A non-invasive method for the assessment of gingival thickness in the aesthetic zone and the concept of the gingival geometric ratio in an Asian population.

The aim of this study was to investigate the gingival thickness and biologic width in the aesthetic zone (maxillary central and lateral incisors) in an Asian population using cone beam computed tomography (CBCT) as a non-invasive measurement method, prior to immediate implant placement. The gingival geometric ratio is introduced as a new parameter for assessing soft tissue stability and hence predicting the aesthetic outcome. The gingival thickness, biologic width category (normal, high, and low crest), and gingival geometric ratio (shape and configuration of the gingival tissues) were assessed for 171 central and 175 lateral incisors on high-resolution CBCT images. Thick gingivae were found in 93.6% of the central incisors and 64% of the lateral incisors (P < 0.001). The difference in thickness between the central and lateral incisors was statistically significant (P < 0.001). Regarding the biologic width of the facial gingival tissue, the majority of central (64.8%) and lateral (64.3%) incisors were categorized as low crest (>3 mm). The study found that most of the gingivae of the maxillary central incisors were thick, while thin gingivae were more prevalent in the lateral incisors. Therefore, an individual patient may have different gingival thickness types, and 'one individual, one gingival biotype' may not be true. Furthermore, the majority of the facial gingival tissues of the maxillary incisors were found to be low crest.

Segmental mandibular advancement for moderate-to-severe obstructive sleep apnoea: a pilot study.

Segmental mandibular advancement (SMA) consists of a combination of bilateral sagittal split osteotomy, anterior subapical osteotomy with extraction of the first premolars, and genioplasty, to allow an extended advancement of the mandible for the improvement of tongue base obstruction in moderate-to-severe obstructive sleep apnoea (OSA) and to minimize any unfavourable aesthetic change due to the large jaw advancement. The aim of this pilot study was to evaluate the surgical outcomes and complications following SMA in OSA patients. Twelve patients (nine male, three female) underwent SMA as part or whole of their skeletal advancement procedure for OSA. The apnoea-hypopnoea index (AHI) improved from a mean± standard deviation 42.4 ± 22.0/hour preoperatively to 9.0 ± 17.4/hour at 1 year postoperative. Surgical success (50% reduction in AHI) was achieved in 11 of the 12 patients (91.7%) at 1 year postoperative, while seven patients (58.3%) attained surgical cure (AHI<5/hour). The lowest oxygen saturation (LSAT) increased from a mean 73.3% preoperatively to 78.7% at 1 year postoperative. The airway volume increased from a mean 2.4 ± 1.7 cm3 at baseline to 6.7 ± 3.5 cm3 at 1 year postoperative (P < 0.001). No major complication occurred. This pilot study showed that SMA appears to be safe and effective as part or whole of the skeletal advancement surgery for moderate-to-severe OSA.

Orofacial Mycoses in Coronavirus Disease-2019 (COVID-19): A Systematic Review.

OBJECTIVES: Studies reviewing orofacial mycoses in coronavirus disease-2019 (COVID-19) caused by severe acute respiratory syndrome 2 (SARS-CoV-2) infection are sparse. Here we review the major oral and maxillofacial mycoses of COVID-19, the associated comorbidities, and the probable precipitating factors. METHODS: English-language manuscripts published between March 2020 and October 2021 were searched using PubMed, OVID, SCOPUS, and Web of Science databases, using appropriate keywords. RESULTS: We identified 30 articles across 14 countries, which met the inclusion criteria of PRISMA guidelines. These yielded a total of 292 patients with laboratory-confirmed COVID-19, 51.4% (n = 150) of whom presented with oral and maxillofacial fungal infections, mainly comprising candidosis, mucormycosis, and aspergillosis. Candida infections were the most prevalent, present in 64% (n = 96), followed by mucormycosis, and only a single case of aspergillosis was noted. Oral and maxillofacial mycoses were predominantly seen in those with comorbidities, especially in those with diabetes (52.4%). Oral mucormycosis was noted in 8.6% (n = 13) and mainly manifested on the hard palate. An overall event rate of oral/maxillofacial mucormycosis manifestation in patients with COVID-19 with diabetes mellitus type 1/2 was about 94% (49/52; 95% confidence interval, 0.73%-0.89%), implying a very high association between diabetes mellitus and the latter condition. All fungal infections appeared either concurrently with COVID-19 symptoms or during the immediate recovery period. CONCLUSIONS: SARS-CoV-2 infection-related immunosuppression, steroid therapy, as well as comorbidities such as diabetic hyperglycemia appear to be the major predisposing factors for the onset of oral and maxillofacial mycoses in patients with COVID-19 across all age groups.

Le Fort I osteotomy with segmentation for the treatment of maxillary dentoalveolar protrusion: a single-centre, 10-year outcome study.

A retrospective study was conducted to evaluate the stability and complications of Le Fort I osteotomy with segmentation for the treatment of bimaxillary dentoalveolar protrusion. A total of 120 consecutive patients who had undergone orthognathic surgery between 2008 and 2017 at a single centre were recruited. Lateral cephalometric radiographs were taken before surgery, within 6 weeks after surgery, and at 2 years after surgery. U1-SN and U1-PP underwent mean uprighting of 8.7° and 9.6°, respectively, and mean relapse of 2.1° and 2.6°, respectively (both P < 0.05). The only significant risk factor for relapse was the use of intermaxillary fixation (risk ratio (RR) 1.2, P = 0.01). The most common complication was wound dehiscence (41.7%), which was a significant risk factor for wound infection (RR 3.3, P < 0.01) and fixation hardware exposure (RR 3.7, P < 0.01). Other common complications were gingival recession (40.8%), periodontal bone loss (40%), and blood loss requiring transfusion (26.7%), the latter of which was associated with the preoperative diagnosis of vertical maxillary excess (RR 2.4, P = 0.01). Some degree of relapse occurred in more than 90% of the patients by 2 years after surgery. The procedure is not without risks and complications but may be useful in severe cases.

Timing of arthrocentesis in the management of temporomandibular disorders: an integrative review and meta-analysis.

The aim of this study was to assess the best timing to perform arthrocentesis in the management of temporomandibular disorders with regard to conservative treatment. A systematic search based on PRISMA guidelines, including a computer search with specific keywords, reference list search, and manual search was performed. Relevant articles were selected after three search rounds for final review based on six predefined inclusion criteria, followed by a round of critical appraisal. Eleven publications, including eight randomized controlled trials and three prospective clinical studies, were included in the review. The studies were divided into three groups based on the timing of arthrocentesis: (1) arthrocentesis as the initial treatment; (2) early arthrocentesis; and (3) late arthrocentesis. Meta-analysis was carried out to compare the efficacy of improvement in mouth opening and pain reduction in the three groups. All three groups showed improvement in mouth opening and pain reduction, with forest plots suggesting that arthrocentesis performed within 3 months of conservative treatment might produce beneficial results. We conclude that there is a knowledge gap in the current literature regarding the preferable timing to perform arthrocentesis in the management of temporomandibular disorders, and more high-quality randomized controlled trials are required to shed light on this subject.

Mirror-image unilateral condylar hyperplasia in monozygotic twins.

Unilateral condylar hyperplasia (UCH) is an abnormal growth process that results in the development of mandibular asymmetry. The aetiopathogenesis of this entity is still unclear. Various factors including hormonal influences, intrauterine factors, trauma, infection, and genetics have been speculated to lead to the development of UCH. In genetic epidemiology, twins have been a valuable resource for investigating the genetic basis of complex traits and diseases. We present a case of mirror-image UCH in a pair of monozygotic twins, providing evidence of a possible genetic link for this mandibular growth disorder. The concordance in the monozygotic twins appears to be reflected by the precise mirror-image presentation of the congenital dentofacial anomalies. Further twin studies would be useful in clarifying the contributions of genetic and environmental factors to the presence and development of UCH.

Longitudinal recovery pattern of neurosensory deficit after Le Fort I osteotomy.

The purpose of this study was to investigate the incidence and recovery pattern of neurosensory deficit (NSD) following Le Fort I osteotomy, and to identify the possible risk factors that might contribute to the complication. A prospective longitudinal observational study on the incidence of NSD was conducted on patients who received Le Fort I osteotomy. Subjective and objective standardized neurosensory assessments were performed preoperatively as the baseline, and postoperatively at 2 weeks, 6 weeks, 3 months, 6 months, 12 months, and 24 months. Possible risk factors for NSD including patient age and sex, surgeon experience, and Le Fort I osteotomy with or without multi-segmentation were analysed. Sixty-six patients (43 female, 23 male) with 132 sides of Le Fort I osteotomy were recruited. The incidence of NSD at 2 weeks, 6 weeks, 3 months, 6 months, 12 months, and 24 months was 81.8%, 59.8%, 39.4%, 19.7%, 7.6%, and 3.2%, respectively. Subjective severity of NSD improved with time. Older age was found to be a risk factor for NSD in the early postoperative period, but there was no difference in the long-term. Patient sex, surgeon experience, and the need for multi-segmentation were not found to be related to the incidence of NSD after Le Fort I osteotomy.

Is there a difference between the thicknesses of the rami in mandibular asymmetry?

The purpose of this retrospective study was to investigate whether the thicknesses of the two rami differ in patients with mandibular asymmetry. Preoperative cone beam computed tomography scans of 78 patients with mandibular asymmetry were assessed for ramus thickness, mandibular length, and mandibular shift. The results showed that the ramus was thinner on the longer side than on the shorter side in 85.9% of the patients. On average, the longer side of the mandible was 2.74mm longer (range 0.07-9.90mm, standard deviation 1.92mm) and 0.55mm thinner (range -0.61 to 2.02mm, standard deviation 0.59mm) than the shorter side (both P<0.001). This study indicates a trend in the discrepancy in ramus thickness between the longer and shorter side of about 8% of the mean thickness of the ramus. Regression analysis showed that for every 1-mm increase in the length of the mandible, the thickness of the superior aspect of the ramus was reduced by 0.041 mm (P=0.009) and the anterior aspect by 0.125 mm (P=0.001). Age and sex did not have a significant influence on the thickness of the mandible. It is concluded that the longer side of the mandible tends to be thinner at the ramus than the shorter side in patients with mandibular asymmetry. The implication of this finding could be important in relation to the sagittal split ramus osteotomy.

Surgical morbidities of sagittal split ramus osteotomy versus intraoral vertical ramus osteotomy for the correction of mandibular prognathism: a randomized clinical trial.

The sagittal split ramus osteotomy (SSRO) and intraoral vertical ramus osteotomy (IVRO) are two common orthognathic procedures for the treatment of mandibular prognathism. This randomized clinical trial compared the surgical morbidities between SSRO and IVRO for patients with mandibular prognathism over the first 2 years postoperative. Ninety-eight patients (40 male, 58 female) with a mean age of 24.4±3.5 years underwent bilateral SSRO (98 sides) or IVRO (98 sides) as part or all of their orthognathic surgery. IVRO presented less short-term and long-term surgical morbidity in general. The SSRO group had a greater incidence of inferior alveolar nerve deficit at all follow-up time points (P< 0.01). There was more TMJ pain at 6 weeks (P= 0.047) and 3 months (P= 0.001) postoperative in the SSRO group. The SSRO group also presented more minor complications, which were related to titanium plate exposure and infection. There were no major complications for either technique in this study. Despite the need for intermaxillary fixation, IVRO appears to be associated with less surgical morbidity than SSRO when performed as a mandibular setback procedure to treat mandibular prognathism.

Bone regeneration at the distal aspect of the adjacent second molar after lower third molar coronectomy: a long-term analysis.

A residual bone defect at the distal aspect of the adjacent second molar may occur after total removal of the lower third molar. Lower third molar coronectomy has been proved to be a safe alternative to total removal, but the extent of bone regeneration at the adjacent tooth after coronectomy is not well reported. The aim of this prospective study was to investigate the long-term bone regeneration at the distal aspect of the adjacent second molar after lower third molar coronectomy. Preoperative and postoperative cone beam computed tomography scans were measured to assess bone regeneration at the distobuccal (DB), mid-distal (MD), and distolingual (DL) aspects of the lower second molar. Forty-eight coronectomies in 37 patients (23 female) with a mean±standard deviation age of 29.1±7.2 years were assessed. The mean follow-up was 93.2±8.7 months. The mean bone level increase at DB, MD, and DL aspects was 3.2±1.6mm, 3.5±1.5mm, and 3.2±1.6mm, respectively; the bone levels were significantly higher than the preoperative measurements (P<0.001). Age and impaction patterns were not factors affecting bone regeneration. Based on this study, it appears that coronectomy of the lower third molar brings favourable bone regeneration at the distal aspect of the adjacent second molar.