Mahidol Dental Journal

Impact of orthognathic surgical procedure and surgical movement distance on obstructive sleep apnea in skeletal class III malocclusion

Ratanaporn Patharakorn, Nuntinee Nanthavanich Saengfai — Tue, 10 Jun 2025 00:00:00 +0700

Objectives: To investigate the incidence of obstructive sleep apnea (OSA) in relation to the type of surgical procedure and the amount of mandibular setback.

Materials and Methods: The cohort study involved 20 participants (mean age: 25.1 ± 5.74) with skeletal Class III malocclusion. All participants had no prior history of sleep disorders and an apnea-hypopnea index (AHI) of fewer than 5 events/hour pre-surgery. They underwent either mandibular setback alone or two-jaw surgery (maxillary advancement and mandibular setback). OSA-related parameters were assessed at two time points: pre-surgery (T1) and six months post-surgery (T2), using a home sleep test device. The magnitude of surgical jaw movements was determined through data obtained from virtual surgical planning. The association between the type of surgical procedure, the categorized extent of mandibular setback, and the development of OSA was analyzed using Fisher’s exact test.

Results: Twenty- five percent of participants developed an AHI of ≥ 5 events/hour at 6 months post-surgery, regardless of the type of surgical procedure. Notably, 11.11% of patients with a mandibular setback of < 7 mm demonstrated an AHI of ≥ 5 events/hour post-surgery, whereas 36.36% of those with a setback of ≥ 7 mm exhibited similar AHI levels post-surgery. Participants who maintained an AHI of < 5 events/hour post-surgery, had greater maxillary advancement and less mandibular setback compared to those with higher AHI levels.

Conclusions: No statistically significant differences in the incidence of OSA were observed between one-jaw and two-jaw surgeries or between surgical distances using a 7 mm cutoff. However, greater maxillary advancement, combined with limiting mandibular setback to less than 7 mm, may be associated with a lower risk of developing OSA.

In vitro cytotoxicity evaluation of an experimental orthodontic adhesive containing gold nanoparticles

Tue, 10 Jun 2025 00:00:00 +0700

Objective: This study aimed to evaluate and compare the in vitro cytotoxicity of an experimental orthodontic adhesive containing 0.5% wt gold nanoparticles (AuNPs) with a conventional light-cured adhesive (Transbond XT) on human gingival fibroblast (HGF) cells using the MTT assay.

Materials and Methods: Both adhesives, comprising the AuNPs group and the Transbond group, were prepared and incubated in Dulbecco’s Modified Eagle Medium (DMEM) under the same conditions with 20% concentration for 1, 7, 14, and 30 days. After each incubation, the whole medium was extracted for analysis, and the fresh medium was replenished at the same amount. Extracts were tested at concentrations of 20%, 2%, 0.2%, and 0.02%. HGF cells were seeded in 96-well plates 24 hours before cell exposure at each incubation and performing MTT assays. Cell viability was measured spectrophotometrically and analyzed using independent sample t-tests (p<0.05).

Results: At a 20% concentration, the AuNPs group exhibited significantly lower cell viability than the Transbond group across all time points, with severe cytotoxicity observed on Days 1 and 7, moderate on Day 14, and mild on Day 30. In contrast, the Transbond group consistently showed mild cytotoxicity. Both groups showed no cytotoxicity at lower concentrations (2%, 0.2%, 0.02%). Interestingly, at 2% and 0.2% concentrations, the AuNPs group had significantly higher cell viability than the Transbond group in most periods. A general trend of decreasing cytotoxicity over time was observed for both adhesives.

Conclusions: AuNPs adhesive showed higher cytotoxicity than the conventional adhesive at undiluted extract (20%) and both materials were non-cytotoxic at lower concentrations. These findings highlight the importance of concentration and aging in cytotoxicity outcomes and suggest that AuNPs adhesive may be biocompatible under clinical conditions. Further, in vivo studies are necessary to confirm the safety of AuNPs adhesive.

Effect of restorative factors on the periapical status of well-obturated endodontically treated teeth: A retrospective cohort study

Nattheera Poomchart, Danuchit Banomyong, Sittichoke Osiri, Kallaya Yanpiset — Thu, 19 Jun 2025 00:00:00 +0700

Objectives: This retrospective cohort study evaluated the effect of restorative factors on the periapical status of well-obturated endodontically treated teeth.

Materials and Methods: The clinical/radiographic data of restorative factors were gathered from patients receiving non-surgical root canal treatment at the Faculty of Dentistry/Mahidol University, Thailand, from October 2017 to December 2020; only well-obturated endodontically treated teeth were included. Coronal restoration quality, type of restoration, definitive restoration status, defective restorations during follow-up, waiting period for the definitive restoration, post placement, and other factors associated with post-retained restorations were collected. From the clinical/radiographic assessments, endodontic outcomes were evaluated as success (healed) or failure (healing/disease) rate. Multivariable modified Poisson regression analyses were conducted to identify significant risk factors to the outcome.

Results: The study analyzed 405 well-obturated endodontically treated teeth from 319 patients, 9-83 years old. At the 29.9 + 13.9-month recall, the overall success rate (healed) was 84.4%. The restorative factors that significantly decreased the success rate were (1) inadequate/unsealed coronal restoration, (2) temporary (e.g. Cavit or IRM) restoration, (3) absence of a definitive restoration, and (4) >6-month waiting period for definitive indirect restoration. For teeth with post-retained restorations, <4-mm remaining root filling and misdirected post-space preparation significantly reduced the success rate.

Conclusions: The success rate of well-obturated endodontic treatment was 84.4%. The adequate/sealed, definitive coronal restoration and placing an indirect restoration within 6 months improved the success rate. Moreover, >4-mm remaining root filling and appropriate post-space preparation significantly increased the success rate.