A 3D cone beam computed tomography (CBCT) investigation of mandibular condyle morphometry: Gender determination,disparities, asymmetry assessment and relationship with mandibular size

ObjectiveCBCT (cone beam computed tomography) analysis of condyle morphometry, to investigate the gender differences, symmetry and relationship with mandibular size.Materials and methodsThis is a retrospective study. 800 CBCT scan obtained for the measurement of condyle in anterior-posterior and medio-lateral aspect using OnDemand 3D software. Participants were Saudi nationals of age above 18 years. 395 Males and 405 Females with the mean age of 38.2 ± 10.5 years. Right and left anterior-posterior width and medio-lateral width of the condyle were measured. Condyles were not isolated on the CBCT for volume measurement.ResultsMean right and anterior-posterior condyle width was 9.02 mm and 8.74 mm in males whereas in females it was 9.01 mm 8.69 mm respectively. For males mean medio-lateral width of the condyle in right and left side was 17.40 mm and 16.95 mm. For females, mean medio-lateral width of the condyle in right and left side was 17.14 mm and 16.93 mm. The prediction rate of gender was 57.2% for males and 53.3% for females. Statistically significant differences (p < 0.05) were found in the anterior–posterior and medio-lateral width of right and left condyles among males and females. Left anterior-posterior and medio-lateral width of average vs small mandible shows statistically significant difference (p < 0.05).ConclusionCondyle morphometry is a weak predictor for gender. Irrespective of gender, right and left condyle are asymmetrical in relation to condyle morphometry of anterior-posterior and medio-lateral aspect. Left mandibular condyle morphometry is different in relation to the mandible size.     

Three-dimensional analysis of condylar remodeling and skeletal relapse following LeFort-I osteotomy: A one-year follow-up bicenter study

The aim of the study was to quantify the postoperative condylar remodeling after Le Fort I surgery.Patients treated with a Le Fort I osteotomy were investigated. CBCT scans were acquired preoperatively, one week and one year postoperatively. A preoperative 3D cephalometric analysis was performed on the preoperative CBCT. Surgical movements were quantified using a voxel-registration based method (OrthoGnaticAnalyser). After rendering of the condyles from the CBCT, a volumetric analysis was performed. The correlation between the surgical movement of the maxilla and the postoperative condylar volume changes was determined with analysis of variance.ResultsA total of 45 subjects were included in this study. 47 of 90 condyles (52%) showed a mean volume reduction of 93 mm³ (4.9 volume-%) postoperatively. The maxilla was impacted in 12 patients (2.44 ± 2.49 mm) and extruded in 33 patients (1.78 ± 1.29 mm). The maxillary impaction group showed a volume reduction of 50 ± 122 mm³ and the extrusion group showed a mean volume gain of 21 ± 139 mm³ (p = 0.028).ConclusionClinicians should be aware of potential condylar remodeling following solitary Le Fort I osteotomies, particularly in female patients with maxillary impaction.     

Analysis of the Volumetric Asymmetry of the Mandibular Condyles Using CBCT

ObjectivesThe aim of this study was to analyse volumetric asymmetries between the right and left condyles in relation to age, gender, and dental status.Materials and methodsA retrospective analysis of 150 cone beam computed tomography (CBCT) scans was conducted. A single investigator performed the volumetric analysis of the CBCT scans using Vesalius 3D software. The volumetric data were analysed in relation to the gender, age, and dental status.ResultsThe mean right condylar volume was significantly higher (P < .01) than the left condylar volume. Right and left condylar volumes were significantly higher (P < .01) in male study participants when compared to female study participants. There was no significant difference (P = .47) in the volumetric asymmetry between the male and female study participants. The volumetric asymmetry was significantly higher (P < .01) in the older age groups when compared to the younger age groups. The volumetric asymmetry was significantly higher (P < .01) in the partially and completely edentulous patients when compared to the dentate study participants. The condylar volume on the side having a partially edentulous area was significantly lower than the condylar volume of the contralateral dentate side (P < .001).ConclusionsThe volumetric asymmetry between the right and left condyle significantly increases with age and edentulousness. The result of the study encourages the clinicians to perform volumetric evaluation of the condyles in cases of radiographically evident condylar asymmetries to obtain a more accurate diagnosis.     

Assessment of aging characteristics of female condylar trabecular structure by cone-beam computed tomography

Objectives

This study was performed to analyze the aging-related changes of the female condylar bone mineral density (BMD) and trabecular structure by cone-beam computed tomography (CBCT), and determine whether the condylar structure shows obvious changes after menopause.

Methods

The CBCT images of 160 female patients who met the inclusion criteria for the study were collected and divided into four groups by age (20–29 years, 30–39 years, premenopausal, and postmenopausal groups). Computer processing software CT-Analyser (Version 1.15.2.2+; SkyScan, Antwerp, Belgium) was used to measure the condylar BMD and related indexes, namely the bone volume/tissue volume ratio (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp), trabecular structure model index (SMI), and bone surface area/volume ratio (BS/BV). SPSS 12.0 (SPSS Inc., Chicago, IL, USA) was used to analyze the radiographic findings and statistical differences.

Results

No significant differences were found between the bilateral condyles in each group (P?>?0.05). BV/TV, Tb.N, and Tb.Th of the condyle decreased with age, and the postmenopausal group showed significantly different values for each index compared with the other groups (P?<?0.01). Tb.Sp, SMI, and BS/BV of the condyle increased with age, and the postmenopausal group showed significantly different values for each index compared with the other groups (P?<?0.01).

Conclusions

With increasing age, the female condylar bone volume decreases, the Tb.N and Tb.Th decrease, the gap between the trabecular bone increases, and plate-like trabecular bone gradually transforms into a rod-like form. These changes are much more obvious in postmenopausal women.

     

Is the quality of root canal filling obtained by cone-beam computed tomography associated with periapical lesions? A systematic review and meta-analysis

Aim

To evaluate the influence of root canal filling quality on periapical lesion status using cone-beam computed tomography (CBCT).

Materials and Methods

The bibliographic search was conducted in electronic databases of PubMed, Embase, Scopus, and Web of Science without restrictions related to the year of publication and language. Inclusion criteria were prospective or retrospective cohort studies that followed periapical pathosis for, at least, 1 year. Three reviewers independently evaluated the eligibility for inclusion, extracted data, and assessed the risk of bias. The quality of the studies was based on the Newcastle–Ottawa Scale. This meta-analysis was performed to evaluate the quality of treatment by the homogeneity and apical extension of the filling.

Results

Of the 1179 studies initially recovered, six cohort studies were included, out of which four were considered with a low risk of bias. The results showed that the absence of gaps in the filling reduced the chance of unhealed periapical lesions by 2.39 times (RR?=?2.39; 95% CI: 1.62–3.53; p?<?0.00001; I² = 55%). An apical filling extension of 0–2 mm below the apex also contributed significantly to the absence of unhealed periapical lesions (RR?=?1.49; 95% CI: 1.15–1.94; p?=?0.003; I² = 2%).

Conclusion

The homogeneity and apical extension of the filling influenced the presence of unhealed periapical lesions in endodontically treated teeth evaluated using CBCT.

Clinical relevance

Apical extension of the filling ranging between 0 and 2 mm short of the apical foramen and the homogeneity of the filling without gaps are directly related to the success rate of root canal treatment.

     

Three-dimensional condylar positions and forms associated with different anteroposterior skeletal patterns and facial asymmetry in Chinese adolescents

Abstract

Objective. To evaluate the association of condylar asymmetry and chin position with different anteroposterior skeletal patterns using three-dimensional models reconstructed from cone-beam computed tomography (CBCT) images. Materials and methods. CBCT scans of 123 Chinese adolescents (aged 11–15 years, 68 girls and 55 boys) with 64 skeletal Class I, 46 Class II and 13 Class III were selected from scans of patients attending the orthodontic clinic. The condyles of the subjects were reconstructed bilaterally and 25 linear, angular and volumetric measurements were performed to evaluate the asymmetry of the condyles and position of the chin. The proportions of condylar asymmetry in the different skeletal groups were calculated by the absolute difference value between the left and right sides to the smaller side value. One-way analysis of variance and Pearson's correlations were used to analyse the data. Results. The values for RV, RCL, LCH, RCH, LCGM, RCGM, LCo-Me and RCo-Me were significantly different among the three skeletal groups (p < 0.05). There were significant positive correlations between Pog-Ss and Co-Sh, Co-Me in the Class I and II groups (p < 0.05). Asymmetries for Co-Ss, Co-Sh, CP and SP between the left and right condyles exceeded a ratio of 20% for more than 30% of the subjects. Conclusion. Condylar asymmetry varied significantly among the three skeletal groups, with the vertical position of the condyle (Co-Sh) and height of the mandibular ramus (Co-Me) being significantly and positively related to the chin position.     

Effects of impacted maxillary canines on root resorption of lateral incisors

Objectives

The aim of this study was to analyze the amount of root resorption of maxillary lateral incisors by relating the position, location, and angulation of the impacted canine using cone-beam computed tomography (CBCT).

Materials and methods

The study sample consisted of panoramic and CBCT radiographs of 46 patients with a unilateral impacted canine (16 males and 30 females; mean age: 19.53 ± 6.66 and 19.44 ± 5.77 years, respectively). Sector location and canine angulation were measured in panoramics. All tomographs were obtained using CBCT (NewTom 5G, QR, Verona, Italy) and three-dimensional (3D) reconstructions of the maxillary laterals assessed by Mimics 14.01 image analysis software.

Results

Upper lateral incisor volume was smaller on the impacted side (401.95 ± 83.69 mm³) than on the nonimpacted side (433.54 ± 92.6 mm³, P < 0.05). There were no significant differences of lateral root resorption volume when comparing the impacted canines being on the labial or palatal sides (P > 0.05), but impacted canine angulation was significantly steeper on the labial side (70.85°) than on the palatal side (46.09°, P < 0.05). The volume of root resorption of laterals when comparing the various positions of the canine in different sectors or canine angulation in 30^o intervals was not statistically significantly different (P > 0.05).

Conclusions

The impacted canines caused root resorption of lateral incisors. The angulation of the canine was steeper on the labial side than on the palatal side but root resorption of adjacent laterals was not different. There were no statistically significant differences in the amount of root resorption of the laterals when the canine was evaluated according to localization and angulation.

     

The quality of root canal treatment and periapical status of permanent teeth in Turkish children and teens: a retrospective CBCT study

Objective

This study aimed to assess the quality of root canal fillings and the prevalence of periapical radiolucencies in the permanent teeth of 6–18 year-old Turkish children.

Methods

CBCT images of 150 patients’ 235 teeth with a mean age of 16.0?±?2.06 years were included. Root development stage, quality of root canal filling, the presence and severity of periapical radiolucencies, and their relationship with anatomical structures were recorded. Correlations between the quality of root canal filling, periapical lesion, and lesion size were assessed using regression analyses.

Results

A total of 235 teeth (528 root canals) were evaluated. 65.5% of root canals had periapical lesions. Immature roots and mandibular teeth had the highest prevalence and the largest size of periapical radiolucencies (p?<?0.05). Overfilling (n?=?52), underfilling (n?=?93), unfilled (n?=?46), inhomogeneously filled (n?=?113) root canals and poor coronal restoration (n?=?85 teeth) were observed in terms of technical failures of endodontic treatment. The quality of endodontic treatment was associated with the presence of periapical lesion and lesion size (p?<?0.05). Teeth with under-filled, overfilled or inhomogeneously filled root canals and poor coronal restoration had a periapical lesion larger than 5 mm (p?<?0.05). Immature teeth were most associated with the presence of lesion (OR?=?4.07) and the lesion size?>?5 mm (OR?=?3.71).

Conclusion

The prevalence of periapical radiolucencies in young permanent teeth showed an increase when the tooth was an incisor, had incomplete root development, or the root filling had technical errors.

     

Investigation of the effectiveness of CBCT and gray scale values in the differential diagnosis of apical cysts and granulomas

Purpose

The aim of this study was to investigate the effectiveness of cone-beam CT (CBCT) findings and gray scale values (GSV) in the differential diagnosis of apical cysts and granulomas.

Methods

Two independent researchers retrospectively analyzed the CBCT images of 21 teeth and histopathologically diagnosed them as having radicular cysts or apical granulomas. In the CBCT images, apical lesions were evaluated and categorized according to 7 criteria. These criteria were determined as relationship of lesions with dental roots, periphery of the lesion, shape, darker focus in the center, root resorption, displacement in related teeth, and cortical bone perforation. In addition, the minimum and maximum gray scale values of the lesions were measured and compared.

Results

There was a statistically significant relationship between histopathological (HP) diagnosis and well-defined cortical border and lesion shape (p?=?0.003, p?=?0.014, respectively). According to the HP diagnosis, no statistically significant difference was found among other variables (p?>?0.05)

Conclusion

The presence of a well-defined cortical border or partial cortical border is a distinctive criterion for cysts. Additionally, the shape of the lesion was found to be a significant criterion for the separation of the two lesions. The shape of cystic lesions was circular and apical granulomas had a more curved shape. There was no relationship between the histopathological diagnosis of lesions and CBCT gray scale values.

     

Mandibular condylar dimensions: Correlation between 3D tomography and dried skull measurements

Objective Compare the anatomical dimensions of mandibular condyles with the same CBCT measurements.

Methods Four landmarks were identified on the condyles of dried skulls and are measured with their corresponding areas in CBCT images: Right Width of Condyle (RW), Left Width of Condyle (LW), Right Length of Condyle (RL), and Left Length of Condyle (LL).

Results With respect to direct measurements on the dry skulls, statistically significant differences were found between sexes (p < 0.001). When the real values were compared with the CBCT, it was observed that the bias depends on the magnitude of the measurement. It means that there is an underestimation for smaller values and an overestimation for larger values.

Conclusion CBCT is reliable imaging modality, but when compared real measures of condyle length are more reliable then width.     

The effect of lockdown during SARS-CoV-2 pandemic on maxillofacial injuries in a level I trauma centre: a comparative study

Introduction

The SARS-CoV-2 pandemic forced many governments to impose nation-wide lockdowns. Government legislation forced limited travel on the population with restrictions on the normal way of life to limit spread of the SARS-CoV-2 virus. The aim of this study is to explore the effects of lockdown on the presentation of maxillofacial trauma in a level I trauma centre.

Methods

Comparative analysis was carried out using prospective and retrospective review of all consecutive patients admitted with any maxillofacial fracture in the lockdown period between 15th March and 15th June 2020 with the same period in 2019 to a Regional Trauma Maxillofacial Surgery Unit. Data included basic demographics and mechanism of injury including alcohol/drug influence, polytrauma, site of injury and treatment modality including escalation of care.

Results

Across both periods, there were a total of one hundred and five (n?=?105) recorded episodes of traumatic fractures with fifty-three (n?=?53) in the pre-lockdown cohort and fifty-two (n?=?52) in the lockdown. Included patients were significantly (p?=?0.024) older during lockdown (mean age 41.44 years SD 20.70, range 5–96) with no differences in gender distribution between cohorts (p?=?0.270). Patients in lockdown were more likely to be involved in polytrauma (p?<?0.05) and have sustained their injury by cycling/running or any outdoor related activity (p?=?0.013). Lockdown saw a significant reduction in alcohol and drug related violence (p?<?0.05). Significantly more patients required operative management (p?=?0.038).

Conclusion

Local lockdowns form part of the governments public health strategy for managing future outbreaks of SARS-CoV-2. Our study showed no significant reduction in volume of trauma during lockdown. It is vital that hospitals maintain trauma capacity to ensure that patients are treated in a timely manner.

     

Cone beam computed tomographic assessment of mandibular condyle in Kennedy class I patients

Objectives

The aim of this study was to assess the dimensional and volumetric changes in the mandibular condyle in Kennedy class I patients versus completely dentate patients by cone beam computed tomography (CBCT) to estimate the effect of loss of posterior teeth on the mandibular condyle.

Patients and methods

This study was performed on one hundred patients requesting CBCT scans: fifty Kennedy class I patients and fifty fully dentate controls. Condyle dimensions mesio-distal, cranio-caudal and antero-posterior as well as condyle volume were measured in both the groups.

Results

Kennedy class I patients showed statistically significant higher mean condyle width but lower mean condyle height than the control group. No statistically significant difference was found between the study group and the control group regarding condyle AP dimension. There was no statistically significant difference between condyle volumes in the two groups.

Conclusion

Loss of posterior teeth is accompanied by significant decrease in condyle height and increase in condyle width with no change in the total condyle volume or antero-posterior dimensions.

     

Validation of a novel semi-automated method for three-dimensional surface rendering of condyles using cone beam computed tomography data

Morphological changes of the condyles are often observed following orthognathic surgery. In addition to clinical assessment, radiographic evaluation of the condyles is required to distinguish the physiological condylar remodelling from pathological condylar resorption. The low contrast resolution and distortion of greyscale values in cone beam computed tomography (CBCT) scans have impeded an accurate three-dimensional (3D) rendering of the condyles. The current study proposes a novel semi-automated method for 3D rendering of condyles using CBCT datasets, and provides a clinical validation of this method. Ten patients were scanned using a standard CBCT scanning protocol. After defining the volume of interest, a greyscale cut-off value was selected to allow an automatic reconstruction of the condylar outline. The condylar contour was further enhanced manually by two independent observers to correct for the under- and over-contoured voxels. Volumetric measurements and surface distance maps of the condyles were computed. The mean within-observer and between-observer differences in condylar volume were 8.62 mm³ and 6.13 mm³, respectively. The mean discrepancy between intra- and inter-observer distance maps of the condylar surface was 0.22 mm and 0.13 mm, respectively. This novel method provides a reproducible tool for the 3D rendering of condyles, allowing longitudinal follow-up and quantitative analysis of condylar changes following orthognathic surgery.     

The impact of partially removing the Bichat fat pad in the linear facial measurements,satisfaction with facial aesthetics and quality of life: a single-arm CONSORT-guided clinical trial

Objective

To evaluate the influence of Bichat’s ball removal on postoperative inflammatory parameters (pain, edema, and trismus), facial volume reduction, facial esthetic satisfaction, and oral health-related quality of life.

Material and methods

A single-arm clinical trial with 21 patients undergoing Bichat’s ball removal. The following parameters were assessed at baseline and up to 3 months postoperatively: Visual Analogue Scale pain scores (0–10), rescue medication consumption, mouth opening, AM-Tr, AM-CEO, AM-NA, AM-CL, and AM-PM measurements, Oral Health Impact Profile (OHIP)-14 QoL scores, and satisfaction with facial esthetics (FACE-Q Satisfaction with Facial Appearance Overall Scale (SFAOS). X², analysis of variance-repeated measures/Bonferroni, or Friedman/Dunn tests were used (p?<?0.05, SPSS v20.0).

Results

Peak pain occurred after 2 h and, 10 h later, the levels returned to baseline values (p?<?0.001). Rescue medication consumption peaked in the first 24 h reducing significantly after 72 h (p?<?0.001). Mean mouth opening decreased after 24 h and returned to baseline levels after 1 month, and all linear facial measures reduced significantly after 1 or 3 months (p?<?0.05). OHIP-14 scores and FACE-Q SFAOS scores showed significant improvement after 1 month (p?<?0.001), but patients aged?>?25 years showed a significant reduction in FACE-Q SFAOS at the end of the study (p?=?0.006).

Conclusions

Surgical removal of the Bichat’s ball induces a mild inflammatory process controlled by rescue medication, significantly reduces face volume, and improves QoL and satisfaction with facial esthetics 3 months postoperatively. However, the efficacy of this procedure in patients?>?25 years old is questionable.

Clinical relevance

Evaluate the effectiveness of bichectomy in terms of clinical effects and impact on quality of life.

     

Comparison of cone-beam computed tomography with bitewing radiography for detection of periodontal bone loss and assessment of effects of different voxel resolutions: an in vitro study

Objective

The aim of the study was to compare intraoral radiographs and CBCT images for detection of horizontal periodontal bone loss, and to investigate the diagnostic effect of different voxel resolutions in CBCT imaging.

Methods

A total of 240 sites with horizontal bone loss were measured on the buccal, lingual, mesial, and distal surfaces of 60 posterior teeth in four maxillary and six mandibular bones obtained from cadavers (dry skulls). Direct measurements on the dry skulls were accepted as the gold standard values. Measurements on CBCT images at two different voxel resolutions (0.250 and 0.160 mm³) and intraoral bitewing radiographs were compared with one another and with the gold standard values.

Results

The measurements on the CBCT images at two voxel resolutions and bitewing radiographs did not differ significantly (p?>?0.05) from the direct measurements on the dry skulls. No significant difference was found between the bitewing radiographs and CBCT images for measurements in the mesial and distal regions (p?>?0.05). There was no significant difference between the measurements on the buccal and lingual surfaces at the two different voxel resolutions (p?>?0.05).

Conclusions

CBCT scans are recommended for evaluation of buccal and lingual bone loss to avoid intraoral radiographs that exceed routine examination of interproximal alveolar bone loss. Furthermore, instead of basing the voxel size on the required CBCT scans, it is recommended to select the smallest possible field of view to reduce the dose of radiation.

     

Comparative determination of skeletal maturity by hand–wrist radiograph,cephalometric radiograph and cone beam computed tomography

Objectives

The purpose of this study is to assess the stages of skeletal maturity in cone beam computed tomography (CBCT), hand–wrist radiography (HWR) and cephalometric radiography (CR) techniques of orthodontic patients, and associate skeletal maturity stages with chronological age, in a Turkish subpopulation.

Methods

Hand–wrist radiographs, cephalometric radiographs and CBCT of 105 patients were evaluated. For evaluation of HWR, the “Hand Bone Age A Digital Atlas of Skeletal Maturity” of Vicente Gilsanz and Osman Ratib (2005) was used. Skeletal maturation in the cephalometric radiographs and sagittal sections of cervical vertebrae obtained by CBCT were evaluated with Hassel and Farman’s method (1995). All results were re-evaluated 3 weeks later to assess intra-observer reliability.

Results

Intra-observer reliability coefficients of the skeletal maturity stages in HWR, CR, and CBCT were 0.912, 0.595, 0.756 respectively (p?<?0.05). Spearman’s correlation coefficient value between skeletal developmental stages in in HWR, CR, and CBCT was found to be 0.785, 0.875, and 0.791, respectively (p?<?0.05).

Conclusion

Results of this study reveal that the determination of the skeletal development status with analysis of cervical vertebrae using cephalometric radiographs and CBCT is as reliable method as the evaluation of the hand–wrist radiographs and is compatible with chronological age in a subgroup of the Turkish population. When assessing the skeletal development stages of patients, both CBCT and CR can be used validly, so no extra hand–wrist radiography is required. This information is important for the prevention of increased radiation doses in patients.

     

Imaging of nano-hydroxyapatite/chitosan scaffolds using a cone beam computed tomography device on rat calvarial defects with histological verification

Objectives

Τhis study aims at determining the ability of cone beam computed tomography (CBCT) to visualize critical-size defects (CSD) created at rat calvaria and filled with 75/25 w/w nano-hydroxyapatite/chitosan (nHAp/CS) scaffolds, prior to their histological investigation.

Materials and methods

Thirty adult Sprague Dawley rats, 15 males and 15 females, were used. Two CSD, 5 mm in diameter, were bilaterally trephined in the parietal bone. The right CSD was filled with nHAp/CS scaffold, while the left CSD remained empty, as the control group. Two female rats died post-operatively. Rats were euthanized at 2, 4, and 8 weeks post-surgery. Twenty-eight specimens (15 × 2 × 10 mm) were resected—containing both CSDs—and then scanned using a NewTom VGi CBCT imaging unit (Verona, Italy). The manufacturer’s software trace region profile tool (NNT v6.2, Verona, Italy) was used in selected axial slices. The greyscale value (in ^VGiHU) and the traced/selected region of interest (ROI, in mm²) of those areas were automatically calculated. Subsequently, all specimens were histologically examined.

Results

An increased ^VGiHU (P = 0.000), was observed in the experimental group relative to the control group. The ROI of CSD (in mm²) was significantly reduced (P = 0.001) from the fourth to the eighth week in both groups. No statistically significant difference between male and female rats (P = 0.188) was observed with respect to ^VGiHU.

Conclusions

The nHAp/CS scaffolds are easily visualized using a particular high-resolution CBCT device.

Clinical relevance

Both the CBCT measurements and also the histological results suggest that the nHAp/CS scaffold presence contributes to new bone formation in rat calvarial CSD.

     

Osseous alterations in the condylar head after unilateral surgical directional change in rabbit mandibular condyles: Preliminary study

The purpose of this study was to investigate bony changes in the mandibular condyle when the surface not normally subjected to masticatory forces was subjected to functional loading using a unilateral surgical experiment. Fifteen male New Zealand white rabbits, divided into two groups, were used. Oblique vertical body osteotomies of the mandible and counterclockwise rotation (CCWR) of the proximal segment (PS) [six with 1 mm (group I), six with 3 mm (group II)] were performed on the right side. Osseous changes of condyles were analyzed using micro-computed tomography and histological evaluation four weeks postoperatively. The comparison was performed between condyles on the right and left sides. Since the left condyle (control) might be affected by the operation on the right side, the results were also compared with the healthy control (group III, n = 3, 6 condyles). CCWR of the PS led to osteoporotic changes of the condyle including significantly reduced bone volume and bone mineral density (p < 0.05), thin and small number of trabeculae (p < 0.05). In addition, thinning of condylar cartilage and reduced density of cartilaginous cells were observed. However, these changes were not affected by the amount of CCWR of the PS.