information on antireflux surgery for patients undergoing this surgery in China.

METHODS

Patients who underwent antireflux surgery in the Gastroesophageal Reflux Center of the Zhejiang Provincial People's Hospital from January 2016 to June 2021 were selected as survey subjects, and a questionnaire survey was conducted by telephone.

RESULTS

A total of 358 questionnaires were distributed, and 320 valid questionnaires were recovered, yielding a 89.4% completion rate. Among patients' sources of information about antireflux surgery, the media was the primary source (33.8%) followed by recommendations from relatives or friends (27.8%), referrals from physicians (23.4%) and other sources (15.0%). Patients of different ages and educational levels have different sources for obtaining information about the procedure. Most of the information on surgery for patients aged 20 to 49 years was derived from recommendations from friends or relatives, whereas most of the information on surgery for patients aged 50 to 80 years was obtained from the media. Most of the information on surgery for patients with a primary school education or less was derived from physicians' recommendations, whereas most of the information for patients with a junior secondary school education or higher was obtained from the media. The recommendation of patients for surgery varied among the different departments (X² = 36.011, p < 0.001), and a two-to-two comparison found that the recommended rates for cardiology and gastroenterology differed from the rates of other groups (p < 0.001, Table 2).

CONCLUSIONS

The results of this investigation show that a large number of patients who underwent antireflux surgery learned about the operation through the media and recommendations from relatives or friends rather than physicians at the hospital. Notably, physicians specializing in GERD need to increase their knowledge of the disease and surgical treatment options to provide correct medical information to patients and to conduct media campaigns.