Versatility of uniplanar prearthoplastic distraction osteogenesis in the correction of post-ankylosis facial deformities—a report of five different cases

Purpose

Unilateral or bilateral ankylosis can lead to severe micrognathia and facial deformity that requires multiple, often, staged surgical corrections. To date, there is no ideal treatment modality that satisfactorily corrects the complex anatomy, restores the ramal height, and corrects the micrognathia and microgenia. Distraction osteogenesis has been acclaimed as a successful modality for the treatment of such deformities. It is a cost-effective approach with low morbidity and less relapse thus providing better functional and esthetic outcomes. It allows the surgeon to correct the deformity in various planes by using various devices by changing osteotomy designs and vectors, with simultaneous hard tissue and soft tissue reconstruction.

Patients and methods

Here, we present a series of five cases where different types of distraction osteogenesis were combined with various other procedures to correct post-ankylotic facial asymmetry. In one case, simultaneous maxillo-mandibular distraction [Molina’s technique] was used.

Results

All patients showed significant improvement in function and esthetics. Outcome assessment was made using clinical photographs and radiographs.

Conclusion

Pre-arthroplastic distraction osteogenesis is a versatile cost effective approach that can be customized for every patient based on their needs.

     

Strain Distribution and Amount of Force Required During Pterygomaxillary Dysjunction: A Comparison of Pterygoid Versus Shark-fin Osteotome

Objective

This study was conducted to compare the efficacy of Obwegeser’s pterygoid osteotome and Laster shark-fin osteotome by measurement of strain adjacent to the pterygomaxillary suture and the amount of force required for dysjunction.

Materials and Methods

Two popular instruments Obwegesser’s pterygoid and shark-fin osteotome were tested on dry human skulls. The external force required for separation of the pterygomaxillary suture with these osteotomes was generated by an electronically controlled ‘Instron’ tester Bi-06-108. Tests were performed with pterygoid osteotome placed on one randomly chosen side and shark-fin osteotome on the other side of the same specimen. The amount of strain developed by each of these instruments was recorded using two strain gauges on the right and left lateral pterygoid plates.

Results

Instrument used	Mean force to achieve dysjunction	Mean strain developed
Pterygoid osteotome	169 N	887.66 microstrain
Shark-fin osteotome	175.5 N	677.33 microstrain

Conclusion

Based on the distribution of strain, from this study, we conclude that Laster shark-fin osteotome is efficacious over Obwegeser’s Pterygoid osteotome, in Le fort I osteotomy.

     

Evaluation of the palatal split pattern in surgically rapid maxillary expansion—comparison of two techniques

Purpose

Surgically assisted rapid maxillary expansion is performed to correct transverse deficiencies of the maxilla, and it is indicated in specific clinical situations. The literature presents different opinions in several aspects, mainly regarding the effect of disjunction of the pterygoid plates. The aim of this study was to evaluate the pattern of maxillary expansion obtained with two surgical techniques, with and without disjunction of the pterygoid plates.

Methods

Twenty patients treated with surgically assisted rapid maxillary expansion for correction of transversal discrepancies were included in this retrospective study and divided into two groups: (G1) patients operated without disjunction of pterygoid plates and (G2) patients treated with release of the pterygoid plates.

Results

There were seven male and 13 female patients, and the mean age was 29.9 years. Cone beam computed tomography images obtained after final activation of the expansion device were evaluated and complete disjunction of the midpalatal suture (type I) was present in 75 % of the patients whereas incomplete disjunction of the midpalatal suture (type II) was observed in 25 %. Chi-square test showed no statistically significant difference between groups (p = 0.606).

Conclusion

No difference was found in relation to the maxillary disjunction pattern irrespective of the treatment given to pterygoid plates.

     

A Self-Retaining Lingual Flap Guarding Device During Surgical Removal of Impacted Mandibular Third Molar

Introduction

Lingual nerve damage is one of the common complications following mandibular third molar surgery. On considering the impact of lingual nerve damage on the patient’s quality of life, it is necessary to exercise caution to minimize its occurrence.

Material and methods

Although many lingual retractors are available, in this article we describe an indigenously designed lingual retractor for use in mandibular third molar surgery.

Conclusion

The indigenous lingual retractor described in this article provides advantages like clear access and excellent retention unlike conventional retractors.

     

Nasal Profile Changes Following Anterior Maxillary Segmental Osteotomy: A Lateral Cephalometric Study

Purpose

Orthognathic surgery in reference to the maxilla attempts to correct underlying skeletal deformities and improve function. Consequently it has the potential to significantly alter the central esthetic unit of the face, the nasolabial region. In order to evaluate the nasal morphological changes which would result following anterior maxillary segmental osteotomy (superior and posterior repositioning); four angles namely, nasolabial, nasal tip projection, columellar labial and supra tip break angle were evaluated.

Method and materials

In ten selected subjects who have undergone anterior maxillary segmental osteotomy with superior and posterior repositioning, pre (T1) and post operative (T2) lateral cephalometric parameters pertaining to the four angles were analysed using Wilcoxon signed rank test.

Results

A significant increase in nasolabial angle and mild changes in nasal tip projection, columellar labial angle and supra tip break angle were observed.

Conclusion

The results of this study emphasize the need for the pre surgical evaluation of nasal morphology in every individual planned for anterior maxillary segmental osteotomy.

     

Superolateral Dislocation of Bilateral Intact Mandibular Condyles: A Rare Case Series

Background and Purpose

The dislocation of mandibular condyle is a clinical condition in which the head of condyle has been displaced out of the glenoid fossa. Complete dislocation of the mandibular condyle can occur in anterior, posterior, lateral and superior direction. Among these dislocations, bilateral superolateral dislocation of mandibular condyles is quite rare and often misdiagnosed. Because of its rare occurrence and unusual clinical course, the best treatment is debatable.

Patients and Method

We present the first case series of true bilateral superolateral dislocation of intact mandibular condyles (Type 2B) without fracturing the Zygomatic arch, associated with symphysis fracture.

Conclusion

This article intends to provide information regarding the possible biomechanics and management of bilateral superolateral dislocation of mandibular condyles associated with symphysis fracture.

     

Factors affecting observer agreement in morphological evaluation of mandibular cortical bone on panoramic radiographs

Objectives

To assess intra- and inter-observer agreement in the morphological evaluation of mandibular cortical bone on panoramic radiographs, to examine factors affecting the diagnosis, and to determine causes of diagnostic discrepancy.

Methods

Three experienced observers evaluated mandibular cortical shape on panoramic radiographs of 228 females, and divided the images into three classes. The intra- and inter-observer agreements were calculated. The effect of mandibular cortical width on shape classification was examined. Causes of diagnostic discrepancy were investigated.

Results

Overall intra- and inter-observer kappa values in diagnosing mandibular cortical shape were 0.58–0.76 and 0.62–0.69, respectively. The kappa values in diagnosing Class 2 were low. In radiographs diagnosed as Class 2 and Class 3, the ranges of mandibular cortical width overlapped. Discrepancies in diagnosis were caused by slight resorption at the endosteal margin of the cortical bone, endosteal cortical residues near the thinned smooth cortex, and superimposition of the hyoid bone over the mandible.

Conclusions

Inter-observer agreement in evaluating mandibular cortical shape was moderate to substantial. Diagnostic discrepancies were mainly caused by differences in evaluation of the endosteum near the cortical bone.

     

A Cost-Effective,In-House,Positioning and Cutting Guide System for Orthognathic Surgery

Introduction

Technological advances in 3D printing can dramatically improve orthognathic surgical planning workflow. Custom positioning and cutting guides enable intraoperative reproduction of pre-planned osteotomy cuts and can result in greater surgical accuracy and patient safety.

Objectives

This short paper describes the use of freeware (some with open-source) combined with in-house 3D printing facilities to produce reliable, affordable osteotomy cutting guides.

Methods

Open-source software (3D Slicer) is used to visualise and segment three-dimensional planning models from imported conventional computed tomography (CT) scans. Freeware (Autodesk Meshmixer ©) allows digital manipulation of maxillary and mandibular components to plan precise osteotomy cuts. Bespoke cutting guides allow exact intraoperative positioning. These are printed in polylactic acid (PLA) using a fused-filament fabrication 3D printer. Fixation of the osteotomised segments is achieved using plating templates and four pre-adapted plates with planned screw holes over the thickest bone. We print maxilla/ mandible models with desired movements incorporated to use as a plating template.

Results

A 3D printer capable of reproducing a complete skull can be procured for £1000, with material costs in the region of £10 per case. Our production of models and guides typically takes less than 24 hours of total print time. The entire production process is frequently less than three days. Externally sourced models and guides cost significantly more, frequently encountering costs totalling £1500–£2000 for models and guides for a bimaxillary osteotomy.

Conclusion

Three-dimensional guided surgical planning utilising custom cutting guides enables the surgeon to determine optimal orientation of osteotomy cuts and better predict the skeletal maxilla/mandible relationship following surgery. The learning curve to develop proficiency using planning software and printer settings is offset by increased surgical predictability and reduced theatre time, making this form of planning a worthy investment.

     

Erratum to: Nasal Profile Changes Following Anterior Maxillary Segmental Osteotomy: A Lateral Cephalometric Study

Purpose

Orthognathic surgery in reference to the maxilla attempts to correct underlying skeletal deformities and improve function. Consequently, it has the potential to significantly alter the central esthetic unit of the face, the nasolabial region. In order to evaluate the nasal morphological changes which would result following anterior maxillary segmental osteotomy (superior and posterior repositioning), four angles, namely nasolabial, nasal tip projection, columellar labial and supra tip break angle, were evaluated.

Method and Materials

In ten selected subjects who have undergone anterior maxillary segmental osteotomy with superior and posterior repositioning, preoperative (T1) and postoperative (T2) lateral cephalometric parameters pertaining to the four angles were analyzed using Wilcoxon’s signed-rank test.

Results

A significant increase in nasolabial angle and mild changes in nasal tip projection, columellar labial angle and supratip break angle were observed.

Conclusion

The results of this study emphasize the need for the presurgical evaluation of nasal morphology in every individual planned for anterior maxillary segmental osteotomy.

     

A morphometric analysis of the mandibular canal by cone beam computed tomography and its relevance to the sagittal split ramus osteotomy

Purpose

The aim of the present study was to morphometrically analyze the mandibular canal through the mandibular ramus by cone beam computed tomography (CBCT) and to relate the findings to performing sagittal split ramus osteotomy.

Methods

CBCT of 200 patients were analyzed. Five parameters were measured at the axial scan, from the mandibular foramen to 21 mm below it (3-mm intervals). The canal was classified according to the position within the bone marrow space. Variations were evaluated according to age, sex, side, and number of mandibular teeth.

Results/conclusions

The following measurements increased gradually towards the most inferior level of measurement: the total thickness of the mandibular ramus through the center of the mandibular canal, the width of the bone marrow space (both buccal and lingual), and the narrowest width from the mandibular canal inner cortical to the mandibular ramus external cortical. The inner diameter of the mandibular canal slightly decreased to the same direction. Concerning the mandibular canal position within the bone marrow space, the percentage of the separate type increased towards the most inferior level of measurement, and the contact and fusion types decreased. Age, number of teeth, and sex had no significant influence on the total thickness of the mandibular ramus and on the narrowest width from the mandibular canal inner cortical to the mandibular ramus external cortical.

     

Mandibular war injuries caused by bullets and shell fragments: a comparative study

Purpose

Is to compare the patterns, severity, and management of the high- and low-velocity mandibular war injuries managed at Al Shaheed Gazi Al-Hariri Hospital in Baghdad Medical City, Iraq, during a 2-year period.

Methods

Forty-one patients with a history of mandibular war injuries treated by our maxillofacial team were reviewed during a period of 2 years (2015–2017). All patients were treated in the Maxillofacial Unit of the Hospital of Specialized Surgeries in Baghdad Medical City.

Results

A 2-year retrospective study evaluated 41 patients with mandibular war injuries with a total of 94 fractures (comminution represents 79.06% of the bullet injuries, while it is only 62.74% with IED injuries). Management of these injuries was varied according to the severity of the injuries and resources available. Close reduction was used in 72.72% of the linear fracture cases, whereas open technique was used in 56.6% of the comminuted fractures.

Conclusions

Bullet injuries were associated with a higher number of mandibular comminuted fractures, in addition to more extensive bone loss. While shell injuries of IED (improvised explosive devices), on the other hand, were associated with higher infection rate and more postoperative complication.

     

Osteoporotic mandibular changes caused by type 2 diabetes mellitus: a comparative study by cone beam computed tomography imaging

Objectives

Studies on bone mineral density and fracture risk in diabetic patients have attracted interest in the last few years. This study was aimed at comparing mandibular osteoporotic changes assessed by qualitative and quantitative radiographic methods in the mandibles of type 2 diabetes mellitus patients with those of non-diabetic subjects using cone beam computed tomographic images.

Methods

This quantitative and qualitative study of mandibular bone in diabetic patients included 23 type 2 diabetes mellitus patients and an equal number of healthy subjects. Radiomorphometric measurements were performed for each subject using cone beam computed tomography images. Changes in cortical bone thickness were determined by measuring bone area. Fractal dimension analysis was applied to evaluate the trabecular structure of the bone.

Results

No statistically significant difference could be established between the type 2 diabetes mellitus group and the control group in regard to either radiomorphometric measurements or fractal dimension analysis. Quantitative assessment of mandibular bone indicated a thinning of the cortical bone, with a statistically significant difference between the type 2 diabetes mellitus patients and the healthy controls.

Conclusions

Bone condition related to diabetes involves complex pathophysiological mechanisms; thus, radiographic imaging parameters may be useful as an adjunct to clinical parameters.

     

Fate of Costochondral Graft in Temporomandibular Joint Reconstruction: A Histological Study

Objective

To asses the fate of the costochondral graft (CCG) used to stimulate mandibular growth in the management of Temporomandibular joint (TMJ) reconsrtuction in ankylosis—histologically.

Materials and Methods

Ten patients who had undergone CCG grafting for TMJ ankylosis between 1994–2009 in the department of Oral & Maxillofacial Surgery, Tamil Nadu Govt Dental College and Hospital, Chennai and had come back with reankylosis, were surgically explored and the graft along with the ankylotic mass was excised and evaluated histologically. There is no documented human study and clinically it is not possible.

Results

Histological evaluation revealed the presence of osseous tissue, fibrous tissue and osteocytes but no evidence of any chondroid tissue.

Conclusion

Our study showing the absence of chondroid tissue raises the question on the rationale of CCG in TMJ reconstruction when other interpositional gap arthroplasty can achieve a disease free joint.

     

Clinical and radiological analysis of osteochondromas of the mandible using cone-beam computed tomography

Objectives

Osteochondroma (OC) is rare in the mandibular condyle. The radiographic appearance of this lesion is diverse. Most radiologists and surgeons agree that helical computed tomography (CT) has great diagnostic potential for OC. Cone-beam CT (CBCT) can also afford three-dimensional information, and it is widely used to evaluate oral and maxillofacial diseases. The purpose of this study was to elucidate the CBCT characteristics of OC in the mandible and increase the radiographic knowledge of mandibular OC.

Methods

The CBCT radiographs of 31 cases of mandibular OC (29 cases in the condyle and two cases in the coronoid process) were reviewed. All data were obtained from the oral radiology department of our institution from 2009 to 2014. The final diagnoses of all cases were based on pathological examination. Patient age, sex, symptoms, and radiographic findings were considered in all cases. Percentages, the t test, and the χ ² test were used for statistical analyses.

Results

Progressive facial asymmetry, malocclusion, and opening deviation were the most common symptoms. There was no sex-related difference in age at onset, symptoms, or tumor location. Although the mandibular OCs exhibited diverse shapes, they could be divided into two types: bony outgrowth (more common) and condylar expansion. The structures adjacent to the mandibular OC were often affected by the tumor; cortical hyperostosis of the affected glenoid fossa was found in most cases.

Conclusions

Mandibular OCs may show different growth positions encircling the condyle and exhibit varying shapes. CBCT can provide enough information for use in the diagnosis of OCs.

     

Radiographic evaluation of condylar positioning in patients undergoing orthognathic surgery

Objective

The aim of this study was to evaluate alterations in condylar positioning through submentovertex projection (Hirtz Radiographic Technique) in patients who underwent orthognathic surgery for maxillary advancement and mandibular setback with stable internal fixation.

Methods

A prospective longitudinal clinical study of 40 surgical patients presenting dentofacial deformity admitted in the Oral and Maxillofacial Surgery Department of Federal University of Paraná (UFPR) in the period between March 2013 and December 2015. We performed two submentovertex digital radiographs, one 7 days before surgery and the other one 30 days after the procedure. Cephalometric tracings were made using Radiocef® Studio 2 Software and measured the intercondylar and condylar angles (right and left).

Results

There was a decrease in the intercondylar angle (p < 0.001) and an increase in condylar angles both the right and the left side (p < 0.001) when compared with the pre and postoperative period. There was a larger increase in condylar angle on the right side in males (p = 0.007).

Conclusion

There is a tendency of decreasing of the intercondylar angle after orthognathic surgery, regardless of the alteration in the condylar angles, creating a new position of the condyle in the glenoid fossa. Patients with asymmetry may present greater alterations in the positioning of the opposite condylar to the deviation of the mandibular midline.

     

The Jugaad Technique for Jaw Reconstruction: Denture Based Inverse Planning

Aim

The aim of this clinical paper is to introduce a technique to plan for functional maxillofacial reconstructions.

Materials and Methods

Preoperative dental casts were made of the patient and mock surgery performed on the casts. A fibula analogue was then placed in an ideal functional reconstruction position. New dentures were fabricated on the fibula analogue and drill holes for the placement of implants were placed through the denture. This denture formed as a guide to position the fibula transplant during surgery.

Results

This technique was useful in producing functional and rehabilitative outcomes in cases of both maxillary and mandibular reconstructive surgeries.

Conclusion

The Jugaad technique—denture based inverse planning—is a cost effective method for planning and executing maxillofacial reconstructions using mock surgery on casts and interim dentures.

     

Deterioration of teeth and alveolar bone loss due to chronic environmental high-level fluoride and low calcium exposure

Objectives

Health risks due to chronic exposure to highly fluoridated groundwater could be underestimated because fluoride might not only influence the teeth in an aesthetic manner but also seems to led to dentoalveolar structure changes. Therefore, we studied the tooth and alveolar bone structures of Dorper sheep chronically exposed to very highly fluoridated and low calcium groundwater in the Kalahari Desert in comparison to controls consuming groundwater with low fluoride and normal calcium levels within the World Health Organization (WHO) recommended range.

Materials and methods

Two flocks of Dorper ewes in Namibia were studied. Chemical analyses of water, blood and urine were performed. Mineralized tissue investigations included radiography, HR-pQCT analyses, histomorphometry, energy-dispersive X-ray spectroscopy and X-ray diffraction-analyses.

Results

Fluoride levels were significantly elevated in water, blood and urine samples in the Kalahari group compared to the low fluoride control samples. In addition to high fluoride, low calcium levels were detected in the Kalahari water. Tooth height and mandibular bone quality were significantly decreased in sheep, exposed to very high levels of fluoride and low levels of calcium in drinking water. Particularly, bone volume and cortical thickness of the mandibular bone were significantly reduced in these sheep.

Conclusions

The current study suggests that chronic environmental fluoride exposure with levels above the recommended limits in combination with low calcium uptake can cause significant attrition of teeth and a significant impaired mandibular bone quality.

Clinical relevance

In the presence of high fluoride and low calcium-associated dental changes, deterioration of the mandibular bone and a potential alveolar bone loss needs to be considered regardless whether other signs of systemic skeletal fluorosis are observed or not.

     

Patient’s Self-Assessment of Social-Approval After Mandibulectomy with Disarticulation: the Necessity for Jaw Reconstruction Following Loss of Facial Symmetry in a Resource-Poor African Setting

Objective

Mandibulectomy with disarticulation is usually carried out without reconstruction in Low-Income-Countries. Lower standards of living are usually acceptable and adapted to, in poor societies. This study compares patient’s self-assessment of social approval among reconstructed and non-reconstructed cases of mandibulectomy with disarticulation in a resource-poor African setting.

Material and Method

This questionnaire-based study documented patient’s self-assessment of social approval of themselves following mandibulectomy with disarticulation. 12 derived queries were administered on each patient, to test what they perceived of social acceptability of their facial features following mandibulectomy.

Results

All 10 patients who underwent mandibular reconstruction reported that they felt confident engaging in all forms of social activity, while all 10 who had resection without reconstruction did not.

Conclusion

The low social approval perceived by patients who have undergone mandibulectomy with disarticulation without reconstruction necessitates that surgeons must strive to reconstruct this anatomical region even under circumstances of severe resource-constraint. The culture in the third-world is not supportive of patients who have not undergone reconstruction following resection, in spite of being victims of all-pervading poverty.

Level of Evidence

Level IV, investigative study.

     

Modified Le Fort III Osteotomy: Different Applications

Summary

Based on the new concepts of the modified Le Fort III osteotomy (MLFIIIO), Three variations of this technique are implemented: (A) the modified osteotomy Le Fort III Champy (1980) technique to be described with the use of surgical guides, and subciliary approach or an transconjunctival approach. Excellent technique for horizontal advancement no further to 6 mm, without requiring any type of graft.. (B) The modified Le Fort III osteotomy in “Z”: to solve horizontal (posterior anterior) problems of more than 6 mm without bone grafting. It is itself a modification of the technique described by Champy. (C) The modified Le Fort III osteotomy ascending: modified the original technique described by Bell and Epker with interpositional grafts, was modified by the called ascendant, making it higher in cases where the patient has an acceptable nasal bridge, but exorbitism the lateral wall of the orbit. Le Fort III osteotomy combined with a Le Fort I osteotomy and a front implant.

Method

As pointed out in Part I for the modified oblique Le Fort III osteotomy, methods for the design of the osteotomy Le Fort III property will depend on the requirements of individual patients, and this has led us to design specific techniques for the deformity.

Results

Patients have a right projection of the middle third, and protection of the eyeball.

Conclusions

The techniques presented for the advancement of the middle third have excellent results with the ability to be tailored to each patient deformity.