The assessment of halitosis with a new screening tool in medication-related osteonecrosis of the jaw.

OBJECTIVES: This study aimed to identify the levels of halitosis in patients with Medication-related osteonecrosis of the jaw (MRONJ) and osteoporosis and to suggest a new MRONJ screening method using halitosis measurement. MATERIALS AND METHODS: From October 2019 to April 2023, participants aged 19 years or older without periodontal disease were selected. Seventy-five participants, 25 in each group, were divided into an MRONJ group, an osteoporosis group without MRONJ, and a control group without osteoporosis and not taking osteoporosis drugs or antibiotics. Each participant underwent halitosis assessment twice using an exhaled breath analyzer to measure halitosis twice by blowing a straw for 1 min. Measured concentrations of hydrogen, hydrogen sulfide, and methyl mercaptan were compared between groups. RESULTS: Data from 22 patients in the MRONJ group, 25 in the osteoporosis group, and 25 in the control group were analyzed. The concentrations of hydrogen sulfide and methyl mercaptan were significantly higher in the MRONJ group than in the other groups, but the concentrations of hydrogen did not differ between the groups. When comparing the concentrations of hydrogen sulfide and methyl mercaptan in osteoporosis patients and solid cancer patients in the MRONJ group, there was a significant difference in hydrogen sulfide concentration, but there was no significant difference in methyl mercaptan. CONCLUSIONS: Quantifying the level of halitosis can be used to screen for MRONJ in patients taking bisphosphonates, such as patients with osteoporosis, prostate cancer, and breast cancer. CLINICAL RELEVANCE: MRONJ is accompanied by bad breath, and the concentrations of hydrogen sulfide and methyl mercaptan are associated with MRONJ.

Effects of the Mandibular Functional Units and Soft Tissue on Facial Asymmetry.

Mandibular asymmetry has a variety of patterns because they are affected the position and the shape of mandible in addition to the overlying soft tissue. This study aimed to assess the factor in mandibular asymmetry, focusing on each mandibular functional units and the soft tissue thickness in the mandibular angle area. Forty patients who were diagnosed with facial asymmetry and undergone the orthognathic surgery without genioplasty were enrolled in this study. The skeletal patterns of the patients were analyzed by using cone-beam computed tomography data and 3D virtual images divided into 2 categories; the mandibular functional unit length and the soft tissue depth. All difference in bilateral mandibular functional unit lengths had a statistically significant with chin top deviation ( P <0.05). The greatest correlation was the condylar unit length compared with other functional units. The soft tissue thickness in the mandibular angle area was not statistically related to chin top deviation ( P >0.05), and the soft tissue did not change remarkably after orthognathic surgery ( P >0.05). This study suggests that the considerations of a surgical plan for treatment based on the mandibular asymmetry.

Which Skeletal Factors Can Affect Lip Canting in Facial Asymmetry?: Statistical Analysis.

Lip canting, which is a noticeable factor in patients with facial asymmetry, can be influenced by the dentofacial skeleton. During orthognathic surgery, postoperative changes in facial soft tissue occur along the newly positioned hard tissue. Therefore, the evaluation of soft tissue before surgery is important. The purpose of this study was to investigate the skeletal factors that can affect lip canting by statistically comparing 2 facial horizontal planes using a three-dimensional reconstruction model. The findings of the present study showed a statistical correlation between lip canting and 3 skeletal factors: menton deviation, maxillary canting, and ramal length differences. Furthermore, a statistical correlation was identified between the Frankfort Horizontal plane and the intercanthal plane compared with the lip canting line. This result suggests that the intercanthal plane could be a standard horizontal plane in three-dimensional reconstruction model analysis.

Predictors of Blood Loss During Orthognathic Surgery and the Need for Pre-Deposit Autologous Blood Donation.

ABSTRACT: The aim of this study was to identify the clinicolaboratory predictors of relative blood loss (RBL) during orthognathic surgery and determine the need for predeposit autologous blood donation (PABD) for the surgery. Using a retrospective study design, 297 patients who underwent bimaxillary orthognathic surgery between 2016 and 2020 were enrolled. To investigate patient-specific risk factors, we calculated the allowable blood loss (ABL) for each patient and RBL as the ratio of estimated intraoperative blood loss (EiBL) to ABL. The correlations between the clinico-laboratory variables and EiBL and RBL were analyzed using stepwise multivariate regression analysis, and independent t test and one-way ANOVA were performed.There was no significant difference in transfusion rate between the PABD group (N = 202/279) and non-PABD group (N = 77/279) ( P   =  0.052). Sex ( P   <  0.001), body mass index class ( P   =  0.001), operative time ( P  < 0.001), and baseline hematocrit ( P  < 0.001) were significant predictors of EIBL and RBL. EIBL exceeded ABL in only 2 patients. The significant factors of RBL in orthognathic surgery were hematocrit, body mass index, and operative time. Clinicians should be more careful about bleeding in patients with low baseline hematocrit level or high body mass index, or those expected to undergo prolonged surgeries owing to a complicated surgical plan. The need for PABD before orthognathic surgery is low.

Three-Dimensional Analysis of Transverse Width of Hard Tissue and Soft Tissue After Mandibular Setback Surgery Using Intraoral Vertical Ramus Osteotomy: A Retrospective Study.

PURPOSE: Some clinicians are concerned that if an intraoral vertical ramus osteotomy (IVRO) is used to position the mandible posteriorly, the proximal segments should be positioned laterally to the distal segment, which could increase the transverse mandibular width, leading to esthetically unfavorable results. This study investigated short- and long-term postoperative transverse mandibular width changes in the soft and hard tissue after IVRO for mandibular prognathism. MATERIALS AND METHODS: The study comprised 44 patients who were treated with mandibular setback surgery using an IVRO. They were categorized into either the facial symmetry group or facial asymmetry group based on their preoperative levels of chin top deviation. Three-dimensional cone-beam computed tomography images were obtained at the preoperative, 1-month postoperative, and 12-month postoperative stages, designated as T1, T2, and T3, respectively. We set hard tissue width 1 (HW1) and hard tissue width 2 (HW2) as the sum of the distance at the bilateral ends of the angle and ramus, respectively, and set soft tissue width 1 (SW1) and soft tissue width 2 (SW2) as the sum of the distance at the bilateral ends of the soft tissue angle and ramus, respectively. RESULTS: Compared with the value at T1, the HW1 value increased by 8.16% (P < .05) and HW2 increased by 4.39% (P > .05) at T2; HW1 increased by 4.35% (P < .05) and HW2 increased by 2.95% (P > .05) at T3. Compared with the value at T1, the SW1 value increased by 2.49% and SW2 increased by 2.50% at T2; however, SW1 decreased by 0.85% and SW2 increased by 0.37% at T3. The soft tissue variations between T1 and T2, as well as between T2 and T3, were statistically significant. However, no significant difference was found between T1 and T3 (P > .05). No difference between the facially symmetrical and asymmetrical groups was found over time for soft and hard tissues (P > .05). CONCLUSIONS: Notably, IVRO does not seem to impact the transverse facial profile and enables reliable prediction of the esthetic results of surgery.

Intraoral Premaxillary Distraction in a Patient With Maxillary Retrognathic Cleft Lip and Palate: A Case Report.

Patients with cleft lip and palate sometimes have a retruded maxilla. Here, we describe the case of a young man in whom crowding of the maxillary teeth and an anteroposterior discrepancy of the maxilla were resolved by premaxillary distraction osteogenesis (DO) using 3 individual intraoral distractors. Our experience in this patient confirms that premaxillary DO with 3 intraoral distractors and preoperative simulation can achieve stable maxillary advancement and arch expansion without impairing velopharyngeal incompetence.

Treatment of Medication-Related Osteonecrosis of the Jaw Around the Dental Implant With a Once-Weekly Teriparatide: A Case Report and Literature Review.

Managing medication-related osteonecrosis of the jaw (MRONJ) around a dental implant can be difficult. Although conservative treatment of MRONJ is recommended as the first-line form of management, many patients exhibit no improvement. The human recombinant parathyroid hormone teriparatide has recently been introduced for the management of MRONJ. Teriparatide is effective in the treatment of postmenopausal osteoporosis and is the only US Food and Drug Administration-approved anabolic agent that directly affects osteoblast function and contributes to bone remodeling. Herein we describe a case of MRONJ in an 85-year-old woman who was successfully treated with teriparatide. Teriparatide was administered once per week without any surgical interventions such as a sequestrectomy. Compared with most recently reported cases involving daily treatment with teriparatide, once-weekly administration of teriparatide may minimize side effects and patient discomfort. Once-weekly teriparatide application without sequestrectomy may be effective in the management of MRONJ around a dental implant.

Preparation of Fe-Carbon Nanocomposite by Pyrolyzing Fe Adsorbed 1,8-Diamminonaphthalene for the Adsorption of Cr (VI).

In the present work, a facile method for the preparation of nanocomposite adsorbents composed of carbon and iron compounds was demonstrated. The adsorbents were produced by pyrolyzing an iron-coordinated 1,8-diaminonaphthalene at various temperatures under an N2 stream (FeDN X, where X represents the pyrolysis temperatures 600, 700, and 800 °C). Prepared FeDNs were employed as adsorbents for the removal of Cr (VI). The Cr (VI)-adsorption behavior of FeDNs were well-fitted to a Langmuir isotherm model. Among the samples prepared, FeDN 700 showed the best performance for the removal of Cr (VI). In particular, the maximum adsorption capacity of FeDN 700 was evaluated to be 34.81 mg/g. A variety of characterizations were carried out to elucidate the relationship between physical properties of adsorbents and their adsorption behaviors.

Safety and Stability of Postponed Maxillomandibular Fixation After Intraoral Vertical Ramus Osteotomy.

The purpose of this study was to evaluate the postoperative safety and long-term stability of bimaxillary orthognathic patients with postponed maxillomandibular fixation (MMF) after intraoral vertical ramus osteotomy.A total of 61 patients (21 male and 40 female patients; average age [SD], 21.7 [4.7]) were enrolled. All patients underwent maxillary LeFort I osteotomy and bilateral intraoral vertical ramus osteotomy for mandibular prognathism. During the hospital stay, postoperative airway compromise was observed and patients underwent MMF with wire at the second postoperative day. Stability was evaluated by measuring the position at each period: preoperative (T0), 2-day postoperative (T1), and 1-year postoperative.Postoperative dyspnea and respiratory distress were absent in all patients. The mean number of refixations in physiotherapy was 0.62 (0.86) and the mean duration of physiotherapy was 11.6 (5.5) days. The mean amount of mandibular setback was 12.56 (5.76) mm and menton movement 0.98 (2.36) mm superiorly (T1). The mean mandibular relapse at Pog was 0.87 (1.96) mm anteriorly. Menton showed 1.11 (1.41) mm superiorly movement 1-year postoperatively (T2).Despite its many advantages, intraoral vertical ramus osteotomy requires a period of MMF which can lead to early discomfort and airway-related emergency. In this study, the physiotherapy procedure and postoperative long-term stability in the postponed MMF group were not different from those of an immediate MMF group studied previously. It therefore constitutes a viable option for oral breathers and other compromised patients.

Recovery pattern of mandibular movement by active physical therapy after bilateral transoral vertical ramus osteotomy.

PURPOSE: The purpose of the present study was to evaluate the effect of an active physical therapy (PT) protocol after transoral vertical ramus osteotomy and to investigate the rehabilitation patterns of mandibular movement. MATERIALS AND METHODS: The study included 187 patients diagnosed with mandibular prognathism with or without facial asymmetry who had undergone bilateral transoral vertical ramus osteotomy from 2001 to 2009. The subjects were evaluated preoperatively and 1, 3, 6, 12, 18, and 24 months postoperatively in terms of the periods of PT and range of mandibular movement. The data were analyzed using 1-way analysis of variance (significance level, P < .05). RESULTS: Of the 187 patients, 108 (57.8%) did not receive repeat intermaxillary fixation (IMF) during the PT period, 58 (31.0%) received it once, 15 (8.0%) twice, and 6 patients more than 3 times. The average PT period for all was 10.9 days (range 5 to 45). The mean maximal mouth opening was 50.7 mm before surgery, decreasing to 33.9 mm at 1 month postoperatively. This was followed by an increase to 46.3 mm at 6 months postoperatively, with the maximal mouth opening thereafter showing 93.9% to 95.7% recovery compared with the preoperative state. CONCLUSIONS: About 88% of the patients with transoral vertical ramus osteotomy responded well to the reduced IMF duration and active PT protocols, receiving repeat IMF less than twice. It required about 6 months to recover 90% of the preoperative maximal mouth opening and 12 months to recover near preoperative levels statistically. The benefits of reduced IMF duration and the PT protocols seem to promote rehabilitation of the masticatory muscles and prevention of mandibular hypomobility.

A 5-year retrospective cohort study of denosumab induced medication related osteonecrosis of the jaw in osteoporosis patients.

Denosumab has been suggested as a first-line therapy for osteoporotic patients. However, a standardized protocol for the prevention of denosumab induced medication-related osteonecrosis of the jaw (MRONJ) has not yet been established. The purpose of this study was to report denosumab induced MRONJ cases, and investigate the factors affecting the occurrence of MRONJ in patients who underwent denosumab and invasive dental treatment (especially tooth extraction) between October 2016 and March 2020. Four of the 98 patients developed MRONJ before and after tooth extraction. The participants were divided into two groups: receiving only denosumab (n = 51) and receiving bisphosphonate as first treatment and denosumab as second treatment (n = 47). There was no significant difference between groups in the occurrence of MRONJ and factors affecting MRONJ. Two out of 4 patients developed MRONJ regardless of invasive treatment after denosumab administration and proceeded with extraction; one patient developed MRONJ after denosumab administration and extraction. The other patient underwent a tooth extraction without osteoporosis treatment, and non-identified MRONJ developed after denosumab administration. MRONJ cases reported in this study show that MRONJ can develop as chronic inflammation without invasive dental treatment; therefore, implementing preventive dental treatment before initiating denosumab treatment is necessary to reduce the occurrence of MRONJ.

Activation of Wnt signalling reduces the population of cancer stem cells in ameloblastoma.

OBJECTIVES: The treatment of ameloblastoma, an odontogenic epithelial tumour destroying jawbone, mainly depends on radical destructive resections. Other therapeutic options are limited by the characteristics of ameloblastoma, such as high recurrence rates and resistance to radiation and chemotherapy, which implies possible existence of cancer stem cells (CSCs) in ameloblastoma. Here, we identified a putative CSC population in immortalized and primary human ameloblastoma cells and examined possible therapeutic reagents to reduce the CSC population. METHODS: We investigated subpopulations of AM-1 cell line and human ameloblastoma cells using immunocytochemistry and flow cytometry and the effects of Wnt signalling activators on the 2- and 3-dimensional cultured ameloblastoma cells using molecular biological analyses. RESULT: Among heterogenous ameloblastoma cells, small-sized and round-shaped cells were found to be proliferative and expressed a marker of dental epithelial stem cells, SRY-box 2 (Sox2). Exogenous activation of Wnt signalling using glycogen synthase kinase 3ß inhibitors, lithium chloride (LiCl) and valproic acid (VPA), increased the cell size and decreased proliferation of cells and expression of Sox2 in 2 dimensionally cultured AM-1 and human primary ameloblastoma cells. Furthermore, the growth of 3 dimensionally cultured AM-1 cells as suspended or embedded in gel was suppressed by treatment with Wnt signalling activators, VPA and CHIR99021, or antibodies to sclerostin, an antagonist of Wnt signalling. CONCLUSION: We suggest that Wnt signalling activators are potential drug candidates to suppress CSCs in ameloblastoma.

Factors Affecting Total Treatment Time in Patients Treated with Orthognathic Surgery Using the Surgery-First Approach: Multivariable Analysis Using 3D CT and Scanned Dental Casts.

The aim of this study was to analyze factors affecting treatment times in patients treated with the surgery-first approach (SFA) for orthognathic surgery. Fifty skeletal class III patients who had undergone SFA bimaxillary orthognathic surgery were enrolled. Retrospective chart reviews and analysis of 3D CT and digitally scanned casts were conducted to assess the total treatment time. Statistical analysis was then performed with multiple study variables. Longer treatment times were required for patients with severe maxillary or mandibular teeth crowding (p = 0.009), a preoperative anterior open bite (p = 0.021), and those undergoing orthodontic extractions (p < 0.001). Longer treatment times were also observed when setting surgical occlusion in the postoperative anterior open bite (p = 0.007) and in patients with postoperative dental midline deviation (p < 0.001) and transverse maxillary deficiencies (p = 0.035). Treatment times were shorter when a class I molar key was formed in the surgical occlusion setup (p = 0.002) and in bilateral anterior and posterior occlusion with a minimum of four contact points (p < 0.001). The number of contact points, the number of extracted teeth, and postoperative midline deviation were identified as significant predictors. These results suggest that proper patient selection is important when considering SFA and that surgeons can reduce total treatment time with an appropriate surgical occlusion setup.

Three-dimensional evaluation of the correlation between lip canting and craniofacial planes.

OBJECTIVE: This study aimed to analyze the correlation of horizontal and sagittal planes used in two-dimensional diagnosis with lip canting by using threedimensional (3D) analysis. METHODS: Fifty-two patients (25 men, 27 women; average age: 24 years) undergoing treatment for dentofacial deformity were enrolled. Computed tomography images were acquired, and digital imaging and communication in medicine files were reconstructed into a 3D virtual model wherein horizontal and sagittal craniofacial planes were measured. Subsequently, the correlations of lip canting with these horizontal and sagittal planes were investigated. RESULTS: The mandibular symmetry plane, the occlusal plane, Camper's plane, the mandibular plane, Broadbent's plane, and the nasal axis plane were correlated with the amount of lip canting (Pearson's correlation coefficients: 0.761, 0.648, 0.556, 0.526, 0.438, and 0.406, respectively). Planes associated with the lower part of the face showed the strongest correlations; the strength of the correlations decreased in the midfacial and cranial regions. None of the planes showed statistically significant differences between patients with clinical lip canting (> 3°) and those without prominent lip canting. CONCLUSIONS: The findings of this study suggest that lip canting is strongly correlated with the mandibular symmetry plane, which includes menton deviation. This finding may have clinical implications with regard to the treatment of patients requiring correction of lip canting. Further studies are necessary for evaluating changes in lip canting after orthognathic surgery.

Accuracy of modified CAD/CAM generated wafer for orthognathic surgery.

The aim of this study was to investigate an accuracy of modified CAD/CAM generated wafers for orthognathic surgery. A total of 20 patients who had undergone bimaxillary orthognathic surgery were included and divided into two groups: A conventional CAD/CAM generated intermediate wafer and a modified CAD/CAM generated intermediate wafer. A series of CT images were taken to compare the virtual simulations with the actual postoperative outcomes(1 month after surgery). In conventional group, the mean difference of maxillary position between virtual simulation models and postoperative results was 0.78mm and overall average error within 1mm was observed in 66.4% of the repositioned maxilla. In modified group, the mean difference was 0.77mm and overall average error within 1mm was observed in 68.3%. There were no significant statistic differences between two groups in maxillary position. This study suggests that the CAD/CAM generated wafer provides excellent accuracy. The modified CAD/CAM wafer was only comparable to conventional design in accuracy and it cannot guarantee the superior precision. However, the modified design could be beneficial in cases with unstable condylar position or for inexperienced surgeons.

Volume change pattern of decompression of mandibular odontogenic keratocyst.

OBJECTIVES: This study was aimed to analyze the reducing pattern of decompression on mandibular odontogenic keratocyst and to determine the proper time for secondary enucleation. MATERIALS AND METHODS: Seventeen patients with OKC of the mandible were treated by decompression. Forty-five series of CT data were taken during decompression and measured by using InVivo software (Anatomage, San Jose, Calif) and were analyzed. RESULTS: The expected relative volume during decompression is calculated using the following formula: V(t) = V initial × exp.(at + 1/2bt 2) (t = duration after decompression (day)). There was no significant directional indicator in the rate of reduction between buccolingual and mesiodistal widths. CONCLUSION: The volume reduction rate gradually decreased, and 270 days were required for 50% volume reduction following decompression of OKC. The surgeon should be aware of this pattern to determine the timing for definitive enucleation. CLINICAL RELEVANCE: The volume reduction rate and pattern of decompression of the OKC can be predicted and clinicians should be considered when treating OKC via decompression.

Changes in position of the hyoid bone and volume of the pharyngeal airway after mandibular setback: three-dimensional analysis.

Important aspects of orthognathic surgery are the effects of skeletal movement and changes in the position of the hyoid bone, tongue, soft palate, and dimensions of the pharyngeal airway. Our aims were to evaluate the 3-dimensional changes in the pharyngeal airway and in the position of the hyoid bone after mandibular setback in 30 patients who were diagnosed with mandibular prognathism and were treated by intraoral vertical ramus osteotomy (IVRO). Three-dimensional cone-beam computed tomographic (CT) images were obtained preoperatively, one month postoperatively, and one year postoperatively. The total pharyngeal volume decreased between the preoperative state and one month and one year afterwards. The hyoid bone had moved 2.0mm posteriorly and 3.15mm superiorly by one month postoperatively. The position of the hyoid bone was affected by changes in posterior and superior movement of the B point at one month (r=0.44, p=0.015 and R=0.63, p=0.000, respectively) and also by superior movement of the B point at one year (r=0.57, p=-0.001). There was an advantageous relation between posterior positional changes in the B point (mandibular setback), and volumetric changes in the hypopharyngeal and total pharyngeal airway, so maxillofacial surgeons should consider the reduction in airway when planning excessive mandibular setback.

Anatomical study of the location of the antilingula, lingula, and mandibular foramen for vertical ramus osteotomy.

BACKGROUND: The purpose of this study was to identify the location of the antilingula, lingula, and mandibular foramen in Korean cadavers and to promote safe and accurate surgery without damage to the inferior alveolar neurovascular bundle (IANB) when performing a vertical ramus osteotomy (VRO). METHODS: This study was conducted on the dried mandibles of 20 adult cadavers. Digital calipers were used to measure the distances from the anatomical reference points (antilingula, lingula, and mandibular foramen). RESULT: The antilingula was located at the anterior 44% and superior 31% in the ramus. The lingula was located at the anterior 55% and superior 30% in the ramus. The mandibular foramen was located at the anterior 58% and superior 46% in the ramus. Regarding the positional relationship with the antilingula, the lingula was located 0.54 mm superior and 4.19 mm posterior, and the mandibular foramen was located 6.95 mm inferior and 4.98 mm posterior. The results suggested that in order to prevent damage to the IANB, osteotomy should be performed in the posterior region of ramus at least 29% of the total horizontal length of the ramus. CONCLUSION: Using only the antilingula as a reference point is not guaranteed to IANB injury. However, it is still important as a helpful reference point for the surgeon in the surgical field.