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Developmental Dynamics : An Official... May 2006Classic neontology (comparative embryology and anatomy), through the application of the concept of homology, has demonstrated that the development of the gnathostome... (Comparative Study)
Comparative Study Review
Classic neontology (comparative embryology and anatomy), through the application of the concept of homology, has demonstrated that the development of the gnathostome (jawed vertebrate) skull is characterized both by a fidelity to the gnathostome bauplan and the exquisite elaboration of final structural design. Just as homology is an old concept amended for modern purposes, so are many of the questions regarding the development of the skull. With due deference to Geoffroy-St. Hilaire, Cuvier, Owen, Lankester et al., we are still asking: How are bauplan fidelity and elaboration of design maintained, coordinated, and modified to generate the amazing diversity seen in cranial morphologies? What establishes and maintains pattern in the skull? Are there universal developmental mechanisms underlying gnathostome autapomorphic structural traits? Can we detect and identify the etiologies of heterotopic (change in the topology of a developmental event), heterochronic (change in the timing of a developmental event), and heterofacient (change in the active capacetence, or the elaboration of capacity, of a developmental event) changes in craniofacial development within and between taxa? To address whether jaws are all made in a like manner (and if not, then how not), one needs a starting point for the sake of comparison. To this end, we present here a "hinge and caps" model that places the articulation, and subsequently the polarity and modularity, of the upper and lower jaws in the context of cranial neural crest competence to respond to positionally located epithelial signals. This model expands on an evolving model of polarity within the mandibular arch and seeks to explain a developmental patterning system that apparently keeps gnathostome jaws in functional registration yet tractable to potential changes in functional demands over time. It relies upon a system for the establishment of positional information where pattern and placement of the "hinge" is driven by factors common to the junction of the maxillary and mandibular branches of the first arch and of the "caps" by the signals emanating from the distal-most first arch midline and the lamboidal junction (where the maxillary branch meets the frontonasal processes). In this particular model, the functional registration of jaws is achieved by the integration of "hinge" and "caps" signaling, with the "caps" sharing at some critical level a developmental history that potentiates their own coordination. We examine the evidential foundation for this model in mice, examine the robustness with which it can be applied to other taxa, and examine potential proximate sources of the signaling centers. Lastly, as developmental biologists have long held that the anterior-most mesendoderm (anterior archenteron roof or prechordal plate) is in some way integral to the normal formation of the head, including the cranial skeletal midlines, we review evidence that the seminal patterning influences on the early anterior ectoderm extend well beyond the neural plate and are just as important to establishing pattern within the cephalic ectoderm, in particular for the "caps" that will yield medial signaling centers known to coordinate jaw development.
Topics: Animals; Animals, Newborn; Humans; Infant, Newborn; Mandible; Maxilla; Skull
PubMed: 16598716
DOI: 10.1002/dvdy.20796 -
BMC Oral Health Jun 2023The insertion positions of mini-implant in infrazygomatic crest has been reported, but due to the anatomical variation, the precise location of this site is not clear...
BACKGROUND
The insertion positions of mini-implant in infrazygomatic crest has been reported, but due to the anatomical variation, the precise location of this site is not clear yet. This study used cone-beam computed tomography (CBCT) to analyze the position and angle of mini-implants successfully inserted in the infrazygomatic crest, with the goal of providing reference data for clinical practice.
METHODS
CBCT was used to image 40 mini-implants and their surrounding tissues in adult orthodontic patients who successfully underwent mini-implant insertion in the infrazygomatic crest. The insertion positions and angles of mini-implants were measured, and the thicknesses of buccal and palatal bone adjacent to the mini-implants were also recorded. Then, we proposed the position and implantation angle for infrazygomatic crest insertion. According to the position and angle, the cortical bone thickness and distance to the root of another 54 randomly selected infrazygomatic crests were recorded to verify its feasibility.
RESULTS
In the coordinate system, the implantation position of the 40 successful mini-implants was (-0.4 ± 2, 8.2 ± 2.5) and the implantation angle between the long axis of the mini-implant and horizontal reference plane was 56.4° ± 7.7°. The bone thicknesses on buccal and palatal sides of infrazygomatic crest adjacent to mini-implants were 4.1 ± 2.5 mm and 7.2 ± 3.2 mm, respectively, and the cortical bone thickness was 2.4 ± 0.6 mm. Among 54 infrazygomatic crests, 75.9% of them met the safety and stability requirements. When the implantation height was increased by 1, 2, and 3 mm, the proportions of implants that met requirements for success were 81.5%, 90.7%, and 94.4%, respectively. But, the proportions of eligible implants were limited at implantation angle increases of 5° and 10°.
CONCLUSIONS
Using the long axis of the maxillary first permanent molar (U6) as the vertical reference line, mini-implants could be safely inserted in the infrazygomatic crest at a distal distance of 0.4 mm and height of 8.2 mm from the central cementum-enamel junction of U6, with an implantation angle of 56.4°. The success rate increased when the implant height increased, but the proportion of eligible implantation was limited with the increase of implantation angle.
Topics: Adult; Humans; Dental Implants; Orthodontic Anchorage Procedures; Cone-Beam Computed Tomography; Molar; Palate; Maxilla
PubMed: 37264370
DOI: 10.1186/s12903-023-03081-0 -
Head and Neck Pathology Dec 2010A case of compound odontomas of the anterior maxilla is discussed. Multiple tooth like structures were discovered upon surgical excision.
A case of compound odontomas of the anterior maxilla is discussed. Multiple tooth like structures were discovered upon surgical excision.
Topics: Child; Female; Hamartoma; Humans; Maxilla; Odontoma; Radiography; Tooth Abnormalities
PubMed: 20533004
DOI: 10.1007/s12105-010-0186-2 -
Brazilian Journal of Otorhinolaryngology 2022To evaluate, by a three-dimensional study, the volumetric and integumentary effects of rapid maxillary expansion on the nose, in mouth breathing kids with maxillary...
OBJECTIVE
To evaluate, by a three-dimensional study, the volumetric and integumentary effects of rapid maxillary expansion on the nose, in mouth breathing kids with maxillary hypoplasia, in the short term, assessing the possible interference of gender, growth and age on the results achieved.
METHODS
120 mouth breathing patients with maxilla hypoplasia were divided into an Experimental Group treated by rapid maxillary expansion (n = 104, 62 males and 42 females, mean age 10.1 years, SD = 2.10, ranging from 5.1 to 13.9 years); and Control Group, constituted by 16 patients (9 males and 7 females, mean age 9.3 years, SD = 2.1 years, ranging from 6.1 to 13.2 years). Patients in the experimental group underwent multislice computed tomography examinations at two different times: (T1) pre-expansion and (T2) post-expansion. The control group was submitted to the same tests at the same time intervals. Six soft tissue variables of the nose were studied, besides the volume and area of the nasal cavity, and the measurement and comparison of data between T1 and T2 were performed using the Dolphin Imaging 11.7 Premium software.
RESULTS
The experimental group showed significant mean increases in all soft tissue variables studied (p < 0.005), yet there were no significant changes in the control group. In the comparison between groups, only inclination of the nasal dorsum did not present any significant change.
CONCLUSION
Rapid maxillary expansion may alter the nasal shape and physiology, by anatomical changes in the nose soft tissues, making it an important aid in the treatment of mouth breathing in childhood.
LEVEL OF EVIDENCE
The soft tissues of the nose play an important role in nasal shape and physiology and facial esthetics, and since they are directly related to the nasal valves, they are fundamental for maintenance and stability of the nasal breathing pattern.
Topics: Male; Female; Humans; Palatal Expansion Technique; Mouth Breathing; Imaging, Three-Dimensional; Maxilla; Nose; Respiration
PubMed: 35241386
DOI: 10.1016/j.bjorl.2022.01.007 -
International Journal of Environmental... Apr 2021Mini-dental implants (MDIs) have been used to support and retain overdentures, providing patients with a less invasive placement procedure. Although lucrative, the use... (Meta-Analysis)
Meta-Analysis Review
PURPOSE
Mini-dental implants (MDIs) have been used to support and retain overdentures, providing patients with a less invasive placement procedure. Although lucrative, the use of MDIs to retain a maxillary overdenture is still not an established treatment modality. This systematic review aims to answer the question: Do mini-implant-retained maxillary overdentures provide a satisfactory treatment outcome for complete edentulism?
METHODS
A systematic search for relevant articles was conducted to include articles published until April 2021 in the following electronic databases: CINAHL, Cochrane, EMBASE, PubMed, and Web of Science. All empirical studies evaluating the biological, survival, or patient-reported outcomes after placing mini-implant-retained overdentures in maxilla were considered for inclusion. The risk of bias was assessed by utilizing the Joanna Briggs Institute critical appraisal checklist. Study screening and data extraction were conducted by three reviewers independently.
RESULTS
The electronic search retrieved 1276 titles after omitting duplicates. Twenty articles were considered for full-text review, of which six studies were included in this systematic review. The included studies evaluated a total of 173 participants with a mean age of 66.3 years. The overall mini-implant survival rate was 77.1% (95% CI: 64.7-89.5%) with a mean follow-up time of 1.79 years (range: 6 months to 3 years). Implant survival differed significantly when comparing complete and partial palatal coverage overdentures. Those with complete palatal coverage exhibited less bone loss overall compared to partial coverage overdentures. Participants of all studies reported an increase in the quality of life and in satisfaction after rehabilitation treatment with MDIs.
CONCLUSIONS
The survival rate of mini-implants retaining an overdenture in the maxilla was observed to be lower than the values reported for traditional implants in the literature. Improvements were observed in all aspects in terms of patient satisfaction, quality of life, oromyofunction, and articulation after the treatment.
Topics: Aged; Denture, Overlay; Humans; Jaw, Edentulous; Maxilla; Mouth, Edentulous; Quality of Life
PubMed: 33924167
DOI: 10.3390/ijerph18084377 -
The Kurume Medical Journal Jul 2023The purpose of this study was to investigate the structure of the incisive canal using dry maxillae harvested from human cadavers.
BACKGROUND
The purpose of this study was to investigate the structure of the incisive canal using dry maxillae harvested from human cadavers.
METHODS
Seven dry maxillae were harvested from adult Caucasian human cadavers. The incisive canals in all specimens were observed from an intraoral viewpoint with the naked eye and under a surgical microscope with 20× magnification.
RESULTS
All specimens had a single incisive foramen leading to different numbers of canals. Two specimens had a single canal (Type I), two were double (Type II), and three had triple canals (Type III). In both type I specimens, the canal was centered in the incisive foramen. Type II had a septum between the two canals. This septum was irregular in shape near the entrance of the canal but smooth inside the canal. The canals were positioned asymmetrically within the foramen. Type III had two septa between the three canals. Again, those located near the entrance of the canal were irregular while those inside the canal were smooth. The orientation of the lumina differed from one another in the type III canals.
CONCLUSION
The study identified morphological variations in the anatomy of the incisive canal, underscoring the importance of pre-surgical planning in the administration of local anesthesia, placement of dental implants, or removal of impacted teeth in the anterior maxillary region.
Topics: Adult; Humans; Cone-Beam Computed Tomography; Maxilla; Cadaver
PubMed: 37183019
DOI: 10.2739/kurumemedj.MS682016 -
Medicina Oral, Patologia Oral Y Cirugia... Jul 2020Oral rehabilitation of atrophic maxillae features high complexity, for which there are several therapeutic modalities reported on scientific literature. Zygomatic... (Review)
Review
BACKGROUND
Oral rehabilitation of atrophic maxillae features high complexity, for which there are several therapeutic modalities reported on scientific literature. Zygomatic implant placement is a viable option that features low morbidity and allows immediate prosthetic loading. The purpose of the present study was to determine the methodological quality of systematic reviews that assessed the effectiveness of zygomatic implants placed in atrophic maxillae.
MATERIAL AND METHODS
Searches were conducted on Medline via Pubmed, LILACS, Dare Cochrane, Scopus, and Sigle via Open Grey up to June 2019.
RESULTS
Seven systematic reviews were eligible for Overview and comprised a total of 2313 patients, 4812 zygomatic implants, and a 96,72% success rate. Common surgical complications, in decreasing order, were: maxillary sinusitis, peri-implant mucositis, prosthetic fracture, and infections. Methodological quality was assessed using the AMSTAR 2 tool, which revealed that six systematic reviews showed critically low methodological quality and one review was assessed as of low methodological quality.
CONCLUSIONS
Zygomatic implants seem to be an adequate option for atrophic maxilla rehabilitation, however, new studies with a higher methodological rigor are needed to provide more reliable results to professionals and patients undergoing this modality of oral rehabilitation.
Topics: Dental Implantation, Endosseous; Dental Implants; Dental Prosthesis, Implant-Supported; Follow-Up Studies; Humans; Jaw, Edentulous; Maxilla; Maxillary Sinusitis; Systematic Reviews as Topic
PubMed: 32520920
DOI: 10.4317/medoral.23569 -
Journal of Oral Science 2021Backsliding is a major problem when moving the maxilla significantly forward in orthognathic surgery. For example, in sleep surgery, maxillomandibular advancement is an...
Backsliding is a major problem when moving the maxilla significantly forward in orthognathic surgery. For example, in sleep surgery, maxillomandibular advancement is an application of orthognathic surgery, and it is well known that the anterior movement of the maxilla back and forth is an important factor that greatly widens the pharyngeal airway. However, postoperative backsliding is a major problem in this surgery. Therefore, a surgical method was devised to prevent the maxilla from retracting by adjusting the bone when moving the maxilla forward.
Topics: Cephalometry; Maxilla; Orthognathic Surgery; Orthognathic Surgical Procedures; Osteotomy, Le Fort
PubMed: 34193780
DOI: 10.2334/josnusd.21-0151 -
Progress in Orthodontics Dec 2022The aim of this study is to introduce a novel 3D cephalometric analysis (3DCA) and to validate its use in evaluating the reproducibility of virtual orthodontic-surgical...
OBJECTIVES
The aim of this study is to introduce a novel 3D cephalometric analysis (3DCA) and to validate its use in evaluating the reproducibility of virtual orthodontic-surgical planning (VOSP) in surgery-first approach (SF) comparing VOSP and post-operative outcome (PostOp).
METHODS
The cohort of nineteen patients underwent bimaxillary orthognathic surgery following the VOSP designed in SimPlant O&O software by processing cone-beam computed tomography (CBCT) scans and intraoral digital scanning of the dental arches. Said records were re-acquired once the post-operative orthodontic treatment was completed. The 3DCA was performed by three expert operators on VOSP and PostOp 3D models. Descriptive statistics of 3DCA measures were evaluated, and outcomes were compared via Wilcoxon test.
RESULTS
In the comparison between cephalometric outcomes against planned ones, the following values showed significant differences: Wits Index, which suggests a tendency towards skeletal class III in PostOp (p = 0.033); decreased PFH/AFH ratio (p = 0.010); decreased upper incisors inclination (p < 0.001); and increased OVJ (p = 0.001). However not significant (p = 0.053), a tendency towards maxillary retroposition was found in PostOp (A/McNamara VOSP: 5.05 ± 2.64 mm; PostOp: 4.1 ± 2.6 mm). On average, however, when McNamara's plane was considered as reference, a tendency to biprotrusion was found. Upper incisal protrusion was greater in PostOp as an orthodontic compensation for residual maxillary retrusion (VOSP: 5.68 ± 2.56 mm; PostOp: 6.53 ± 2.63 mm; p = 0.084). Finally, the frontal symmetry in relation to the median sagittal plane decreased in craniocaudal direction.
LIMITATIONS
A potential limit of studies making use of closest point distance analysis is represented by the complexity that surgeons and orthodontists face in applying this three-dimensional evaluation of SF accuracy/predictability to everyday clinical practice and diagnosis. Also, heterogeneity and limited sample size may impact the results of the study comparison.
CONCLUSIONS
The presented 3DCA offers a valid aid in performing VOSP and analysing orthognathic surgery outcomes, especially in SF. Thanks to the cephalometric analysis, we found that surgery-first approach outcome unpredictability is mainly tied to the sagittal positioning of the maxilla and that the transverse symmetry is progressively less predictable in a craniocaudal direction.
Topics: Humans; Orthognathic Surgical Procedures; Reproducibility of Results; Maxilla; Tooth; Cone-Beam Computed Tomography; Imaging, Three-Dimensional; Cephalometry
PubMed: 36581697
DOI: 10.1186/s40510-022-00448-x -
Plastic and Reconstructive Surgery Nov 2021The maxilla position is essential for the aesthetic and functional outcomes of orthognathic surgery. Previous studies demonstrated the advantages of patient-specific... (Comparative Study)
Comparative Study Randomized Controlled Trial
BACKGROUND
The maxilla position is essential for the aesthetic and functional outcomes of orthognathic surgery. Previous studies demonstrated the advantages of patient-specific implants in orthognathic surgery. However, more data are needed to confirm the superiority of patient-specific implants over surgical splints created with computer-aided design/computer-aided manufacturing (CAD/CAM). This randomized controlled trial aimed to compare the accuracy of patient-specific implants and CAD/CAM splints for maxilla repositioning in orthognathic surgery.
METHODS
Patients (n = 64) who required orthognathic surgery were randomly assigned to use either patient-specific implants (patient-specific implant group) or CAD/CAM surgical splints (splint group) to reposition the maxilla. The outcome evaluation was completed by comparing virtual plans with actual results. The primary outcome was the discrepancies of the centroid position of the maxilla. Other translation and orientation discrepancies of the maxilla were also assessed.
RESULTS
The authors analyzed 27 patients in the patient-specific implant group and 31 in the splint group. The maxilla position discrepancy was 1.41 ± 0.58 mm in the patient-specific implant group and 2.20 ± 0.94 mm in the splint group; the between-group difference was significant (p < 0.001). For the patient-specific implant group, the largest translation discrepancy was 1.02 ± 0.66 mm in the anteroposterior direction, and the largest orientation discrepancy was 1.85 ± 1.42 degrees in pitch. For the splint group, the largest translation discrepancy was 1.23 ± 0.93 mm in the mediolateral direction, and the largest orientation discrepancy was 1.72 ± 1.56 degrees in pitch.
CONCLUSION
The result showed that using patient-specific implants in orthognathic surgery resulted in a more accurate maxilla position than CAD/CAM surgical splints.
CLINICAL QUESTION/LEVEL OF EVIDENCE
Therapeutic, I.
Topics: Adult; Computer-Aided Design; Equipment Design; Female; Humans; Imaging, Three-Dimensional; Male; Malocclusion; Maxilla; Orthognathic Surgical Procedures; Patient Care Planning; Splints; Treatment Outcome; Young Adult
PubMed: 34705785
DOI: 10.1097/PRS.0000000000008427