Lateral Cephalometry Research Articles

Reliability and accuracy of Artificial intelligence-based software for cephalometric diagnosis. A diagnostic study

BackgroundArtificial intelligence (AI) is revolutionizing cephalometric diagnosis in orthodontics, streamlining the patient assessments. This study aimed to assess the reliability, accuracy, and time consumption of artificial intelligence (AI)-based software compared to a conventional digital cephalometric analysis method on 2D lateral cephalogram.Methods408 lateral cephalometries were analysed using three methods: manual landmark localization, automatic localization, and semi-automatic localization with AI-based software. On each lateral cephalogram, 15 variables were selected, including skeletal, dental, and soft tissue measurements. The difference between the two AI-based software options (automatic and semi-automatic) was compared with the conventional digital technique. The time required to produce a complete cephalometric tracing was evaluated for each method using Student’s t-test.ResultsStatistically significant differences in the accuracy of landmark positioning were detected among the three different techniques (p < 0,01). However, it is noteworthy that almost all of these differences were not clinically significant. There was a small difference in accuracy between the semi-automatic AI-based option and conventional digital techniques. Regarding the time used for each technique, the automatic version was the fastest, followed by the semi-automatic option and the conventional digital technique. (p < 0,000).ConclusionsThe study showed a statistical difference in accuracy between the conventional digital technique and two AI-based software alternatives, but these differences were not clinically significant except for specific measurements. The semi-automatic option was more accurate than the automatic one and faster than conventional tracing. Further research is needed to confirm AI’s accuracy in cephalometric tracing.

Evaluation of the diagnostic ability of the Fränkel manoeuvre to detect the contributing jaw in angle class II division 1 malocclusion

BackgroundA correct diagnosis of patients with an Angle Class II malocclusion is needed to guide treatment decisions toward the contributing jaw and to achieve better treatment outcomes. The aim of the study is to evaluate the diagnostic potential of the Fränkel manoeuvre (FM) for detecting the components determining sagittal discrepancy in Angle Class II division 1.Materials and methodsAnonymous questionnaires containing photographs were distributed totwo groups: general practitioner (GP) dentists and orthodontists. The level of the patient’s profile aesthetics before (T0) and after (T1) the manoeuvre was determined using a 100 mm visual analog scale, and the ‘profile improvement’ score was defined as T1 minus T0. The diagnostic ability of the FM was calculated by comparison with lateral cephalometry as a reference standard using receiver operating characteristic (ROC) curve analysis.ResultsA total of 102 respondents participated in the survey; 40 were orthodontists, and 62 were GP dentists. According to the post-FM images, the “profile improvement” score (T1-T0) was significantly greater in patients with mandibular retrusion than in those with maxillary protrusion (p < 0.05). The predictive power of FM, coinciding with the area under the ROC curve, was 0.62 for GPs and 0.78 for orthodontists.ConclusionsThe FM method is a useful and accurate tool for diagnosing skeletal Angle Class II malocclusion etiology (mandibular retrusion or maxillary protrusion), especially when used by orthodontists.

Correlation of Clivus Length and Angle with Chronological Age, Gender, Sagittal Growth Pattern of the Jaws, and Skeletal Maturation Using Lateral Cephalometry.

Determination of remaining growth potential of patients is the most important factor in orthodontic treatment. This study aimed to assess the correlation of clivus length and angle with age, gender, sagittal growth pattern of the jaws, and skeletal maturation using lateral cephalometry. This cross-sectional study was conducted on 390 lateral cephalograms (Vatech, paX-i3D Green, South Korea) of patients aged 6 to 25 years. The patients were assigned to three groups of skeletal class I, II, III (n=130) with equal gender distribution. The clivus length and angle, Welcher angle, maxillary and mandibular effective length, sella turcica to Nasion (SN), and the angles between SN and point A (SNA), between SN and point B (SNB), and between NA and NB (ANB )were measured. Correlations of variables with age and gender, and cervical vertebral maturation stage (CVMS) were analyzed using the Pearson and Spearman's correlation tests, independent t-test, and one-way ANOVA at 0.05 level of significance. Clivus length had a significant correlation with SNA (r= 0.103, p= 0.042), SNB (r= 0.108, p= 0.033), maxillary (r= 0.547, p< 0.001) and mandibular (r= 0.589, p< 0.001) effective lengths, SN length (r= 0.586, p< 0.001), and CVMS (r= 0.697, p< 0.001). Clivus angle had a significant correlation with SNA (r= 0.105, p= 0.039), SNB (r= 0.155, p= 0.002), maxillary (r= 0.507, p< 0.001) and mandibular (r= 0.596, p= 0.001) effective lengths, SN length (r= 0.566, p< 0.001), and CVMS (r= 0.699, p< 0.001). The mean clivus length (p= 0.006) and angle (p= 0.002) were significantly higher in males, and had a significant correlation with age (r= 0.636 and r= 0.718, p< 0.001). The mean clivus length and angle were not significantly different in class I, II, III (p> 0.05). All parameters were greater in males, and increased with age (except Welcher angle). Clivus length and angle had significant correlations with position of both jaws but not with sagittal relationship.

Differences in linear and angular measurement of the lower facial third in lateral cephalometry and lateral photometry: A comparative study

BackgroundIn clinical orthodontic practice, to evaluate aesthetics in dentistry, lateral cephalometry and lateral photometry are used to measure and assess craniofacial morphology. In contrast to cephalometry, photometry has no radiation hazard and is less expensive. There has been a paradigm shift in contemporary orthodontics that now emphasizes soft tissue aesthetics, rather than depending entirely on hard tissue evaluation from lateral cephalometry. Therefore, the key question is whether lateral photometry can be a substitute for conventional cephalometry for diagnostics, prognostic analysis, and treatment planning. ObjectiveTo differentiate between lateral cephalometry and lateral photometry measurement in children with stage 2 and 3 vertebrae maturation in the Deutero Malay population. Materials and MethodsA standardized protocol was followed for all lateral cephalograms and photographs from 38 subjects who met the inclusion criteria. Three parameters focusing on the lower third craniofacial measurement were investigated: two linear parameters (mandibular ramus length and mandibular length) and one angular parameter (gonial angle). These parameters were measured using Webceph software. All parameters were digitized on both cephalograms and photographs and were compared using an independent sample t-test. ResultsWhen comparing the angular cephalometric and photometric variables, we found that the mandible length (Go-Me) and gonial angle (∠Go) in the cephalometry measurements had an insignificant difference compared to the photometric measurements, while the ramus length (Co-Go) in the cephalometry measurement had a significant difference compared to the photometric measurements. ConclusionAlthough we cannot rule out cephalometry as the primary record in orthodontics, lateral photometry assessment can be used as an alternative candidate for measuring mandibular body measurements and gonial angle in stage 2 and 3 cervical maturation in the Deutero Malay race.

Research on drug-induced sleep endoscopy's effect on treatment approaches for obstructive breathing while sleeping

The research aims to investigate how various medications for obstructive breaths during sleep (OBS) are affected by drug-induced sleep endoscopy (DISE).A thorough examination of the literature revealed that treatment suggestions impacted by DISE had been implemented. The percentage change for every research and collapse location was noted. The cumulative level of modifications and related 94 % confidence interval (CI) were estimated. According to the patient's age, the sample size, the DISE method, and the major diagnostic modality used prior to DISE, analysis of subgroups were conducted. These 1 246 patients (68,1 % men, 58,6 % kids, and 77,03 % with a multilevel collapse) were involved in nine trials in all. In 42,69 % of patients (CI, 32,74 to 52,53), the course of treatment altered. The variation in rates increased following awake endoscopy (61,1 % opposed to 43,5 percent following clinical basic examination (CBE) and 40,1 percent opposed to Muller man oeuvre, P = 0,02), CBE, and lateral cephalometry and midazolam-based DISE procedures. Target-controlled infusion is widely used, and randomized studies that compared its efficacy with different methods of diagnosis can be used to examine its therapeutic benefits. The DISE approach can be encouraged by introducing uniform categorization systems of blockage locations.

Association of apnea-hypopnea index and lateral cephalometry pre- and post-surgery in obstructive sleep apnea patients

Background: Snoring and obstructive sleep apnea are new emerging medical entity and require early diagnosis and treatment because of their increasing implication on physical, mental, social and emotional health. Aim of this study is to assess severity of OSHAS and co-relate efficacy of various post-surgical parameter on objective and subjective improvement in patients. Methods: 43 patients having the symptoms were included in the study and followed over a period of three months and during their post operative visit their lateral cephalometric findings, ESS were recorded and compared to pre operative values to see if any association exists between them. Results: it was seen that various surgical interventions did bring about subjective and objective improvement in patients and these were statistically significant. Conclusions: OSHAS is a spectrum of disorders and has great impact on persons physical, mental and emotional well-being. Early diagnose and treatment eliminated the future risks. Surgical intervention helps improve symptoms of OSHAS and should be undertaken without delay wherever indicated.

Differences in Polysomnographic and Craniofacial Characteristics of Catathrenia Phenotypes: A Cluster Analysis.

Catathrenia is a rare sleeping disorder characterized by repetitive nocturnal groaning during prolonged expirations. Patients with catathrenia had heterogeneous polysomnographic, comorbidity, craniofacial characteristics, and responses to treatment. Identifying phenotypes of catathrenia might benefit the exploration of etiology and personalized therapy. Sixty-six patients diagnosed with catathrenia by full-night audio/video polysomnography seeking treatment with mandibular advancement devices (MAD) or continuous positive airway pressure (CPAP) were included in the cohort. Polysomnographic characteristics including sleep architecture, respiratory, groaning, and arousal events were analyzed. Three-dimensional (3D) and 2D craniofacial hard tissue and upper airway structures were evaluated with cone-beam computed tomography and lateral cephalometry. Phenotypes of catathrenia were identified by K-mean cluster analysis, and inter-group comparisons were assessed. Two distinct clusters of catathrenia were identified: cluster 1 (n=17) was characterized to have more males (71%), a longer average duration of groaning events (18.5±4.8 and 12.8±5.7s, p=0.005), and broader upper airway (volume 41,386±10,543 and 26,661±6700 mm3, p<0.001); cluster 2 (n=49) was characterized to have more females (73%), higher respiratory disturbance index (RDI) (median 1.0 [0.3, 2.0] and 5.2 [1.2, 13.3]/h, p=0.009), more respiratory effort-related arousals (RERA)(1 [1, 109] and 32 [13, 57)], p=0.005), smaller upper airway (cross-sectional area of velopharynx 512±87 and 339±84 mm2, p<0.001) and better response to treatment (41.2% and 82.6%, p=0.004). Two distinct phenotypes were identified in patients with catathrenia, primary catathrenia, and catathrenia associated with upper airway obstruction, suggesting respiratory events and upper airway structures might be related to the etiology of catathrenia, with implications for its treatment.

Classification of Childhood Obstructive Sleep Apnea based on X-ray images analysis by Quasi-conformal Geometry

Craniofacial profile is one of the anatomical causes of obstructive sleep apnea (OSA). By medical research, cephalometry provides information on patients’ skeletal structures and soft tissues. In this work, a novel approach to cephalometric analysis using quasi-conformal geometry based local deformation information was proposed for OSA classification. Our study was a retrospective analysis based on 60 case-control pairs with accessible lateral cephalometry and polysomnography (PSG) data (mean age: 8.9 ± 2.3 years). By using the quasi-conformal geometry to study the local deformation around 15 landmark points, and combining the results with three linear distances between landmark points, a total of 1218 information features were obtained per subject. A L2 norm based classification model was built. Under experiments, our proposed model achieves high testing accuracy. The accurate classification tool provides us with a reliable and accurate screening tool for childhood OSA.

Changes in smile parameters after surgical-orthodontic treatment for skeletal Class III malocclusion

Background/purposeMany patients pursue attractive smiles, and surgical-orthodontic treatment is a common method. We aimed to analyze the changes in smile parameters after surgical-orthodontic treatment in patients with skeletal Class III pattern and identify factors influencing postoperative outcomes. Materials and methodsThis retrospective study comprised 34 patients with skeletal Class III malocclusion and pure mandible prognathism who received surgical-orthodontic treatment. Hard and soft tissue parameters were assessed through lateral cephalometry, and smile esthetics were evaluated through extraoral photography. Postoperative changes in smile parameters and between-parameter correlations were analyzed. Random forest and decision tree deep learning models were used to identify factors influencing postoperative changes. ResultsSubstantial postoperative changes were observed in the buccal corridor, upper lip height, and smile index. Significant between-sex differences were noted in the upper midline and right chelion. Strong, positive correlations were found between upper lip height and upper lip ratio and between lower lip height and lower lip ratio. By contrast, strong negative correlations were observed between lower teeth exposure and smile index and between interlabial gap and smile index. The highest degrees of postoperative changes were noted in asymmetry-associated smile parameters: lower lip area, interlabial gap, smile index, buccal corridor, and arc ratio. ConclusionConsiderable changes were noted in skeletal, dental, and soft tissue parameters after surgical-orthodontic treatment. However, the changes in smile esthetics were less prominent from the frontal view. As for chin asymmetry, the most to least prominent changes were in the lower lip area, interlabial gap, smile index, buccal corridor, and arc ratio, respectively.

Evaluating anchorage loss in upper incisors during distalization of maxillary posterior teeth using clear aligners in adult patients: A prospective randomized study.

: To evaluate the effect of clear aligner treatment and differential sequence distalization of maxillary posterior teeth on anchorage loss in the upper incisors (U1s). : This study used lateral cephalometries and digital models of 12 patients treated with 33% sequential distalization (group 1, mean age: 22.9 ± 0.7 years, five males, seven females) and 12 treated with 50% sequential distalization (group 2, mean age: 25.83 ± 0.5 years, three males, nine females) acquired before and after distalization of upper second premolars (U5) and upper first molars (U6) and upper second molars (U7). The amount of distalization was determined as 2.5 mm in both the groups. Independent Samples t test was used to compare normally distributed parameters. Mann-Whitney U and Wilcoxon tests were used to compare parameters that were not normally distributed. : In both groups, the posterior teeth significantly moved by tipping distally and the U1s were displaced anteriorly. Increase in maxillary posterior transverse width (P < 0.001) and distopalatal rotation were observed in U5, U6, and U7 after distalization. It was also observed that U1 was significantly more proclined (1.82°; P < 0.001) and protruded (0.62 mm; P < 0.001), and the overjet (0.45 mm; P < 0.001) increased more in group 1 than in group 2. : After sequential distalization of maxillary posterior teeth, more anchorage loss was observed in the anterior region in group 1 than in group 2.

Occlusal Outcomes in Non-Robin Sequence Patients with Isolated Cleft Palate.

1. To assess the skeletal class occlusion and lateral cephalometry in children with isolated cleft palates (non-Robin sequence) and 2. to identify associations between these findings and pre-palatoplasty cleft palate measurements. Retrospective cohort study. North American Institutional Tertiary Paediatric Center. Our cleft database was reviewed, and patients were included if they had an isolated cleft palate without a Robin Sequence diagnosis, had a Furlow palatoplasty and had available per operative cleft palate measurements and available lateral cephalogram between 6 and 8 years old. Thirty-two patients matched to inclusion criteria. Furlow's Palatoplasty. Cleft size at palatoplasty, cephalometric measurements and skeletal occlusal classes were analysed. ANOVA was used to test the association between cephalometric measurements and occlusal classes. Results are presented as means with a 95% confidence interval. The association between cleft measurements and cephalometric parameters was tested with Spearman Correlation (rs). The skeletal occlusal outcome at 7 years old for this series of patients was: Class I: 19%; Class II: 59% and Class III: 22%. No single cleft measurement at palatoplasty was predictive of the skeletal occlusal outcome. A larger hard palate cleft was associated with a shorter antero-posterior maxilla. The skeletal occlusal class outcomes were similar to those found in a previous study in the literature. The occlusal prognosis appears to be better than in patients with Robin Sequence or with an associated cleft lip. No preoperative measurement was found to be associated with the occlusal outcome.

Predictability of the Orthodontic-Surgical Planning: A Comparative Study Between the Post-Operative Outcome and the Visual Treatment Objective

Objective:To test the validity of lateral pre-treatment and pre-surgical VTO, by comparing them with the post-treatment lateral cephalometry. Methods: A total of 26 patients affected by Class III who underwent orthognathic surgery were evaluated. For all patients, pre-treatment (T0), pre-surgical (T1) and post-treatment (T2) cephalometric tracings, pre-treatment and pre-surgical VTO were performed. Nine measurements of hard tissues were considered. A comparison was made between pre-treatment and pre-surgical cephalometric measurements, post-treatment cephalometric tracing and pre-treatment VTO, post-treatment cephalometric tracing, and pre-surgical VTO. Descriptive and inferential statistics along with Bland-Altman plot were used to analyze the agreement between the outcome and the program. Results: From the comparison between pre-treatment and pre-surgical values, a statistically significant difference was found for the SNB angle ( P = .0292), the inclination of the upper ( P = .0309) and lower incisors ( P &lt; .000) and the over-jet ( P &lt; .000). The comparison between the post-treatment cephalometry (T2) and pre-treatment VTO (T0) highlighted good agreement between over-bite and over-jet values. The comparison between the post-treatment cephalometry (T2) and pre-treatment VTO (T0) highlighted good agreement with over-jet and IMPA angle. All parameters had high dispersion and the Bland-Altman plot appeared to be scattered. Conclusion: Given the bias and the imprecisions between the orthodontic-surgical program and the outcome, the indications given by 2-dimensional VTO should be used with caution.

Exploring different methods for assessing anchorage loss during orthodontic space closure: A narrative review

ABSTRACT To ensure successful treatment and to prevent undesired tooth movements, it’s essential to manage reciprocal forces effectively. Anchorage control becomes particularly crucial in cases involving extractions, where it can help prevent unwanted tooth movement. However, during treatment, there’s a risk of anchorage loss, which can undermine the treatment objectives. Therefore, it’s imperative to monitor molar movement and assess for anchorage loss throughout treatment. Research publications were searched on search engines such as Scopus, PubMed, and Google Scholar, and articles with terms such as “anchorage management, assessment of anchorage loss, anchorage loss, space closure , en masse retraction and canine retraction” were collected. Various methods for evaluating anchorage loss are dental casts, 3-Dimensional assessment and lateral cephalogram superimposition. Dental casts works well for assessing anteroposterior anchorage loss in maxillary first molars. However, their utility in the mandibular arch is limited due to the absence of a stable reference point. Lateral cephalometry faces the challenge of superimposing bilateral structures. The recent introduction of 3D superimposition techniques offers a potential solution for assessing anchorage loss in the vertical dimension using dental casts.

Endoscopic septoplasty below the age of 17 years

BackgroundThe claim that septoplasty in children should not be done was raised in the early last century. Pediatric septoplasty is highly controversial. Some surgeons are concerned that early surgical intervention before age 17 can adversely affect the normal growth of the nose and face. On the contrary, there is evidence of significant dental, palatal, and facial abnormalities following traumatic damage to the septal cartilage. Therefore, surgical correction of the deviated nasal septum may be performed regardless of the patient’s age. The recommendation of early surgery is based on the explanation that the earlier the correction of septal deviation, the better the outcome of developing normal breath and acceptable facial growth. This study evaluates the nasal and facial bony growth after endoscopic septoplasty for patients below the age of 17 years.MethodsThis retrospective study reviewed 39 patients who underwent endoscopic septoplasty. The involved patients’ age at surgery was below 17 years old. Postoperative evaluation was done for all patients subjectively using the visual analog scale (VAS) and objectively by endoscopic nose examination. The nasal and facial bony growth were evaluated using lateral cephalometry, which was carried out for each patient when they reached the age of 17.ResultsThirty-nine patients underwent endoscopic septoplasty. The median visual analog scale for nose block and headache significantly declined after the procedure significant differences were observed between patients and controls regarding the following parameters: palatal length, anterior skull base, mid-face protrusion, and mid-face length.ConclusionEarly endoscopic septoplasty below the age of 17 is a safe procedure and does not compromise the nasal or facial growth when indicated for patients with severe persistent nose block and poor quality of life.

Comparison of Lateral Cephalometry and Cone-beam Computed Tomography Techniques for Measuring Alveolar Bone Thickness around Maxillary Incisors

Comparison of Lateral Cephalometry and Cone-beam Computed Tomography Techniques for Measuring Alveolar Bone Thickness around Maxillary Incisors

Upper airway assessment in obstructive sleep apnea patients: can computed tomography with lateral cephalometry replace drug-induced sleep endoscopy (DISE)?

ObjectiveTo evaluate the association between results from drug-induced sleep endoscopy (DISE) and computed tomography with lateral cephalometry (CTLC) of the pharynx in obstructive sleep apnea (OSA) patients, regarding the same anatomic level, in order to understand if CTLC could replace DISE in selected patients. Study designCross-sectional. SettingTertiary hospital. MethodsA total of 71 patients who attended the Sleep Medicine Consultation in the Otorhinolaryngology Department of Hospital CUF Tejo between 1.6.2019 and 30.9.2021, performed a polysomnographic sleep study and were elected to undergo DISE and CTLC of the pharynx for diagnostic purposes were selected. Obstructions at the same anatomic levels – tongue base, epiglottis and velum - were compared in both exams. ResultsPatients with reduction of epiglottis-pharynx space on CTLC had also a complete obstruction at epiglottis level on the VOTE classification of DISE (p = 0,027). Reduction of velum-pharynx space or tongue base-pharynx space were not related to complete obstruction of the velum (P = 0,623) or the tongue base (p = 0,594) found in DISE. Those with two or more space reductions had a tendency to multilevel obstruction observed in DISE (p = 0.089). ConclusionWhen evaluating the obstruction level(s) of an OSA patient, efforts should be made to perform DISE, since CTLC measures, though regarding at the same structures, don´t correlate completely with obstructions observed in DISE.

Investigating the Relationship between the Dimensions and Morphology of Sella Turcica with the Long-Face Growth Pattern and the Vertical Growth Pattern.

The sella turcica is one of the important landmarks of lateral cephalometry, which is used in orthodontics for the diagnosis, treatment plan, and evaluation of skeletal development and maturity. The purpose of the present study is to investigate the relationship between the dimensions and morphology of sella turcica with the long-face growth pattern and people with an open bite. This study also examines the relationship between sella turcica bridging (STB) and the vertical growth pattern. As many as 153 radiographs were analyzed using the Romexis software, considering the basal, gonial, and FMA angles to determine the vertical growth pattern of the face. The basal angle was also used to check for an open bite. Of these patients, 80 had a long vertical face growth pattern, and 73 had a normal face growth pattern. The four landmarks of tuberculum sellae, dorsum sellae, sellae floor, and posterior clinoid were determined on the cephalograms to measure the length, depth, and anteroposterior diameter of the sella turcica. In this study, it was found that the chance of developing a long face in people with partial and complete bridging is 8.37 and 1.92, respectively. An increase in the length of the sella turcica for one unit decreases the chance of a long face, and as the depth of the sella turcica increases, the chance of a long face increases. STB is frequently seen in people with long faces. However, this finding should be considered in relation to other diagnostic parameters. The shorter the length and higher the depth of sella turcica, the higher the chance of developing a long face.

Age Estimation using Cephalometrics-A Cross-Sectional Study among Teenagers of Salem District, Tamil Nadu.

Age estimation is important not only in identifying dead body of a person but also in living persons since there is an increasing rate of juvenile delinquencies recorded every year. To avoid foul play by age fabrication, legal age estimation becomes important. Facial growth alteration takes place in the jawbones as age advances which can be observed with lateral cephalometry. Thus, the aim of the study is to create a regression formula for age estimation using cephalometrics of teenagers in Salem population. A cross-sectional study was done using 770 lateral cephalometrics of teenagers (13-19 yrs) in Salem population. Nine cephalometric points with two linear hard tissue measurements (condylion to mandibular plane (AFH) and palatal plane to menton (PFH)) and one angular soft tissue measurement (z angle) were recorded as predictor variables using a digital lateral cephalometric software (Carestream CS8100 SC) which were subjected to regression analysis using SPSS version 21.0 to develop a formula for age estimation. Significant association on age was obtained for the two linear measurements. The regression formula generated for estimating the age was Age = 7.146 + 0.044 (AFH) + 0.146 (PFH) with R2 value = 0.674. Within the limitations of the present study, age estimation of teenagers in Salem population can be estimated. The predictability of the age can be increased by taking more cephalometric variables in generating the formula with increase in sample size.

Upper airway assessment in obstructive sleep apnea patients: can computed tomography with lateral cephalometry replace drug-induced sleep endoscopy (DISE)?

ObjectiveTo evaluate the association between results from drug-induced sleep endoscopy (DISE) and computed tomography with lateral cephalometry (CTLC) of the pharynx in obstructive sleep apnea (OSA) patients, regarding the same anatomic level, in order to understand if CTLC could replace DISE in selected patients. Study designCross-sectional. SettingTertiary hospital. MethodsA total of 71 patients who attended the Sleep Medicine Consultation in the Otorhinolaryngology Department of Hospital CUF Tejo between 1.6.2019 and 30.9.2021, performed a polysomnographic sleep study and were elected to undergo DISE and CTLC of the pharynx for diagnostic purposes were selected. Obstructions at the same anatomic levels – tongue base, epiglottis and velum - were compared in both exams. ResultsPatients with reduction of epiglottis-pharynx space on CTLC had also a complete obstruction at epiglottis level on the VOTE classification of DISE (p = 0,027). Reduction of velum-pharynx space or tongue base-pharynx space were not related to complete obstruction of the velum (P = 0,623) or the tongue base (p = 0,594) found in DISE. Those with two or more space reductions had a tendency to multilevel obstruction observed in DISE (p = 0.089). ConclusionWhen evaluating the obstruction level(s) of an OSA patient, efforts should be made to perform DISE, since CTLC measures, though regarding at the same structures, don´t correlate completely with obstructions observed in DISE.

COMPARATIVE CEPHALOMETRIC AND 3D CONE BEAM COMPUTED TOMOGRAPHY ANALISIS OF ALVEOLAR BONE DESTRUCTION FOR TEETH IN ANTERIOR CROSSBITE

Purpose: To assess the degree of bone destruction for teeth in anterior crossbite by means of 3D cone beam computed tomography and lateral cephalometry. Material/methods: 20 patients with anterior crossbite underwent 3D cone beam computed tomography and lateral cephalometry of the anterior segments of the maxilla and mandible. The destruction of the bone in the anterior segments of the maxilla and mandible was measured (vestibularly and lingually)– the distance from the cemento-enamel junction to the top of the alveolar bone. The parameters of bone resorption for teeth 21 and 31 on cephalogramsand 3D computed tomography images were compared. For both incisors, the mean value registered by means of cephalometry was slightly higher than that registered with 3D. Results: The total mean value of bone destruction for anterior teeth was significantly higher vestibularly compared to lingually, both for the maxilla (p = 0.030) and mandible (p = 0.030). Significantly higher mean values ​​of bone destruction were found in the mandible compared to the maxilla. For both incisors (21 and 31), the mean value of resorption recorded by cephalometry was slightly higher than that recorded by 3D cone beam computed tomography, but without statistical significance. Conclusion: We found significantly higher values ​​of vestibular bone destruction compared to lingual bone destruction. Bone destruction in the mandible reached a significantly higher level than that in the maxilla. No statistically significant difference was found between the mean values ​​of bone destruction measured by means of cephalometry and 3D cone beam computed tomography.