CN115813426A - Head shadow measurement method for sagittal positioning of maxillary central incisor - Google Patents

Abstract

The invention provides a method for measuring a head shadow for sagittal positioning of maxillary central incisors, which comprises the following steps: shooting an X-ray skull positioning lateral film; selecting a mark point, a reference plane and a reference plane on an X-ray skull positioning side sheet; and measuring the line distance of the sagittal position of the incisor in the upper jaw according to the selected mark point, the reference plane and the reference plane, and defining the sagittal position of the incisor in the upper jaw. The application adopts the more stable anterior nasal spine point as a measurement reference point and the extracranial true horizontal plane as a reference plane, on the basis of enhancing the stability and measurement repeatability of the reference point and the reference plane, the reliability of the sagittal position of the incisor in the upper jaw is increased to the greatest extent, and the measurement convenience of the sagittal position of the incisor in the upper jaw is increased, so that the influence of other unstable reference points on the measurement of the sagittal position of the incisor in the upper jaw is eliminated, the length coordinate of the sagittal distance of the incisor in the upper jaw more accurately reflects the clinical condition of a patient, and the orthodontics and the clinical diagnosis and treatment of the orthognathic surgery are more accurately guided.

Description

A Cephalometric Method for Sagittal Positioning of Maxillary Central Incisors

technical field

The invention relates to the technical field of orthodontic X-ray cephalometric measurement, in particular to a cephalometric method for sagittal positioning of maxillary central incisors.

Background technique

X-ray cephalometric analysis is an important means of clinical diagnosis and treatment design in orthodontics and orthognathic surgery. It is mainly to measure the images obtained from X-ray cephalometric photos, and to draw certain line angles for dental, jaw and craniofacial landmarks. Analysis, so as to assist diagnosis and treatment design.

The protrusion of maxillary central incisors has an important impact on facial aesthetics and soft tissue protrusion. Therefore, the sagittal position of maxillary central incisors is an important landmark point for the plan design before orthodontic treatment and the contour overlap after treatment. The methods commonly used in orthodontics to locate the upper anterior teeth include Tweed analysis method and Andrews six elements. plane perpendicular to the distance). However, the inventors of the present application have found through clinical research that the upper alveolar seat point will change due to tooth movement and alveolar bone remodeling during the current orthodontic treatment process, so the upper alveolar seat point is used as the evaluation method for maxillary central incisors. A moving reference point has insufficient reliability. In addition, when evaluating the sagittal relationship of maxillofacial position, the anterior skull base plane (SN plane) and the orbito-auricular plane have large variability, but the true horizontal plane belongs to the extracranial reference plane, and its variability is very small in the natural head position , so its stability is reliable.

The anterior nasal spine point is the tip of the anterior nasal spine, and its stability has been confirmed by research. The anterior nasal spine is far away from the maxillary alveolar bone and is not affected by the remodeling of the alveolar bone. At the same time, it is closer to the maxillary central incisor. The positional relationship with the maxillary central incisor can be more intuitively reflected on the lateral cephalogram. Therefore, if the anterior nasal spine can be used as a reference point for the sagittal position of the maxillary central incisor, it will have important research significance and clinical application value.

Contents of the invention

In the current orthodontic treatment process, the distance between the upper anterior teeth and the vertical line from the maxillary central incisor to the upper alveolar seat point is usually expressed, but the upper alveolar seat point will change due to tooth movement and alveolar bone remodeling , so using the upper alveolar seat as a reference point for evaluating the movement of the maxillary central incisors has a technical problem of insufficient reliability. The present invention provides a cephalometric method for the sagittal positioning of the maxillary central incisors. The anterior nasal spine point is used as the reference point for measurement, and the true horizontal plane of the extracranium is used as the reference plane, so as to eliminate the influence of other unstable reference points on the measurement of the sagittal position of the maxillary central incisor, so that the length of the sagittal distance of the maxillary central incisor The coordinates more accurately reflect the clinical situation of the patient, and more accurately guide the clinical diagnosis and treatment of orthodontics and orthognathic surgery.

In order to solve the problems of the technologies described above, the present invention adopts the following technical solutions:

A cephalometric method for sagittal positioning of maxillary central incisors, comprising the following steps:

S1. Take X-ray cephalometric lateral films;

S2. Select landmarks, datum planes and reference planes on X-ray cephalometric lateral films;

S3. Perform line distance measurement of the sagittal position of the maxillary central incisor according to the selected landmarks, datum plane and reference plane, and define the sagittal position of the maxillary central incisor.

Further, the body position requirements for taking the X-ray cephalometric lateral view in the step S1 include that the patient's mouth is in the cusp crossing position, and the head position is in the natural head position.

Further, the landmark points in the step S2 include: maxillary central incisor points, anterior nasal spine points, and orbital points.

Further, the reference plane in the step S2 is a true horizontal plane.

Further, the reference plane in step S2 is a plane parallel to the true horizontal plane passing through the anterior nasal spine point.

Further, in the step S3, the line distance measurement of the sagittal position of the maxillary central incisor is performed according to the selected landmark point, reference plane and reference plane, and the definition of the sagittal position of the maxillary central incisor specifically includes: using the maxillary central incisor point as a reference The vertical line of the plane measures the distance from the foot of the maxillary central incisor to the anterior nasal spine point, and defines that when the foot of the maxillary central incisor is on the nasal side of the anterior nasal spine, it is the positive direction, which is recorded as +; the maxillary central incisor When the foot of the tooth point is on the ear side of the anterior nasal spine point, it is in the negative direction, recorded as -.

Compared with the prior art, the cephalometric method of the sagittal positioning of the maxillary central incisor provided by the present invention, through the vertical projection of the maxillary central incisor point to the reference plane parallel to the true horizontal plane, the sagittal position of the maxillary central incisor point The definition and position changes before and after treatment can be measured and compared on a more stable reference plane; by introducing the anterior nasal spine point, which is stable in position and can represent the protrusion of the maxilla, as a reference point, the sagittal axis of the maxillary central incisor The position can be quantitatively evaluated and compared with the position of the maxilla, reflecting the protrusion and distance of the maxillary central incisor relative to the maxilla, which increases the objectivity and comparability of the data. In addition, by adjusting the body position when taking lateral cephalometric films, that is, the patient's head is fixed by positioning the nose bar and earplugs, and the line of sight is fixed on the wall at the same level as the eyes, so it is relatively easy to obtain a natural head position. The lower true horizontal plane is perpendicular to the image on the X-ray film of the metal vertical line placed outside the plane when taking pictures in the natural head position, and the positions of the anterior nasal spine point and the maxillary central incisor point are relatively close on the lateral cephalometric film, so Clinically, the sagittal position of the maxillary central incisor can be judged by measuring the position difference between the anterior nasal spine point and the maxillary central incisor point on the horizontal edge of the cranial radiograph in a local and small range, so as to quickly and accurately evaluate the maxillary central incisor. The protrusion of the incisors increases the practicality and clinical significance of the data.

Description of drawings

Fig. 1 is a schematic flowchart of a cephalometric method for sagittal positioning of maxillary central incisors provided by the present invention.

Fig. 2 is a schematic diagram of body position requirements for natural head position when taking X-ray cephalometric measurements provided by the present invention.

Fig. 3 is a schematic diagram of selection of measurement marker points provided by the present invention.

Fig. 4 is a schematic diagram of selection of datum plane and reference plane provided by the present invention.

Fig. 5 is a schematic diagram of measuring the line distance of the sagittal position of the maxillary central incisor provided by the present invention.

Detailed ways

In order to make the technical means, creative features, goals and effects achieved by the present invention easy to understand, the present invention will be further described below in conjunction with specific illustrations.

Please refer to Fig. 1, the present invention provides a cephalometric method for sagittal positioning of maxillary central incisors, comprising the following steps:

S1. Take X-ray cephalometric lateral films;

S2. Select landmarks, datum planes and reference planes on X-ray cephalometric lateral films;

S3. Perform line distance measurement of the sagittal position of the maxillary central incisor according to the selected landmarks, datum plane and reference plane, and define the sagittal position of the maxillary central incisor.

As a specific example, the body position requirements for taking the X-ray cephalometric lateral view in the step S1 include the intercuspal position (ICP) in the patient's mouth and the natural head position (NHP). Please refer to Figure 2, the subject is in a natural head position. When taking a cephalometric lateral view, adjust the height of the machine according to the height of the patient so that the opening of the external auditory canal is aligned with the earplugs, and put the earplugs on both sides into the opening of the external auditory canal. The cusp position in the patient's mouth refers to the positional relationship between the upper and lower jaw when the upper and lower teeth are at the cusp and reach the widest and closest contact. The head is in the natural head position, and the subject is naturally standing upright with his legs apart (or sitting on a stool with natural relaxation), and a metal vertical line hangs in the middle of the subject's nose, and the normal position is 150-170cm directly in front of the subject. Place a standing mirror, look straight ahead with both eyes, and adjust the head position according to the image in the mirror. At the same time, fix the head with a nose rod and earplugs to obtain a natural head position, and perform a cephalometric lateral view at this position.

As a specific embodiment, the landmark points in the step S2 include: the upper incisor (U1), the anterior nasal spine (ANS), and the orbital (Orbitale). Please refer to Figure 3, the definitions of the aforementioned measurement landmarks are: maxillary central incisor point (U1), the incisal point of the maxillary central incisor; anterior nasal spine point (ANS), the tip of the anterior nasal spine; orbital point ( Or), the lowest point of the infraorbital rim, overlapping orbital shadows on the left and right sides are often seen on X-ray films, and should usually be selected.

As a specific embodiment, the reference plane in the step S2 is a true horizontal plane. For details, please refer to Figure 4. The true horizontal plane (the true horizontal, TH) is selected as the reference plane on the cephalometric lateral view; The true vertical line is composed of horizontal lines perpendicular to each other, and the true vertical line is the image on the X-ray film of the metal vertical line placed outside the plane when the camera is taken in the natural head position.

As a specific embodiment, please refer to Fig. 4, the reference plane in the step S2 is the parallel plane of the true horizontal plane (TH) passing through the anterior nasal spine (ANS), that is, passing through the anterior nasal spine on the lateral cephalogram (ANS) as a plane parallel to the true horizontal plane (TH) as a reference plane.

As a specific embodiment, please refer to Fig. 5, in the step S3, the line distance measurement of the sagittal position of the maxillary central incisor is carried out according to the selected landmark point, the reference plane and the reference plane, and the specific position of the sagittal position of the maxillary central incisor is defined. Including: take a vertical line through the maxillary central incisor point (U1) as a reference plane, and mark the foot of U1; measure the distance from the foot of the maxillary central incisor point to the anterior nasal spine (ANS), and define, maxillary central incisor When the foot of the maxillary central incisor is on the nasal side of the anterior nasal spine (ANS), it is in a positive direction, and it is recorded as +; when the foot of the maxillary central incisor is on the ear side of the anterior nasal spine (ANS), it is in a negative direction, and it is recorded as -.

Compared with the prior art, the cephalometric method of the sagittal positioning of the maxillary central incisor provided by the present invention, through the vertical projection of the maxillary central incisor point to the reference plane parallel to the true horizontal plane, the sagittal position of the maxillary central incisor point The definition and position changes before and after treatment can be measured and compared on a more stable reference plane; by introducing the anterior nasal spine point, which is stable in position and can represent the protrusion of the maxilla, as a reference point, the sagittal axis of the maxillary central incisor The position can be quantitatively evaluated and compared with the position of the maxilla, reflecting the protrusion and distance of the maxillary central incisor relative to the maxilla, which increases the objectivity and comparability of the data. In addition, by adjusting the body position when taking lateral cephalometric films, that is, the patient's head is fixed by positioning the nose bar and earplugs, and the line of sight is fixed on the wall at the same level as the eyes, so it is relatively easy to obtain a natural head position. The lower true horizontal plane is perpendicular to the image on the X-ray film of the metal vertical line placed outside the plane when taking pictures in the natural head position, and the positions of the anterior nasal spine point and the maxillary central incisor point are relatively close on the lateral cephalometric film, so Clinically, the sagittal position of the upper and middle incisors can be judged by measuring the position difference between the anterior nasal spine point and the maxillary central incisor point on the horizontal edge of the cranial radiograph in a local and small range, so as to quickly and accurately evaluate the maxillary The protrusion of the central incisors increases the practicality and clinical significance of the data.

Finally, it is noted that the above embodiments are only used to illustrate the technical solutions of the present invention without limitation. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be carried out Modifications or equivalent replacements without departing from the spirit and scope of the technical solution of the present invention shall be covered by the claims of the present invention.

Claims (6)

1. a cephalometric method of maxillary central incisor sagittal positioning, is characterized in that, comprises the following steps: S1. Take X-ray cephalometric lateral films; S2. Select landmarks, datum planes and reference planes on X-ray cephalometric lateral films; S3. Perform line distance measurement of the sagittal position of the maxillary central incisor according to the selected landmarks, datum plane and reference plane, and define the sagittal position of the maxillary central incisor. 2. The cephalometric method for sagittal positioning of maxillary central incisors according to claim 1, characterized in that the body position requirements for taking X-ray cephalometric lateral films in the step S1 include that the patient's mouth is in the cusp interlaced position , and the head position is in the natural head position. 3. The cephalometric method for sagittal positioning of maxillary central incisors according to claim 1, wherein the landmark points in step S2 include: maxillary central incisor points, anterior nasal spine points, and orbital points. 4. The cephalometric method for sagittal positioning of maxillary central incisors according to claim 3, characterized in that the reference plane in the step S2 is a true horizontal plane. 5. The cephalometric method for sagittal positioning of maxillary central incisors according to claim 4, wherein the reference plane in the step S2 is a plane parallel to the true horizontal plane passing through the anterior nasal spine point. 6. The cephalometric method for sagittal positioning of maxillary central incisors according to claim 3, characterized in that, in the step S3, carry out the sagittal position of maxillary central incisors according to the selected landmarks, datum planes and reference planes Defining the sagittal position of the maxillary central incisor specifically includes: taking the vertical line through the maxillary central incisor point as a reference plane, measuring the distance from the foot of the maxillary central incisor to the anterior nasal spine point, and defining the maxillary central incisor When the foot of the incisor point is on the nasal side of the anterior nasal spine point, it is in a positive direction, which is recorded as +; when the foot of the maxillary central incisor point is on the ear side of the anterior nasal spine point, it is in a negative direction, which is recorded as -.

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