The effect of head posture on the pharyngeal airway space (PAS)

The purpose of this study was to investigate the relationship between cranio-cervical inclination and pharyngeal airway space (PAS) by measuring these parameters at different head postures in the same subjects and to obtain a regression equation to correct the values measured. Fifty lateral cephalometric radiographs taken at five different head postures per individual were obtained from ten adults (seven males and three females) aged from 25 to 30 years with nose breathers and Class I occlusion. The changes in cranio-cervical inclination produced by head extension were correlated with changes in the variables describing the PAS. The OPT/NSL (cranio-cervical inclination in the second vertebrae) and C3-Me (distance between the third vertebrae and the Menton) correlated strongly with PAS-TP (the most proximal distance measured between the posterior pharyngeal wall and the tongue base) in the pharyngeal airway space (r = 0.807 and 0.854 respectively). The regression equations were Y = - 27.177+0.39X (Y = PAS-TP, X = OPT/NSL), and Y = -21.105+0.402X (Y = PAS-TP, X = C3-Me), respectively. From these equations we could conclude that an increase of 10 degrees in OPT/NSL or 10 mm in C3-Me increased the pharyngeal airway space (PAS-TP) by about 4 mm.     

Changes in head posture and nasopharyngeal airway following surgical correction of mandibular prognathism

It was the aim of the present study to cast light on the role of the mandible in relation to head posture and airway space by evaluating patients before and after surgical correction of mandibular prognathism. The material comprised standardized profile cephalograms of 52 patients with mandibular prognathism. All patients had received orthodontic adjustments prior to mandibular osteotomy. Mean age of the patients was 24.3 years, and 12 males and 40 females participated in the study. The first profile radiograph of each patient was obtained the day before surgery in the natural head (mirror) position. All patients underwent mandibular surgery with a bilateral vertical ramus osteotomy. Approximately one year after surgery, the cephalometric investigation was repeated. Head posture was evaluated by the craniocervical angulation (NSL/CVT and NSL/OPT) and airway space as nasopharyngeal airway size (ad1 and ad2). Changes in posture and airway (ex.2-ex.1) were evaluated by paired t-tests. The results showed a mean increase in head posture of 2.7 degrees (p less than 0.001) and a mean reduction in airway space of 2.3 mm (p less than 0.001).     

Change in cranio-cervical angulation following orthognathic surgery

Changes in natural head posture (NHP) were investigated in 33 patients (10 males, 23 females) with an age range of 16-40 years (median 21 years) following orthognathic surgery to change vertical face height. The reproducibility of the radiographer's technique of taking radiographs in NHP was investigated using a photographic method and found to be acceptable. The patients were divided into two groups: group 1, patients who had more than 3 mm of vertical change in anterior total face height (ATFH) and group 2, those who had less than 3 mm vertical change.For group 1 there was a significant relationship between ATFH change and cranio-cervical angulation (NSL/OPT) change (r = 0.532, P = 0.023), compared with group 2 (r = -0.247, P = 0.376). A similar relationship was revealed between lower anterior face height (LAFH)/ATFH ratio and NSL/OPT, where the correlation was also higher in group 1 (r = -0.635, P = 0.005) compared with group 2 (r = -0.182, P = 0.515). The correlation between cranio-vertical angulation (NSL/VER) and ATFH was not significant for group 1 (r = 0.406) or group 2 (r = 0.239) patients. Additionally, NSL/VER and LAFH/ATFH correlation for the two groups was not significant (r = -0.392 and -0.338, respectively).There appears to be a relationship between the reduction in vertical face height following orthognathic surgery and neck posture (as indicated by NSL/OPT). As no significant relationship was found between the reduction in face height and head posture (as indicated by NSL/VER) this suggests that neck posture, rather than head posture, had changed.     

Effect of bilateral sagittal split ramus osteotomy setback on the soft palate and pharyngeal airway space

To evaluate the effect of bilateral sagittal split ramus osteotomy setback on the morphology of the pharyngeal airway, especially the structures of the soft palate and pharyngeal airway space (PAS), lateral cephalograms obtained from 49 women before treatment and 1 year after surgery were traced and compared. All patients underwent this osteotomy to correct mandibular hyperplasia. The data were corrected with the use of regression equations for the PAS, taking into account head posture. On average, the SNB angle decreased by 3.9 degrees, resulting in an increase of 4.1 degrees in OPT/NSL (head posture, defined as the craniocervical angulation at the uppermost part of the cervical spine). The morphology of the PAS and soft palate changed significantly (p<0.01). The mean reduction in the PAS was 2.6mm retropalatinally and 4.0mm retrolingually. On average, the soft-palate length increased by 3.2mm and the soft-palate angle increased by 4 degrees. These results show that mandibular setback surgery markedly decreases the PAS and changes the morphology of the soft palate.     

A re-investigation of the relationship between head posture and craniofacial growth

This investigation was designed to repeat classic studies into the associations between head posture and growth as a single unified study using up-dated methods for gathering and analysing the data. The material comprised the cephalometric radiographs of 59 children (34 males and 25 females) recorded in natural head posture (self-balance position), at the beginning and end of a period of observation during which no treatment was performed (mean age at initial radiograph 11.76 years, mean interval between radiographs 3.52 years). Correlation analysis (corrected for multiple inference and adjusted for dependency between the variables) showed the strongest associations to be between growth direction of the face and the change in posture. No association was found between growth (direction or magnitude) and pre-observation posture. The most prominent associations were between the change in cranio-cervical posture (CCP) and variables representing the growth directions of the mandible (r = 0.72, P < 0.0001); anterior maxilla (r = 0.49, P < 0.001); posterior cranial base (r = 0.45, P < 0.01); temporomandibular joint (r = 0.56, P < 0.001); and the change in postural height of the tongue (r = 0.54, P < 0.0001). These findings do not support the hypothesis of a causal relationship between initial posture and subsequent facial growth. Instead, they indicate that it is the change in posture that is primarily linked to the growth direction of the face. The patterning of the correlations and the inter-relationships between the main growth variables suggest that this linkage arises from the coordinated changes that occur in the postures of the mandible and tongue. These coordinated postural changes appear to determine the growth direction of the mandible and, at the same time, influence CCP, possibly via an effect on pharyngeal patency.     

Effects of neuromuscular deprogramming on the head position

Objectives:

The aim of this study was to evaluate the effects of the neuromuscular deprogramming of the mandible on the craniocervical position.

Methods:

Participants (n?=?65) were separated into two groups: 25 untreated controls (10 men and 15 women) and 40 patients (17 men and 23 women) and underwent neuromuscular deprogramming with upper occlusal splints for an average of 6 months and 7 days, before orthodontic treatment. Lateral cephalograms were obtained from each subject in the natural head position (NHP), before and after neuromuscular deprogramming. Craniocervical cephalometric analysis was performed to evaluate craniovertical (NSL/VER), craniocervical (OPT/NSL and CVT/NSL), and cervicohorizontal (OPT/HOR and CVT/HOR) angulation, and the angle of the cervical curvature (OPT/CVT).

Results:

After neuromuscular deprogramming, significant changes in three angles — NSL/VER (P<0·001), OPT/NSL (P<0·001) and CVT/NSL (P<0·001) — were found between the two groups. For the cervical spine position, no significant changes were observed.

Conclusion:

The results indicate that neuromuscular deprogramming using occlusal splint causes significant extension of the head.     

Oral breathing and head posture

OBJECTIVE: To determine the head posture and cephalometric characteristics in oral breathing children. MATERIALS AND METHODS: Lateral cephalograms taken in natural head posture of 35 oral breathing patients (OB) (mean age 8.8 +/- 2.2 years SD; range 5-13 years) and of 35 patients with varied malocclusions and physiological breathing (PB) (mean age 9.7 +/- 1.6 years SD; range 7-13 years) were examined. RESULTS: A Student's t-test showed that an increase in angles NSL/OPT (P = .000), NSL/CVT (P = .001), FH/OPT (P = .000), FH/CVT (P = .005), and NSL/VER (P = .000); a decrease in the distance MGP-CV1p (P = .0001); and a decrease in the angles MGP/OP (P = .000) and OPT/ CVT (P = .036) were found in the OB group. A low position of the hyoid bone (H-MP, P = .009), a major skeletal divergence (ANS-PNS/Go-Me, P = .000), and an increased value of the ANB angle (P = .023) were present in OB patients. To ascertain if the changes in posture were connected with posterior obstruction of the upper respiratory airways, the OB group was divided into two subgroups based on the distance Ad2-PNS being greater than or less than 15 mm. No significant differences were found between these two groups. CONCLUSIONS: Our data suggest that OB children show greater extension of the head related to the cervical spine, reduced cervical lordosis, and more skeletal divergence, compared with PB subjects.     

Relationship between the pharyngeal airway space and craniofacial morphology, taking into account head posture

This study assessed the relationship between craniofacial characteristics and the size of the pharyngeal airway space (PAS), taking into account head posture. Sixty dental students 25-30 years of age (30 men and 30 women) were examined by lateral cephalometry. The data were corrected with the use of appropriate regression equations for the PAS. The PAS significantly correlated with hyoid position, maxillary and mandibular size, maxillary and mandibular prognathism, and mandibular inclination. A large, anteriorly positioned mandible was associated with a large PAS-TP (the most proximal distance between the posterior pharyngeal wall and the tongue base). Uvula length and PNS-Ba (the distance between the most posterior point of the hard palate and the most inferior point of the anterior foramen magnum) correlated with PAS-UP (the most proximal distance between the posterior pharyngeal wall and uvula). Our results suggest that the anteroposterior dimension of the PAS is substantially affected by the size of the enclosure surrounding the PAS, including the maxilla, mandible and soft palate.     

No Correlation between Primary Mandibular Anterior Crowding and Vertical Craniofacial Configuration or Lower Incisor Inclination

The aim of the present study was to evaluate the correlation between primary mandibular anterior crowding and vertical craniofacial configuration or sagittal lower incisor inclination. The collective comprised 100 consecutive patients (50 males, 50 females) subject to 4 selection criteria: mandibular anterior crowding > or = 1.0 mm, no previous orthodontic therapy, completely preserved deciduous canines and molars, and lateral cephalograms of good diagnostic quality before initiation of orthodontic treatment. Study casts of all patients were used to measure the mesiodistal width of the incisors and deciduous canines as well as the anterior arch circumference. The difference between the 2 represented the amount of crowding. On all cephalograms 16 parameters of vertical craniofacial configuration and 9 parameters of lower incisor inclination were measured. For error evaluation all measurements were repeated independently on 10 randomly selected study casts and cephalograms. This error amounted for the combined tooth width to 0.51% +/- 0.81, for arch circumference to 0.03% +/- 0.68, and for all cephalometric parameters to 0.38% +/- 4.81. For all parameters, arithmetic means, standard deviations and ranges were calculated. Further, correlation coefficients were calculated between anterior crowding and all 25 cephalometric parameters. The arithmetic mean of crowding was m = 2.0 +/- 1.3 mm with a range of 1.0 to 6.6 mm. The values of all cephalometric parameters were close to well accepted norms in the literature. The correlation coefficients between crowding and all cephalometric parameters varied from r = 0.0 to 0.3. According to this study there is no correlation between primary mandibular anterior crowding and vertical craniofacial configuration or sagittal lower incisor inclination.     

Relationship of TMJ osteoarthritis / osteoarthrosis to head posture and dentofacial morphology

OBJECTIVE: The purpose of this study was to test the hypothesis that there is a relationship between the temporomandibular joint (TMJ) osteoarthritis/osteoarthrosis (OA), head posture and dentofacial morphology. DESIGN: Case-control study. SUBJECTS AND METHODS: The subjects consisted of 34 Japanese females with TMJ OA (aged 24.7 +/- 6.1 years) and a control group of 25 healthy Japanese females (aged 23.6 +/- 1.3 years). Six cranio-cervical angular measurements were constructed for head posture analysis. Nine angular and three linear measurements were constructed for the skeletal hard tissue analysis. Five angular and one linear measurements were constructed for the dental hard tissue analysis. Unpaired t-tests were used to compare the mean differences of head posture measurements and dentofacial cephalometric measurements between the TMJ OA and the control group. RESULTS: The TMJ OA group had significantly larger cranio-cervical angles (p < 0.05) and had more posteriorly rotated mandibles (p < 0.0001) than those in the control group. They also had a significantly shorter posterior facial height (p < 0.0001). The TMJ OA group had more retroclined lower incisors (p < 0.05). CONCLUSION: These results suggest that an association may exist between TMJ OA, head posture and dentofacial morphology.     

Changes in posterior airway space and hyoid bone position after surgical mandibular advancement

Objective: To evaluate cephalometric changes in posterior airway space (PAS) and in hyoid bone distance to mandibular plane (MP) 1–3 years after bilateral sagittal split osteotomy (BSSO).

Material and methods: The sample consisted of 36 females and 16 males who underwent mandibular advancement by BSSO. To observe sagittal changes in PAS and in hyoid bone distance to MP both pre- and postoperative cephalograms were analyzed using WinCeph^® 8.0 software. For the statistical analyses paired T-test and multivariate logistic regression models were used.

Results: By the surgical-orthognathic treatment the sagittal dimension of PAS showed variable changes but it mainly diminished when the mandibular advancement exceeded 6?mm. In most cases the hyoid bone moved superiorly by BSSO. Logistic regression models showed that males, patients with narrow PAS at the baseline, and those with counterclockwise rotation of the mandible by the treatment gained more increase in PAS. However, an increase in sagittal PAS dimension tended to relapse over time. Concerning the movement of the hyoid it was found that the more PAS increased the less hyoid moved superiorly. In males the change in hyoid position was more obvious than in females.

Conclusion: Males, patients with narrow PAS at the baseline, and those whose mandible moved in the counterclockwise direction with moderate advancement gained more retrolingual airway patency by BSSO.     

Surgical mandibular setback and changes in uvuloglossopharyngeal morphology and head posture: a short- and long-term cephalometric study in males

A detailed cephalometric analysis was conducted on a sample of 31 adult males who underwent correction of mandibular prognathism by mandibular setback osteotomy (BSRO) with rigid fixation to evaluate the changes in uvuloglossopharyngeal morphology, hyoid bone position and head posture. Lateral cephalograms were obtained 1-3 days prior to the operation and at standardized 6 months and 3 years post-operative follow-up. Statistical evaluation was performed by paired Student's t-test and Pearson product moment correlation analysis. Inferior position of the hyoid bone (AH perpendicular FH, AH perpendicular ML, AH perpendicular S) and valeculla (V perpendicular FH) was recorded at the 6-month follow-up, a transient finding as at 3 years almost complete recovery to their pre-surgical position was noted. No posterior displacement of the above structures (AH-C3 Hor, V-C3) was recorded. Soft palate length (pm-U) was increased and maintained at the long-term follow-up while its posture (NL/pm-U) became less upright. The tongue showed increased length (V-T) and sagittal area (TA) and a more upright posture (VT/FH) at the late follow-up. Increased contact length between tongue and the soft palate (CL) and less residual oropharyngeal area [area not occupied by soft tissues, (TA + SPA)/OPA] was found at the long-term follow-up. Craniocervical agulation (NSL/OPT, NSL/CVT) was increased indicating cervical hyperflexion at the 3-year follow-up. Reduction of the sagittal dimension of the oropharyngeal airway space (U-MPW) appeared at the first follow-up and was sustained at the longest follow-up which, in conjunction with the decrease in residual oropharyngeal area, could raise questions regarding airway patency after mandibular setback osteotomy.     

Relationship of natural head position to craniofacial morphology.

This investigation aimed at discussing the utility of natural head position-based cephalometric variables and to evaluate the relationship between natural head position and craniofacial morphology. Lateral facial photographs and cephalograms of 284 young adult males taken in a natural head position were analyzed. The average inclination of the intracranial reference planes, Frankfurt horizontal, and palatal plane, in relation to the true horizontal were nearly similar and smaller than 1 degrees. Variables based on the true vertical to describe mandibular sagittal position like B-N(vert) and Pg-N(vert) had very high variances. To study the topographic error, flexors and extenders were identified on basis of four positional variables: NSL/VER; FH/VER; PP/VER; and PMvert/VER. Only 15 measurements were different, according to at least 2 of the 4 positional variables. The 3 that were different in all categories were: facial axis (NBa/PmGn), lower face height (ANS-Me), and the facial ratio (N-ANS/ANS-Me). The "extenders" had higher values for the facial axis and lower face height, and smaller for the face height ratio. Besides these 3 measurements, there was a tendency for the extenders to have increased anterior vertical height, distal sagittal relations, and smaller and retrognathic mandibles. Correlation coefficients between postural and morphologic variables tended to confirm these observations.     

A method for defining targets in contemporary incisor inclination correction

Different craniofacial properties require individual targets in incisor inclination. These requirements are mostly scheduled on the basis of cephalometric diagnosis, but, however, performed using straightwire appliances, which refer to third-order angles and not to cephalometric data. The objective of this study was to analyze the relationship between incisor third-order angles, incisor inclination, and skeletal craniofacial findings in untreated ideal occlusion subjects with natural dentoalveolar compensation of skeletal variation, in order to link the field of cephalometric assessment of incisor inclination with that of contemporary orthodontic incisor inclination correction. This study utilized lateral cephalograms and corresponding dental casts of 69 untreated Caucasians (21 males and 48 females between 12 and 35 years of age) with neutral (Angle Class I) molar and canine relationships and an incisor relationship that was sagittaly and vertically considered as ideal by three orthodontists (i.e. well supported by the antagonistic teeth and without the need for either deep or open bite correction). Upper (U1) and lower (L1) axial incisor inclinations were assessed with reference to the cephalometric lines NA and NL, and NB and ML, respectively. Sagittal and vertical skeletal relationships were classified using SNA (SNB) and NSL-ML (NSL-NL) angles. Third-order angles (U1TA and L1TA) were derived from direct dental cast measurements using an incisor inclination-recording appliance. The relationships between cephalometric and third-order measurements evaluated by calculating Pearson product-moment correlation coefficients (a = 0.05) showed strong correlations between cephalometric axial inclination data (U1NA/deg, L1NB/deg, U1NA/mm, L1NB/mm, U1NL, and L1ML) and sagittal-skeletal data, but no significant relationship between skeletal-vertical findings and incisor inclination. The mean U1TA was 4.9 (standard deviation [SD] 5.85) and the mean L1TA -3.0 (SD 6.9) degrees. Regression analyses were used for axial inclination (ANB angle designated as the independent variable) and for third-order data (U1NA, L1NB, U1NL, and L1ML designated as independent variables). Based on the correlations found in this study, a novel method for defining targets in upper and lower incisor third-order correction according to natural standards is presented. As a consequence, third-order movements can be adapted to cephalometric diagnosis with enhanced accuracy.     

Alterations of hyoid bone position and pharyngeal depth and their relationship after surgical correction of mandibular prognathism

The present investigation studied changes of hyoid bone position and pharyngeal depth at the levels of the second and fourth cervical vertebrae and their relationships in mandibular prognathism patients who received combined orthodontic-surgical treatment. The material consisted of presurgical and 1-year postsurgical profile cephalograms of 52 adult orthognathic surgery patients (40 females and 12 males) who initially had mandibular prognathism and had undergone bilateral vertical ramus osteotomy through an extraoral incision in the retroangular area. Hyoid bone position and pharyngeal depth were assessed on the profile radiographs with 10 cephalometric variables. Paired t tests were used to evaluate the operative changes in all cephalometric parameters. The relationships between pairs of variables describing hyoid bone position and pharyngeal depth were assessed by means of Pearson's product-moment correlation analysis. Significant differences (p less than 0.01) were observed for the distances of the hyoid bone to the maxilla and the mandible. The distances of the hyoid bone with the anterior cranial base, the vertebral column, and the anterior pharyngeal wall, and the measurements representing pharyngeal depth exhibited no significant changes (p greater than 0.05). Moderate correlations were seen between (1) the depth of the pharynx at the fourth cervical vertebra and the hyosymphyseal distance (r = 0.34) and the distance between the point of the projection of the hyoid bone to the mandibular line with its posterior border (r = -0.34), and (2) the depth of the pharynx at the second cervical vertebra and the distance of the hyoid bone with the anterior pharyngeal wall at the level of the fourth cervical vertebra (r = -0.33).(ABSTRACT TRUNCATED AT 250 WORDS)     

Determining Skeletal Parameters in Angle Classes II, Division 1 and II, Division 2*

AIM: Aim of the study was to find out whether significant differences in skeletal morphology exist between Angle Class II, Division 1 and II, Division 2. MATERIAL AND METHOD: Fifty-nine patients without previous orthodontic treatment showing Class II occlusion and distobasal jaw relation were evaluated by cephalometric analysis. RESULTS: Significant differences existed in skeletal morphology between patients with Angle Class II, Division 1 and II, Division 2, with only minor gender-specific differences: angleML/NSL in Class II, Division 2 males (p < 0.01) and females (p < 0.05) was smaller compared to Class II, Division 1 patients. angleML/NL was also noticeably smaller in Class II, Division 2 males (p < 0.001) and females (p < 0.01) compared to Class II, Division 1 patients. Patients with Class II, Division 2 had a smaller gonial angle (angleArGoMe), with the difference being significant only in males (p < 0.05).     

Cervical column morphology related to head posture, cranial base angle, and condylar malformation

The present study describes the cervical column as related to head posture, cranial base, and mandibular condylar hypoplasia. Two groups were included in the study. The 'normal' sample comprised 21 subjects, 15 females aged 23-40 years (mean 29.2 years), and six males aged 25-44 years (mean 32.8 years) with neutral occlusion and normal craniofacial morphology. The condylar hypoplasia group comprised the lateral profile radiographs of 11 patients, eight females, and three males, aged 12-38 years (mean 21.6 years). For each individual, a profile radiograph was taken to perform a visual assessment of the morphology of the cervical column. For the normal group only, the profile radiographs were taken in the standardized head posture to measure the head posture and the cranial base angle. Cervical column: Morphological deviations of the cervical column occurred significantly more often in the subjects with condylar hypoplasia compared with the normal group (P < 0.05 and P < 0.01, respectively). The pattern of morphological deviations was significantly more severe in the subjects with condylar hypoplasia compared with the normal group (P < 0.01). Cervical column related to head posture and cranial base: The cervicohorizontal and cranial base angles were statistically larger in females than in males (P < 0.05 and P < 0.01, respectively). No statistically significant age differences were found. Only in females was the cervical lordosis angle (OPT/CVT, P < 0.01), the inclination of the upper cervical spine (OPT/HOR, P < 0.05), and the cranial base angle (n-s-ba, P < 0.05) significantly positively correlated with fusion of the cervical column. These associations were not due to the effect of age.     

Evaluation of pharyngeal airway space amongst different skeletal patterns

The aim of the present study was to evaluate the dimensions of the pharyngeal airway space (PAS) in awake, upright children with different anteroposterior skeletal patterns using cone beam computed tomography (CBCT). The volume, area, minimum axial area and seven linear measurements of PAS were obtained from the CBCT images of 50 children (mean age 9.16 years). The patients were divided in two groups according to the ANB angle (group I 2° ≤ ANB ≤ 5°; group II ANB > 5°). Means and standard deviations of each variable were compared and correlated using independent t-test and Pearson's correlation test. There were statistically significant differences in the following parameters: angle formed by the intersection between NA and NB lines (p<0.001), angle formed by the intersection between SN and NB lines (p<0.05), Minimal pharyngeal airway space between the uvula and the posterior pharyngeal wall (p<0.05), airway volume (p<0.01), airway area (p<0.01) and minimum axial area (p<0.05). The anteroposterior cephalometric variable SNB had positive correlation with the variables PAS-UP (p<0.01), Minimal pharyngeal airway space between the uvula tip and the posterior pharyngeal wall (p<0.05), Pharyngeal airway space on mandibular line (p<0.05), Minimal pharyngeal airway space between the back of the tongue and the posterior pharyngeal wall (p<0.05), volume airway (p<0.05), airway area (p<0.05) and minimum axial area (p<0.05). The vertical cephalometric variables angle formed by the intersection between SN and GoGn lines (p<0.05) and angle formed by the intersection between FH and mandible plane (p<0.05) showed negative correlation with PAS-UT. These results showed that PAS was statistically larger in group I than group II, indicating that the dimensions of the PAS are affected by different anteroposterior skeletal patterns.     

Craniofacial development in obese adolescents

The purpose of this study was to investigate craniofacial morphology in obese adolescents and to compare the morphological data with those of normal adolescents. The study was based on measurements of lateral cephalometric roentgenograms of adolescents who had been diagnosed as obese. Linear and angular measurements were obtained from cephalometric tracings of 27 females (mean age 15.6 +/- 0.83 years) and 23 males (mean age 13.9 +/- 0.98 years). The data were compared with corresponding measurements of gender and age matched controls. The results showed that both males and females in the obesity group exhibited significantly larger mandibular and maxillary dimensions than the controls. On average, mandibular length (Cd-Pgn) was 10 mm greater in males and 8 mm greater in females. Maxillary length (Pm-A) was 3.5 mm greater in males and 3 mm greater in females. When considering vertical dimensions, lower anterior (Ans-Gn) and posterior (S-Go) face height were 4 and 5 mm greater in the obese males, respectively, while in the obese females both these distances were 4 mm greater compared with the controls. Both maxillary (SNA) and mandibular (SNB, SNPg) prognathism were more pronounced in the obesity group than in the control group. This also influenced the average soft tissue profile, which was less convex in the obesity groups. The mandibular plane angle (ML/SN) was smaller in the obesity group than in the control group. Craniofacial morphology differs between obese and normal adolescents. In general, obesity was associated with bimaxillary prognathism and relatively greater facial measurements.     

Skeletal-versus soft-tissue-based cephalometric analyses: is the correlation reproducible?

Objectives: Dentofacial deformities can be analyzed by skeletal and soft tissue cephalometric analysis (CA). The aim was to evaluate the difference in reproducibility between both methods.

Materials and methods: Lateral cephalograms of 112 patients (65 females and 47 males, 27.7?±?9.0 years) were oriented in natural head position (NHP) and digitized. The distances of skeletal (SNA, SNB, SnPog) and soft tissue (A′, B′ and Pog′) landmarks relative to the respective norm values and the angles between the Nasion Sella line (NSL) and Frankfurt horizontal (FH) to NHP were measured for statistical evaluation and compared with respective data of an adult control group (CG) with class I occlusion and harmonic facial balance.

Results: The mean differences (mm?±?SD) of skeletal and soft tissue landmarks were –2.4?±?4.4 (A), –7.0?±?9.3 (B), –6.3?±?11.2 (Pog), –0.9?±?1.8 (A′), –4.7?±?6.2 (B′), and –6.1?±?7.8 (Pog′), respectively. Pearsons’s correlation (r) between the measurements of SNA/A′, SNB/B′ and SNPog/Pog′ were r?=?.158 (p?=?.092), r?=?.662 (p?<?.001) and r?=?.655 (p?<?.001), respectively. The mean (±SD) angles between NSL and FH to NHP were –9.8°?±?5 and 0.0°?±?3.9, respectively.

Conclusion: Variability of cranial-based measurements could give a possible explanation for the high variation and the low reproducibility of skeletal cephalometric analysis with soft tissue measurements. Soft-tissue cephalometric analysis would probably improve facial analysis and treatment planning.